Focusing ring assembly, lower electrode structure and semiconductor device

Abstract

The utility model provides a focusing ring assembly, a lower electrode structure and a semiconductor device, the focusing ring assembly comprises a focusing ring main body and an annular electrode, the focusing ring main body can be arranged on a bearing part used for bearing a wafer and can be arranged around a bearing surface of the bearing part used for bearing the wafer, and the annular electrode is arranged on the focusing ring main body. An annular accommodating groove is formed in the bottom of the focusing ring main body; and the annular electrode is accommodated in the accommodating groove and can be electrically connected with a lower radio frequency source for providing lower radio frequency. According to the focusing ring assembly, the lower electrode structure and the semiconductor equipment provided by the utility model, the direction and the speed of bombarding the edge of the wafer by the plasma are the same as the direction and the speed of bombarding the middle part of the wafer, so that the etching uniformity of the wafer can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, and in particular to a focusing ring component, a lower electrode structure and a semiconductor device. Background Art

[0002] Some current semiconductor processes (eg, inductively coupled plasma (ICP) and capacitively coupled plasma (CCP)) rely on the interaction between plasma and the wafer surface to cause various physical and chemical reactions to etch the wafer.

[0003] An existing semiconductor device includes a process chamber and a lower electrode structure, wherein the lower electrode structure is arranged at the bottom of the process chamber. Figure 1 As shown, the lower electrode structure includes a carrying component 201, a lower electrode plate 202, a lower RF source 203 and a focusing ring 204. The carrying component 201 is arranged in the process chamber for carrying the wafer 100. The lower electrode plate 202 is arranged inside the carrying component 201 and is arranged corresponding to the middle of the wafer 100 on the carrying component 201. The lower RF source 203 is arranged outside the process chamber and is electrically connected to the lower electrode plate 202 for loading RF power to the lower electrode plate 202 so as to couple the lower electrode plate 202 to the wafer 100. 00 forms a bias voltage above the surface, thereby attracting the plasma in the process chamber to bombard the wafer 100. The focusing ring 204 is arranged on the supporting component 201 and can surround the edge of the wafer 100 supported on the supporting component 201. By designing the thickness of the focusing ring 204, the electric potential above the edge of the wafer 100 can be similar to the electric potential above the middle of the wafer 100, thereby making the direction and speed of the plasma bombarding the edge of the wafer 100 similar to the direction and speed of the plasma bombarding the middle of the wafer 100.

[0004] However, in the prior art, even with the presence of the focus ring 204, the potential lines above the surface of the wafer 100 will still bend above the edge of the wafer 100 toward the direction close to the wafer 100 (eg, Figure 1 That is, the electric potential above the edge of the wafer 100 is still smaller than the electric potential above the middle of the wafer 100, resulting in the direction in which the plasma bombards the edge of the wafer 100 (as shown in FIG. Figure 1 The plasma shown is along the edge electric field lines (such as Figure 1 The bombardment is tilted in the direction indicated by the arrow in the middle edge (as shown in the figure). Figure 1 and Figure 3 As shown)) and the speed and the direction in which the plasma bombards the middle of the wafer 100 (as shown Figure 1 The plasma shown is along the edge electric field lines (such as Figure 1The vertical bombardment (as indicated by the arrow in the middle) Figure 1 and Figure 2 As shown in FIG. 1 , the etching rate and the etching rate may still differ greatly, thereby causing poor etching uniformity of the wafer 100 . Utility Model Content

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art, and proposes a focusing ring assembly, a lower electrode structure and a semiconductor device, which can make the direction and speed of plasma bombarding the edge of the wafer the same as the direction and speed of plasma bombarding the middle of the wafer, thereby improving the etching uniformity of the wafer.

[0006] In order to achieve the purpose of the utility model, a focusing ring assembly is provided, comprising:

[0007] A focusing ring body, which can be arranged on a bearing component for bearing a wafer, and can be arranged around a bearing surface of the bearing component for bearing the wafer, and a ring-shaped receiving groove is arranged at the bottom of the focusing ring body;

[0008] The annular electrode is accommodated in the accommodating groove and can be electrically connected to a lower radio frequency source for providing a lower radio frequency.

