Apparatus and method for controlling electric potential of object in plasma

Abstract

The method for controlling the voltage of an object according to an embodiment of the present invention comprises: a step in which, in a plasma device including a structure in which an electrode, a dielectric layer, and an object are stacked, a bipolar pulse voltage (VG) is applied to the electrode, thereby obtaining the maximum time (tmax) at which zero current flows through the electrode in a negative voltage range; and a step in which the maximum time (tmax) is used to calculate the density (Ji) of ion currents incident on the object exposed to plasma.

Description

Device for controlling potential of an object in plasma and method for controlling potential thereof

[0001] The present invention relates to a plasma device, and more particularly, to controlling the potential of an object by applying a voltage to an electrode in an electrode / dielectric / object structure.

[0002] The sputtering device and etching device induce a potential in the target object, so that the ions of the plasma are incident on the target object and act on the target object.

[0003] To control the voltage or potential of an object, voltage can be applied directly to the object, but this can cause a large current to flow, potentially causing an arc. Therefore, the potential is typically applied to the object through the electrode / dielectric / object structure.

[0004] The potential of the object depends on the structure of the object holder and the driving voltage applied to the electrodes, and the potential of the object can be changed by changing the waveform of the driving voltage. The potential of the object is related to the ion energy.

[0005] The present invention is to control the potential of an object exposed to plasma according to the applied voltage of an electrode in a capacitor structure of an electrode / dielectric / object.

[0006] [Claim 1](1)

[0007] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0008] The applied voltage of the bipolar pulse to the above electrode (V G ) to obtain the maximum time (tmax) at which the current flowing through the electrode becomes zero in the negative voltage range; and

[0009] A method for controlling an object voltage, comprising: a step of calculating an ion current density (Ji) incident on the object exposed to plasma using the maximum time (tmax);

[0010] [Claim 2]

[0011] In the first paragraph,

[0012] A method for controlling the voltage of an object, characterized in that the ion current density (Ji) is given as follows.

[0013]

[0014] Here, Vo is the measurement voltage applied to the electrode, and V G + is the positive applied voltage applied to the electrode, and c1 is the capacitance per unit area due to the dielectric between the electrode and the object.

[0015] [Claim 3]

[0016] In the first paragraph,

[0017] A method for controlling a voltage of an object, further comprising: a step of setting a potential (Vs) of the object based on the ion current density (Ji).

[0018] [Claim 4]

[0019] In the third paragraph,

[0020] A method for controlling the voltage of an object, characterized in that the potential (Vs) of the object is given as follows.

[0021]

[0022] Here, ρ d is the charge density of the plasma, V G is the applied voltage applied to the above electrode, and u B is the spring speed, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0023] [Claim 5]

[0024] In paragraph 4,

[0025] The above applied voltage (V G) A method for controlling the voltage of an object, characterized in that it further includes a step of calculating the potential change amount (ΔVs) of the object.

[0026]

[0027] Here, X is the change in voltage (dV / dt) over the time interval (τ) in the negative interval of the applied voltage (VG).

[0028] [Claim 6]

[0029] In the first paragraph,

[0030] A method for controlling a voltage of an object, characterized in that it further comprises a step of applying a driving voltage of a bipolar waveform having an application time of a negative applied voltage less than the maximum time (tmax) to the electrode.

[0031] [Claim 7]

[0032] In the third paragraph,

[0033] A method for controlling the voltage of an object, characterized in that the potential (Vs) of the object is given as follows.

[0034]

[0035] Te is the temperature of the electron, k is the Boltzmann constant, q is the absolute value of the electron's charge, and M is the mass of the ion.

[0036] [Claim 8]

[0037] In the third paragraph,

[0038] A method for controlling the voltage of an object, characterized in that the potential (Vs) of the object is given as follows.

[0039]

[0040] Here, α=0.3 ~0.5, and ρ d is the charge density of the plasma, V Gis the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated in the target at a positive driving voltage.

[0041] [Claim 9]

[0042] In paragraph 4,

[0043]

[0044] A method for controlling the voltage of an object, characterized by:

[0045] [Claim 10]

[0046] In paragraph 4,

[0047]

[0048] A method for controlling the voltage of an object, characterized by:

[0049] [Claim 11]

[0050] In the first paragraph,

[0051] Current (I) flowing through the above electrode G ) and the above current (I G ) is a target voltage control method characterized in that the maximum time (tmax) at which the voltage becomes zero is given as follows.

[0052]

[0053] Here V s0 is the initial voltage of the object, C1 is the electrostatic capacitance due to the dielectric, and V f is the floating potential, and I G0 is the current flowing in the electrode at a negative applied voltage.

[0054] [Claim 12]

[0055] In the first paragraph,

[0056] Current (I) flowing through the above electrode G ) is given as follows,

[0057]

[0058] A method for controlling the voltage of an object, characterized by:

[0059] Here, X is the applied slope voltage in the negative applied voltage range, C1 is the electrostatic capacitance due to the dielectric, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0060] [Claim 13]

[0061] In Article 12,

[0062]

[0063] A method for controlling the voltage of an object, characterized by:

[0064] [Claim 14]

[0065] In the first paragraph,

[0066] The initial charge per unit area (Qi) of the above object at a positive applied voltage is

[0067]

[0068] A method for controlling the voltage of an object, characterized in that it is given as .

[0069] [Claim 15]

[0070] In the first paragraph,

[0071] Positive applied voltage (V) of the above object G + ) A method for controlling the voltage of an object, characterized in that the following conditions are satisfied.

[0072]

[0073] Here, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and τ is the time interval during which the negative applied voltage is applied.

[0074] [Claim 16]

[0075] In the first paragraph,

[0076] Charge density of plasma (ρ d ) is further included in the step of obtaining the target voltage control method.

[0077]

[0078] Here, ρ d is the charge density of the plasma, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, and ε2 is the permittivity of the plasma sheath region. V G is the negative applied voltage. ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0079] [Claim 17]

[0080] In the first paragraph,

[0081] A step of applying a driving voltage of a bipolar waveform having a negative voltage application time less than the maximum time (tmax) to the electrode; and

[0082] A method for controlling a voltage of an object, characterized in that it further includes a step of applying a high-frequency sine wave to the electrode in synchronization with the negative voltage section of the driving voltage.

[0083] [Claim 1](2)

[0084] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0085] A positive voltage (V) is applied to the above electrode G + ) is applied, the current density (J) flowing through the electrode in the negative applied voltage section G0 ) to obtain; and

[0086] The above current density (J G0 ) to calculate the ion current density (Ji) flowing into the target object exposed to plasma. A method for controlling the voltage of a target object, characterized in that it comprises:

[0087] [Claim 2]

[0088] In the first paragraph,

[0089]

[0090] A method for controlling the voltage of an object, characterized in that it is determined by the above relationship.

[0091] Here, V G is the driving voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, ρi is the initial surface charge density accumulated on the object at a positive driving voltage. u B is the spring speed.

[0092] [Claim 3]

[0093] In the second paragraph,

[0094] In the negative applied voltage range corresponding to the above ion current density (Ji), the slope voltage (dV G A method for controlling a target voltage, characterized in that it further comprises a step of setting / dt= X).

[0095] [Claim 4]

[0096] In paragraph 3,

[0097] The above slope voltage (dV G / dt= X) is a target voltage control method characterized in that (d1 Ji ) / ε1.

[0098] [Claim 1]

[0099] In a method for controlling an object voltage, the method comprises the step of applying a bipolar pulse voltage (VG) having a slope voltage (X) in a negative voltage range to the electrode in a plasma device including a structure in which an electrode / dielectric layer / object are laminated,

[0100] Current (I) flowing through the above electrode G )Is

[0101]

[0102] A method for controlling the voltage of an object, characterized in that it is given as follows.

[0103] Here, C1 is the capacitance due to the dielectric, Ii is the ion current flowing into the object, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0104] [Claim 2]

[0105] In the first paragraph,

[0106] The current (I) flowing in the electrode for the above slope voltage G ) and obtain the ion current density (Ii) and β from the above equation.

[0107] [Claim 3]

[0108] In the first paragraph,

[0109] The above C1 is given as a value multiplied by a correction factor (α) for the electrostatic capacitance due to the dielectric,

[0110] A method for controlling a target voltage, characterized in that the above correction coefficient (α) is 0.3 to 0.5.

[0111] [Claim 1](3)

[0112] In a method for controlling an object voltage, the method comprises the step of applying a bipolar pulse voltage (VG) having a slope voltage (X) in a negative voltage range to the electrode in a plasma device including a structure in which an electrode / dielectric layer / object are laminated,

[0113] Current (I) flowing through the above electrode G )Is

[0114]

[0115] is given as,

[0116] Here, C1 is the electrostatic capacitance due to the dielectric layer, Ii is the ion current flowing into the object, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, ρi is the initial surface charge density accumulated on the object at a positive applied voltage, A is the area of ​​the object,

[0117] A method for controlling a target voltage, characterized in that the correction coefficient (α) is 0.3 to 0.5.

[0118] [Claim 2]

[0119] In the first paragraph,

[0120] The current (I) flowing in the electrode for the above slope voltage (X) G ) and obtain the ion current density (Ii) and C2 from the above formula.

[0121] [Claim 1](4)

[0122] In a method for controlling an object voltage, the method comprises the step of applying a bipolar pulse voltage (VG) having a slope voltage (X) in a negative voltage range to the electrode in a plasma device including a structure in which an electrode / dielectric layer / object are laminated,

[0123] A method for controlling the voltage of an object, characterized in that the amount of change in potential (ΔVs) of the object is given as follows.

[0124]

[0125] Here, Ji is the ion current density flowing into the target, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, ρi is the initial surface charge density accumulated on the object at a positive applied voltage, X is the change in voltage (dV / dt) in the negative time interval (τ) of the bipolar pulse voltage (VG).

[0126] [Claim 2]

[0127] In the first paragraph,

[0128] A method for controlling the voltage of an object, characterized in that the amount of change in the potential of the object (ΔVs) is changed by changing the slope voltage (X), ion current density (Ji), or negative time interval (τ) so as to satisfy a set value.

[0129] [Claim 1](5-1)

[0130] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0131] A bipolar pulse voltage (V) is applied to the above electrodes G ) and

[0132] A method for controlling a voltage of an object, characterized by comprising a step of changing a voltage (Vs) of the object by changing a plasma density.

[0133] [Claim 2]

[0134] In the first paragraph,

[0135] The step of changing the voltage of the target object by changing the plasma density is:

[0136] By controlling the power of the high frequency power source that generates the plasma, the plasma density is changed and the bipolar pulse voltage (V G ) A method for controlling the voltage of an object, characterized by changing the voltage of the object corresponding to the voltage.

[0137] [Claim 3]

[0138] In the first paragraph,

[0139] A method for controlling the voltage of an object, wherein the voltage (Vs) of the object is given as follows.

[0140]

[0141] Here, ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0142] [Claim 4]

[0143] In the first paragraph,

[0144] A method for controlling the voltage of an object, characterized in that the voltage of the object is alternately changed between being below the etching threshold voltage due to a high plasma density and exceeding the etching threshold voltage due to a low plasma density.

[0145] [Claim 1](6-1)

[0146] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0147] A step of connecting a first capacitor and a second capacitor connected in parallel to each other to the above electrodes; and

[0148] A method for controlling the voltage of an object, comprising: a step of alternatingly selecting one of the first capacitor and the second capacitor and connecting the bipolar pulse power source to the electrode to change the potential of the object.

[0149] [Claim 2]

[0150] In the first paragraph,

[0151] A method for controlling a voltage of an object, characterized in that the first electrostatic capacitance of the first capacitor and the second electrostatic capacitance of the second capacitor are different from each other.

[0152] [Claim 3]

[0153] In the first paragraph,

[0154] It includes a first switch connected in series to the first capacitor and a second switch connected in series to the second capacitor,

[0155] A method for controlling a target voltage, wherein the first switch and the second switch are synchronized with the bipolar pulse power supply.

[0156] [Claim 1](7-1)

[0157] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0158] A low frequency sinusoidal voltage (V) having an amplitude (V) and an angular frequency (ω) is applied to the above electrodes. G ) and

[0159] Current density (J) flowing through the above electrode G ) and calculating the ion current density (Ji) flowing through the target object.

[0160]

[0161] Here, ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0162] [Claim 2]

[0163] In the first paragraph,

[0164] Current density (J) flowing through the above electrode G ) by fitting the initial surface charge density (ρi) of the object and the charge density of the plasma (ρ d ), a method for controlling the voltage of an object, characterized by obtaining an ion current density (Ji).

[0165] [Claim 3]

[0166] In the first paragraph,

[0167] Current density (J) flowing through the above electrode G ) is characterized in that it further includes an electron current density (Je).

[0168] [Claim 1](8)

[0169] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0170] A bipolar low-frequency pulse voltage (V) is applied to the above electrodes G ) and

[0171] The above bipolar low-frequency pulse voltage (V G ) A method for controlling a voltage of an object, characterized in that it includes a step of applying a high-frequency voltage synchronized to the electrode.

[0172] [Claim 2]

[0173] In the first paragraph,

[0174] The step of applying the high frequency voltage to the electrode is the step of applying the bipolar low frequency pulse voltage (V G ) A method for controlling the voltage of an object, characterized in that it is synchronized to the negative section.

[0175] [Claim 3]

[0176] In the first paragraph,

[0177] Bipolar low-frequency pulse voltage (V G) is characterized in that the amplitude of the target voltage control method is greater than the full width of the high-frequency voltage.

[0178] [Claim 1](9)

[0179] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0180] A low frequency sinusoidal voltage (V) is applied to the above electrodes G ) and

[0181] The above low frequency sinusoidal voltage (V G ) A method for controlling the voltage of an object, characterized by including a step of applying a high-frequency sine wave voltage synchronized to the electrode.

[0182] [Claim 2]

[0183] In the first paragraph,

[0184] The step of applying the high frequency voltage to the electrode is to apply the low frequency sinusoidal voltage (V G ) A method for controlling the voltage of an object, characterized in that it is synchronized to the negative section.

[0185] [Claim 3]

[0186] In the first paragraph,

[0187] The above low frequency sinusoidal voltage (V G ) is characterized in that the amplitude of the target voltage control method is greater than the full width of the high-frequency voltage.

[0188] [Claim 1](10)

[0189] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0190] A bipolar low-frequency pulse voltage (V) is applied to the above electrodes G ) and

[0191] The above bipolar low-frequency pulse voltage (V G ) A method for controlling a target voltage, characterized in that it includes a step of applying a synchronized plasma potential (Vp).

[0192] [Claim 2]

[0193] In the first paragraph,

[0194] The step of applying the above plasma potential (Vp) is the step of applying the above bipolar low-frequency pulse voltage (V G ) A method for controlling the voltage of an object, characterized in that it is synchronized to the negative section.

[0195] [Claim 3]

[0196] In the first paragraph,

[0197] A bipolar low-frequency pulse voltage (V) is applied to the above electrodes G ) is characterized in that the step of applying the voltage control voltage to the target object comprises a slope voltage (X) in a negative voltage range.

[0198] [Claim 4]

[0199] In the first paragraph,

[0200] The above plasma potential (Vp) is the bipolar low-frequency pulse voltage (V G ) is characterized in that the target voltage control method is changed immediately after the voltage is changed to negative.

[0201] [Claim 5]

[0202] In the first paragraph,

[0203] A bipolar low-frequency pulse voltage (V) is applied to the above electrodes G ) has a slope voltage (X) in the negative voltage range,

[0204] The above plasma potential (Vp) has a constant slope (Y) over time,

[0205] Y is given by X + Ji / ceff,

[0206] Here, Ji is an ion current density incident on the target object, and ceff is an effective electrostatic capacitance per unit area between the electrode and the target object. A method for controlling target voltage.

[0207] [Claim 1](11)

[0208] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0209] A low frequency sinusoidal voltage (V) is applied to the above electrodes G ) and

[0210] The above low frequency sinusoidal voltage (V G ) A method for controlling a target voltage, characterized in that it includes a step of applying a synchronized plasma potential.

[0211] [Claim 2]

[0212] In the first paragraph,

[0213] The above plasma potential has a high state and a low state,

[0214] The above plasma potential is the low frequency sinusoidal voltage (V G ) A method for controlling the voltage of an object, characterized in that it is synchronized to the maximum positive value.

[0215] [Claim 1](12)

[0216] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0217] A low frequency sinusoidal voltage (V) is applied to the above electrodes G ) and

[0218] The above low frequency sinusoidal voltage (V G ) A method for controlling a target voltage, characterized by including a step of periodically applying a plasma potential having a high state and a low state.

[0219] [Claim 2]

[0220] In the first paragraph,

[0221] A method for controlling the voltage of an object, characterized in that the value (Vs-Vp) obtained by subtracting the plasma potential (Vp) from the potential (Vs) of the object decreases over time for a plurality of cycles.

[0222] [Claim 1](13)

[0223] In a plasma device including a stacked structure of electrode / first dielectric layer / electrostatic electrode / second dielectric layer / object,

[0224] A low frequency pulse voltage (V) is applied to the above electrode G ) and

[0225] The above low frequency pulse voltage (V G ) and providing a charge to the electrostatic electrode. A method for controlling the voltage of an object, characterized in that the method comprises the step of:

[0226] [Claim 2]

[0227] In the first paragraph,

[0228] The charge applied to the above electrostatic electrode has a positive value,

[0229] A method for controlling the voltage of an object, characterized in that the amount of charge accumulated in the object in the positive section of the low-frequency pulse voltage increases in proportion to the amount of charge charged to the electrostatic electrode.

[0230] [Claim 3]

[0231] In the first paragraph,

[0232] A method for controlling a voltage of an object, characterized in that the first dielectric constant of the first dielectric layer is smaller than the second dielectric constant of the second dielectric layer.

[0233] [Claim 4]

[0234] In the first paragraph,

[0235] The above low frequency pulse voltage (V G ) and the pulse of the electrostatic electrode are synchronized. A method for controlling the voltage of an object.

[0236] [Claim 1](14)

[0237] In a plasma device including a structure in which electrodes / first dielectric layer / electrostatic electrodes / second dielectric layer / object are laminated, a bipolar pulse voltage (V) having a slope voltage (X) in a negative voltage range is applied to the electrodes. G ) in a method for controlling the voltage of an object, comprising the step of:

[0238] Current (I) flowing through the above electrode G )Is

[0239]

[0240] A method for controlling the voltage of an object, characterized in that it is given as follows.

[0241] Here, Ji is the ion current density flowing into the target, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the first dielectric layer, and ε1 is the permittivity of the first dielectric layer. d2 is the thickness of the second dielectric layer, and ε2 is the permittivity of the second dielectric layer. ε3 is the permittivity of the plasma sheath region. ρi is the initial surface charge density accumulated on the object at a positive applied voltage. ρ ESC is the charge per unit area charged to the above electrostatic electrode. A is the area of ​​the object. Vs is the potential of the object.

[0242] [Claim 2]

[0243] In the first paragraph,

[0244] The change in potential (ΔVs) of the above object is given as follows.

[0245]

[0246]

[0247] Here, τ is the negative time interval of the bipolar pulse voltage (VG).

[0248] [Claim 1](15)

[0249] In a plasma device including a stacked structure of electrode / first dielectric layer / electrostatic electrode / second dielectric layer / object,

[0250] A low frequency sinusoidal voltage (V) is applied to the above electrodes G ) and

[0251] The above low frequency sinusoidal voltage (V G ) and providing a charge to the electrostatic electrode. A method for controlling the voltage of an object, characterized in that the method comprises the step of:

[0252] [Claim 2]

[0253] In the first paragraph,

[0254] The above low frequency sinusoidal voltage (V G ) and the pulse of the electrostatic electrode are synchronized. A method for controlling the voltage of an object.

[0255] [Claim 1](16)

[0256] In a plasma device including a stacked structure of electrode / first dielectric layer / electrostatic electrode / second dielectric layer / object,

[0257] A plasma device characterized in that the first dielectric constant of the first dielectric layer is smaller than the dielectric constant of the second dielectric layer.

[0258] [Claim 2]

[0259] In the first paragraph,

[0260] A low frequency pulse voltage (V) is applied to the above electrode G ) further comprising a low-frequency pulse power source.

[0261] [Claim 3]

[0262] In the first paragraph,

[0263] A plasma device further comprising a pulsed voltage source for applying a pulse voltage to the electrostatic electrode.

[0264] [Claim 4]

[0265] In the first paragraph,

[0266] A low frequency sinusoidal voltage (V) is applied to the above electrodes G ) further comprising a low-frequency sine wave power source.

[0267] [Claim 1](17)

[0268] In a plasma device including a structure in which variable capacitors / electrodes / objects are sequentially connected,

[0269] A low frequency pulse voltage (V) is applied to the above variable capacitor G ) and

[0270] A method for controlling the voltage of an object, characterized in that it comprises a step of controlling the voltage of the object which is a dielectric.

[0271] [Claim 2]

[0272] In the first paragraph,

[0273] In the step of controlling the voltage of the above-mentioned object, which is the above-mentioned dielectric.

[0274] A method for controlling the voltage of an object, characterized in that the amount of change (ΔVs) of the voltage of the object is given as follows.

[0275]

[0276]

[0277] Here, Ji is the ion current density flowing into the target, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d2 is the thickness of the object, and ε2 is the permittivity of the object. C1 is the capacitance of the variable capacitor, and S2 is the area of ​​the object. ε3 is the permittivity of the plasma sheath region. ρi is the initial surface charge density accumulated on the object at a positive applied voltage. Vs is the potential of the object. τ is the low-frequency pulse voltage (V G ) is the negative time interval.

[0278] [Claim 3]

[0279] In the first paragraph,

[0280] The current (I) flowing through the above variable capacitor G ) is a target voltage control method characterized by being given as follows.

[0281]

[0282]

[0283] Here, Ji is the ion current density flowing into the target, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d2 is the thickness of the object, and ε2 is the permittivity of the object. C1 is the capacitance of the variable capacitor, S2 is the area of ​​the object, ε3 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0284] [Claim 1](18)

[0285] In a plasma device including a structure in which variable capacitors / electrodes / objects are sequentially connected,

[0286] A low frequency pulse voltage (V) is applied to the above variable capacitor G ) and

[0287] A method for controlling the voltage of an object, characterized in that it controls the voltage of the object which is a conductor.

[0288] [Claim 2]

[0289] In the first paragraph,

[0290] In the step of controlling the voltage of the above object which is a conductor.

[0291] A method for controlling the voltage of an object, characterized in that the voltage fluctuation amount of the object is given as follows.

[0292]

[0293] Here, Ji is the ion current density flowing into the target, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, C1 is the capacitance of the variable capacitor, S2 is the area of ​​the object, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0294] [Claim 3]

[0295] In the first paragraph,

[0296] A method for controlling the voltage of an object, characterized in that the current flowing through the variable capacitor is given as follows.

[0297]

[0298] Here, Ji is the ion current density flowing into the target, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, C1 is the capacitance of the variable capacitor, S2 is the area of ​​the object, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

[0299] [Claim 1](19)

[0300] In a plasma device including a structure in which variable capacitors / electrodes / dielectrics / objects are sequentially connected,

[0301] A low frequency pulse voltage (V) is applied to the above variable capacitor G ) and

[0302] A method for controlling the voltage of an object, characterized in that it controls the voltage of the object which is a conductor.