[0009] Optionally, a side of the accommodating groove facing the bottom surface of the focusing ring body and a side of the accommodating groove facing the inner edge of the focusing ring body are both openings.

[0010] Optionally, the inner edge of the ring electrode is flush with the inner edge of the focusing ring body, and / or the bottom surface of the ring electrode is flush with the bottom surface of the focusing ring body, and / or the outer diameter of the ring electrode is smaller than the outer diameter of the focusing ring body.

[0011] The utility model also provides a lower electrode structure, including a bearing component and the focusing ring assembly provided by the utility model, the bearing component is used to bear the wafer, the focusing ring assembly is arranged on the bearing component and surrounds the bearing surface of the bearing component for bearing the wafer.

[0012] Optionally, the lower electrode structure further includes a variable impedance component, and the annular electrode is electrically connected to the lower RF source via the variable impedance component.

[0013] Optionally, the variable impedance component includes a variable impedance component and a control component, the variable impedance component is electrically connected to the lower RF source and the annular electrode respectively, and the control component is signal-connected to the variable impedance component for controllably changing the impedance value of the variable impedance component.

[0014] Optionally, the variable impedance component includes a plurality of fixed impedance elements, the plurality of fixed impedance elements are connected in parallel, and the control component is respectively connected to a plurality of parallel branches formed by the plurality of fixed impedance elements in parallel, and is used to control the number of the fixed impedance elements electrically connected to the lower RF source and the annular electrode respectively by respectively controlling the on and off of the plurality of parallel branches.

[0015] Optionally, the control component includes a fiber optic control module, multiple on-off devices and multiple fiber optic signal lines, the multiple on-off devices are connected one-to-one with the multiple parallel branches, the multiple fiber optic signal lines are connected one-to-one with the multiple on-off devices, and the fiber optic control module is signal-connected to the multiple fiber optic signal lines respectively, for sending control signals to the multiple on-off devices through the multiple fiber optic signal lines one-to-one, so as to control the on and off of the multiple parallel branches through the multiple on-off devices one-to-one.

[0016] Optionally, the impedance values ​​of the plurality of fixed impedance elements are binary increasing, and / or the fixed impedance elements are all fixed capacitors, and the minimum capacitance of the plurality of fixed impedance elements is 1 pF.

[0017] Optionally, the lower electrode structure further includes a radio frequency feeding electrode, which is disposed inside the supporting component and can be electrically connected to the lower radio frequency source.

[0018] Optionally, the variable impedance component is electrically connected to the lower RF source through the RF feeding electrode.

[0019] Optionally, the RF feeding electrode is provided with a connecting protrusion, and the variable impedance component is electrically connected to the RF feeding electrode via the connecting protrusion.

[0020] Optionally, the lower electrode structure further includes an electrical connection component, and the variable impedance component is electrically connected to the annular electrode via the electrical connection component;

[0021] The electrical connection component includes a first electrical connection member, an adapter and a second electrical connection member, the first electrical connection member is electrically connected to the variable impedance component, the second electrical connection member is electrically connected to the ring electrode, and the first electrical connection member is electrically connected to the second electrical connection member through the adapter.

[0022] Optionally, the lower electrode structure also includes a base ring and an insulating ring, and the insulating ring, the base ring and the focusing ring assembly are stacked in sequence on the supporting component, and the first electrical connector, the adapter and the second electrical connector are respectively arranged inside the base ring and the insulating ring.

[0023] Optionally, the electrical connection assembly also includes a seal, which is arranged on a side of the adapter that is electrically connected to the first electrical connector, and / or the seal is arranged on a side of the adapter that is electrically connected to the second electrical connector, and the seal is used to seal the gap between the adapter and the insulating ring and / or the base ring.

[0024] The utility model also provides a semiconductor device, comprising a process chamber and the lower electrode structure provided by the utility model, wherein the lower electrode structure is arranged at the bottom of the process chamber.

[0025] The utility model has the following beneficial effects:

[0026] The focusing ring assembly provided by the utility model is provided with an annular accommodating groove at the bottom of the focusing ring body, and an annular electrode is accommodated in the accommodating groove, and the annular electrode is electrically connected to a lower radio frequency source for providing the lower radio frequency. The lower radio frequency provided by the lower radio frequency source can be coupled to the upper part of the focusing ring body by means of the annular electrode to generate an electric potential, so that the electric potential above the edge of the wafer can be equal to the electric potential above the middle of the wafer, and then the direction and speed of plasma bombarding the edge of the wafer can be made the same as the direction and speed of plasma bombarding the middle of the wafer, thereby improving the etching uniformity of the wafer.