[0303] [Claim 2]

[0304] In the first paragraph,

[0305] In the step of controlling the voltage of the above object which is a conductor,

[0306]

[0307]

[0308] A method for controlling the voltage of an object, characterized in that the amount of change (ΔVs) of the voltage (Vs) of the object is given as follows.

[0309] Here, Ji is the ion current density flowing into the target, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, C4 is the capacitance of the variable capacitor, S2 is the area of ​​the object, ε2 is the permittivity of the plasma sheath region, ρi is the initial surface charge density accumulated on the object at a positive applied voltage, d1 is the thickness of the dielectric, and ε1 is the permittivity of the dielectric.

[0310] [Claim 3]

[0311] In the first paragraph,

[0312] The current (I) flowing through the above variable capacitor G ) is a target voltage control method characterized by being given as follows.

[0313]

[0314]

[0315] Here, Ji is the ion current density flowing into the target, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, C4 is the capacitance of the variable capacitor, S2 is the area of ​​the object, ε2 is the permittivity of the plasma sheath region, ρi is the initial surface charge density accumulated on the object at a positive applied voltage, d1 is the thickness of the dielectric, and ε1 is the permittivity of the dielectric.

[0316] [Claim 1] (20)

[0317] plasma chamber;

[0318] A high-frequency power source connected to a first electrode placed inside the chamber to form plasma;

[0319] An object holder comprising a second electrode / dielectric layer / object and arranged inside the chamber;

[0320] a third electrode exposed inside the chamber; and

[0321] A plasma processing device characterized by including an auxiliary low-frequency power source for controlling a plasma potential having a high state and a low state periodically on the third electrode.

[0322] [Claim 2]

[0323] In the first paragraph,

[0324] The above plasma potential is a bipolar low-frequency pulse voltage (V) applied to the second electrode. G ) and characterized by being synchronized with each other.

[0325] [Claim 3]

[0326] In the first paragraph,

[0327] A bipolar low-frequency pulse voltage (V) is applied to the second electrode G ) and approve it,

[0328] The above bipolar low-frequency pulse voltage (V G ) has a slope voltage (X) in the negative voltage range,

[0329] The above plasma potential (Vp) has a constant slope (Y) over time,

[0330] Y is given by X + Ji / ceff,

[0331] A plasma processing device characterized in that, here, Ji is the ion current density incident on the target object, and ceff is the effective electrostatic capacitance per unit area between the second electrode and the target object.

[0332] [Claim 1](21)

[0333] plasma chamber;

[0334] An auxiliary low-frequency power source connected to a first electrode disposed inside the chamber and controlling a plasma potential having a high state and a low state periodically;

[0335] An object holder comprising a second electrode / dielectric layer / object and arranged inside the chamber;

[0336] a low frequency power source connected to the second electrode; and

[0337] A plasma processing device characterized by including a high-frequency power source connected to the second electrode to form plasma.

[0338] [Claim 2]

[0339] In the first paragraph,

[0340] The above plasma potential is a bipolar low-frequency pulse voltage (V) applied to the second electrode. G ) and characterized by being synchronized with each other.

[0341] [Claim 3]

[0342] In the first paragraph,

[0343] A bipolar low-frequency pulse voltage (V) is applied to the second electrode G ) and approve it,

[0344] The above bipolar low-frequency pulse voltage (V G ) has a slope voltage (X) in the negative voltage range,

[0345] The above plasma potential (Vp) has a constant slope (Y) over time,

[0346] Y is given by X + Ji / ceff,

[0347] A plasma processing device characterized in that, here, Ji is the ion current density incident on the target object, and ceff is the effective electrostatic capacitance per unit area between the second electrode and the target object.

[0348] [Claim 1](22)

[0349] plasma chamber;

[0350] A high-frequency power source connected to a first electrode placed inside the chamber to form plasma;

[0351] An auxiliary low-frequency power source connected to the first electrode and controlling the plasma potential to have a high state and a low state periodically;

[0352] An object holder comprising a second electrode / dielectric layer / object and arranged inside the chamber;

[0353] A plasma processing device characterized by including a low-frequency power source connected to the second electrode and controlling the voltage of the object.

[0354] [Claim 2]

[0355] In the first paragraph,

[0356] The above plasma potential is a bipolar low-frequency pulse voltage (V) applied to the second electrode. G ) and characterized by being synchronized with each other.

[0357] [Claim 3]

[0358] In the first paragraph,

[0359] A bipolar low-frequency pulse voltage (V) is applied to the second electrode G ) and approve it,

[0360] The above bipolar low-frequency pulse voltage (V G ) has a slope voltage (X) in the negative voltage range,

[0361] The above plasma potential (Vp) has a constant slope (Y) over time,

[0362] Y is given by X + Ji / ceff,

[0363] A plasma processing device characterized in that, here, Ji is the ion current density incident on the target object, and ceff is the effective electrostatic capacitance per unit area between the second electrode and the target object.

[0364] [Claim 1](23-1)

[0365] plasma chamber;

[0366] A high frequency power source connected to an antenna placed outside the chamber to form an inductively coupled plasma;

[0367] An auxiliary low-frequency power source arranged inside the chamber and connected to an auxiliary electrode to control the plasma potential by periodically having a high state and a low state;

[0368] An object holder comprising an electrode / dielectric layer / object and arranged inside the chamber;

[0369] A plasma processing device characterized by including a low-frequency power source connected to the electrode and controlling the voltage of the object.

[0370] [Claim 2]

[0371] In the first paragraph,

[0372] The above plasma potential is a bipolar low-frequency pulse voltage (V) applied to the electrode. G ) and characterized by being synchronized with each other.

[0373] [Claim 3]

[0374] In the first paragraph,

[0375] A bipolar low-frequency pulse voltage (V) is applied to the above electrodes G ) and approve it,

[0376] The above bipolar low-frequency pulse voltage (V G ) has a slope voltage (X) in the negative voltage range,

[0377] The above plasma potential (Vp) has a constant slope (Y) over time,

[0378] Y is given by X + Ji / ceff,

[0379] A plasma processing device characterized in that, here, Ji is the ion current density incident on the target object, and ceff is the effective electrostatic capacitance per unit area between the second electrode and the target object.

[0380] [Claim 1](24)

[0381] plasma chamber;

[0382] A plasma source for forming plasma in the plasma chamber;

[0383] An object holder including an electrode / first dielectric layer / electrostatic electrode / second dielectric layer / object and disposed inside the chamber;

[0384] a low frequency power source connected to the above electrode; and

[0385] Including an electrostatic electrode power source connected to the electrostatic electrode,

[0386] A plasma processing device characterized in that the voltage waveform of the above-mentioned electrostatic positive electrode is synchronized with the voltage waveform of the above-mentioned low-frequency power source to control the potential of the above-mentioned object.

[0387] [Claim 2]

[0388] In the first paragraph,

[0389] A plasma processing device characterized in that the voltage of the above target object is given as follows.

[0390]

[0391]

[0392] Here, ρ d is the charge density of the plasma, V Gis the applied voltage applied to the electrode, d1 is the thickness of the first dielectric layer, and ε1 is the permittivity of the first dielectric layer. d2 is the thickness of the second dielectric layer, and ε2 is the permittivity of the second dielectric layer. ε3 is the permittivity of the plasma sheath region. ρi is the initial surface charge density accumulated on the object at a positive applied voltage. ρ ESC is the charge per unit area charged to the above electrostatic electrode. Vs is the potential of the object.

[0393] [Claim 1](25)

[0394] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0395] A step of applying a sinusoidal voltage to the electrode and measuring the current flowing through the electrode over time; and

[0396] A method for controlling a voltage of an object, characterized by comprising a step of fitting the current to extract the amount of charge charged to the object and the plasma charge density.

[0397] [Claim 2]

[0398] In the first paragraph,

[0399] A plasma processing device characterized by further comprising a step of obtaining a voltage (Vs) of the target object.

[0400] [Claim 3]

[0401] In the first paragraph,

[0402] The plasma in contact with the above object has a plasma potential that fluctuates over time,

[0403] A method for controlling a voltage of an object, characterized in that it further comprises a step of measuring the plasma potential or calculating the plasma potential by fitting a current flowing in the electrode.

[0404] [Claim 4]

[0405] In the third paragraph,

[0406] A method for controlling the voltage of an object, characterized in that it further comprises a step of calculating the potential of the object using the plasma potential.

[0407] [Claim 5]

[0408] In paragraph 4,

[0409] A method for controlling the voltage of an object, characterized in that it further includes a step of calculating the energy of ions incident on the object by using the potential of the object.

[0410] [Claim 6]

[0411] In the first paragraph,

[0412] A method for controlling a voltage of an object, characterized in that it further comprises a step of controlling a plasma potential of plasma in contact with the object.

[0413] [Claim 7]

[0414] In the first paragraph,

[0415] A method for controlling the voltage of an object, characterized in that it further includes a step of controlling the plasma charge density by controlling a plasma power source that generates plasma, thereby controlling the potential of the object.

[0416] [Claim 1](26)

[0417] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0418] A step of applying a sinusoidal voltage to the electrode and measuring the current flowing through the electrode over time;

[0419] a step of calculating plasma charge density; and

[0420] A method for controlling the voltage of an object, characterized in that it includes a step of extracting a charge amount charged to the object by fitting the current.

[0421] [Claim 2]

[0422] In the first paragraph,

[0423] The plasma in contact with the above object has a plasma potential that fluctuates over time,

[0424] A method for controlling a voltage of an object, characterized in that it further comprises a step of measuring the plasma potential or calculating the plasma potential by fitting a current flowing in the electrode.

[0425] [Claim 3]

[0426] In the second paragraph,

[0427] A method for controlling the voltage of an object, characterized in that it further comprises a step of calculating the potential of the object using the plasma potential.

[0428] [Claim 4]

[0429] In the third paragraph,

[0430] A method for controlling the voltage of an object, characterized in that it further includes a step of calculating the energy of ions incident on the object by using the potential of the object.

[0431] [Claim 5]

[0432] In the first paragraph,

[0433] A method for controlling a voltage of an object, characterized in that it further comprises a step of controlling a plasma potential of plasma in contact with the object.

[0434] [Claim 1](27)

[0435] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0436] A step of applying a sinusoidal voltage to the electrode and measuring the current flowing through the electrode over time;

[0437] A step of calculating plasma potential using the area ratio of the target object and the area of ​​the grounded electrode;

[0438] A method for controlling the voltage of an object, characterized in that it comprises a step of extracting the amount of charge charged to the object and the plasma charge density by fitting the current.

[0439] [Claim 1](28)

[0440] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0441] A method for controlling the voltage of an object, characterized in that the potential of the object is given as follows.

[0442]

[0443] Here, ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the surface charge density accumulated on the object at a positive applied voltage.

[0444] [Claim 1](29)

[0445] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0446] A method for controlling the voltage of an object, characterized in that the potential (Vs) of the object is given as follows.

[0447]

[0448] Here, ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, ρi is the surface charge density accumulated on the object at a positive applied voltage, and Vp is the plasma potential.

[0449] [Claim 1](30)

[0450] In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated,

[0451] A method for controlling the voltage of an object, characterized in that the plasma potential of plasma adjacent to the object is controlled by an auxiliary electrode that controls the plasma potential, thereby controlling the potential difference (Vs-Vp) between the potential of the object and the plasma potential.

[0452] [Claim 2]

[0453] In paragraph 1.

[0454] A method for controlling a target voltage, characterized in that the voltage applied to the electrode is a pulse DC voltage, and the plasma potential is synchronized with the negative section of the pulse DC voltage.

[0455] [Claim 1](31)

[0456] In a method of operating a plasma device including an electrode / dielectric layer / object structure,

[0457] A step of applying a first DC pulse voltage including a first slope voltage (X) to the electrode; and

[0458] A method of operating a plasma device, comprising: applying a second DC pulse voltage including a second slope voltage (Y) by an auxiliary electrode that controls the plasma potential so as to change the plasma potential of the plasma adjacent to the target object over time;

[0459] [Claim 2]

[0460] In the first paragraph,

[0461] Y = X + Ji / c eff

[0462] is given as,

[0463] The first DC pulse voltage is synchronized with the second DC pulse voltage,

[0464] Here, c effA method of operating a plasma device, characterized in that Ji is an effective electrostatic capacitance per unit area between the target object and the electrode, and Ji is an ion current density incident on the target object.

[0465] [Claim 1](32)

[0466] In a plasma device including an electrode / dielectric layer / object structure,

[0467]

[0468] A plasma device that satisfies the conditions.

[0469] Here, ρ d is the charge density of the plasma, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, and ε2 is the permittivity of the plasma sheath region.

[0470] A plasma device that satisfies the conditions.

[0471] [Claim 1](33)

[0472] In a plasma device including an electrode / dielectric layer / object structure,

[0473]

[0474] A plasma device that satisfies the conditions.

[0475] Here, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, Ji is the density of the ionic current, V is the amplitude of the applied voltage, and ω is the angular frequency of the applied voltage.

[0476] [Claim 1](34)

[0477] In a plasma device including an electrode / dielectric layer / object structure,

[0478]

[0479] A plasma device that satisfies the conditions.

[0480] Here, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, Ji is the density of the ionic current, V is the amplitude of the applied voltage, t this the application time of negative applied voltage.

[0481] [Claim 1](35)

[0482] In a plasma device including an electrode / dielectric layer / object structure,

[0483]

[0484] A plasma device that satisfies the conditions.

[0485] Here, ρ d is the charge density of the plasma, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and V is the amplitude of the applied voltage.

[0486] [Claim 1](36)

[0487] In a plasma device including an electrode / dielectric layer / object structure,

[0488]

[0489] A plasma device that satisfies the conditions.

[0490] Here, ρ d is the charge density of the plasma, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, V is the amplitude of the applied voltage, ω is the angular frequency of the applied voltage, ρi is the surface charge density accumulated on the object at a positive applied voltage, and Vp is the plasma potential. C4 is the capacitance of the parasitic capacitor connected in parallel to the electrodes.

[0491] The present invention can control the potential of an object exposed to plasma according to the voltage applied to the electrode in a capacitor structure of electrode / dielectric / object.

[0492] FIG. 1 is a conceptual diagram showing a plasma device according to one embodiment of the present invention.

[0493] Figures 2 and 3 are conceptual diagrams showing the electrode, dielectric, target, and plasma of Figure 1.

[0494] Figure 4 is a graph showing the potential of an object according to a pulse voltage waveform alternating between positive and negative voltages.

[0495] Figures 5a to 5c are drawings showing a plasma sheath structure when the thickness of the object is ignored.

[0496] Figure 6 shows the applied voltage (V) of the electrode according to the voltage (Vs) of the object according to the matrix model, electron temperature consideration model, and Child-Langmuir (CL) model. G ) is a graph representing the

[0497] Figure 7 shows the applied voltage (V) of the electrode according to the matrix model, electron temperature consideration model, and Child-Langmuir model by changing the coordinate axis. G ) is a graph showing the voltage (Vs) of the target object.

[0498] Figure 8 is a graph showing the relationship between the voltage of the target and the applied voltage considering the floating potential.

[0499] Figure 9 shows the current (I) flowing through the electrode according to the bipolar pulse applied voltage waveform of the electrode. G ) and the voltage (Vs) of the target object.

[0500] Figure 10 shows the negative applied voltage (V) of the electrode G - ) shows the thickness of the plasma sheath over time.

[0501] Figure 11 shows the negative applied voltage (V) of the electrode G - ) represents the negative sum of the charge density of the plasma sheath over time and the surface charge density of the object.

[0502] Figure 12 is a graph showing various characteristics according to the applied voltage of the electrode.

[0503] Figure 13 is a graph showing the voltage of the target object according to the applied voltage.

[0504] Figure 14 is a graph showing the charge density in each region.

[0505] Figure 15 shows the applied voltage (V) of the electrode (18). G ) is a graph showing the charge amount (Qi) of the target (16), the plasma sheath charge amount (Qsh) and the sum (QT) of the charge amount (Qi) of the target and the plasma sheath charge amount (Qsh).

[0506] Figure 16 is a graph showing the charge amount (Qi) and plasma sheath charge amount (Qsh) of a target object according to the applied voltage of the electrode.

[0507] Figure 17 is a graph showing the relationship between maximum time (tmax) and ion current density.

[0508] Figure 18 is a graph showing the reciprocal of the maximum time (tmax) and the ion current density.

[0509] Figure 19 is a graph showing the relationship between maximum time (tmax) and capacitance per unit area.

[0510] Figure 20 shows the voltage (Vs) of the target object as a positive applied voltage (V G + ) is a graph standardized.

[0511] Figure 21 shows the applied voltage (V) of the electrode when there is no slope voltage (X = 0). G ) The current flowing through the electrode ((I) G ) is a graph representing the

[0512] Figure 22 is a graph showing β according to the applied voltage of the electrode when there is no slope voltage (X=0).

[0513] Figure 23 is a graph showing the gain (1- β).

[0514] Figure 24 is a graph showing the current of an electrode according to the applied voltage of the electrode.

[0515] Figure 25 shows the current (I) of the electrode for the ion current (Ii) according to the plasma density. G ) of the incision ratio (I G0 / Ii) is indicated.

[0516] Figure 26 shows the current density (J) flowing through the electrode for the ion current density (Ji). G0 ) represents the relationship.

[0517] Figure 27 is a graph showing the voltage of a target object according to the applied voltage of the electrode.

[0518] Figure 28 shows the current (I) of the electrode according to the slope voltage (X). G ) is a graph representing the

[0519] Figure 29 is a graph showing the change in voltage (ΔVs) of an object according to a slope voltage (X).

[0520] Figure 30 is a graph showing the change in voltage (ΔVs) of a target object according to plasma density.

[0521] Figure 31 is a conceptual diagram illustrating a plasma system according to one embodiment of the present invention.

[0522] Figure 32 is a graph showing the current of the electrode according to the slope voltage when there is an auxiliary capacitor (C4).

[0523] Figure 33 is a graph showing the voltage of a target object according to the low-frequency applied voltage of an electrode according to one embodiment of the present invention.

[0524] Figure 34 is a graph showing the charge amount (Qi) of a target object according to the applied voltage of an electrode according to one embodiment of the present invention.

[0525] Figure 35 is a graph showing the amount of charge and potential according to the applied voltage of an electrode according to one embodiment of the present invention.

[0526] Figure 36 shows the potential of the target for low-frequency pulse ramp voltage driving.

[0527] Figure 37 shows the charge amount of the target and the charge amount of the plasma sheath for low-frequency pulse ramp voltage driving.

[0528] Figures 38 to 41 are flowcharts explaining an operating method for low-frequency pulse driving.

[0529] Figure 42 shows the voltage of the target according to low-frequency pulse voltage driving.

[0530] Figure 43 shows the potential of the object according to the plasma density.

[0531] Figure 44 shows the potential of the object according to the plasma density.

[0532] Figure 45 shows the potential of the object according to the plasma density.

[0533] Figure 46 shows the potential of the object according to the plasma density.

[0534] Figure 47 shows the potential of the object according to the plasma density.

[0535] Figure 48 shows the potential of the object according to the driving voltage waveform of the electrode.

[0536] Figure 49 shows the potential of the object according to the driving voltage waveform of the electrode.

[0537] Figure 50 is a conceptual diagram showing a plasma device including a battery connected to an electrode.

[0538] Figure 51 shows the potential of an object according to the electrostatic capacity of a battery connected to the electrode of Figure 50.

[0539] Figure 52 shows the potential of the object and the current flowing in the electrode under a sinusoidal applied voltage.

[0540] Figure 53 shows the current flowing through the electrodes under a sinusoidal applied voltage.

[0541] Figure 54 shows the potential of the object under a sinusoidal applied voltage.

[0542] Figure 55 shows the potential of the object under a sinusoidal applied voltage.

[0543] Figure 56 shows the potential of the target object at a sinusoidal applied voltage according to the plasma density.

[0544] Referring to Figure 56, as the plasma density increases, the absolute value of the potential (Vs) of the object decreases.

[0545] Figure 57 is a plasma system showing the applied voltage of an electrode with high frequency modulation.

[0546] Figure 58 shows the voltage of a target object according to the applied voltage of an electrode with high frequency modulation.

[0547] Figure 59 shows the voltage of the target object under low frequency pulse applied voltage with high frequency modulation of the electrode.

[0548] Figure 60 shows a waveform synchronized with a low-frequency pulse waveform and a high-frequency sine wave and the potential of the target.

[0549] Figure 61 shows the potential of an object when low-frequency sine waves and high-frequency sine waves are applied to the electrodes.

[0550] Figure 62 shows the potential (Vs) of the object when low-frequency sine waves and high-frequency sine waves are simultaneously applied to the electrodes.

[0551] Figure 63 is a conceptual diagram explaining the voltage of an object when plasma potential is taken into account.

[0552] Figure 64 is a graph showing the voltage of the target according to the applied voltage of the electrode when the plasma potential is taken into account.

[0553] Figure 65 shows the amount of charge on an object according to the applied voltage of the electrode when considering the plasma potential.

[0554] Figure 66 is a flow chart for driving the electrodes of a plasma device.

[0555] Figure 67 shows the potential of an object according to the pulse applied voltage when there is a plasma potential.

[0556] Figure 68 shows the potential of an object according to the pulse applied voltage when the plasma potential changes over time.

[0557] Figure 69 shows the value obtained by subtracting the plasma potential from the potential of the target according to the pulse applied voltage when the plasma potential changes over time.

[0558] Figure 70 shows the charge amount of the object according to the pulse applied voltage when the plasma potential changes over time.

[0559] Figure 71 is a flow chart for driving an applied voltage to an electrode of a plasma device.

[0560] Figure 72 shows the potential of the object when the plasma potential is maintained constant.

[0561] Figure 73 shows the potential of an object when the plasma potential oscillates over time.

[0562] Figure 74 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[0563] Figure 75 shows the value obtained by subtracting the plasma potential from the potential of the target object synchronized with the driving voltage.

[0564] Figure 76 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[0565] Figure 77 shows the potential of an object whose plasma potential is synchronized with the pulse driving voltage.

[0566] Figure 78 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[0567] Figure 79 shows the charge of an object whose plasma potential is synchronized with the driving voltage.

[0568] Figure 80 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[0569] Figure 81 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[0570] Figure 82 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[0571] Figure 83 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[0572] Figure 84 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[0573] Figure 85 shows the potential of an object when the plasma potential is constant and a sinusoidal driving voltage is applied.

[0574] Figure 86 shows the potential of an object in which the sinusoidal plasma potential is synchronized with the sinusoidal driving voltage.

[0575] Figure 87 shows the current waveform flowing through the electrode when the sinusoidal plasma potential is synchronized with the sinusoidal driving voltage.

[0576] Figure 88 shows the potential of the object when the plasma potential is synchronized with the sinusoidal driving voltage.

[0577] Figure 89 shows the potential of the object over time when the plasma potential is synchronized with the sinusoidal driving voltage.

[0578] Figure 90 shows the potential of an object whose plasma potential is synchronized with the sinusoidal driving voltage.

[0579] Figures 91 to 94 are conceptual diagrams showing a plasma device that changes plasma potential.

[0580] Figure 95 is a conceptual diagram showing a plasma system including a static electrode and an electrode.

[0581] Figure 96 is a conceptual diagram showing an electrode, a first dielectric, an electrostatic electrode, a second dielectric, and a plasma sheath.

[0582] Fig. 97 is a graph showing the potential of an object according to the applied voltage of the electrode.

[0583] Figure 98 is a graph showing the amount of charge of a target object according to the applied voltage of the electrode.

[0584] Figure 99 is a graph showing the amount of charge on an object according to the amount of charge on the electrostatic electrode.

[0585] Fig. 100 shows the positive charge (ρ) of the electrostatic electrode. esc ) has a surface charge density (ρ) of the object according to the thickness (d1) of the first region. i ) is a drawing that is lazy.

[0586] Fig. 101 shows the negative charge (ρ) of the electrostatic electrode. esc ) has a surface charge density (ρ) of the object according to the thickness (d1) of the first region. i ) is a drawing that is lazy.

[0587] Figure 102 shows the potential of an object when the charge amount of the electrostatic electrode changes over time.

[0588] Figure 103 is a graph showing the potential of an object according to the applied voltage of the electrode.

[0589] Figure 104 is a graph showing the potential of an object according to the applied voltage of the electrode.

[0590] Figure 105 is a graph showing the potential of an object according to the applied voltage of the electrode.

[0591] Figure 106 is a flowchart showing a method for controlling the voltage of an object.

[0592] Figure 107 shows the potential of an object according to the applied voltage of the electrode when the charge of the electrostatic electrode is in a pulse form.

[0593] Figure 108 shows the potential of an object according to the applied voltage of the electrode when the charge of the electrostatic electrode is in a pulse form.

[0594] Figure 109 is a conceptual diagram illustrating a plasma device according to one embodiment of the present invention.

[0595] Figure 110 is a conceptual diagram showing electrode / dielectric / object / plasma.

[0596] Figure 111 shows the potential of the object according to the applied voltage of the electrode in the structure of Figure 110.

[0597] Figure 112 is a conceptual diagram showing a plasma system including an electrostatic electrode.

[0598] Figures 113 to 116 are conceptual diagrams showing a plasma system including a variable capacitor.

[0599] Figures 117 and 118 are conceptual diagrams illustrating a method for controlling target voltage according to embodiments of the present invention.

[0600] Figure 119 is a conceptual diagram for distinguishing the waveform of displacement current according to conditions according to one embodiment of the present invention.

[0601] Figure 120 is a conceptual diagram dividing the ion energy distribution by region according to the ion current density (Ji) according to a temporary example of the present invention.

[0602] Fig. 121 is a graph showing the damping conditions according to the angular frequency (ω) and applied voltage (V) of the bias power supply.

[0603] Figure 122 is a graph showing the damping conditions according to the product of the angular frequency (ω) of the bias power supply and the applied voltage (V) and the ion current density (Ji).

[0604] Figure 123 shows the potential (Vs) waveform of the target object according to the ion current density at a sinusoidal applied voltage.

[0605] Figures 124 and 125 show the potential of the object according to the capacitance per unit area (ε1 / d1) between the object and the electrode under a sinusoidal applied voltage.

[0606] Figure 126 shows the potential (Vs) of the object according to the capacitance per unit area (ε1 / d1) between the object and the electrode under a bipolar DC pulse applied voltage.

[0607] Figure 127 shows the potential (Vs) of the object according to the ion current density at a bipolar DC pulse applied voltage.

[0608] Figure 128 shows the potential (Vs) of an object according to the capacitance per unit area (ε1 / d1) at a bipolar DC pulse applied voltage.

[0609] Figure 129 shows the potential (Vs) of the object according to the slope voltage (X=dV / dt) at a bipolar DC pulse applied voltage.

[0610] Figure 130 shows the potential (Vs) waveform and current waveform of the object according to conditions under a sinusoidal applied voltage.

[0611] Figure 131 shows the potential (Vs) waveform and current waveform of the object according to conditions under a sinusoidal applied voltage.

[0612] Figure 132 shows the potential (Vs) waveform and current waveform of the object according to conditions under a sinusoidal applied voltage.

[0613] Plasma is used in a variety of applications, including luminescence, semiconductor processing, coating, deposition, etching, sputtering, ion implantation, and surface treatment.

[0614] The present invention calculates and controls the potential and current of an object exposed to plasma through a structure that applies a potential to the object via a capacitor or dielectric. Various examples of controlling the potential of the object are described. In particular, the potential of the object is closely related to ion energy.

[0615] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosure is thorough and complete and to sufficiently convey the spirit of the present invention to those skilled in the art. In the drawings, components are exaggerated for clarity. Parts denoted by the same reference numerals throughout the specification represent the same components.

[0616] FIG. 1 is a conceptual diagram showing a plasma device according to one embodiment of the present invention.

[0617] Figures 2 and 3 are conceptual diagrams showing the electrode, dielectric, target, and plasma of Figure 1.

[0618] Referring to FIGS. 1 to 3, a plasma system (100) includes a chamber (12), a plasma source (20) for generating plasma within the chamber (12), and an object holder (14) for mounting an object (16). The object (16) may be a semiconductor substrate, a dielectric substrate, or a material to be processed. The chamber (12) may be made of a dielectric material or a metallic material and may be grounded. The plasma source (20) may include a high-frequency power source (28), a plasma electrode (22), an impedance matching network (26) disposed between the plasma electrode (22) and the high-frequency power source (28), and a capacitor (24) disposed between the impedance matching network (26) and the plasma electrode (22). The chamber (12) may be injected with gas and evacuated by a vacuum system.

[0619] The plasma source (20) may be a high-frequency capacitively coupled plasma source, a high-frequency inductively coupled plasma source, and an ultra-high frequency plasma source.

[0620] The object holder (14) may have a structure in which an electrode (18), a dielectric (17), and an object (16) are sequentially stacked. Plasma may contact the object (16). A plasma sheath may be formed between the object (16) and the plasma. The object (16) may be a conductor, a dielectric, or a semiconductor.

[0621] The voltage-current sensor can measure at least one of the current and voltage flowing to the electrode (18). The output of the voltage-current sensor is calculated by the control unit, and the control unit can control the plasma system (e.g., low-frequency power supply) using the mathematical formulas described below.

[0622] For example, the electrode (18) is subjected to an applied voltage (V G ) is applied, the target (16) is a semiconductor or a conductor, and the target (16) accumulates electrons or positive ions on its surface. A plasma sheath is formed between the plasma and the target (16). The plasma sheath can be treated as a space having a positive space charge. The target (16) can perform at least one of sputtering, etching, ion implantation, deposition, and surface treatment.

[0623] A low frequency power source (LF) is applied to the electrode (18) by applying a voltage (V G ) or a driving voltage can be applied. The low frequency power source (LF) can be a pulsed low frequency power source or a sinusoidal low frequency power source. The boundary between the high frequency and the low frequency can be 10 MHz. The boundary between the high frequency and the low frequency can be an ion plasma frequency. The high frequency power source (HF, 28) generates plasma by stochastic heating, and the low frequency power source (LF) can control the potential (Vs) of the target (16).

[0624] The thickness of the plasma sheath (d3) is determined by the applied voltage (V G ) is changed according to the dielectric (17). The dielectric (17) is the first region, the object (16) is the second region, and the plasma sheath is the third region. The thickness of the dielectric is d1. The thickness of the object (16) is d2. The thickness of the plasma sheath is d3. The voltage of the object (16) is Vs. The surface charge density of the object (16) is ρ i The permittivity of the first region is ε1, and the permittivity of the third region is ε3. The permittivity (ε3) of the plasma sheath may be the permittivity of a vacuum. The area of ​​the electrode (18) and the area of ​​the object (16) are A.

[0625] The general solutions for the voltage (V1) in the first region, the general solutions for the voltage (V2) in the second region, and the general solutions for the voltage (V3) in the third region are given as follows. In addition, the electric field (E1) in the first region and the electric field (E3) in the third region are given as follows. The origin of the coordinate system is the electrode. x is a coordinate in the rectangular coordinate system.

[0626] [Considering the matrix model]

[0627] The matrix model is the charge density (ρ) of the plasma sheath. d ) is treated as a constant that does not depend on position.

[0628] [Mathematical Formula 1]

[0629]

[0630] Here, the charge density in the plasma sheath or plasma is ρ d is. A1, A2, B1, C1, C2 are unknowns. Using boundary conditions and initial conditions, A1, A2, B1, C1, C2 are given as follows. As an initial condition, at the boundary between the plasma and the plasma sheath, the electric field (E3) is assumed to be zero. The object (16) is a conductor, and the first surface charge density of the surface facing the dielectric (17) is ρ ia , and the second surface charge density on the surface facing the plasma sheath is ρ ib The sum of the first surface charge density and the second surface charge density is the surface charge density (ρi).

[0631] [Equation 2]

[0632]

[0633] [Equation 3]

[0634]

[0635] The electric field in each region is given as follows:

[0636] [Equation 4]

[0637]

[0638] The voltage or potential (Vs) of the target object (16) is given as follows.

[0639] [Equation 5]

[0640]

[0641] That is, the thickness of the plasma sheath (d3) and the voltage (Vs) of the target (16) are given as negative values ​​as follows.

[0642] [Equation 6]

[0643]

[0644]

[0645] When the thickness (d3) of the plasma sheath is zero, i.e., the electrode (18) is subjected to a positive voltage (V G + ) are in a parallel state, the object (16) and electrode 18) are treated as a capacitor with a dielectric (17). In this case, a positive applied voltage (V G + ) can be given as follows:

[0646] [Equation 7]

[0647]

[0648] Positive applied voltage (V) of electrode (18) G + ) in a parallel state, the object (16) is initially charged with a negative charge. The applied voltage (V) of the electrode (18) G ) is a positive value (V G + ) in the negative value (V G - ) is suddenly transitioned to a negative voltage, the object (16) transitions to a negative voltage while maintaining a negative charge. In this case, a plasma sheath is formed, and a displacement current flows in the electrode (18).

[0649] Figure 3 is a diagram showing a case where a negative voltage is applied to the electrode and it is in an equilibrium state.

[0650] Referring to Figure 3, a negative voltage (V) is applied to the electrode (18). G - ) is maintained, the target (16) is positively charged by the inflow of ion current density (Ji), the voltage (Vs) of the target (16) becomes zero, and the plasma sheath disappears. In this case, it operates as a simple capacitor at Vs = 0, and the amount of positive charge charged to the target (16) is given as follows.

[0651] [Equation 8]

[0652]

[0653] The applied voltage of the electrode (18) is a negative value (V G - ) in positive values ​​(V G + ) suddenly transitions to a positive voltage, the object (16) maintains a positive charge and transitions to a positive voltage. In this case, at a positive applied voltage, if the potential (Vs) of the object is greater than or equal to zero, the plasma and the object (16) simultaneously increase in potential, so that a second plasma sheath can be formed on the ground, which is the wall of the chamber. Electrons are rapidly introduced into the object (16), so that the second plasma sheath disappears and the object (16) is charged with a negative charge.

[0654] Figure 4 is a graph showing the potential of an object according to a pulse voltage waveform alternating between positive and negative voltages.

[0655] Referring to Fig. 4, a negative voltage (V) is applied to the electrode (18). G - ) If the applied state continues, the object (16) is charged with a positive charge due to the inflow of ion current density (Ji), and at point c, the voltage (Vs) of the object (16) becomes zero and the plasma sheath disappears.

[0656] The applied voltage of the electrode (18) is a negative value (VG - ) in positive values ​​(V G + ) suddenly transitions, it can transition from point c to point b via a different path, rather than transitioning from point c to b`-b. Since electrons have very high mobility, they respond immediately to changes in applied voltage.

[0657] If the applied voltage of the electrode (18) suddenly transitions from a negative value to a positive value, and electrons do not rapidly flow into the object (16), the voltage (Vs) of the object (16) is given as follows at point b', and a new second plasma sheath is formed at the ground. If the object is positively charged, and the applied voltage of the electrode (18) suddenly transitions from a negative value to a positive value, the potential of the object approaches the plasma potential (Vp), and the plasma potential rises.

[0658] [Equation 9]

[0659] Vs= Vp

[0660] However, when electrons are rapidly introduced into the object (16), the voltage (Vs) of the object (16) transitions from point c to point b.

[0661] When a positive voltage is applied to the electrode (18), the object (16) is charged with a negative charge in the equilibrium state. When the applied voltage of the electrode (18) suddenly transitions from a positive value to a negative value from point b to point a, a plasma sheath is formed, and the ion current density (Ji) slowly charges the object (16) to a positive value through the plasma sheath.

[0662] Figure 5A is a drawing showing a plasma sheath structure when the thickness of the object is ignored.

[0663] Referring to FIG. 5A, a plasma system (100) includes a chamber (12), a plasma source (20) for generating plasma within the chamber (12), and an object holder (14) for mounting an object (16). The object (16) may be a semiconductor substrate, a dielectric substrate, a sputtering target, an edge ring, a focus ring, or a workpiece disposed around the substrate. The chamber (12) may be made of a dielectric material or a metal material, and a chamber made of a metal material may be grounded. The plasma source (20) may include a high-frequency power source (HF, 28), a plasma electrode (22), an impedance matching network (26) disposed between the plasma electrode and the high-frequency power source, and a capacitor (24) disposed between the impedance matching network and the plasma electrode. A gas may be injected into the chamber (12) and exhausted by a vacuum system.

[0664] The electrode (18) is provided with a voltage (V) G ) is applied, the object (16) is a semiconductor or a conductor, and the object (16) accumulates electrons or positive ions on its surface. A plasma sheath is formed between the plasma and the object (16). The plasma sheath can be treated as a space having a positive space charge. The thickness (d2) of the plasma sheath is determined by a voltage (V G ) is changed according to the dielectric region. The dielectric region is the first region, and the plasma sheath is the second region. The thickness of the dielectric (17) is d1. If the object (16) is a conductor, the thickness of the object (16) is ignored. The thickness of the plasma sheath is d2. The voltage of the object (16) is Vs. The surface charge density of the object (16) is ρ i The permittivity of the first region is ε1, and the permittivity of the plasma sheath (ε2) can be the permittivity of vacuum.

[0665] The general solution of the voltage (V1) in the first region and the general solution of the voltage (V2) in the second region are given as follows. In addition, the electric field (E1) in the first region and the electric field (E2) in the second region are given as follows. The origin of the coordinate system is the electrode. x is a coordinate of the rectangular coordinate system.

[0666] [Equation 10]

[0667]

[0668] Here, the charge density in the plasma sheath is ρ d A1, A2, B1, and B2 are unknowns.

[0669] Using boundary conditions and initial conditions, A1, A2, B1, and B2 are given as follows. As an initial condition, the electric field (E2) at the boundary between the plasma and the plasma sheath is assumed to be zero.

[0670] [Equation 11]

[0671]

[0672] The electric field in each region is given as follows:

[0673] [Equation 12]

[0674]

[0675] The voltage (Vs) of the target object (16) is given as follows.

[0676] [Equation 13]

[0677]

[0678] A positive voltage (V) is applied to the electrode (18) G + ) is authorized, when the equilibrium is reached, the electrode (18) and the object (16) become a simple capacitor, and the charged amount (ρ) of the object (16) i ) is given as follows.

[0679] [Equation 14]

[0680]

[0681] Meanwhile, the thickness (d2) of the plasma sheath and the surface potential (Vs) of the target (16) are given as follows.

[0682] [Equation 15]

[0683]

[0684] The surface potential (Vs) of the target object (16) is given as follows.

[0685] [Equation 16]

[0686]

[0687] The potential (Vs) of the object (16) has two solutions according to the root formula of the second-order equation, but a positive sign was selected so that the potential (Vs) of the object (16) includes zero. The voltage (Vs) of the object (16) has a negative value due to the initial negative charge charging, which causes a DC bias. The plasma charge density (ρ d ) can be measured using a Langmuir probe, etc. Plasma charge density (ρ d ) can be obtained, the potential (Vs) of the object (16). If the object is a conductor, the same result as the result of ignoring the thickness of the object is obtained.

[0688] We compare the matrix model, the model considering electron temperature, and the Child-Langmuir model.

[0689] [Considering electron temperature]

[0690] Figure 5b is a drawing showing a plasma sheath structure when the thickness of the object is ignored.

[0691] Referring to Fig. 5b, the Poisson equation is transformed as follows. The electric field is zero in the plasma region, and the electric field is Es at the boundary between the plasma sheath and the object (16). The plasma potential is assumed to be zero. In addition, the potential (φ) is zero in the plasma region, and is Vs at the boundary between the plasma sheath and the object. Using the boundary condition of Gauss's law, the surface charge density (ρs) charged on the surface of the object (16) is determined by Es. q is a positive unit charge. k is the Boltzmann constant, and Te is the electron temperature. The origin of the coordinate system is the boundary between the plasma and the sheath.

[0692] [Equation 17]

[0693]

[0694] The voltage (Vs) of the target object (16) is given as follows.

[0695] [Equation 18]

[0696]

[0697] [Considering the Child-Langmuir model]

[0698] Figure 5c is a drawing showing a plasma sheath structure when the thickness of the object is ignored.

[0699] Referring to Fig. 5c, the Child-Langmuir model has a Bohm velocity (u B), ions start at the boundary of the plasma preheath and the plasma sheath with spring velocity, and due to conservation of energy and conservation of flux, ions are accelerated in the plasma sheath. The plasma potential (Vp) is assumed to be zero. The electric field is zero in the plasma region, and the electric field is Es at the boundary between the plasma sheath and the object (16). In addition, the potential (φ) is zero in the plasma region, and is Vs at the boundary between the plasma sheath and the object (16). Using the boundary condition of Gauss's law, the surface charge density (ρs) charged on the surface of the object (16) is determined by Es. q is a positive unit charge. k is the Boltzmann constant, and Te is the temperature of the electron. M is the mass of the ion. ρ0 is the charge density in the preheath. ρ0 can be 0.61 times the charge density of the plasma. The origin of the coordinate system is the boundary between the plasma and the sheath.

[0700] [Equation 19]

[0701]

[0702] The voltage (Vs) of the target object (16) is given as follows.

[0703] [Equation 20]

[0704]

[0705] Figure 6 shows the applied voltage (V) of the electrode according to the voltage (Vs) of the object according to the matrix model, electron temperature consideration model, and Child-Langmuir (CL) model. G ) is a graph representing the

[0706] Figure 7 shows the applied voltage (V) of the electrode according to the matrix model, electron temperature consideration model, and Child-Langmuir model by changing the coordinate axis. G ) is a graph showing the voltage (Vs) of the target object.

[0707] Referring to Figures 6 and 7, the matrix model and the electron temperature consideration model show the same voltage (Vs) of the object (16) for the same electrode voltage, except for the region that affects the electron temperature. However, the Child-Langmuir model shows a lower voltage (Vs) for the same electrode applied voltage compared to the matrix model.

[0708] When the voltage (Vs) of the object (16) by the Child-Langmuir model is added to the matrix model with a correction factor (α), the voltage (Vs) of the object (16) by the Child-Langmuir model is given as follows.

[0709] [Correcting the CL model to a matrix model α=0.3 ~ 0.5 α=0.33]

[0710] [Equation 21]

[0711]

[0712] The voltage (Vs) of the object (16) according to the Child-Langmuir model appears to be an increase in the electrostatic capacitance (ε1 / d1) per unit area of ​​the dielectric (17). The correction factor (α) depends on the applied voltage of the electrode (18), and when the applied voltage of the electrode (18) is several tens of V, the correction factor (α) is at the level of 0.5. When the applied voltage of the electrode is several hundreds of V, the correction factor (α) is at the level of 0.3.

[0713] [She's electrostatic capacity]

[0714] The capacitance per unit area of ​​the plasma sheath (c) sh ) is given as follows.

[0715]

[0716] [Electron Temperature and Floating Potential]

[0717] Figure 8 is a graph showing the relationship between the voltage of the target and the applied voltage considering the floating potential.

[0718] Referring to Figure 8, considering the electron temperature (Te) and floating potential, V GF is an additional applied voltage to generate a floating potential (Vf). The potential (Vs) of the object (16) is given as follows.

[0719] [Equation 22]

[0720]

[0721] Floating Potential (Vf) represents the initial potential state in the equilibrium state of the object (16). Therefore, a positive applied voltage (V G + ) the potential (Vs) of the object (16) is offset from zero and has a floating potential (Vf). That is, for the floating potential (Vf), the object (16) is overcharged with a negative charge. The floating potential (Vf) can be measured by a Langmuir probe, etc., or can be predicted theoretically.

[0722] Figure 9 shows the current (I) flowing through the electrode according to the bipolar pulse applied voltage waveform of the electrode. G ) and the voltage (Vs) of the target object.

[0723] Figure 10 shows the negative applied voltage (V) of the electrode G - ) shows the thickness of the plasma sheath over time.

[0724] Figure 11 shows the negative applied voltage (V) of the electrode G - ) represents the negative sum of the charge density of the plasma sheath over time and the surface charge density of the object.

[0725] Figure 12 is a graph showing various characteristics according to the applied voltage of the electrode.

[0726] Referring to FIGS. 9 to 12, the applied voltage of the electrode (18) is a positive value (V G +), in the equilibrium state, the object (16) is charged with a negative charge. When the applied voltage of the electrode (18) is a positive value (V G + ) in the negative value (V G - ) is rapidly transitioned, a plasma sheath is formed, and an ion current density (J) is applied to the electrode (18) through the plasma sheath. i ) flows. Also, the ion current density (J i ) flows, and as the object (16) is charged with positive charge, displacement current flows simultaneously. Therefore, the current (I) flowing in the electrode (18) GO ) is expressed as the sum of the ion current density (Ji) and the displacement current (Jd).

[0727] Meanwhile, the applied voltage of the electrode (18) is a negative value (V G - ) is maintained, the object (16) reaches an equilibrium state by the ion current density (Ji), and no more current flows through the electrode (18). In this case, the charge of the object (16) is a positive value, and the voltage (V) of the electrode (18) G - ) is given by. The negative sum of the charge of the plasma sheath and the surface charge density of the object is the charge of the electrode (Q G )am.

[0728] Referring to FIGS. 9 to 12, after a negative applied voltage is applied, a positive ion current density (Ji >0) is incident on the target (16) through the plasma sheath and accumulated. Accordingly, the negative applied voltage (V G - ) is applied, the absolute value of the voltage (Vs) of the object (16) decreases over time, and the absolute value of the voltage (Vs) of the object (16) becomes zero at the maximum time (tmax).

[0729] In the mattress model, a negative applied voltage (V G -) is applied, the absolute value of the voltage (Vs) of the object (16) decreases over time, and the maximum time (tmax) at which the voltage (Vs) of the object (16) becomes zero is given as follows. It is assumed that the applied voltage has a time-dependent slope voltage (X=dV / dt) from a predetermined measured voltage value (V0).

[0730] [Equation 23]

[0731]

[0732] Therefore, the maximum time (tmax) is the positive applied voltage (V G + ) is the initial negative charge (ρ) i0 ), the capacitance per unit area of ​​the dielectric (17) (ε1 / d1=c1), the measurement voltage (V0), the gradient voltage (X), and the ion current density (Ji).

[0733] Positive applied voltage (V G + ) is the initial negative charge (ρ) i0 , Q i0 ) is given as follows.

[0734]

[0735] The maximum time (tmax) is expressed as follows, ignoring the electron temperature (Te).

[0736]

[0737] Here, c1 is the capacitance per unit area of ​​the dielectric (17). In the absence of a ramp voltage (X=dV / dt), the maximum time (tmax) is given as follows. When the maximum time (tmax) is measured at the measurement voltage (V0), the ion current density (Ji) is obtained.