[0027] The lower electrode structure provided by the utility model can make the direction and speed of plasma bombarding the edge of the wafer the same as the direction and speed of plasma bombarding the middle of the wafer by arranging the focusing ring assembly provided by the utility model on the bearing component, thereby improving the etching uniformity of the wafer.

[0028] The semiconductor device provided by the utility model sets the lower electrode structure provided by the utility model at the bottom of the process chamber, so that the direction and speed of plasma bombarding the edge of the wafer are the same as the direction and speed of plasma bombarding the middle of the wafer, thereby improving the etching uniformity of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a lower electrode structure in the prior art;

[0030] Figure 2 A schematic diagram of the direction of plasma etching the central part of a wafer in the prior art;

[0031] Figure 3 A schematic diagram of the direction of plasma etching the edge of a wafer in the prior art;

[0032] Figure 4 A schematic diagram of the structure of the lower electrode provided in an embodiment of the utility model;

[0033] Figure 5 A schematic diagram of the structure of the lower electrode structure and the semiconductor device provided by the embodiment of the utility model;

[0034] Figure 6 A schematic diagram of the structure of a variable impedance component provided by an embodiment of the utility model;

[0035] Figure 7 A schematic diagram of the structure of the on-off device and the corresponding parallel branch provided in the embodiment of the utility model;

[0036] Figure 8 A schematic diagram of the structure of an electrical connection assembly provided in an embodiment of the utility model;

[0037] Description of reference numerals:

[0038] 1-carrying component; 2-focusing ring body; 3-RF feeding electrode; 31-connecting protrusion; 4-ring electrode; 5-variable impedance component; 51-input end; 52-output end; 53-fixed impedance element; 54-optical fiber control module; 55-on-off device; 56-optical fiber signal line; 61-first electrical connector; 62-adapter; 63-second electrical connector; 64-seal; 65-conducting wire; 71-base ring; 72-insulating ring; 8-process chamber; 91-lower RF source; 92-lower matching component; 93-upper electrode coil; 94-upper RF source; 95-upper matching component; 100-wafer; 201-carrying component; 202-lower electrode plate; 203-lower RF source; 204-focusing ring. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the focusing ring assembly, the lower electrode structure and the semiconductor device provided by the present invention are described in detail below in conjunction with the accompanying drawings.

[0040] like Figure 4 and Figure 5 As shown, an embodiment of the utility model provides a focusing ring assembly, including a focusing ring body 2 and an annular electrode 4, wherein the focusing ring body 2 can be set on a carrying component 1 for carrying a wafer 100, and can be set around the carrying surface of the carrying component 1 for carrying the wafer 100, and the bottom of the focusing ring body 2 is provided with an annular accommodating groove; the annular electrode 4 is accommodated in the accommodating groove, and can be electrically connected to a lower RF source 91 for providing a lower RF.

[0041] The focusing ring assembly provided by the utility model is provided with an annular receiving groove at the bottom of the focusing ring body 2, and an annular electrode 4 is provided in the receiving groove, and the annular electrode 4 is electrically connected to a lower RF source 91 for providing a lower RF. The RF power provided by the lower RF source 91 can be coupled to the upper part of the focusing ring body 2 by means of the annular electrode 4 to generate a bias voltage, so that the electric potential above the edge of the wafer 100 can be equal to the electric potential above the middle of the wafer 100, and then the direction and speed of plasma bombarding the edge of the wafer 100 can be made the same as the direction and speed of plasma bombarding the middle of the wafer 100, thereby improving the etching uniformity of the wafer 100.