[0738] [Equation 24]

[0739]

[0740] Current (I) flowing in the electrode (18) G) is given as follows. In the mattress model, the current (I) of the electrode (18) G ) is the surface charge density (ρ) of the electrode (18). G ) is given as follows in time derivative, where A is the area of ​​the electrode (18) and the object (16).

[0741] [Equation 25]

[0742]

[0743] A constant negative voltage (V) is applied to the electrode (18) G - ) is applied, the current (I) flowing through the electrode (18) G ) is given by the following, including the electron current (Ie component) due to the ion current density (Ji) (or ion current (Ii)) and electron temperature (Te).

[0744] [Equation 26]

[0745]

[0746]

[0747] Here, Vp is the plasma potential, Te is the electron temperature, and C1 is the capacitance of the dielectric (17).

[0748] The current (I) flowing in the electrode (18) by the electron current (Ie) and ion current (Ii) G ) is zero, the current (I) of the electrode (18) G ) is given by the following at the floating potential (Vf) of the object. The electron current (Iei) is the electron flux toward the object. ve is the average velocity of electrons. u B is the Bohm velocity.

[0749]

[0750] Therefore, the object (16) is the current (I) of the electrode G ) has a floating potential (Vf) in the zero equilibrium state.

[0751] When the voltage applied to the electrode (18) is fixed, the current (I component) due to electrons flowing in the electrode (18) is included, and the current (I G ) is displayed as follows.

[0752] [Equation 27]

[0753]

[0754] It is assumed that β has a constant value at the applied voltage. In this case, the potential (Vs) of the object (16) is given as follows.

[0755] [Equation 28]

[0756]

[0757] Here, C is the integration constant.

[0758] When the normalized potential (χ) of the object (16) has a negative value, the absolute value of the normalized potential (χ) of the object (16) shows a result that decreases linearly with time (t). Therefore, the time (tmax) at which the current flowing in the electrode (18) becomes zero is given as follows when the plasma potential (Vp) is zero.

[0759] [Equation 29]

[0760]

[0761] The initial voltage (Vso) of the target (16) is given as follows.

[0762]

[0763] Therefore, the maximum time (tmax) and the current (I) flowing in the electrode (18) G0 ) is measured, the initial voltage (Vso) of the object (16) is obtained. From the initial voltage of the object, the charge density of the plasma is obtained. In addition, the maximum time (tmax) and the current (I) flowing in the electrode (18) are obtained. G0 ) is measured, and the floating potential (Vf) is measured or taken into account, the initial voltage (Vso) of the object (16) is obtained, and the plasma density is obtained.

[0764] Also, the plasma charge density (ρ d ), electron temperature (Te), floating potential (Vf), and plasma potential (Vp) can be measured by a Langmuir probe, etc. Conversely, plasma charge density (ρ d ) and the current (I) flowing through the electrode (18) G0 ) can be used to find the maximum time (tmax).

[0765] The maximum time (tmax) is given by ignoring the floating potential (Vf):

[0766]

[0767] Considering the floating potential (Vf), the maximum time (tmax) is given by:

[0768] [Equation 30]

[0769]

[0770] A negative voltage (V) is applied to the electrode (18) G - ) is applied, the current (I) of the electrode (18) G0 ) As the ion current density (Ji) charges the object (16), the absolute value of the voltage (Vs) of the object (16) decreases, and the current (I) of the electrode (18) G0 ) is a value that is almost constant over time (I G0 ), and the current of the electrode (I G0 ) becomes zero when the potential (Vs) of the object reaches zero (or floating potential).

[0771] The ion current density (Ji) is determined by the plasma charge density (ρ) according to the Child-Langmuir model. d ) and Bohm velocity (u B ) is given. Therefore, once the ion current density (Ji) is determined, the plasma charge density (ρ d ) is obtained. Here, k is the Boltzmann constant and Te is the electron temperature.

[0772] [Equation 31]

[0773]

[0774] Additionally, the plasma sheath charge (Qsh) is given as the charge per unit area within the plasma sheath as follows.

[0775] [Equation 32]

[0776]

[0777] A positive voltage (V) is applied to the electrode (18) G + ) is in equilibrium, the plasma sheath charge (Qsh) is zero (or close to zero), and the electrodes are subjected to a positive applied voltage (V G + ) with a negative applied voltage (V G - ), the plasma sheath charge (Qsh) depends on the voltage (Vs) of the target.

[0778] Meanwhile, a positive voltage (V) is applied to the electrode (18). G + ) is in an equilibrium state, the charge quantity (Q) of the object (16) i0 , ρ i ) has a negative value. The electrode (18) is subjected to a positive applied voltage (V G + ) with a negative applied voltage (V G - ) in case of a rapid transition, the charge quantity (Q) of the object (16) i0 ) remains at the same value. Negative applied voltage (V G - ) is maintained, when the charge amount (Qi) of the object (16) changes due to the ion current density (Ji), the plasma sheath charge amount (Qsh) changes accordingly. The change in the charge amount (Qi) of the object over time is due to the ion current density (Ji), and the change in the plasma sheath charge amount (Qsh) over time induces a displacement current.

[0779] Figure 13 is a graph showing the voltage of the target object according to the applied voltage.

[0780] Figure 14 is a graph showing the charge density in each region.

[0781] Figure 15 shows the applied voltage (V) of the electrode (18). G ) is a graph showing the charge amount (Qi) of the target (16), the plasma sheath charge amount (Qsh) and the sum (QT) of the charge amount (Qi) of the target and the plasma sheath charge amount (Qsh).

[0782] Figure 16 is a graph showing the charge amount (Qi) and plasma sheath charge amount (Qsh) of a target object according to the applied voltage of the electrode.

[0783] Referring to FIGS. 13 to 16, the plasma sheath charge (Qsh) gradually increases as the applied voltage of the electrode (18) decreases to a negative value. When the bipolar applied voltage is applied alternately with a small cycle, it mainly operates at the points a and b.

[0784]

[0785] Figure 17 is a graph showing the relationship between maximum time (tmax) and ion current density.

[0786] Figure 18 is a graph showing the reciprocal of the maximum time (tmax) and the ion current density.

[0787] Figure 19 is a graph showing the relationship between maximum time (tmax) and capacitance per unit area.

[0788] Referring to FIGS. 17 to 19, the ion current density (Ji) and the maximum time (tmax) are inversely proportional. Accordingly, in high-density plasmas or when the ion current density (Ji) is large, the maximum time (tmax) decreases. If the time interval (τ) during which the negative applied voltage is applied is greater than the maximum time (tmax), the potential (Vs) of the object has a zero value, so the voltage (Vs) of the object is severely distorted.

[0789] Therefore, the time interval (τ) during which the negative voltage is applied in the waveform of the bipolar applied voltage can be sufficiently smaller than the maximum time (tmax). Specifically, the time interval (τ) during which the negative voltage is applied in the waveform of the bipolar applied voltage can be 1 / 10 times the maximum time (tmax). The frequency (f) of the bipolar applied voltage LF ) can be at least 10 times the reciprocal of the maximum time (tmax) (fmin).

[0790] [Equation 33]

[0791]

[0792] In addition, the maximum time (tmax) may depend on the capacitance per unit area of ​​the dielectric (c1=ε1 / d1). The maximum time (tmax) depends on the applied voltage (V) of the electrode. G ) can depend on the frequency (f) of the bipolar applied voltage. Therefore, in order to minimize the waveform distortion of the voltage (Vs) of the target, LF ) can be determined by the ion current density (Ji), the capacitance per unit area of ​​the dielectric (17) (c1=ε1 / d1) and the applied voltage.

[0793] In the search mode, the applied voltage in the form of a bipolar pulse has a low enough frequency to obtain the maximum time (tmax). The ion current density (Ji), the maximum time (tmax), or the current density (J) obtained in the search mode G0 ), in the driving mode, the driving frequency of the bipolar pulse is increased to prevent the potential (Vs) of the object from rapidly decreasing over time. Meanwhile, in the driving mode, the bipolar pulse can be compensated to have a slope voltage (X).

[0794] Figure 20 shows the voltage (Vs) of the target object as a positive applied voltage (V G + ) is a graph standardized.

[0795] Referring to Figure 20, the potential (Vs) of the object is . That is, the absolute value of the voltage (Vs) of the object (16) depends on the applied voltage (V G + ), it may be desirable to have the following conditions:

[0796] [Equation 34]

[0797]

[0798] Also, the applied voltage (V G + ) increases, the normalized voltage (Vs) of the object increases. is less sensitive to the applied voltage (V G + ) is less than several tens of V, It is desirable that it be 5 or less.

[0799] Applied voltage (V) G + ) is more than several hundred V, It is desirable that it be less than 10.

[0800] Applied voltage (V) G + ) is constant, as the plasma density increases, the absolute value of the potential (Vs) of the object decreases. The absolute value of the potential (Vs) of the object decreases when the applied voltage (V G + ) to use 90 percent of can be less than or equal to 1.

[0801] Also, the applied voltage (V G + ) is constant, when the electrostatic capacitance per unit area of ​​the dielectric (17) (c1=ε1 / d1) increases, the absolute value of the voltage (Vs) of the object (16) increases. Therefore, the larger the electrostatic capacitance per unit area of ​​the dielectric (17), the more desirable it is.

[0802]

[0803] [Mattress Model]

[0804] In the mattress model, the current (I) of the electrode (18) G) is the surface charge density (ρ) of the electrode (18). G ) is given by the time derivative as follows, where A is the area of ​​the object and electrode.

[0805] [Equation 35]

[0806]

[0807] The voltage (Vs) of the target object (16) is given as follows.

[0808] [Equation 36]

[0809]

[0810] Applied voltage (V) of electrode (18) G ) is the slope voltage (X=dV G / dt), the time derivative of the potential (Vs) of the object (16) is given as follows.

[0811] [Equation 37]

[0812]

[0813] Current (I) of electrode (18) G ) is given as follows. Here, C1 is the electrostatic capacitance of the dielectric (17).

[0814] [Equation 38]

[0815]

[0816] Current (I) of electrode (18) G ) is given as follows.

[0817] [Equation 39]

[0818]

[0819] β is in the range of normal applied voltage, and β can be from 0.4 to 0.01.

[0820] Figure 21 shows the applied voltage (V) of the electrode when there is no slope voltage (X = 0). G ) The current flowing through the electrode ((I) G ) is a graph representing the

[0821] Referring to Figure 21, the ratio of electrode current (I) to ion current (Ii) G0 / Ii=β-1) has a constant negative value at negative applied voltage and increases to zero as the positive applied voltage increases.

[0822] Also, 1-β can be a gain, i.e., the applied voltage (V G ) represents the gain. The gain is the difference between the applied voltage (V G ) is almost constant when the applied voltage (V G ) has a positive value, the gain may decrease.

[0823] [Equation 40]

[0824]

[0825] Figure 22 is a graph showing β according to the applied voltage of the electrode when there is no slope voltage (X=0).

[0826] Referring to Fig. 22, β≤ 0.4 or less at a negative applied voltage. Preferably, β≤ 0.2 or less. β can be interpreted as the ratio of the effective capacitance to the capacitance of the dielectric.

[0827] The capacitance of the plasma sheath increases with increasing plasma density at negative voltages. Accordingly, as the plasma density increases, β increases at negative voltages.

[0828] Figure 23 is a graph showing the gain (1- β).

[0829] Referring to Fig. 23, can be. In this case, at a positive applied voltage, the gain (1- β) decreases, and when a sine wave waveform with a small amplitude near the maximum applied voltage is applied, the voltage of the target is severely distorted from the sine wave. This distortion of the waveform can generate harmonics, which can adversely affect the plasma. Therefore, when a bipolar pulse and a high-frequency sine wave (HF=hsinωt) are applied together to the electrode (18), the high-frequency sine wave has a low gain at a positive applied voltage and can be severely distorted.

[0830] Figure 24 is a graph showing the current of an electrode according to the applied voltage of the electrode.

[0831] Referring to Fig. 24, when there is no slope voltage (X=0), the current (I) of the electrode (18) G ) has a smaller absolute value than the absolute value of the ion current (Ii) at negative applied voltage. The difference between these values ​​can be very small.

[0832] Figure 25 shows the current (I) of the electrode for the ion current (Ii) according to the plasma density. G ) of the incision ratio (I G0 / Ii) is indicated.

[0833] Referring to Fig. 25, when the negative applied voltage increases, the ratio (-I G0 / Ii) approaches 1. Therefore, at negative applied voltages of -hundreds of V, the ratio (-I G0 / Ii) approaches 1. On the other hand, at a negative applied voltage of -tens of V, the ratio (-I G0 / Ii) can be reduced to 0.6 or less. When the applied voltage is 40 V, 80 V is applied by the bipolar pulse, and the plasma density (Ne) has 10^17 / m^3, it has about 0.5. On the other hand, when the applied voltage is 400 V, 800 V is applied by the bipolar pulse, and when Ne has 10^17 / m^3, it has about 0.82. On the other hand, when the applied voltage is 4000 V, 8000 V is applied by the bipolar pulse, and when Ne has 10^17 / m^3, it has about 0.95.

[0834] Figure 26 shows the current density (J) flowing through the electrode for the ion current density (Ji). G0 ) represents the relationship.

[0835] Referring to Fig. 26, when there is no gradient voltage (X=0), the current density (J) flowing in the electrode (18) for the ion current density (Ji) G0 ) is given as follows.

[0836] [Equation 41]

[0837]

[0838] Current density (J) flowing in the electrode (18) G0 ) is obtained, a certain negative applied voltage (V G ) is given the ion current density (Ji). If the peak-to-peak voltage (40 V) of the bipolar pulse is small, the current density (J G0 ) shows a large difference from the ion current density (Ji). On the other hand, when the peak-to-peak voltage (4000 V) of the bipolar pulse is large, the current density (J G0 ) does not show any difference from the ion current density (Ji).

[0839] Figure 27 is a graph showing the voltage of a target object according to the applied voltage of the electrode.

[0840] Referring to Fig. 27, for a given capacitance per unit area (ε1 / d1) of a dielectric (17), as the plasma density increases, the absolute value of the voltage (Vs) of the object (16) decreases. Therefore, in order to increase the absolute value of the voltage (Vs) of the object (16), the plasma density can be maintained below a predetermined value.

[0841] Figure 28 shows the current (I) of the electrode according to the slope voltage (X). G ) is a graph representing the

[0842] Figure 29 is a graph showing the change in voltage (ΔVs) of an object according to a slope voltage (X).

[0843] Referring to FIG. 28 and FIG. 29, the current (I) of the electrode (18) according to the slope voltage (X) G ) is given.

[0844] [Equation 42]

[0845]

[0846] Here, ρ i0 is the initial value charged to a positive applied voltage. V G0 is the initial value of the negative applied voltage. τ is the time interval during which the negative applied voltage is applied. In addition, when using the mattress model, the variation (ΔVs) of the voltage (Vs) of the object (16) is given as follows.

[0847] [Equation 43]

[0848]

[0849]

[0850]

[0851] When the ion current (Ii) or the ion current millimeter (Ji) is known, the potential (Vs) of the object (16) can be obtained. Accordingly, when the ion current (Ii) or the ion current millimeter (Ji) is known, the gradient voltage (X1) that makes the variation (ΔVs) of the potential (Vs) of the object (16) zero can be obtained.

[0852] In the absence of a gradient voltage (X=0), the current (I) flowing in the electrode (18) G0 ) is set to correspond to the slope voltage (X), which is given as follows.

[0853]

[0854] In this case, the change in potential of the target object (ΔVs) is given as follows.

[0855] [Equation 44]

[0856]

[0857] In the absence of a gradient voltage (X=0), the current (I) flowing in the electrode (18) G0 ) is set to correspond to the applied voltage (V) of the bipolar pulse. G ) is more than several hundred V, β approaches zero, so the amount of change (ΔVs) in the potential of the object (16) approaches zero.

[0858] [Calibrate the CL model to the mattress model]

[0859] If the Child-Langmuir model is used as the correction factor (α) of the mattress model, the voltage fluctuation amount (ΔVs) of the target object (16) is given as follows.

[0860] [Equation 45]

[0861]

[0862] Therefore, when corrected using the Child-Langmuir model, the voltage fluctuation (ΔVs) of the target (16) increases more than with the matrix model.

[0863] Figure 30 is a graph showing the change in voltage (ΔVs) of a target object according to plasma density.

[0864] Referring to Fig. 30, when there is no gradient voltage (X=0), a high-density plasma has a smaller variation in the potential of the object (ΔVs) than a low-density plasma. The voltage (Vs) of the object (16) can represent an ion energy distribution function.

[0865] [Calculation of plasma density or plasma charge density]

[0866] β and β' are defined as follows.

[0867] [Equation 46]

[0868]

[0869] Plasma charge density (ρ d ) is given in the mattress model as follows.

[0870] [Equation 47]

[0871]

[0872] [Calibrating the CL model using a matrix model: correction factor α]

[0873] When correction is made with a correction factor (α), the electrode current (I G ) is given as follows.

[0874] [Equation 48]

[0875]

[0876] The correction factor (α) can be 0.3 to 0.5. The correction factor (α) can be 0.4 at voltages of several tens of V and 0.3 at voltages of several hundred V.

[0877] Figure 31 is a conceptual diagram illustrating a plasma system according to one embodiment of the present invention.

[0878] Figure 32 is a graph showing the current of the electrode according to the slope voltage when there is an auxiliary capacitor (C4).

[0879] Referring to FIGS. 31 and 32, the electrode is connected to ground by an auxiliary capacitor (C4). The auxiliary capacitor (C4) may be a parasitic capacitor.

[0880] When a parasitic capacitance or auxiliary capacitor (C4) is connected in parallel to the electrode, the current (I) flowing in the electrode (18) G ) is given as follows.

[0881] [Mattress Model]

[0882] [Equation 49]

[0883]

[0884] Current of the electrode (I G ) is increased by the auxiliary capacitor (C4). X1C1=-I i In this case, the ion current (Ii) can be obtained. In the case of an auxiliary capacitor (C4), the current of the electrode (I G ) depends on the auxiliary capacitor (C4).

[0885] Figure 33 is a graph showing the voltage of a target object according to the low-frequency applied voltage of an electrode according to one embodiment of the present invention.

[0886] Figure 34 is a graph showing the charge amount (Qi) of a target object according to the applied voltage of an electrode according to one embodiment of the present invention.

[0887] Figure 35 is a graph showing the amount of charge and potential according to the applied voltage of an electrode according to one embodiment of the present invention.

[0888] Referring to FIGS. 33 to 35, the applied voltage (V G ) is sufficiently small compared to the maximum time (tmax). The negative applied voltage (V G -) when the ion current density (Ji) is incident through the plasma sheath, the absolute value of the potential (Vs) of the target (16) decreases. That is, it changes from point a to point a'. Accordingly, the ion energy distribution has an expanded line width. When the negative applied voltage (V G - ) is sufficiently smaller than the maximum time (tmax). Specifically, the duration (τ) may be less than 1 / 10 of the maximum time (tmax). The maximum time (tmax) may be tens of usec to tens of msec. The duration (τ) may be several usec to hundreds of usec.

[0889] [Equation 50]

[0890]

[0891] The applied voltage is a negative value (V G - ) in positive values ​​(V G + ) is rapidly changed, the charge (Qi) of the object (16) remains the same value, and the charge (Qsh) of the plasma sheath decreases to zero. In addition, at points b` and b``, the electron current density (Je) is rapidly introduced into the object, so that the charge (Qi) of the object is charged to a negative value.

[0892] Figure 36 shows the potential of the target for low-frequency pulse ramp voltage driving.

[0893] Figure 37 shows the charge amount of the target and the charge amount of the plasma sheath for low-frequency pulse ramp voltage driving.

[0894] Referring to FIGS. 36 and 37, the period of the applied voltage is sufficiently small compared to the maximum time (tmax). At a negative applied voltage, when the ion current density (Ji) is incident through the plasma sheath, the absolute value of the potential (Vs) of the target (16) decreases. However, when there is a slope voltage (X1) at the negative applied voltage, the voltage (Vs) of the target (16) can be kept constant. That is, it changes from point a to point a'. The charge amount (Qsh) of the plasma sheath can be kept constant in the slope voltage section. In the slope voltage section, the absolute value of the charge amount (Qi) of the target (16) decreases when the ion current density (Ji) is incident.

[0895] The applied voltage of the electrode (18) is a negative value (V G - ) in positive values ​​(V G + ) is suddenly transitioned, the charge (Qi) of the target is maintained, while the charge of the plasma sheath decreases to zero. In addition, electron current flows from the plasma into the target, and the charge of the target reaches a negative value.

[0896] Figure 38 is a flowchart illustrating an operating method for low-frequency pulse driving.

[0897] Referring to Fig. 38, plasma is generated (S10). Subsequently, a bipolar pulse voltage is driven to the electrode (18) (S11). The negative pulse section is set to be sufficiently large, and the maximum time (tmax) at which the current flowing through the electrode becomes zero is measured (S12). The ion current density is obtained (S14) using the relationship between the maximum time (tmax) and the ion current density (Ji). The time at which the negative voltage is applied from the driving voltage is set to be sufficiently smaller than the maximum time (tmax) (S13). The plasma charge density (ρ) is calculated using the ion current density (Ji). d) is produced. The voltage (Vs) of the target is set (S16). The voltage (Vs) of the target (16) determines the ion energy. The waveform (V) of the driving voltage corresponding to the voltage (Vs) of the target G ) is determined (S16). The amount of change (ΔVs) of the voltage (Vs) of the target object (16) due to the ion current density (Ji) is confirmed (S17). The slope voltage (X) that compensates for the amount of change (ΔVs) of the voltage of the target object due to the ion current density (Ji) is determined (S18), and a low-frequency pulse waveform is driven (S19).

[0898] Figure 39 is a flowchart illustrating an operating method for low-frequency pulse driving.

[0899] Referring to Fig. 39, plasma is generated (S20). Subsequently, a bipolar low-frequency pulse voltage is driven to the electrode (S21). In the negative pulse section, a current (I) flowing to the electrode (18) G0 ) is measured. The current (I) of the electrode (18) G0 ) and the ion current density (Ji) is used to obtain the ion current density (Ji) (S23). The time (τ) for which a negative voltage is applied from the driving voltage is set to be sufficiently smaller than the maximum time (tmax) determined by the ion current density (Ji). The plasma charge density (ρ) is obtained using the ion current density (Ji). d ) is calculated (S24). The voltage (Vs) of the target (16) is set (S25). The voltage (Vs) of the target determines the ion energy. The waveform of the driving voltage corresponding to the voltage (Vs) of the target is determined (S25). The variation (ΔVs) of the voltage (Vs) of the target due to the ion current density (Ji) is confirmed (S26). The slope voltage (X) that compensates for the variation (ΔVs) of the voltage of the target due to the ion current density (Ji) is determined (S27). A low-frequency pulse waveform is driven (S28).

[0900] Figure 40 is a flowchart illustrating an operating method for low-frequency pulse driving.

[0901] Referring to Fig. 40, plasma is generated (S30). Subsequently, a bipolar low-frequency pulse voltage is driven to the electrode (18) (S31). In the negative pulse section, a current (I) flowing to the electrode (18) G0 ) is measured. The current of the electrode (I G0 ) and the electrostatic capacitance of the plasma sheath (Csheath) are used to obtain the ion current density (Ji) (S34). The electrostatic capacitance of the plasma sheath (Csheath) can be measured directly or the plasma charge density (ρ d ) can be used to calculate the time (τ) during which a negative voltage is applied at the driving voltage, which is sufficiently smaller than the maximum time (tmax) determined by the ion current density (Ji). Using the ion current density (Ji), the plasma charge density (ρ) is calculated. d ) is calculated (S35). The voltage (Vs) of the target is set (S36). The voltage (Vs) of the target determines the ion energy. The waveform of the driving voltage corresponding to the voltage (Vs) of the target is determined (S36). The amount of change (ΔVs) of the voltage of the target due to the ion current density (Ji) is confirmed (S37). The slope voltage (X) that compensates for the amount of change (ΔVs) of the voltage of the target due to the ion current density (Ji) is determined (S38). A low-frequency pulse waveform is driven (S39).

[0902] Figure 41 is a flowchart illustrating an operating method for low-frequency pulse driving.

[0903] Referring to Fig. 41, plasma is generated (S40). Subsequently, a bipolar low-frequency pulse voltage is driven to the electrode (16) (S41). A driving voltage with a slope voltage is applied in the negative pulse section, and a current (I) flowing in the electrode G ) is measured (S42). The slope voltage (X) is changed, and a driving voltage with the slope voltage (X) is applied in the negative pulse section, and the current (I) flowing in the electrode is measured. G ) is measured. The current (I) of the electrode (16) G) and the slope voltage (X) are used to calculate the capacitance of the plasma sheath (Csheath). When the slope voltage (X) is zero, the current (I) flowing in the electrode G0 ) and the electrostatic capacity of the plasma sheath (Csheath) are used to obtain the ion current density (Ji) (S43). The time (τ) for which a negative voltage is applied from the driving voltage is set to be sufficiently smaller than the maximum time (tmax) determined by the ion current density (Ji). The plasma charge density (ρ) is obtained using the ion current density (Ji). d ) is calculated (S44). The voltage (Vs) of the target is set (S45). The voltage (Vs) of the target determines the ion energy. The waveform of the driving voltage corresponding to the voltage (Vs) of the target is determined (S45). The variation (ΔVs) of the voltage (Vs) of the target due to the ion current density (Ji) is checked. The slope voltage (X) that compensates for the variation (ΔVs) of the voltage of the target due to the ion current density (Ji) is determined, and a low-frequency pulse waveform is driven (S48).

[0904] Figure 42 shows the voltage of the target according to low-frequency pulse voltage driving.

[0905] Referring to Fig. 42, the low-frequency pulse voltage can have three forms for the same peak to peak. There are three forms: when the magnitude of the positive voltage is smaller than the magnitude of the negative voltage, when the magnitude of the positive voltage is equal to the magnitude of the negative voltage, and when the magnitude of the positive voltage is larger than the magnitude of the negative voltage. In the three cases, the potential (Vs) of the object (16) is the same in the negative voltage section. In the three cases, the positive applied voltage (V G + ), the charge quantity (Qi,ρ) of the object (16) i ) are different. At positive applied voltage, the voltage difference (V) applied to the dielectric (17) G-Vs) are different. When the magnitude of the positive voltage is greater than the magnitude of the negative voltage, a large voltage is applied to the dielectric (17), which may increase the electrostatic force, but there is a possibility that dielectric insulation breakdown may occur.

[0906] Figure 43 shows the potential of the object according to the plasma density.

[0907] Referring to Fig. 43, the absolute value of the voltage (Vs) of the object (16) decreases as the plasma density increases. For example, if the power of the power source for plasma generation is removed at some point, the plasma density decreases over time. In this case, if a bipolar pulse voltage is applied to the electrode (18), the absolute value of the voltage (Vs) of the object increases. Therefore, in order to increase the absolute value of the voltage (Vs) of the object, the plasma power or plasma density can be modulated over time.

[0908] Figure 44 shows the potential of the object according to the plasma density.

[0909] Referring to Fig. 44, the absolute value of the potential (Vs) of the target decreases as the plasma density increases. For example, if the plasma power is reduced at some point, the plasma density decreases. In this case, if a bipolar pulse voltage is applied to the electrode (16), the absolute value of the voltage (Vs) of the target increases. Therefore, in order to increase or decrease the absolute value of the voltage (Vs) of the target, the plasma power or plasma density can be modulated over time.

[0910] Figure 45 shows the potential of the object according to the plasma density.

[0911] Referring to Fig. 45, the absolute value of the voltage (Vs) of the object (16) decreases as the plasma density increases. For example, when the plasma power is reduced at a certain moment, the plasma density decreases. In this case, when a bipolar pulse voltage is applied to the electrode (18), the absolute value of the potential (Vs) of the object increases. Therefore, the absolute value of the potential (Vs) of the object can be increased to more than the etching threshold. That is, when the plasma density is high, a material can be deposited on the surface of the object (16), and when the plasma density is low, a material can be etched on the surface of the object (16). The etching threshold varies depending on the material, but can be several tens of volts to several hundred volts.

[0912] Figure 46 shows the potential of the object according to the plasma density.

[0913] Referring to FIG. 46, the absolute value of the potential (Vs) of the object (16) decreases as the plasma density increases. For example, when the plasma power is reduced at a certain moment, the plasma density decreases. In this case, when a bipolar pulse voltage is applied to the electrode, the absolute value of the potential of the object increases. Therefore, the absolute value of the voltage (Vs) of the object can be increased to more than the etching threshold. That is, when the plasma density is high, the positive applied voltage of the bipolar pulse is reduced so that the surface material of the object is deposited, and when the plasma density is low, the applied voltage (V) of the bipolar pulse G ) can be increased to etch the surface material of the target object. The etching threshold varies depending on the material, but can be tens to hundreds of volts.

[0914] Figure 47 shows the potential of the object according to the plasma density.

[0915] Referring to Fig. 47, the absolute value of the potential of the target object (16) decreases as the plasma density increases. For example, when the plasma power is reduced at a certain moment, the plasma density decreases. In this case, when a bipolar pulse voltage is applied to the electrode, the absolute value of the potential of the target object increases. Therefore, the absolute value of the potential (Vs) of the target object can be maintained below the etching threshold. That is, when the plasma density is high, the bipolar pulse voltage is reduced so that the surface material of the target object is deposited, and when the plasma density is low, the bipolar pulse voltage is increased so that ion energy below the etching threshold can be transferred to the surface material of the target object. Therefore, the deposition temperature can be reduced.

[0916] Figure 48 shows the potential of the object according to the driving voltage waveform of the electrode.

[0917] Referring to Fig. 48, when the driving voltage waveform of the electrode (18) has a step shape in the negative voltage section, the potential of the object may have a corresponding step shape.

[0918] Figure 49 shows the potential of the object according to the driving voltage waveform of the electrode.

[0919] Referring to FIG. 49, when the driving voltage waveform of the electrode (18) has the same height in the negative voltage section but different heights in the positive voltage section, the potential of the object may have different values ​​depending on the height of the positive voltage section.

[0920] Figure 50 is a conceptual diagram showing a plasma device including a battery connected to an electrode.

[0921] Figure 51 shows the potential of an object according to the electrostatic capacity of a battery connected to the electrode of Figure 50.

[0922] Referring to FIGS. 50 and 51, the plasma system (100) includes a chamber (12), a plasma source (20) that generates plasma within the chamber (12), and an object holder (14) that mounts an object (16).

[0923] A first capacitor (C41) is connected in parallel with a second capacitor (C42) through a second switch (SW2) between an electrode (18) and a low-frequency pulse power source (LF) via a first switch (SW1). The first switch (SW1) and the second switch (SW2) operate so that only one of the first capacitor (C41) and the second capacitor (C42) operates. Accordingly, when the driving voltage applied to the electrode (18) is the same, the potential (Vs) of the object changes according to the first capacitance of the first capacitor (C41) and the second capacitance of the second capacitor (C42).

[0924] Figure 52 shows the potential of the object and the current flowing in the electrode under a sinusoidal applied voltage.

[0925] Figure 53 shows the current flowing through the electrodes under a sinusoidal applied voltage.

[0926] Referring to Fig. 52, the current (I) flowing in the electrode (18) at a sinusoidal applied voltage G ) or current density (J G ) is expressed as follows: ω is the angular frequency of the sinusoidal applied voltage.

[0927] [Considering sinusoidal voltage]

[0928] [Equation 51]

[0929]

[0930]

[0931] Current (I) flowing in electrode (16) G ) or current density (J G ) includes an ion current component (Ji) and a displacement current component (second component). The current density (J) flowing in the electrode (18) G) is distorted from a sine wave and approaches a sawtooth wave shape. When an overcharge amount (ρi) or a floating potential is introduced, the current density (J') flowing in the electrode (18) G ) is close to a sine wave.

[0932] Referring to Figure 53, adding the electron current density (Je) results in the current density of the electrode (J G ) is given as follows.

[0933] [Equation 52]

[0934]

[0935] Here, Vp is the plasma potential, k is the Boltzmann constant, and Te is the electron temperature. The electron current density (Je) depends on the electron flux (Jei) and the target potential (Vs). The electron temperature (Te) and plasma potential (Vp) are known values. The target potential (Vs) is determined using the mathematical formula already obtained above.

[0936] When the potential of the target (Vs) approaches the plasma potential (Vp), the electron current density (Je) flows into the target. Accordingly, the current density (J) of the electrode G ) is transformed. Therefore, the current density of the electrode (J G ) is measured and fitted, the overcharge state (ρi) of the object (16) and the charge density (ρ) of the plasma are obtained. d ), the ion current density (Ji) can be obtained.

[0937] If the electron current density (Je) and ion current density (Ji) are ignored and a given frequency condition is applied, the current density is given as follows.

[0938] [Equation 53]

[0939]

[0940] That is, the angular frequency (ω) of the applied voltage can be sufficiently large to ignore the ion current density (Ji). In addition, the electron temperature (Te) can be sufficiently low so that the components of the electron current density can be ignored.

[0941] Current density (J) flowing in the electrode (18) G ) is the displacement current component of the target (16) overcharge state (ρi) and the charge density of the plasma (ρ d ) depends on the current density of the electrode (J G ) is measured and fitted, the charge amount (ρi) of the object (16) and the charge density (ρ) of the plasma are obtained. d ) can be obtained.

[0942] [Method for obtaining the potential (Vs) of an object (16) by measuring a sine wave current]

[0943] Current flowing through the electrode (I) G ) or current density (J G ) is obtained by fitting the mathematical formula above. The initial charge amount (ρi) of the target and the charge density (ρ) of the plasma d ) is obtained. The charge density of the plasma (ρ d ) is obtained, the potential (Vs) and the amount of potential change (ΔVs) of the target object (16) are obtained.

[0944] Figure 54 shows the potential of the object under a sinusoidal applied voltage.

[0945] Referring to Fig. 54, curve 1 represents the potential curve of an object (16) in an equilibrium state. Curve 2 represents the potential curve of an object slightly charged with positive charges due to the ion current density (Ji). That is, the potential (Vs) of the object starts from point b of curve 1 at a positive applied voltage, passes through point a' of curve 2, and returns to point b' and point b, which are positive applied voltages of curve 2. In the voltage range where the potential (Vs) of the object becomes zero, it has a flat shape.

[0946] Figure 55 shows the potential of the object under a sinusoidal applied voltage.

[0947] Referring to Fig. 55, as the applied voltage decreases from a positive to a negative sine wave, the potential curve of the object (16) changes from a to a' according to the inflow of the ion current density (Ji). Therefore, the potential (Vs') of the object has an asymmetrical shape. As the plasma density or ion current density (Ji) increases, the potential (Vs) of the object becomes more distorted near the maximum value of the positive applied voltage.

[0948] Figure 56 shows the potential of the target object at a sinusoidal applied voltage according to the plasma density.

[0949] Referring to Figure 56, as the plasma density increases, the absolute value of the potential (Vs) of the object decreases.

[0950] Figure 57 is a plasma system showing the applied voltage of an electrode with high frequency modulation.

[0951] Figure 58 shows the voltage of a target object according to the applied voltage of an electrode with high frequency modulation.

[0952] Figure 59 shows the voltage of the target object under low frequency pulse applied voltage with high frequency modulation of the electrode.

[0953] Referring to Figures 57 to 59, a high-frequency sine wave power source (HF) is used for high-frequency modulation. The output of the low-frequency pulse power source (LF) and the output of the high-frequency sine wave power source (HF) are applied to the electrode (18). In this case, the current (I) flowing in the electrode (18) G ) is given as follows. The high frequency sine wave power (HF) is a plasma generating power source, and the high frequency can be 13 MHz or higher.

[0954] [small signal high frequency modulation]

[0955] [Equation 54]

[0956]

[0957] Positive applied voltage (V) of low frequency pulse G + ), when a high frequency sine wave (HF) is applied, the voltage (Vs) of the target is distorted from the high frequency sine wave. This distortion forms harmonics, which makes the system unstable.

[0958] Figure 60 shows a waveform synchronized with a low-frequency pulse waveform and a high-frequency sine wave and the potential of the target.

[0959] Referring to Figure 60, the low-frequency pulse waveform is a bipolar pulse waveform, and a high-frequency sine wave is not applied to the positive voltage section. On the other hand, a high-frequency sine wave is applied to the negative voltage section. The high-frequency sine wave can form plasma through stochastic heating. In addition, by applying a high-frequency sine wave to the negative voltage section, the formation of harmonics can be suppressed, thereby stabilizing the system.

[0960] Figure 61 shows the potential of an object when low-frequency sine waves and high-frequency sine waves are applied to the electrodes.

[0961] Figure 62 shows the potential (Vs) of the object when low-frequency sine waves and high-frequency sine waves are simultaneously applied to the electrodes.

[0962] Referring to Fig. 61, when a high frequency sine wave (HF) is applied at a positive applied voltage of a low frequency sine wave (LF), the voltage (Vs) of the object (16) may be distorted in the high frequency sine wave. This distortion forms harmonics, which makes the system unstable.

[0963] Additionally, the current density (J) flowing through the electrode (18) G ) fluctuates with an envelope due to high frequency at positive applied voltage. The current (I G ) is very sensitive to the initial charge (ρi) of the object. The current (I G) can be used to obtain the initial charge (ρi) of the object (16). The electron current density (Je) depends on the potential (Vs) of the object or the initial charge (ρi) of the object (16). The current density (J) flowing in the electrode (18) G ) is measured and fitted, the plasma charge density (ρd) and the initial charge amount (ρi) of the target (16) are obtained.

[0964] Referring to Figure 62, in the low-frequency sinusoidal waveform, a high-frequency sinusoidal wave is not applied in the positive maximum applied voltage range. On the other hand, a high-frequency sinusoidal wave is applied in the negative applied voltage range. The high-frequency sinusoidal wave can form plasma through stochastic heating. When a high-frequency sinusoidal wave is applied in the negative applied voltage range, the formation of harmonics is suppressed, thereby stabilizing the system.

[0965] Figure 63 is a conceptual diagram explaining the voltage of an object when plasma potential is taken into account.

[0966] Figure 64 is a graph showing the voltage of the target according to the applied voltage of the electrode when the plasma potential is taken into account.

[0967] Figure 65 shows the amount of charge on an object according to the applied voltage of the electrode when considering the plasma potential.

[0968] Referring to FIGS. 63 to 65, the plasma system (100) includes a chamber (12), a plasma source (20) that generates plasma within the chamber (12), and an object holder (14) that mounts an object (16).

[0969] Plasma has a plasma potential (Vp). Using the matrix model, the potential (Vs) of the object (16) is given as follows. The ion energy of ions incident on the object (16) is given by the value (Vs-Vp) obtained by subtracting the plasma potential (Vp) from the potential (Vs) of the object (16). The plasma potential (Vp) and plasma charge density, etc. can be measured using a Langmuir probe, etc. The potential (Vs) of the object (16) is given as follows.

[0970] [Handling cases with plasma potential]

[0971] [Mattress Model]

[0972] [Equation 55]

[0973]

[0974]

[0975] Positive applied voltage (V G + ) is authorized, in the equilibrium state (Vs-Vp = 0), as a simple capacitor, the charge (Qi,ρi) of the object is given as follows.

[0976] [Equation 56]

[0977]

[0978] Negative applied voltage (V G - ) is applied, the potential (Vs) of the object (16) reaches the plasma potential (Vp) or the floating potential (Vf) by the ion current density (Ji). In this case, the maximum time (tmax) for the potential (Vs) of the object to reach the plasma potential (Vp) is given as follows.

[0979] [Equation 57]

[0980]

[0981] Considering the plasma potential (Vp) and the floating potential (Vf), the maximum time (tmax) can be given as follows.

[0982]

[0983] Negative applied voltage (V G - ) is applied, the charge amount (Qi, ρi) of the object increases over time and has a positive value due to the ion current density (Ji) or ion current (Ii), and when the potential (Vs) of the object is the plasma potential (Vp), the charge amount (Qi) of the object (16) is given as follows.

[0984]

[0985] The absolute value of the charge quantity (Qi, ρi) of the target (16) is greater than the absolute value of the charge quantity by electrons at a positive applied voltage.

[0986] At a negative applied voltage, the plasma potential (Vp) can increase in proportion to the ion current density (Ji) so that the difference (Vs-Vp) between the potential of the target object (Vs) and the plasma potential (Vp) is constant.

[0987]

[0988] Considering the plasma potential (Vp), the current (I) flowing in the electrode (18) G ) is given as follows.

[0989] [Equation 58]

[0990]

[0991]

[0992] Considering the time derivative of the plasma potential with respect to time (dVp / dt), the current (I) flowing in the electrode (18) G ) depends on the time derivative of the plasma potential (dVp / dt). Therefore, if the plasma potential is known, β can be obtained.

[0993] When generated by a high-frequency plasma source, the current is represented by the driving frequency of the high-frequency plasma. By extracting the driving frequency component of the high-frequency plasma from the current, information on the plasma potential and plasma charge density can be extracted.

[0994] The voltage fluctuation (ΔVs) of the target object (18) is given as follows.

[0995] [Equation 59]

[0996]

[0997] If the plasma potential changes (ΔV P ), the variation in the difference between the potential of the target and the plasma potential (variation in ion energy) is given as follows.

[0998]

[0999] Therefore, a negative voltage can be applied to a separate auxiliary electrode to reduce the variation in plasma potential.

[1000] To reduce the variation in the difference between the potential of the target object and the plasma potential (variation in ion energy), the plasma potential can have a gradient voltage by a separate auxiliary electrode as follows.

[1001]

[1002] Figure 66 is a flow chart for driving the electrodes of a plasma device.

[1003] Referring to Fig. 66, plasma is generated and the plasma potential (Vp) is measured. The plasma potential (Vp) may be a known value. Next, a bipolar pulse voltage is driven to the electrode. The negative pulse period is set to be sufficiently large, and the maximum time (tmax) at which the current flowing through the electrode becomes zero is measured. The ion current density (Ji) is obtained using the relationship between the maximum time (tmax) and the ion current density (Ji). The time at which the negative voltage is applied at the driving voltage is set to be sufficiently smaller than the maximum time (tmax). The plasma charge density (ρ) is calculated using the ion current density (Ji). d ) is produced. The voltage (Vs) of the object (16) is set. The voltage (Vs) of the object determines the ion energy. The waveform of the driving voltage corresponding to the voltage (Vs) of the object is determined. The amount of change (ΔVs) of the voltage of the object due to the driving voltage and the ion current density (Ji) is confirmed. The slope voltage (X) that compensates for the amount of change (ΔVs) of the voltage of the object due to the driving voltage and the ion current density (Ji) is determined, and a low-frequency pulse waveform is driven.

[1004] According to a modified embodiment of the present invention, it can operate in various operating methods, so a redundant description is omitted.

[1005] Figure 67 shows the potential of an object according to the pulse applied voltage when there is a plasma potential.

[1006] Referring to Figure 67, the potential (Vs) of the object operates similarly to the case where there is no plasma potential (Vp). The value (Vs-Vp) obtained by subtracting the plasma potential (Vp) from the potential (Vs) of the object is the same as in the case where there is no plasma potential (Vp). However, the difference is that the initial charge amount (ρi) of the object (16) is changed.

[1007] Figure 68 shows the potential of an object according to the pulse applied voltage when the plasma potential changes over time.

[1008] Figure 69 shows the value obtained by subtracting the plasma potential from the potential of the target according to the pulse applied voltage when the plasma potential changes over time.

[1009] Figure 70 shows the charge amount of the object according to the pulse applied voltage when the plasma potential changes over time.

[1010] Referring to FIGS. 68 to 70, it is assumed that the plasma potential (Vp) has a positive value during a predetermined period and zero during the remaining period. When the plasma potential (Vp) is zero, the potential (Vs) of the object follows curve 1 in the equilibrium state. In addition, when the plasma potential (Vp) has a predetermined positive value, the potential (Vs) of the object follows curve 3 in the equilibrium state.

[1011] When the plasma potential (Vp) is zero and the applied voltage changes rapidly from a positive value (Vo+) to a negative value (Vo-), the charge amount of the object is Q io = -c1V0 + When the plasma potential (Vp) is changed to a positive value rapidly while the charge of the object is at this value, the potential (Vp) of the object follows the curve 2 of the non-equilibrium state. Therefore, the potential (Vs) of the object moves from point a along a', and as the ion current density flows into the object, the potential (Vs) of the object moves to point c. At point c, the potential (Vs) of the object is the plasma potential, and the charge is Q i = -c1(V0 - -Vp) is given.

[1012] If the plasma potential is subtracted from the potential of the target (Vs-Vp), the ion energy increases by approximately the plasma potential. That is, when the applied voltage is a positive value (Vo+), electrons according to the plasma potential are accumulated in the target, and then the plasma potential is changed by changing the applied voltage so that electrons can no longer flow into the electrode.

[1013] The value of the target potential minus the plasma potential (Vs-Vp), or ion energy, increases when the plasma potential is increased while initially increasing the target's charge. That is, after the target is initially charged by reaching an equilibrium state at a positive applied voltage, the plasma potential is changed after the applied voltage is changed to a negative applied voltage. When the plasma potential is changed, the target's potential is in a non-equilibrium state and changes until it reaches an equilibrium state.

[1014] Figure 71 is a flow chart for driving an applied voltage to an electrode of a plasma device.

[1015] Referring to Fig. 71, a plasma is generated and the plasma potential is synchronized with the driving voltage, and then a bipolar pulse voltage is driven to the electrode. The negative pulse period is set to be sufficiently long, and the maximum time (tmax) at which the current flowing through the electrode becomes zero is measured. The ion current density is obtained using the relationship between the maximum time (tmax) and the ion current density (Ji). The time for which the negative voltage is applied from the driving voltage is set to be sufficiently smaller than the maximum time (tmax). The plasma density is calculated using the ion current density. The voltage of the target object is set. The voltage of the target object determines the ion energy. The waveform of the driving voltage corresponding to the voltage of the target object is determined. The amount of change in the voltage of the target object due to the ion current density is confirmed. A ramp voltage that compensates for the amount of change in the voltage of the target object due to the ion current density is determined, and a low-frequency pulse waveform is driven.

[1016] Figure 72 shows the potential of the object when the plasma potential is maintained constant.

[1017] Referring to Figure 72, regardless of the value of the plasma potential, the ion energy (Vs-Vp) is constant.