[0042] In practical applications, an RF feeding electrode 3 may be provided inside the carrier component 1, and the RF feeding electrode 3 may be electrically connected to the lower RF source 91, and the lower RF source 91 loads RF power to the RF feeding electrode 3, and the RF power loaded to the RF feeding electrode 3 is coupled to the middle of the wafer 100 carried by the carrier component 1 through the RF feeding electrode 3 to generate a bias voltage, and the lower RF source 91 also loads RF power to the annular electrode 4, and the RF power loaded to the annular electrode 4 is coupled to the upper part of the focusing ring body 2 through the annular electrode 4 to generate a bias voltage, so that the electric potential above the edge of the wafer 100 can be equal to the electric potential above the middle of the wafer 100, and then the electric potential line above the edge of the wafer 100 can be equal to the electric potential line above the wafer 100 0 are all parallel to the surface of the wafer 100, thereby making the electric field lines above the edge of the wafer 100 and the electric field lines above the middle of the wafer 100 both perpendicular to the surface of the wafer 100, thereby making the direction in which the plasma bombards the edge of the wafer 100 and the direction in which the plasma bombards the middle of the wafer 100 both perpendicular to the surface of the wafer 100, that is, the plasma can bombard the edge of the wafer 100 and the middle of the wafer 100 in a direction perpendicular to the surface of the wafer 100, and since the electric potential above the edge of the wafer 100 is equal to the electric potential above the middle of the wafer 100, the rate at which the plasma bombards the edge of the wafer 100 is equal to the rate at which the plasma bombards the middle of the wafer 100.

[0043] In an embodiment of the present invention, a side of the accommodating groove facing the bottom surface of the focus ring body 2 and a side of the accommodating groove facing the inner edge of the focus ring body 2 may both be openings.

[0044] In practical applications, when assembling the annular electrode 4, the annular electrode 4 can be directly placed into the receiving groove from the bottom or inner side of the focus ring body 2, and when the annular electrode 4 is received and arranged in the receiving groove, the bottom surface and the inner edge of the annular electrode 4 will not be covered by the focus ring body 2. Such a design can facilitate the opening of the receiving groove, thereby facilitating the processing of the focus ring body 2, and can facilitate the disassembly and assembly of the focus ring body 2 and the annular electrode 4, thereby facilitating the replacement of the focus ring body 2 or the annular electrode 4.

[0045] like Figure 4 and Figure 5 As shown, in one embodiment of the utility model, the inner edge of the ring electrode 4 can be flush with the inner edge of the focusing ring body 2, and / or, the bottom surface of the ring electrode 4 can be flush with the bottom surface of the focusing ring body 2, and / or, the outer diameter of the ring electrode 4 can be smaller than the outer diameter of the focusing ring body.

[0046] Optionally, the radial dimension of the radial cross section of the accommodating groove may be equal to the radial dimension of the radial cross section of the annular electrode 4, so that the inner edge of the annular electrode 4 can be flush with the inner edge of the focus ring body 2. Optionally, the groove depth of the accommodating groove may be equal to the thickness of the annular electrode 4, so that the bottom surface of the annular electrode 4 can be flush with the bottom surface of the focus ring body 2. Optionally, the difference between the outer diameter of the focus ring body 2 and the outer diameter of the annular electrode 4 may be less than 10 mm.

[0047] like Figure 4 and Figure 5 As shown, optionally, part of the focus ring body 2 can be located below the edge of the wafer 100 carried by the carrying component 1 , and part of it can surround the edge of the wafer 100 carried by the carrying component 1 .

[0048] By enabling a portion of the focusing ring body 2 to be located below the edge of the wafer 100 supported by the supporting component 1, a portion of the annular electrode 4 can be located below the edge of the wafer 100 supported by the supporting component 1, thereby being more conducive to controlling the electric potential above the edge of the wafer 100 supported by the supporting component 1.

[0049] like Figure 4 and Figure 5 As shown, an embodiment of the utility model further provides a lower electrode structure, including a carrying component 1 and a focusing ring assembly as provided in the embodiment of the utility model, the carrying component 1 is used to carry the wafer 100, the focusing ring assembly is arranged on the carrying component 1, and is arranged around the carrying surface of the carrying component 1 for carrying the wafer 100.

[0050] The lower electrode structure provided by the embodiment of the utility model can make the direction and speed of plasma bombarding the edge of the wafer 100 the same as the direction and speed of plasma bombarding the middle of the wafer 100 by setting the focusing ring assembly provided by the embodiment of the utility model on the supporting component 1, thereby improving the etching uniformity of the wafer 100.