[1018] Figure 73 shows the potential of an object when the plasma potential oscillates over time.

[1019] Referring to Figure 73, the plasma potential is a reference value (V p0 ) with amplitude (B) and angular frequency (ω) p ) vibrates. The plasma potential (Vp) is given as follows.

[1020]

[1021] A low-frequency pulse waveform has an amplitude (V) and a constant angular frequency (ω). In this case, the potential (Vs) of the target is given by:

[1022]

[1023] Therefore, the ion energy (Vs-Vp) oscillates at an angular frequency (ω). The ion energy distribution depends on the plasma potential (Vp).

[1024]

[1025] Figure 74 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[1026] Figure 75 shows the value obtained by subtracting the plasma potential from the potential of the target object synchronized with the driving voltage.

[1027] Referring to FIGS. 74 and 75, it is assumed that the plasma potential (Vp) has a positive value during a given period and zero during the remaining period. When the plasma potential (Vp) is zero, the potential (Vs) of the object follows curve 1 in the equilibrium state. In addition, when the plasma potential (Vp) has a positive value, the potential (Vs) of the object follows curve 3 in the equilibrium state.

[1028] When the plasma potential (Vp) is zero and the applied voltage changes rapidly from a positive value (Vo+) to a negative value (Vo-), the charge amount of the target object is . When the plasma potential changes rapidly to a positive value while the charge of the object is at this value, the potential of the object follows curve 2. Therefore, the potential (Vs) of the object moves from point a to a'. Again, when the applied voltage rapidly transitions from a negative value (Vo-) to a positive value (Vo+), the potential (Vs) of the object follows curve 2 and does not reach an equilibrium state. As the ion current density (Ji) is introduced, the charge of the object changes, and when the potential (Vs) of the object finally reaches the plasma potential, electrons are introduced and reach an equilibrium state along curve 3.

[1029] Figure 76 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[1030] Referring to Figure 76, it is assumed that the plasma potential has a positive value during a certain period and is zero during the remaining period. When the plasma potential has a constant positive value, the potential of the object follows curve 1 in the equilibrium state. Furthermore, when the plasma potential has a zero value, the potential of the object follows curve 3 in the equilibrium state.

[1031] When the plasma potential is positive and the applied voltage changes rapidly from a positive value (Vo+) to a negative value (Vo-), the charge amount of the object is . When the plasma potential is abruptly changed to zero while the target's charge is at this value, the target's potential follows curve 2. Therefore, the target's potential (Vs) moves from point a to a'. Again, when the applied voltage abruptly transitions from a negative value (Vo-) to a positive value (Vo+), the target's potential follows curve 2 and reaches an equilibrium state where the target's potential is zero. That is, when the target's potential reaches zero, electrons are introduced and reach an equilibrium state along curve 3.

[1032] Figure 77 shows the potential of an object whose plasma potential is synchronized with the pulse driving voltage.

[1033] Referring to Figure 77, while the pulse driving voltage has a positive value, the plasma potential (Vp) has a zero value. While the driving voltage has a negative value, the plasma potential (Vp) has a positive value.

[1034] When the plasma potential (Vp) is zero, the potential of the object follows curve 1 in the equilibrium state. In addition, when the plasma potential (Vp) has a certain positive value, the potential of the object (Vs) follows curve 3 in the equilibrium state.

[1035] When the plasma potential (Vp) is zero and the applied voltage has a positive value, the charge amount of the object is When the applied voltage changes abruptly from a positive value (Vo+) to a negative value (Vo-), the charge of the object changes. When the plasma potential (Vp) is abruptly changed to a positive value while the target's charge quantity is at this value, the target's potential (Vs) follows curve 2. Therefore, the target's potential (Vs) moves from point a along a'.

[1036] Again, when the applied voltage abruptly transitions from a negative value (Vo-) to a positive value (Vo+), and the plasma potential (Vp) transitions to a zero state, the potential of the object follows curve 1 and reaches an equilibrium state.

[1037] That is, the ion energy (Vs-Vp) increases only in the section where the applied voltage has a negative value (Vo-).

[1038] Additionally, the plasma potential can have a ramp voltage so that it increases over time. For this purpose, the auxiliary electrode can apply a positive ramp voltage.

[1039]

[1040] Figure 78 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[1041] Figure 79 shows the charge of an object whose plasma potential is synchronized with the driving voltage.

[1042] Referring to FIGS. 78 and 79, while the driving voltage has a positive value, the plasma potential (Vp) has a zero value. While the driving voltage has a negative value, the plasma potential (Vp) has a positive value. While the driving voltage has a negative value, the driving voltage has a slope voltage. In this case, the potential (Vs) of the object has a constant value while the driving voltage has a negative value.

[1043] Figure 80 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[1044] Referring to Fig. 80, while the driving voltage has a positive value, the plasma potential (Vp) has a zero value. While the driving voltage has a negative value, the plasma potential (Vp) has a positive value. While the driving voltage has a negative value, the plasma potential (Vp) oscillates with a constant amplitude at a positive value. In this case, the potential (Vs) of the object depends on the oscillation of the plasma potential while the driving voltage has a negative value.

[1045] Figure 81 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[1046] Referring to Figure 81, while the driving voltage has a positive value, the plasma potential (Vp) has a positive value. While the driving voltage has a negative value, the plasma potential (Vp) has a zero value.

[1047] When the plasma potential (Vp) has a positive value, the potential (Vs) of the object follows curve 1 in the equilibrium state. Also, when the plasma potential (Vp) has a zero value, the potential (Vs) of the object follows curve 3 in the equilibrium state.

[1048] When the plasma potential (Vp) has a positive value and the applied voltage has a positive value, the charge amount of the target object is When the applied voltage changes abruptly from a positive value (Vo+) to a negative value (Vo-), the charge of the object changes. When the plasma potential (Vp) is abruptly changed to have a zero value while the target's charge quantity is at this value, the target's potential (Vs) follows curve 2. Therefore, the target's potential (Vs) moves from point a along a'.

[1049] Again, when the applied voltage rapidly transitions from a negative value (Vo-) to a positive value (Vo+), and the plasma potential (Vp) transitions to a positive value, the potential (Vs) of the object follows curve 1 and reaches an equilibrium state.

[1050] That is, only in the section where the applied voltage has a negative value (Vo-), the ion energy (Vs-Vp) decreases.

[1051] Figure 82 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[1052] Referring to Figure 82, while the driving voltage has a positive value, the plasma potential (Vp) has a positive value. While the driving voltage has a negative value, the plasma potential (Vp) has a zero value.

[1053] When the plasma potential (Vp) has a positive value, the potential of the object follows curve 1 at equilibrium. Also, when the plasma potential (Vp) has a zero value, the potential of the object (Vs) follows curve 3 at equilibrium. While the driving voltage has a positive value, the plasma potential (Vp) oscillates with a constant amplitude at a positive value. In this case, the potential of the object (Vs) oscillates near zero.

[1054] Figure 83 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[1055] Referring to Figure 83, while the driving voltage has a positive value, the plasma potential (Vp) has a positive value. While the driving voltage has a negative value, the plasma potential (Vp) has a zero value.

[1056] When the plasma potential (Vp) has a positive value, the potential of the object follows curve 1 at equilibrium. Also, when the plasma potential (Vp) has a zero value, the potential of the object follows curve 3 at equilibrium. While the driving voltage has a positive value, the plasma potential (Vp) oscillates with a constant amplitude at a positive value. While the driving voltage has a negative value, the driving voltage has a ramp voltage. In this case, the potential (Vs) of the object has a constant value while the driving voltage has a negative value.

[1057] Figure 84 shows the potential of an object whose plasma potential is synchronized with the driving voltage.

[1058] Referring to Fig. 84, in the first time interval, while the plasma potential (Vp) has a positive value, the applied voltage has a positive value. In the second time interval, while the plasma potential (Vp) has a positive value, the applied voltage has a negative value. By changing the synchronization point, the ion energy (Vs-Vp) is adjusted.

[1059] The plasma potential (Vp) has a zero value during a given period, and a positive value during another period. Accordingly, the plasma potential (Vp) alternates with a given period. The period of the sinusoidal applied voltage is sufficiently shorter than the period of the plasma potential.

[1060] Figure 85 shows the potential of an object when the plasma potential is constant and a sinusoidal driving voltage is applied.

[1061] Figure 86 shows the potential of an object in which the sinusoidal plasma potential is synchronized with the sinusoidal driving voltage.

[1062] Figure 87 shows the current waveform flowing through the electrode when the sinusoidal plasma potential is synchronized with the sinusoidal driving voltage.

[1063] Referring to FIGS. 85 to 87, when the driving voltage applied to the electrode is a low-frequency sine wave, the current (I) of the electrode G ) is given as follows.

[1064] [Treatment of sine waves]

[1065] [Equation 60]

[1066]

[1067] If the electron current density (Je) and ion current density (Ji) are neglected, the low-frequency and high-frequency conditions are given as follows. The amplitude of the low-frequency sine wave is V, and the angular frequency is ω.

[1068] [Equation 61]

[1069]

[1070] Current flowing through the electrode (I) G ) or current density (J G ) is transformed by the fluctuation of plasma potential (Vp). In addition, it is transformed into a shape close to a sine wave by overcharging of the object.

[1071] When the plasma potential (Vp) fluctuates, another sheath is formed at the grounded electrode. The electrode area is A1, and the ground electrode area is A2. The current (IG2) flowing to the ground electrode is given by:

[1072]

[1073] If the phases of the current flowing to the electrode and plasma (IG) and the current flowing to the plasma and ground electrode (IG2) are aligned, the current flowing to the plasma and ground electrode (IG2) is given as follows.

[1074]

[1075] By changing the phase of the current flowing in the electrode and plasma (IG) and the current flowing in the plasma and ground electrode (IG2), the magnitudes are compared, which are given as follows.

[1076]

[1077] If we treat the constant term inside the square root in the above equation as the same, it is given as follows.

[1078]

[1079] Increasing the area (A2) of the ground electrode can increase the potential difference between the target and the plasma. To this end, a large-area auxiliary ground electrode with a corrugated tube structure can be placed inside the chamber to increase the area (A2) of the ground electrode.

[1080] Comparing the magnitude of the current, it is given as follows.

[1081]

[1082] If we rearrange the constant terms within the square root in the above equation, we get the following:

[1083]

[1084] The total current (IT) is the sum of the current flowing in the electrode (IG) and the current flowing in the ground electrode (IG2), and is given as a pseudo-sine wave as follows.

[1085]

[1086] [Sinusoidal ion energy distribution]

[1087] The ion energy distribution function (F) is given by: N is the number of ion particles, and W is the ion energy. The ion energy is given by (W=Vp-Vs).

[1088]

[1089]

[1090] When the applied voltage of the electrode (18) is a sinusoidal wave and the plasma potential (Vp) is a sinusoidal wave as follows, the time derivative of the ion energy (dw / dt) is given as follows.

[1091]

[1092]

[1093]

[1094]

[1095] The ion energy distribution (f) is calculated and expressed as follows.

[1096]

[1097]

[1098] The ion energy (W) is given by the potential of the target and the plasma potential, and the ion energy distribution (F) has two peaks in the case of a sinusoidal wave. When the angular frequency (ω) of the sinusoidal wave is close to or larger than the ion plasma angular frequency (ωi), the linewidth (ΔEi) of the ion energy distribution may decrease.

[1099] When the angular frequency (ω) of the applied voltage is smaller than the angular frequency of the ion plasma (ωi, typically several MHz), the ion energy distribution function is given by the above formula.

[1100] However, when the angular frequency (ω) of the sine wave is close to or greater than the angular frequency (ωi) of the ion plasma, the line width (ΔEi) of the ion energy distribution decreases, and the spacing between the double peaks narrows.

[1101]

[1102] A plasma device according to one embodiment of the present invention includes a structure in which electrodes / dielectric layers / objects are laminated. A method for controlling a voltage of an object of the plasma device includes the steps of applying a sinusoidal voltage to the electrodes and measuring a current (IG, JG) flowing through the electrodes over time; and the step of fitting the currents (IG, JG) to extract the amount of charge (ρi) charged to the object and the plasma charge density (ρd).

[1103] The plasma in contact with the target object has a plasma potential (Vp) that fluctuates over time, and the plasma potential (Vp) can be calculated by measuring the plasma potential (Vp) or fitting the current flowing through the electrode.

[1104] The method for controlling the voltage of an object can calculate the potential (Vs) of the object using the plasma potential (Vp). The method can further include a step of calculating the energy of ions incident on the object using the potential of the object. The method for controlling the voltage of the object can further include a step of controlling the plasma potential (Vp) of plasma in contact with the object. Control of the plasma potential (Vp) can be performed by applying voltage to a separate electrode.

[1105] The target voltage control method may further include a step of controlling the plasma charge density by controlling the plasma power that generates the plasma.

[1106] A plasma device according to one embodiment of the present invention includes a structure in which electrodes / dielectric layers / objects are laminated. The method for controlling the voltage of an object of the plasma device includes the steps of: applying a sinusoidal voltage to the electrodes and measuring a current flowing through the electrodes over time; calculating a plasma charge density; and extracting a charge amount charged to the object by fitting the current.

[1107] The ratio of the plasma potential to the applied voltage is determined using the ratio of the electrode area (A1) to the ground electrode area (A2). For example, if A1 / A2=1, then V / B=2. The plasma potential (Vp) is given by Vpo+B sinwt, and Vpo=B is set. By fitting the electrode currents (IG, JG), the plasma charge density (ρd) and the charge amount ((ρi)) of the object are determined. Accordingly, the potential (Vs) of the object is determined. Vp-Vs is the ion energy. The ion energy distribution is determined by the formula calculated above.

[1108] Plasma charge density can be measured by applying a DC pulse waveform, by fitting a current waveform, or by using a separate charge density measuring device. Plasma potential can be measured separately using a Langmuir probe or a plasma potential measuring device.

[1109] Figure 88 shows the potential of the object when the plasma potential is synchronized with the sinusoidal driving voltage.

[1110] Figure 89 shows the potential of the object over time when the plasma potential is synchronized with the sinusoidal driving voltage.

[1111] Referring to FIGS. 88 and 89, the plasma potential (Vp) has a zero value during a predetermined period, and the plasma potential (Vp) has a positive value during another period. Accordingly, the plasma potential (Vp) alternates with a predetermined period. The period of the sinusoidal applied voltage is sufficiently shorter than the period of the plasma potential (Vp).

[1112] When the plasma potential (Vp) has a zero value, the potential (Vs) of the object follows curve 1 in the equilibrium state. When the plasma potential (Vp) has a positive value, the potential (Vs) of the object follows curve 3 in the equilibrium state. When the plasma potential (Vp) has a zero value and the applied voltage is a sine wave, the potential (Vs) of the object follows curve 1. When the plasma potential (Vp) has a zero value, the charge of the object is When the plasma potential (Vp) rapidly transitions from zero to a positive value, the target follows curve 2 of the non-equilibrium state while maintaining its charge.

[1113] In curve 2 of the non-equilibrium state, as the applied voltage, a sinusoidal wave, oscillates, equilibrium is not reached. However, as the ion current density (Ji) continues to be injected, and the target potential (Vs) reaches the plasma potential (Vp), electron current rapidly flows in, reaching equilibrium along curve 3.

[1114] Figure 90 shows the potential of an object whose plasma potential is synchronized with the sinusoidal driving voltage.

[1115] Referring to Fig. 90, the plasma potential (Vp) has a zero value during a certain period, and the plasma potential (Vp) has a positive value during another period. Accordingly, the plasma potential (Vp) alternates with a certain period. The period of the sinusoidal applied voltage is synchronized with the period of the plasma potential (Vp).

[1116] When the plasma potential (Vp) has a zero value, the potential of the object follows curve 1 in the equilibrium state. When the plasma potential (Vp) has a positive value, the potential of the object (Vs) follows curve 3 in the equilibrium state. When the plasma potential (Vp) has a zero value, the applied voltage, which is a sine wave, is synchronized and has a positive value, and the potential of the object (Vs) follows curve 1 in the equilibrium state. When the plasma potential (Vp) has a positive value, the applied voltage, which is a sine wave, is synchronized and has a negative value, and the potential of the object (Vs) follows curve 3 in the equilibrium state.

[1117] When the plasma potential (Vp) has a zero value, the charge of the object is When the plasma potential (Vp) rapidly transitions from zero to a positive value, the object maintains its charge and follows curve 2 of the non-equilibrium state.

[1118] In the next cycle, if the plasma potential (Vp) has a zero value and the applied voltage has a positive value, the charge of the object is , and returns to curve 1.

[1119] [How to change plasma potential]

[1120] Figures 91 to 94 are conceptual diagrams showing a plasma device that changes plasma potential.

[1121] Referring to FIG. 91, the plasma processing device includes a plasma chamber (12); a high-frequency power source (HF, 28) connected to a first electrode (22) disposed inside the chamber to form plasma; a target holder (14) including a second electrode (18) / dielectric layer (17) / target (16) and disposed inside the chamber; a third electrode (31) exposed inside the chamber; and an auxiliary low-frequency power source (32) for controlling a plasma potential having a high state and a low state periodically at the third electrode.

[1122] A first electrode (22) is placed at the top of the plasma chamber, and a high-frequency power source (28) is connected to the first electrode to form plasma. An object holder (14) is placed at the bottom of the chamber, and a second electrode (18) is placed inside the object holder. A low-frequency waveform can be applied to the second electrode by a low-frequency power source.

[1123] A ring-shaped third electrode is placed inside the chamber to control a separate plasma potential. When an auxiliary low-frequency power source applies a pulse-shaped auxiliary voltage to the third electrode, the plasma potential can be controlled over time. The auxiliary voltage can be a pulse waveform having positive and negative values. The auxiliary voltage can be synchronized with the low-frequency pulse waveform by the low-frequency power source. The third electrode (31) is used to control the plasma potential (ramp voltage).

[1124] Referring to FIG. 92, the plasma processing device includes a plasma chamber (12); an auxiliary low-frequency power source (32) connected to a first electrode (31) disposed inside the chamber and controlling a plasma potential (Vp) having a high state and a low state periodically; an object holder (14) including a second electrode (18) / dielectric layer (17) / object (16) and disposed inside the chamber; a low-frequency power source (LF) connected to the second electrode (18); and a high-frequency power source (HF) connected to the second electrode (18) and forming a plasma.

[1125] A first electrode is arranged at the upper part of the chamber, and an auxiliary low-frequency voltage in the form of a pulse can be applied to the first electrode. An object holder is arranged at the lower part of the chamber, and a second electrode is arranged inside the object holder. A low-frequency waveform and a high-frequency waveform can be applied simultaneously to the second electrode. The low-frequency waveform is generated by a low-frequency power source (LF), and the high-frequency waveform is formed by a high-frequency power source (HF). The high-frequency power source (HF) is used to generate plasma, and the low-frequency power source (LF) can be used to control the potential of the object. The low-frequency power source (LF) can be synchronized with the auxiliary low-frequency power source (32).

[1126] The first electrode (31) is used to control the plasma potential (Vp) (slope voltage).

[1127] Referring to FIG. 93, the plasma processing device includes a plasma chamber (12); a high-frequency power source (HF) connected to a first electrode (31) disposed inside the chamber to form plasma; an auxiliary low-frequency power source (32) connected to the first electrode to control a plasma potential having a high state and a low state periodically; an object holder (14) including a second electrode (18) / dielectric layer (17) / object (16) and disposed inside the chamber; and a low-frequency power source (LF) connected to the second electrode to control a voltage of the object.

[1128] A first electrode is arranged at the upper part of the chamber, and a high-frequency power source (HF) and a pulse-type auxiliary low-frequency power source (32) are connected to the first electrode. An object holder is arranged at the lower part of the chamber, and a second electrode is arranged inside the object holder. A low-frequency pulse waveform can be applied to the second electrode by the low-frequency power source (LF). The high-frequency power source (HF) is used to form plasma. An auxiliary voltage is generated by the auxiliary low-frequency power source (32). The auxiliary voltage is synchronized with the pulse waveform of the low-frequency power source (LF), and is used to control the plasma potential (Vp) as a pulse waveform having positive and negative values.

[1129] The first electrode (31) is used to control the plasma potential (Vp) (slope voltage).

[1130] Referring to FIG. 94, the plasma processing device includes: a plasma chamber (12); a high-frequency power source (HF) connected to an antenna (51) disposed outside the chamber to form an inductively coupled plasma; an auxiliary low-frequency power source (32) connected to an auxiliary electrode (31) disposed inside the chamber to periodically control a plasma potential (Vp) by having a high state and a low state; an object holder (14) including an electrode (18) / dielectric layer (17) / object (16) and disposed inside the chamber; and a low-frequency power source (LF) connected to the electrode (18) to control a voltage of the object.

[1131] An antenna (51) for inductively coupled plasma is arranged at the upper part of the chamber, and a high-frequency power source is connected to the antenna. An object holder is arranged at the lower part of the chamber, and an electrode (18) is arranged inside the object holder. A low-frequency voltage waveform can be applied to the electrode. The high-frequency power source (HF) is used to form plasma. An auxiliary voltage applied to the auxiliary electrode (31) is generated by the low-frequency power source. The auxiliary voltage can be a pulse waveform having positive and negative values. The auxiliary voltage can be synchronized with the low-frequency voltage waveform of the low-frequency power source (LF) applied to the electrode.

[1132] The auxiliary electrode (31) is used to control the plasma potential (Vp) (slope voltage).

[1133] [Handling of electrostatic electrodes]

[1134] Figure 95 is a conceptual diagram showing a plasma system including a static electrode and an electrode.

[1135] Figure 96 is a conceptual diagram showing an electrode, a first dielectric, an electrostatic electrode, a second dielectric, and a plasma sheath.

[1136] Fig. 97 is a graph showing the potential of an object according to the applied voltage of the electrode.

[1137] Figure 98 is a graph showing the amount of charge of a target object according to the applied voltage of the electrode.

[1138] Figure 99 is a graph showing the amount of charge on an object according to the amount of charge on the electrostatic electrode.

[1139] Referring to FIGS. 95 to 99, the plasma processing device includes a plasma chamber (12); a plasma source (20) that forms plasma in the plasma chamber (12); an object holder (14) that includes an electrode (18) / a first dielectric layer (17a) / an electrostatic electrode (19) / a second dielectric layer (17b) / an object (16) and is disposed inside the chamber; a low-frequency power supply (LF) connected to the electrode (18); and an electrostatic electrode power supply (49) connected to the electrostatic electrode (19). A voltage waveform of the electrostatic positive electrode (19) is synchronized with a voltage waveform of the low-frequency power supply (LF) to control the potential of the object (18).

[1140] The electrode (18) is provided with a driving voltage (V G ) is applied, the object (16) is a semiconductor or a conductor, and the object (16) accumulates electrons or positive ions on its surface. A plasma sheath is formed between the plasma and the object (16). The plasma sheath can be treated as a space having a positive space charge. The thickness (d3) of the plasma sheath is determined by a voltage (V G ) is changed according to the first dielectric (17a) and the second dielectric (17b) is the second region, and the plasma sheath is the third region. An electrostatic electrode (19) is placed between the first dielectric and the second dielectric.

[1141] The thickness of the first dielectric (17a) is d1. The thickness of the second dielectric (17b) is d2. The thickness of the object (16) is ignored. The thickness of the electrostatic electrode (19) is ignored. The thickness of the plasma sheath is d3. The voltage of the object (16) is Vs. The surface charge density of the object (16) is ρ. i is. The surface charge density of the electrostatic electrode is ρ esc The permittivity of the first region is ε1, the permittivity of the second region is ε2, and the permittivity of the plasma sheath (ε3) may be the permittivity of vacuum.

[1142] The general solution of the voltage (V1) in the first region, the general solution of the voltage (V2) in the second region, and the general solution of the third region are given as follows. In addition, the electric field (E1) in the first region, the electric field (E2) in the second region, and the electric field (E3) in the third region are given as follows. The origin of the coordinate system is the electrode. x is a coordinate of the rectangular coordinate system.

[1143] [Mattress Model]

[1144] [Equation 62]

[1145]

[1146] Here, the volume charge density in the plasma sheath is ρ d is. A1, A2, B1, B2, C1, C2 are unknowns.

[1147] Using boundary conditions and initial conditions, A1, A2, B1, B2, C1, and C2 are given as follows. As an initial condition, the electric field (E3) at the boundary between the plasma and the plasma sheath is assumed to be zero.

[1148] [Equation 63]

[1149]

[1150] The electric field in each region is given as follows:

[1151] [Equation 64]

[1152]

[1153] The surface potential (Vs) of the target object (16) is given as follows.

[1154] [Equation 65]

[1155]

[1156] When the thickness of the plasma sheath is zero, it is given by a simple capacitor as follows.

[1157] [Equation 66]

[1158]

[1159] The thickness (d3) of the plasma sheath and the surface potential (Vs) of the treated material (16) are given as follows.

[1160] [Equation 67]

[1161]

[1162] When a bipolar pulse with a sufficiently large negative voltage range is applied to the electrode (18), the current (I) flowing in the electrode (18) G ) becomes zero, the maximum time (tmax) is given as follows.

[1163] [Equation 68]

[1164]

[1165] A positive voltage is applied to the electrode (18) and the electrostatic electrode (19) is charged with a positive charge (ρ esc ), the surface charge density (ρ) of the object (16) i ) or the charge amount is proportional to the effective capacitance (Ceff) and the charge amount (ρ) of the electrostatic electrode (19) esc ) is proportional to the thickness (d1) of the first region, and inversely proportional to the first permittivity (ε1) of the first region. Therefore, the surface charge density (ρ) of the object i ), to increase the charge (ρ) of the electrostatic electrode (19) esc ) should be set to a positive value, d1 should be increased, and the first permittivity (ε1) should be decreased. Specifically, the first permittivity uses a material with a low permittivity such as quartz, the second permittivity uses a material with a high permittivity such as aluminum oxide, and d1 is set close to the total thickness of the dielectric (d1+d2). In the case of having this structure, the charge amount (ρ) of the electrostatic electrode esc ), the surface charge density (ρ) of the object i ) can increase the surface charge density (ρ) of the object. i ) increases the electrostatic force.

[1166] Fig. 100 shows the positive charge (ρ) of the electrostatic electrode. esc) has a surface charge density (ρ) of the object according to the thickness (d1) of the first region. i ) is a drawing that is lazy.

[1167] Fig. 101 shows the negative charge (ρ) of the electrostatic electrode. esc ) has a surface charge density (ρ) of the object according to the thickness (d1) of the first region. i ) is a drawing that is lazy.

[1168] Referring to FIG. 100 and FIG. 101, a positive applied voltage is applied to the electrode (18), and the positive charge (ρ) of the electrostatic electrode (19) esc ) is reduced, the surface charge density (ρ) of the object (16) i ) or the amount of charge decreases. In this case, damage caused by electrons charged to the target can be suppressed, but the electrostatic force decreases.

[1169] In order to suppress damage caused by charged electrons of the target object (16), the surface charge density (ρ) of the target object (16) i ) or the charge amount can be reduced. To this end, the first dielectric constant (ε1) of the first dielectric (17a) uses a material having a high dielectric constant such as an aluminum oxide film, the second dielectric constant (ε2) of the second dielectric (17b) uses a material having a high dielectric constant such as an aluminum oxide film, and d1 is set to be smaller than the total thickness (d1+d2) of the dielectric.

[1170] A positive applied voltage is applied to the electrode (18), and the negative charge (ρ) of the electrostatic electrode (19) esc ) is charged, the characteristics are changed by the relative magnitude of the positive applied voltage and the voltage of the electrostatic electrode (19). When the positive applied voltage is greater than the voltage of the electrostatic electrode (19), the surface charge density (ρ) of the object (16) i ) or the charge amount is the charge amount (ρ) of the electrostatic electrode (19) esc ), is proportional to the thickness (d1) of the first region, and is inversely proportional to the first permittivity (ε1) of the first region.

[1171] Figure 102 shows the potential of an object when the charge amount of the electrostatic electrode changes over time.

[1172] Referring to Fig. 102, the potential (Vs) of the object (16) is given as follows.

[1173]

[1174] When the electrostatic voltage (electrostatic charge) is a certain value, the electrostatic charge (ρ) of the object (16) is applied to make the potential (Vs) of the object (16) zero at a positive applied voltage. i ) is given as follows.

[1175] [Equation 69]

[1176]

[1177] Therefore, the potential (Vs) of the object (16) in the equilibrium state is given as follows.

[1178] [Equation 70]

[1179]

[1180] The electrostatic voltage (electrostatic charge) is zero in some intervals, and can have negative values ​​in other intervals. The applied voltage is a bipolar pulse.

[1181] When the electrostatic voltage (electrostatic charge) is zero, the voltage (Vs) of the object (16) moves along curve 1 in the equilibrium state. In addition, when the electrostatic voltage (electrostatic charge) has a negative value, the voltage (Vs) of the object (16) moves along curve 3 in the equilibrium state.

[1182] Initially, the electrostatic voltage (electrostatic charge) is zero, and when the electrostatic voltage rapidly transitions to a predetermined negative value at a specific time, the charge amount (ρ) of the object (16) i1 ) is given as follows.

[1183] [Equation 71]

[1184]

[1185] In this case, the potential (Vs) of the object (16) follows curve 2 and is given as follows.

[1186]

[1187] Since the charge of the object (16) does not have a value in the equilibrium state, the voltage (Vs) of the object (16) moves along curve 2.

[1188] Finally, when the charge of the object (16) is changed by the injection of the ion current density (Ji) after the applied voltage has passed through several cycles, the voltage (Vs) of the object (16) moves along curve 3 in an equilibrium state.

[1189] Figure 103 is a graph showing the potential of an object according to the applied voltage of the electrode.

[1190] Referring to Figure 103, the electrostatic voltage (electrostatic charge) is zero in a certain section, and the electrostatic voltage (electrostatic charge) can have a positive value in other sections. The applied voltage is a bipolar pulse.

[1191] When the electrostatic voltage (electrostatic charge) is zero, the voltage (Vs) of the object moves along curve 1 in the equilibrium state. Also, when the electrostatic voltage (electrostatic charge) has a negative value, the voltage (Vs) of the object moves along curve 3 in the equilibrium state.

[1192] When the electrostatic voltage (electrostatic charge) is initially zero and the electrostatic voltage rapidly transitions to a predetermined positive value at a specific time, the charge amount of the object (16) is given as follows.

[1193] [Equation 72]

[1194]

[1195] In this case, the potential (Vs) of the object (16) follows curve 2 and is given as follows.

[1196]

[1197] Since the charge of the object (16) does not have a value in the equilibrium state, the voltage (Vs) of the object (16) moves along curve 2. Eventually, after the applied voltage passes through one cycle, the voltage (Vs) of the object (16) moves along curve 3 in the equilibrium state due to the injection of electron current (Ie).

[1198] Figure 104 is a graph showing the potential of an object according to the applied voltage of the electrode.

[1199] Referring to Figure 104, the electrostatic voltage (electrostatic charge) can have a negative value in a certain section, and a positive value in another section. The applied voltage is a bipolar pulse. The applied voltage can be synchronized with the electrostatic voltage (electrostatic charge).

[1200] When the electrostatic voltage (electrostatic charge) is positive, the voltage (Vs) of the object moves along curve 1 in the equilibrium state. Also, when the electrostatic voltage (electrostatic charge) has a negative value, the voltage (Vs) of the object moves along curve 3 in the equilibrium state.

[1201] When the electrostatic voltage (electrostatic charge) is initially positive and the electrostatic voltage (electrostatic charge) rapidly transitions to a predetermined negative value at a specific time, the charge amount of the object (16) is given as follows.

[1202] [Equation 73]

[1203]

[1204] In this case, the potential (Vs) of the object (16) follows curve 2 and is given as follows.

[1205]

[1206] Therefore, since the charge of the object (16) does not have a value in the equilibrium state, the voltage (Vs) of the object moves along curve 2. Eventually, in the next cycle of the applied voltage, due to the injection of electron current, the voltage (Vs) of the object moves along curve 1 in the equilibrium state.

[1207] Figure 105 is a graph showing the potential of an object according to the applied voltage of the electrode.

[1208] Referring to Figure 105, the electrostatic voltage (electrostatic charge) can have a negative value in a certain section, and the electrostatic voltage (electrostatic charge) can have a positive value in other sections. The applied voltage is a bipolar pulse. The applied voltage can be synchronized with the electrostatic voltage (electrostatic charge).

[1209] When the electrostatic voltage (electrostatic charge) is negative, the voltage (Vs) of the object moves along curve 1 in the equilibrium state. Also, when the electrostatic voltage (electrostatic charge) has a positive value, the voltage (Vs) of the object moves along curve 3 in the equilibrium state.

[1210] When the electrostatic voltage (electrostatic charge) is initially negative and the electrostatic voltage rapidly transitions to a predetermined positive value at a specific time, the charge amount of the object (16) is given as follows.

[1211] [Equation 74]

[1212]

[1213] In this case, the potential (Vs) of the object follows curve 2 and is given as follows.

[1214]

[1215] Therefore, since the charge of the object (16) does not have a value in the equilibrium state, the voltage (Vs) of the object moves along curve 2.

[1216] Eventually, in the next cycle of applied voltage, due to the injection of electron current, the voltage (Vs) of the object moves along curve 1 from the equilibrium state.

[1217] Figure 106 is a flowchart showing a method for controlling the voltage of an object.

[1218] Referring to Fig. 106, plasma is generated and the charge of the electrostatic electrode is synchronized with the driving voltage (S60). Next, a bipolar pulse voltage is driven to the electrode (S61). The negative pulse section is set to be sufficiently long, and the maximum time (tmax) at which the current flowing through the electrode becomes zero is measured (S62). The ion current density is obtained using the relationship between the maximum time (tmax) and the ion current density (Ji) (S64). The time for which the negative voltage is applied from the driving voltage is set to be sufficiently smaller than the maximum time (tmax). The plasma density is calculated using the ion current density (S65). The voltage of the target object is set (S66). The voltage of the target object determines the ion energy. The waveform of the driving voltage corresponding to the voltage of the target object is determined (S66). The amount of change in the voltage of the target object due to the ion current density is confirmed (S67). A slope voltage that compensates for the amount of change in the voltage of the target object due to the ion current density is determined (S68), and a low-frequency pulse waveform is driven (S69).

[1219] The electrostatic voltage (electrostatic charge) can have a positive value in a certain range, and can have a slope in other ranges. The applied voltage is a bipolar pulse. The applied voltage can be synchronized with the electrostatic voltage (electrostatic charge).

[1220] The electrostatic voltage (electrostatic charge) can be given by the slope as follows:

[1221] [Equation 75]

[1222]

[1223] The electrostatic voltage (electrostatic charge) can have a positive value in a certain range, and a negative slope in other ranges. The applied voltage is a bipolar pulse. The applied voltage can be synchronized with the electrostatic voltage (electrostatic charge).

[1224] The electrostatic voltage (electrostatic charge) can be given by the slope as follows:

[1225] [Equation 76]

[1226]

[1227] Current (I) flowing in the electrode (18) G ) is given as follows, if we ignore the time variation of the charge of the positive electrode.

[1228] [Equation 77]

[1229]

[1230] The time derivative of the potential (Vs) of the object is given as follows for a bipolar pulse:

[1231]

[1232]

[1233] Current (I) flowing in the electrode (18) G ) is given as follows, if we ignore the time variation of the charge of the positive electrode.

[1234] [Equation 78]

[1235]

[1236] The change in potential (Vs) of the target object (16) (ΔVs) is given as follows.

[1237]

[1238] In the case of a sine wave, it is calculated similarly to what was calculated previously.

[1239] Figure 107 shows the potential of an object according to the applied voltage of the electrode when the charge of the electrostatic electrode is in a pulse form.

[1240] Referring to Figure 107, the charge amount (ρ) of the electrostatic electrode (19) esc ) has a pulse shape and the applied voltage (V G ) is synchronized to the charge amount (ρ) of the electrostatic electrode (19) esc) In the section having a predetermined negative value, the potential (Vs) of the object can be decreased in synchronization. Accordingly, the potential (Vs) of the object can sequentially repeat etching and deposition over time.

[1241] Figure 108 shows the potential of an object according to the applied voltage of the electrode when the charge of the electrostatic electrode is in a pulse form.

[1242] Referring to Figure 108, the plasma potential (Vp) and the charge amount (ρ) of the electrostatic electrode (19) esc ) has a pulse shape and the applied voltage (V G ) is synchronized to the charge amount (ρ) of the electrostatic electrode (19) esc ) In the section having a predetermined negative value, the potential (Vs) of the object can be decreased in synchronization. Accordingly, the potential (Vs) of the object can sequentially repeat etching and deposition over time.

[1243] Figure 109 is a conceptual diagram illustrating a plasma device according to one embodiment of the present invention.

[1244] Figure 110 is a conceptual diagram showing electrode / dielectric / object / plasma.

[1245] Figure 111 shows the potential of the object according to the applied voltage of the electrode in the structure of Figure 110.

[1246] Referring to FIGS. 109 to 111, a plasma system (100) includes a chamber (12), a plasma source (20) that generates plasma within the chamber (12), and an object holder (14) that mounts an object (16a). The object (16a) may be an insulator or a dielectric.

[1247] The electrode (18) is provided with a driving voltage (V G) is applied, and the target (16a) is a dielectric and accumulates electrons or positive ions on its surface. A plasma sheath is formed between the plasma and the target (16a). The plasma sheath can be treated as a space having a positive space charge. The thickness (d3) of the plasma sheath can be determined by applying a voltage (V G ) is changed according to the first region. The first dielectric (17) is the first region, the object (16a) is the second region, and the plasma sheath is the third region.

[1248] The thickness of the first dielectric (17) is d1. The thickness of the object (16a) is d2. The thickness of the plasma sheath is d3. The voltage of the object (16) is Vs. The surface charge density of the object (16a) is ρ i The permittivity of the first region is ε1, the permittivity of the object (16a) which is the second region is ε2, and the permittivity (ε3) of the plasma sheath may be the permittivity of vacuum. The area of ​​the electrode and the object is A.

[1249] The general solution of the voltage (V1) in the first region, the general solution of the voltage (V2) in the second region, and the general solution of the third region are given as follows. In addition, the electric field (E1) in the first region, the electric field (E2) in the second region, and the electric field (E3) in the third region are given as follows. The origin of the coordinate system is the electrode. x is a coordinate of the rectangular coordinate system.

[1250] [Mattress Model]

[1251] [Genetic target]

[1252] [Equation 79]

[1253]

[1254] The surface potential (Vs) of the target object (16a) is given as follows.

[1255]

[1256] As the thickness (d2) of the object (16a) increases, the absolute value of the surface potential (Vs) of the object decreases, and as the dielectric constant (ε2) of the object (16a) decreases, the absolute value of the potential (Vs) of the object decreases.

[1257] The maximum time (tmax) is given as follows:

[1258]

[1259] Current (I) flowing in the electrode (18) G ) is given as follows.

[1260] [Equation 80]

[1261]

[1262] The change in potential of the target object (ΔVs) is given as follows.

[1263] [Equation 81]

[1264]

[1265] When a target object is sputtered by ions, its thickness may decrease. In this case, the absolute value of the target object's potential (Vs) may increase. Therefore, the applied voltage can be controlled to maintain the target object's potential (Vs) constant.

[1266] When a target object is sputtered by ions, its thickness may decrease. In this case, the position of the plasma sheath may change. Therefore, the applied voltage can be controlled to maintain the position of the plasma sheath constant.

[1267] The same applies to fluctuations in plasma potential (Vp) and electrostatic electrodes. The operating methods described in Figs. 38 to 41 can be applied. Similarly, calculations are made for sinusoidal waves.

[1268] Figure 112 is a conceptual diagram showing a plasma system including an electrostatic electrode.

[1269] Referring to FIG. 112, a plasma system (100) includes a chamber (12), a plasma source (20) that generates plasma within the chamber (12), and an object holder (14) that mounts an object (16a). The object (16a) may be an insulator or a dielectric.

[1270] The electrode (18) is provided with a driving voltage (V G ) is applied, and the target (16a) is a dielectric and accumulates electrons or positive ions on its surface. A plasma sheath is formed between the plasma and the target (16a). The plasma sheath can be treated as a space having a positive space charge. The thickness (d3) of the plasma sheath can be determined by applying a voltage (V G ) is changed according to the first dielectric (17a) and the second dielectric (17b) is the second region, and an electrostatic electrode (19) is placed between the first dielectric (17a) and the second dielectric (17b). The thickness of the electrostatic electrode is ignored. The target (16a) is the third region, and the plasma sheath is the fourth region. A is the area of ​​the target and the electrode.

[1271] The thickness of the first dielectric (17a) is d1. The thickness of the electrostatic electrode (19) is ignored. The charge of the electrostatic electrode is ρ esc The thickness of the second dielectric (17b) is d2. The thickness of the object (16a) is d3. The thickness of the plasma sheath is d4. The voltage of the object (16a) is Vs. The surface charge density of the object (16a) is ρ i The permittivity of the first region is ε1, the permittivity of the second region is ε2, the permittivity of the object (16a) in the third region is ε3, and the permittivity of the plasma sheath (ε4) may be the permittivity of vacuum.

[1272] The surface potential (Vs) of the target object (16a) is given as follows.

[1273] [Equation 82]

[1274]

[1275] The maximum time (tmax) is given as follows:

[1276] [Equation 83]

[1277]

[1278] Current (I) flowing in the electrode (18) G ) is given as follows.

[1279] [Equation 84]

[1280]

[1281] The change in potential (Vs) of the target object (16a) (ΔVs) is given as follows.

[1282] [Equation 85]

[1283]

[1284] When a target object is sputtered by ions, its thickness may decrease. In this case, the absolute value of the target object's potential (Vs) may increase. Therefore, the applied voltage can be controlled to maintain the target object's potential (Vs) constant.

[1285] When a target object is sputtered by ions, its thickness may decrease. In this case, the position of the plasma sheath may change. Therefore, the applied voltage can be controlled to maintain the position of the plasma sheath constant.

[1286] A variable capacitor (Cv) may be additionally connected in series to the electrode (18). When the target object (16) is sputtered over time and the thickness (d3) of the target object (16) decreases, the capacitance (Cv) of the variable capacitor may decrease over time to maintain the same potential (Vs) of the target object (16) or to maintain the same sputtering rate.

[1287] The same applies to sine waves, ramp voltages, maximum time measurements, current measurements, plasma potential variations, and electrostatic electrode variations. The operating methods described in Figs. 38 to 41 can be applied.

[1288] [Connection via capacitor in a dielectric object]

[1289] Figure 113 is a conceptual diagram showing a plasma system including a variable capacitor.

[1290] Referring to FIG. 113, a plasma system (100) includes a chamber (12), a plasma source (20) that generates plasma within the chamber (12), and an object holder (14) that mounts an object (16a). The object (16a) may be an insulator or a dielectric.

[1291] The plasma device may include a structure in which a variable capacitor (C1) / electrode (18) / object (16a) are sequentially connected. The method for controlling the voltage of the object may include the steps of applying a low-frequency pulse voltage (VG) to the variable capacitor (C1); and the step of controlling the voltage (Vs) of the object (16a), which is a dielectric, by controlling the electrostatic capacitance of the variable capacitor (C1). The electrode (18) may be removed.

[1292] The variable capacitor (C1) may be a capacitor having a capacitance (C1 = ε1S1 / d1). The capacitor (C1) may be a variable capacitor. The potential (Vs) of the target (16a), which is a dielectric having an area (S2), is transformed as follows.

[1293] The potential (Vs) of the target (16a) is given as follows.

[1294] [Equation 86]

[1295]

[1296] The maximum time (tmax) is given as follows:

[1297]

[1298] Current (I) flowing in the electrode (18) or variable capacitor (C1) G ) is given as follows.

[1299]

[1300] The change in potential (ΔVs) of the target object is given as follows.

[1301]

[1302] When the target object (16a) is sputtered over time and its thickness (d2) decreases, the capacitance (C1) of the variable capacitor can decrease over time to maintain the same potential (Vs) of the target object (16a) or to maintain the same sputtering rate.

[1303] In addition, by adjusting the variable capacitor (C1) at a predetermined slope voltage (X1), the amount of change in the potential of the object (ΔVs) can become zero.

[1304] When a target object is sputtered by ions, its thickness may decrease. In this case, the position of the plasma sheath may change. Therefore, the applied voltage can be controlled to maintain the position of the plasma sheath constant.

[1305] The same applies to sine waves, ramp voltages, maximum time measurements, current measurements, plasma potential variations, and electrostatic electrode variations. The operating methods described in Figs. 38 to 41 can be applied.

[1306] [Handling of conductor objects when the dielectric is replaced with a capacitor]

[1307] Figure 114 is a conceptual diagram showing a plasma system including a variable capacitor.

[1308] Referring to FIG. 114, a plasma system (100) includes a chamber (12), a plasma source (20) that generates plasma within the chamber (12), and an object holder (14) that mounts an object (16). The object (16) may be a conductor or a semiconductor. The plasma device may include a structure in which a variable capacitor (C1) / electrode (18) / object (16) are sequentially connected. A method for controlling the voltage of an object includes applying a low-frequency pulse voltage (V) to the variable capacitor. G) and a step of controlling the voltage of the conductor object by controlling the electrostatic capacitance of the variable capacitor.

[1309] A variable capacitor (C1) may have a capacitance (C1 = ε1S1 / d1). The capacitor (C1) may be a variable capacitor. The potential (Vs) of an object (16), which is a conductor (including a semiconductor) having an area (S2), is transformed as follows.

[1310] The potential (Vs) of the object is given as follows:

[1311] [Equation 87]

[1312]

[1313] The capacitance per unit area (ε1 / d1) at the potential (Vs) of the object (16) connected in series to the capacitor (C1) is converted into a value obtained by dividing the capacitance (C1) of the capacitor by the area (S2) of the object (16) ((ε1 / d1)(S1 / S2)). When the capacitance of the capacitor (C1) is changed, the potential (Vs) of the object (16) is changed.

[1314] The maximum time (tmax) is given as follows:

[1315] [Equation 88]

[1316]

[1317] Current (I) flowing in the variable capacitor (C1) or electrode (18) G ) is given as follows.

[1318] [Equation 89]

[1319]

[1320]

[1321]

[1322]

[1323] The change in potential of the target object (ΔVs) is given as follows.