[0051] like Figure 4 and Figure 5 As shown, in one embodiment of the present invention, the lower electrode structure may further include a variable impedance component 5 , and the annular electrode 4 is electrically connected to the lower RF source 91 via the variable impedance component 5 .

[0052] Such a design is because as the semiconductor process proceeds, the thickness of the focus ring body 2 will gradually decrease (i.e., gradually become thinner) due to the etching of plasma, resulting in a change in the electric potential above the edge of the wafer 100, thereby causing the electric potential above the edge of the wafer 100 to be unequal to the electric potential above the middle of the wafer 100. In one embodiment of the utility model, by electrically connecting the annular electrode 4 to the lower RF source 91 through the variable impedance component 5, the lower RF source 91 can load RF power to the annular electrode 4 through the variable impedance component 5, so that no matter after assembling a new focus ring body 2 or when the focus ring body 2 is thinned due to plasma etching, the impedance of the variable impedance component 5 can be changed to change the electric potential coupled to the top of the focus ring body 2 through the annular electrode 4, thereby changing the electric potential above the edge of the wafer 100, so that the electric potential above the edge of the wafer 100 and the electric potential above the middle of the wafer 100 can always be equal.

[0053] In practical applications, the portion of the focusing ring body 2 located above the annular electrode 4 can be regarded as a capacitor, and its capacitance is C = (ε0ε r S) / d, its impedance is Z = 1 / (jωC), where ε0 is the dielectric constant of vacuum, ε r is the relative dielectric constant of the focusing ring body 2, S is the area of ​​the positive projection of the focusing ring body 2 on the annular electrode 4, d is the thickness of the portion of the focusing ring body 2 located above the annular electrode 4, j is an imaginary unit, and ω is the angular frequency.

[0054] After assembling a new focus ring body 2, the potential coupled to the focus ring body 2 by the annular electrode 4 can be reduced by increasing the impedance of the variable impedance component 5, or the potential coupled to the focus ring body 2 by the annular electrode 4 can be increased by reducing the impedance of the variable impedance component 5, so that the potential above the edge of the wafer 100 is equal to the potential above the middle of the wafer 100. As the semiconductor process proceeds, the thickness of the focus ring body 2 gradually decreases due to plasma etching. As the thickness d of the focus ring body 2 decreases, the capacitance C of the portion of the focus ring body 2 located above the annular electrode 4 increases and the impedance decreases, which causes the potential above the focus ring body 2 to increase, causing the potential line above the edge of the wafer 100 to bend in a direction away from the surface of the wafer 100, that is, the potential line above the middle of the wafer 100 is parallel to the surface of the wafer 100, while the potential line above the edge of the wafer 100 is tilted relative to the potential line above the middle of the wafer 100. Therefore, as the semiconductor process proceeds and the thickness of the focusing ring body 2 gradually decreases due to plasma etching, the impedance of the variable impedance component 5 can be increased to reduce the electric potential coupled to the focusing ring body 2 by the annular electrode 4, so that the electric potential above the edge of the wafer 100 is kept equal to the electric potential above the middle of the wafer 100, so that the potential lines above the edge of the wafer 100 and the potential lines above the middle of the wafer 100 can be kept parallel to the surface of the wafer 100, and then the electric field lines above the edge of the wafer 100 and the electric field lines above the middle of the wafer 100 can be kept perpendicular to the surface of the wafer 100, and then the direction of plasma bombarding the edge of the wafer 100 and the direction of plasma bombarding the middle of the wafer 100 can be kept perpendicular to the surface of the wafer 100, and the rate of plasma bombarding the edge of the wafer 100 and the rate of plasma bombarding the middle of the wafer 100 can be kept equal.

[0055] Optionally, the material of the RF feeding electrode 3 may be a metallic conductive material.

[0056] Optionally, the material of the ring electrode 4 may be a metallic conductive material.

[0057] Optionally, the bearing component 1 may include an electrostatic chuck.

[0058] In one embodiment of the utility model, the variable impedance component 5 may include a variable impedance component and a control component, the variable impedance component is electrically connected to the lower RF source 91 and the annular electrode 4 respectively, and the control component is signal-connected to the variable impedance component for controllably changing the impedance value of the variable impedance component.