[1324]

[1325] For example, in an ion implantation system or an etching system, by adjusting the capacitance of a variable capacitor (C1), the ion energy or the thickness of the sheath can be controlled at a fixed applied voltage.

[1326] When a target object is sputtered by ions, the thickness of the target object may decrease. In this case, the position of the plasma sheath may change. Therefore, the applied voltage or variable capacitor (C1) can be controlled to maintain the position of the plasma sheath constant.

[1327] In addition, when the variable capacitor (C1) is adjusted at a predetermined slope voltage (X1), the potential (Vs) of the object is adjusted, and the amount of change (ΔVs) in the potential of the object can become zero.

[1328] The same applies to sine waves, ramp voltages, maximum time measurements, current measurements, plasma potential variations, and electrostatic electrode variations. The operating methods described in Figs. 38 to 41 can be applied.

[1329] [Including dielectric (17) and series capacitor (C4)]

[1330] Figure 115 is a conceptual diagram showing a plasma system including a variable capacitor.

[1331] Referring to FIG. 115, a plasma system (100) includes a chamber (12), a plasma source (20) for generating plasma within the chamber (12), and an object holder (14) for mounting an object (16). The object (16) may be a conductor or a semiconductor. The plasma device may include a structure in which a variable capacitor (C4) / electrode (18) / dielectric (17) / object (16) are sequentially connected. A method for controlling an object voltage may include a step of applying a low-frequency pulse voltage (VG) to the variable capacitor (C4); and a step of controlling the voltage of the object (16), which is a conductor, by controlling the electrostatic capacitance of the variable capacitor (C4). The area of ​​the object (16) is S2.

[1332] The dielectric (17) has a permittivity of ε1 and a thickness of d1. When a series variable capacitor (C4) connected in series to the electrode (18) is connected, the potential (Vs) of the object (16), which is a conductor (including a semiconductor), is given as follows.

[1333] The potential (Vs) of the target (16) is given as follows.

[1334] [Equation 90]

[1335]

[1336] The maximum time (tmax) is given as follows:

[1337]

[1338] Current (I) flowing in the variable capacitor (C4) or electrode (18) G ) is given as follows.

[1339]

[1340] The change in potential (ΔVs) of the target object (16) is given as follows.

[1341]

[1342] The series capacitor (C4) is a variable capacitor, and when its capacitance is changed, the potential (Vs) of the object (16) changes.

[1343] In an ion implantation system or etching system, by adjusting the capacitance of the series capacitor (C4), the ion energy or the thickness of the sheath can be controlled at a fixed applied voltage.

[1344] In addition, when the variable capacitor (C4) is adjusted at a predetermined slope voltage (X1), the potential of the object changes, and the amount of change (ΔVs) in the potential of the object can become zero.

[1345] The same applies to sine waves, ramp voltages, maximum time measurements, current measurements, plasma potential variations, and electrostatic electrode variations. The operating methods described in Figs. 38 to 41 can be applied.

[1346] Figure 116 is a conceptual diagram showing a plasma system including a variable capacitor.

[1347] Referring to FIG. 116, a plasma system (100) includes a chamber (12), a plasma source (20) that generates plasma within the chamber (12), and an object holder (14) that mounts an object (16). The object (16) may be a conductor or a semiconductor.

[1348] The variable capacitor (C4) has a driving voltage (V G ) is applied, and the object (16) is a conductor and accumulates electrons or positive ions on its surface. A plasma sheath is formed between the plasma and the object (16). The plasma sheath can be treated as a space having a positive space charge. The thickness (d3) of the plasma sheath can be determined by a voltage (V G ) is changed according to the first dielectric (17a) and the second dielectric (17b) is the second region, and an electrostatic electrode (19) is placed between the first dielectric (17a) and the second dielectric (17b). The thickness of the electrostatic electrode (19) and the electrode (18) is ignored. The plasma sheath is the third region. S2 is the area of ​​the target and the electrode.

[1349] The thickness of the first dielectric (17a) is d1. The thickness of the electrostatic electrode (19) is ignored. The charge of the electrostatic electrode is ρ esc is. The thickness of the second dielectric (17b) is d2. The thickness of the plasma sheath is d3. The voltage of the object (16) is Vs. The surface charge density of the object (16) is ρ i The permittivity of the first region is ε1, the permittivity of the second region is ε2, and the permittivity of the plasma sheath (ε3) may be the permittivity of vacuum.

[1350] The surface potential (Vs) of the target object (16) is given as follows.

[1351] [Equation 91]

[1352]

[1353]

[1354] The maximum time (tmax) is given as follows:

[1355] [Equation 92]

[1356]

[1357] Current (I) flowing in the electrode (18) G ) is given as follows, if we ignore the time variation of the charge of the positive electrode.

[1358] [Equation 93]

[1359]

[1360] The change in potential (Vs) of the target object (16a) (ΔVs) is given as follows.

[1361] [Equation 94]

[1362]

[1363] The series capacitor (C4) is a variable capacitor, and when its capacitance is changed, the potential (Vs) of the object (16) changes.

[1364] In a plasma system, by adjusting the capacitance of the series capacitor (C4), the ion energy or the thickness of the sheath can be controlled at a fixed applied voltage.

[1365] In addition, when the variable capacitor (C4) is adjusted at a predetermined slope voltage (X1), the potential of the object changes, and the amount of change (ΔVs) in the potential of the object can become zero.

[1366] The same applies to sine waves, ramp voltages, maximum time measurements, current measurements, plasma potential variations, and electrostatic electrode variations. The operating methods described in Figs. 38 to 41 can be applied.

[1367] Figures 117 and 118 are conceptual diagrams illustrating a method for controlling target voltage according to embodiments of the present invention.

[1368] Referring to FIGS. 117 and 118, in a plasma device (100) including a structure in which electrodes / dielectric layers / objects are laminated, the plasma potential (Vp) of plasma adjacent to the object (16) is controlled to increase over time by an auxiliary electrode (31) that controls the plasma potential, thereby controlling the potential difference (Vs-Vp) between the potential (Vs) of the object and the plasma potential (Vp).

[1369] Referring to Fig. 117, plasma is continuously generated by a high-frequency power source. The applied voltage (VG) applied to the electrode (18) is a pulse DC voltage, and the plasma potential (Vp) can be synchronized with the negative section of the pulse DC voltage. Specifically, the plasma potential (Vp) is synchronized with the applied voltage (VG) with a slight time delay. The plasma potential (Vp) can be controlled by the voltage waveform of the auxiliary electrode (31) disposed within the chamber. Accordingly, the potential difference (Vs-Vp) between the potential (Vp) of the object and the plasma potential can increase over time according to the inflow of ion current (Ii, Ji).

[1370] Additionally, if the plasma potential (Vp) has a slope voltage (Y), the voltage difference (Vs-Vp) between the potential of the object and the plasma potential can be constant over time depending on the inflow of ion current (Ji).

[1371] In addition, when the applied voltage (VG) applied to the electrode (18) has a first slope voltage (X), the plasma potential (Vp) can have a second slope voltage (Y) to correspond to the ion current and the first slope voltage (X).

[1372]

[1373] Here, c eff is the effective capacitance per unit area between the target and the low-frequency power source (or electrode).

[1374] In addition, the change in the plasma potential (Vp) is affected by the applied voltage (V G ) may not be synchronized.

[1375] A method of operating a plasma device including an electrode / dielectric layer / object structure comprises: applying a first DC pulse voltage (V) including a first slope voltage (X) to the electrode; G ) applying a second DC pulse voltage (Vc) including a second ramp voltage (Y) by an auxiliary electrode that adjusts the plasma potential so as to change the plasma potential of the plasma adjacent to the object over time; The first DC pulse voltage (Vc) may be synchronized with the second DC pulse voltage (Vc). Y = X + Ji / c eff is given as . Here, c eff is the effective capacitance per unit area between the target and the electrode, and Ji is the ion current density incident on the target.

[1376] Referring to Fig. 118, plasma is generated in a pulse form by a high-frequency power source. The plasma may have a turn-on period and a turn-off period. In the turn-on period of the plasma, the voltage (VG) applied to the electrode (18) has a positive value period and can charge the target object with a negative charge. In the turn-on period of the plasma, the plasma potential (Vp) may have a low value.

[1377] In the turn-off section of the plasma, the voltage (VG) applied to the electrode (18) has a section having a negative value and can reduce the potential of the target object charged with a negative charge to a negative value. As the ion current (Ii, Ji) flows into the target object, the potential of the target object increases. The potential difference (Vs-Vp) between the potential (Vs) of the target object and the plasma potential (Vp) is constant over time despite the flow of the ion current (Ii, Ji), so that the plasma potential (Vp) has a slope section that increases over time and can be controlled by the voltage waveform of the auxiliary electrode (31) arranged in the chamber.

[1378] The voltage (VG) applied to the electrode (18) is a pulse DC voltage, and the plasma potential (Vp) can be synchronized with the negative section of the pulse DC voltage. Specifically, the plasma potential (Vp) can be synchronized with the applied voltage (VG) with a slight time delay. The plasma potential (Vp) has a slope section that increases over time, and the voltage waveform can be controlled on the auxiliary electrode (31) placed within the chamber.

[1379] [Current waveform]

[1380] Figure 119 is a conceptual diagram for distinguishing the waveform of displacement current according to conditions according to one embodiment of the present invention.

[1381] Referring to Figure 119, the waveform of the displacement current can be divided into a sawtooth waveform and a sine wave-like waveform.

[1382] In this case, the displacement current has a sinusoidal waveform.

[1383] In this case, the displacement current has a sawtooth waveform.

[1384] Based on this, the displacement current can be distinguished into a sawtooth waveform and a sine-like waveform.

[1385] When there is a parasitic capacitance (C4), the parasitic capacitance connected in parallel with the electrode (118) can flow additional displacement current. Accordingly, when the parasitic capacitance (C4) satisfies the following condition, the displacement current is transformed into a pseudo-sine wave. A is the area of ​​the object (16).

[1386]

[1387] The displacement current flowing through the plasma sheath can be set to be greater than the displacement current flowing through the parasitic capacitor (C4).

[1388]

[1389] Accordingly, the parasitic capacitance (C4) per unit area due to the distance (d4) between the lower portion of the electrode (118) and the grounded electrode housing (not shown) and the permittivity (ε4) of the dielectric disposed between the lower portion of the electrode (118) and the grounded electrode housing can be designed to be smaller than the effective capacitance of the plasma sheath (left side of the equation above). For example, the parasitic capacitance per unit area (ε4 / d4) can be 10^(-7) [F / m^2] or less. The permittivity (ε4) of the dielectric disposed between the lower portion of the electrode (118) and the grounded electrode housing can be smaller than the permittivity (ε1) of the upper portion of the electrode. The distance (d4) between the lower portion of the electrode (118) and the grounded electrode housing can be greater than the distance (d1) between the electrode (118) and the object (116). The distance (d4) between the lower portion of the electrode (118) and the grounded electrode housing may be greater than the plasma sheath distance (d2) between the target (116) and the plasma. Preferably, can be more than 10 times larger than the parasitic capacitance per unit area (ε4 / d4).

[1390]

[1391] [Voltage damping conditions by ion current]

[1392] Figure 120 is a conceptual diagram dividing the ion energy distribution by region according to the ion current density (Ji) according to a temporary example of the present invention.

[1393] Referring to Figure 120, the potential (Vs) characteristics of the object according to the ion current density (Ji) and angular frequency (ω) are given as follows.

[1394]

[1395] In the above equation, the damping condition in which the potential (Vs) of the object decreases due to the ion current density (Ji) is given as follows.

[1396]

[1397] When the above conditions are satisfied, the potential (Vs) of the target is hardly damped. On the other hand, when the angular frequency (ω) of the bias power supply is greater than the angular frequency (ωi) of the ion plasma, the value between the two peaks decreases, resulting in a narrow energy width.

[1398] Therefore, in the coordinate system of the angular frequency (ω) of the bias power supply and the damping condition, the ion energy distribution can be divided into four regions.

[1399] Fig. 121 is a graph showing the damping conditions according to the angular frequency (ω) and applied voltage (V) of the bias power supply.

[1400] Referring to Fig. 121, to satisfy the same damping condition (=0.1), as the applied voltage increases, the angular frequency (ω) of the bias power supply decreases.

[1401] Figure 122 is a graph showing the damping conditions according to the product of the angular frequency (ω) of the bias power supply and the applied voltage (V) and the ion current density (Ji).

[1402] Referring to Fig. 122, in order to satisfy the damping condition (=0.1), Vω is proportional to the ion current density (Ji).

[1403] Figure 123 shows the potential (Vs) waveform of the target object according to the ion current density at a sinusoidal applied voltage.

[1404] Referring to Figure 123, the damping characteristics of the target object's potential (Vs) as a function of the ion current density over time (t) are given as follows.

[1405]

[1406] For example, when the applied voltage is sinusoidal, the potential (Vs) of the target changes along with the rectifier pressure as the ion current density increases.

[1407] Figures 124 and 125 show the potential (Vs) of the object according to the capacitance per unit area (ε1 / d1) between the object and the electrode under a sinusoidal applied voltage.

[1408] Referring to Fig. 124, the amplitude (V) of the applied voltage is 100 V. The capacitances per unit area (ε1 / d1) are 10^(-7), 10^(-6), 10^(-5), 10^(-4), and 10^(-3) [F / m^2], respectively. Ji is 1 [A / m^2]. As the capacitance per unit area (ε1 / d1) increases, the absolute value of the potential (Vs) of the object increases with each frequency and converges to a constant value.

[1409] Meanwhile, the angular frequency (ω) at which the absolute value of the potential (Vs) of the object becomes zero is inversely proportional to the electrostatic capacitance per unit area (ε1 / d1).

[1410] (d1 / ε1)[(J i π) / (Vω)] = 2

[1411] When the capacitance per unit area (ε1 / d1) is sufficiently reduced to approach the capacitance of the sheath, the potential (Vs) of the object decreases. Therefore, the capacitance per unit area (ε1 / d1) and the angular frequency can have optimal values.

[1412] Referring to Fig. 125, the capacitance per unit area (ε1 / d1) is 10^(-7), 10^(-8) [F / m^2]. Ji is 1, 10 [A / m^2]. The amplitude (V) of the applied voltage is 100 V, 200 V.

[1413] The non-dapping condition is determined by the ion current density (Ji), the amplitude of the applied voltage (V), the angular frequency (ω), and the capacitance per unit area (ε1 / d1).

[1414] Figure 126 shows the potential (Vs) of the object according to the capacitance per unit area (ε1 / d1) between the object and the electrode under a bipolar DC pulse applied voltage.

[1415] Referring to Fig. 126, the amplitude (V) of the applied voltage is 100 V. The capacitances per unit area (ε1 / d1) are 10^(-7), 10^(-6), 10^(-5), 10^(-4), and 10^(-3) [F / m^2], respectively. Ji is 1 [A / m^2]. The amplitude (V) of the applied voltage is 100 V.

[1416] For example, if the applied voltage is a bipolar DC pulse, the damping condition is given as follows: Voltage application time (t th ) is the application time during which dipping can be ignored at negative voltage.

[1417]

[1418] Figure 127 shows the potential (Vs) of the object according to the ion current density at a bipolar DC pulse applied voltage.

[1419] Referring to Fig. 127, the amplitude (V) of the applied voltage is 100 V. The capacitance per unit area (ε1 / d1) is 10^(-7)[F / m^2]. Ji is 1, 5, 10 [A / m^2]. The amplitude (V) of the applied voltage is 100 V.

[1420] Figure 128 shows the potential (Vs) of an object according to the capacitance per unit area (ε1 / d1) at a bipolar DC pulse applied voltage.

[1421] Referring to Fig. 128, the amplitude (V) of the applied voltage is 100 V. The capacitances per unit area (ε1 / d1) are 10^(-6), 10^(-5), 5x 10^(-4), and 10^(-4)[F / m^2], respectively. Ji is 1 [A / m^2]. The amplitude (V) of the applied voltage is 100 V.

[1422] Figure 129 shows the potential (Vs) waveform of an object according to a slope voltage (X=dV / dt) in a bipolar DC pulse applied voltage.

[1423] Referring to Fig. 129, the amplitude of the applied voltage (V) is 100 V. The capacitance per unit area (ε1 / d1) is 10^(-7)[F / m^2]. Ji is 1 [A / m^2]. The slope voltages (X=dV / dt) are 0, -0.3 x 10^(7), -0.5 x 10^(7), -0.8 x 10^(7), and - 10^(7)[V / sec], respectively.

[1424] Figure 130 shows the potential (Vs) waveform and current waveform of the object according to conditions under a sinusoidal applied voltage.

[1425] Referring to Fig. 130, the current waveform and voltage waveform are shown under the conditions of (d1 / ε1)sqrt(2ε2 ρd)=1.6, 0.16, and 16. When (d1 / ε1)sqrt(2ε2 ρd) increases by 5 or more, the current waveform has a sine-like waveform. When (d1 / ε1)sqrt(2ε2 ρd) decreases, the current waveform has a sawtooth-like waveform. The operating frequency is 1 MHz, and the applied voltage (V) is 100 V.

[1426] Figure 131 shows the potential (Vs) waveform and current waveform of the object according to conditions under a sinusoidal applied voltage.

[1427] Referring to Fig. 131, the current waveform and voltage waveform are shown under the condition of (d1 / ε1)sqrt(2ε2 ρd)=1.6. The electron current (Je), ion current (Ji), displacement current (Jd), and displacement current due to parasitic capacitor are shown. The operating frequency is 1 MHz, and the applied voltage (V) is 100 V.

[1428] Figure 132 shows the potential (Vs) waveform and current waveform of the object according to conditions under a sinusoidal applied voltage.

[1429] Referring to Fig. 132, the current waveform and voltage waveform are shown under the condition of (d1 / ε1)sqrt(2ε2 ρd)=1.6 sqrt(10). The electron current (Je), ion current (Ji), displacement current (Jd), and displacement current due to parasitic capacitor are shown. The operating frequency is 1 MHz, and the applied voltage (V) is 100 V. As the ion current (Ji) increases (1.6 sqrt(10)), the electron current (Je) also increases.

[1430] In summary, the selection of plasma density, frequency, and capacitance can satisfy the following conditions.

[1431] [Selecting operating conditions]

[1432] 1) Voltage drop conditions

[1433]

[1434] 2) Voltage damping condition by ion current

[1435] For sinusoidal waves, the voltage damping condition is given as follows:

[1436]

[1437] For DC pulse waves, the voltage damping condition is given as follows:

[1438]

[1439] 3) Wide energy conditions between peaks in the ion energy distribution

[1440]

[1441] 4) Conditions for sawtooth wave shape of the current transformer

[1442]

[1443] 5) Conditions for reducing parasitic displacement current due to parasitic capacitor (C4)

[1444]

[1445] The present invention can be applied to plasma etching, plasma deposition, plasma sputtering, plasma cleaning, and plasma surface treatment devices. In addition, the present invention can be applied to a bias power supply or a plasma generation power supply of a plasma device.

[1446] The object of the present invention may be a substrate, a semiconductor substrate, a dielectric substrate, a sputtering target, a focus ring, an edge ring, an electrode for plasma generation, or an electrode of a plasma diagnostic device.

[1447] Although the present invention has been illustrated and described with respect to preferred embodiments of the features, the present invention is not limited to these embodiments, and includes various forms of embodiments that can be implemented by a person having ordinary skill in the art to which the invention pertains without departing from the technical spirit of the present invention claimed in the claims.

Claims

1. In a plasma device including a structure in which electrodes / dielectric layers / objects are laminated, The applied voltage of the bipolar pulse to the above electrode (V G ) to obtain the maximum time (tmax) at which the current flowing through the electrode becomes zero in the negative voltage range; and A method for controlling an object voltage, comprising: a step of calculating an ion current density (Ji) incident on the object exposed to plasma using the maximum time (tmax); 2. In paragraph 1, A method for controlling the voltage of an object, characterized in that the ion current density (Ji) is given as follows. Here, Vo is the measurement voltage applied to the electrode, and V G + is the positive applied voltage applied to the electrode, and c1 is the capacitance per unit area due to the dielectric between the electrode and the object.

3. In paragraph 1, A method for controlling a voltage of an object, further comprising: a step of setting a potential (Vs) of the object based on the ion current density (Ji).

4. In paragraph 3, A method for controlling the voltage of an object, characterized in that the potential (Vs) of the object is given as follows. Here, ρ d is the charge density of the plasma, V G is the applied voltage applied to the above electrode, and u B is the spring speed, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object under a positive applied voltage.

5. In paragraph 4, The above applied voltage (V G ) A method for controlling the voltage of an object, characterized in that it further includes a step of calculating the potential change amount (ΔVs) of the object. Here, X is the change in voltage (dV / dt) over the time interval (τ) in the negative interval of the applied voltage (VG).

6. In paragraph 1, A method for controlling a voltage of an object, characterized in that it further comprises a step of applying a driving voltage of a bipolar waveform having an application time of a negative applied voltage smaller than the maximum time (tmax) to the electrode.

7. In paragraph 3, A method for controlling the voltage of an object, characterized in that the potential (Vs) of the object is given as follows. Te is the temperature of the electron, k is the Boltzmann constant, q is the absolute value of the electron's charge, and M is the mass of the ion.

8. In paragraph 3, A method for controlling the voltage of an object, characterized in that the potential (Vs) of the object is given as follows. Here, α=0.3 ~0.5, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated in the target at a positive driving voltage.

9. In paragraph 4, A method for controlling the voltage of an object, characterized by:

10. In paragraph 4, A method for controlling the voltage of an object, characterized by:

11. In paragraph 1, Current (I) flowing through the above electrode G ) and the above current (I G ) is a target voltage control method characterized in that the maximum time (tmax) at which the voltage becomes zero is given as follows. Here V s0 is the initial voltage of the object, C1 is the electrostatic capacitance due to the dielectric, and V f is the floating potential, and I G0 is the current flowing in the electrode at a negative applied voltage.

12. In paragraph 1, Current (I) flowing through the above electrode G ) is given as follows, A method for controlling the voltage of an object, characterized by: Here, X is the applied slope voltage in the negative applied voltage range, C1 is the electrostatic capacitance due to the dielectric, and ρ d is the charge density of the plasma, V G is the applied voltage applied to the electrode, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

13. In paragraph 12, A method for controlling the voltage of an object, characterized by:

14. In paragraph 1, The initial charge per unit area (Qi) of the above object at a positive applied voltage is A method for controlling the voltage of an object, characterized in that it is given as .

15. In paragraph 1, Positive applied voltage (V) of the above object G + ) A method for controlling the voltage of an object, characterized in that the following conditions are satisfied. Here, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, ε2 is the permittivity of the plasma sheath region, and τ is the time interval during which the negative applied voltage is applied.

16. In paragraph 1, Charge density of plasma (ρ d ) is further included in the step of obtaining the target voltage control method. Here, ρ d is the charge density of the plasma, d1 is the thickness of the dielectric layer, ε1 is the permittivity of the dielectric layer, and ε2 is the permittivity of the plasma sheath region. V G is the negative applied voltage. ρi is the initial surface charge density accumulated on the object at a positive applied voltage.

17. In paragraph 1, A step of applying a driving voltage of a bipolar waveform having a negative voltage application time less than the maximum time (tmax) to the electrode; and A method for controlling a voltage of an object, characterized in that it further includes a step of applying a high-frequency sine wave to the electrode in synchronization with the negative voltage section of the driving voltage.

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