[0059] In practical applications, by controlling the impedance value of the variable impedance component to increase through the control component, the impedance value of the variable impedance component 5 can be controlled to increase, and by controlling the impedance value of the variable impedance component to decrease, the impedance value of the variable impedance component 5 can be controlled to decrease.

[0060] like Figure 6 As shown, optionally, the impedance variable component has an input end 51 and an output end 52, the input end 51 is used to be electrically connected to the lower RF source 91, and the output end 52 is electrically connected to the annular electrode 4, and the RF power provided by the lower RF source 91 is input to the impedance variable component through the input end 51, and after passing through the impedance variable component, it is output to the annular electrode 4 through the output end 52.

[0061] like Figure 6 As shown, in one embodiment of the utility model, the variable impedance component may include a plurality of fixed impedance elements 53, the plurality of fixed impedance elements 53 are connected in parallel, and the control component is respectively connected to a plurality of parallel branches formed by the plurality of fixed impedance elements 53 in parallel, and is used to control the number of fixed impedance elements 53 electrically connected to the lower RF source 91 and the annular electrode 4 respectively by respectively controlling the on and off of the plurality of parallel branches.

[0062] In actual applications, when the control component controls a parallel branch to be connected, the fixed impedance element 53 on the parallel branch is electrically connected to the lower RF source 91 and the annular electrode 4 respectively. When the control component controls a parallel branch to be disconnected, the fixed impedance element 53 on the parallel branch is not electrically connected to the lower RF source 91 and the annular electrode 4. By controlling different numbers of parallel branches to be connected, different numbers of fixed impedance elements 53 can be electrically connected in parallel to the lower RF source 91 and the annular electrode 4 respectively, thereby controlling the impedance value change of the impedance variable component.

[0063] In an embodiment of the present invention, the impedance values ​​of the plurality of fixed impedance elements 53 may be binary increasing, and / or the plurality of fixed impedance elements 53 may all be fixed capacitors, and the minimum capacitance of the plurality of fixed impedance elements 53 may be 1 pF.

[0064] For example, the number of fixed impedance elements 53 can be six, and the six fixed impedance elements 53 can all be fixed capacitors. The capacitance values ​​of the six fixed impedance elements 53 can be 1pF, 2pF, 4pF, 8pF, 16pF, and 32pF, respectively. At this time, the impedance values ​​of the six fixed impedance elements 53 are binary increasing, and the minimum capacitance value of the six fixed impedance elements 53 is 1pF. In this case, when the capacitance of the variable impedance component needs to be adjusted to 49pF, the parallel branch where the fixed impedance element 53 with a capacitance of 1pF is located can be connected, the parallel branch where the fixed impedance element 53 with a capacitance of 16pF is located can be connected, and the parallel branch where the fixed impedance element 53 with a capacitance of 32pF is located can be connected, while the remaining parallel branches are disconnected. At this time, the number of fixed impedance elements 53 electrically connected to the lower RF source 91 and the annular electrode 4 is three, namely, the fixed impedance element 53 with a capacitance of 1pF, the fixed impedance element 53 with a capacitance of 16pF, and the fixed impedance element 53 with a capacitance of 32pF, while the remaining fixed impedance elements 53 are not electrically connected to the lower RF source 91 and the annular electrode 4. The capacitance of these three fixed impedance elements 53 after parallel connection is 49pF, that is, the capacitance of the variable impedance component connected between the lower RF source 91 and the annular electrode 4 is 49pF. By making the impedance values ​​of the multiple fixed impedance elements 53 binary-incremental and making the minimum capacitance of the multiple fixed impedance elements 53 1pF, the capacitance can be continuously adjusted with a step size of 1pF by controlling the on and off of one or more parallel branches, thereby improving the adjustment accuracy of the variable impedance component.

[0065] Optionally, the fixed capacitor may include a chip capacitor.

[0066] Optionally, the chip capacitor may be a ceramic chip capacitor.

[0067] Optionally, a fixed impedance element 53 may be provided on each parallel branch.

[0068] Optionally, the multiple fixed impedance elements 53 may all be fixed inductors or fixed resistors.

[0069] like Figure 6 and Figure 7 As shown, in one embodiment of the utility model, the control component may include a fiber optic control module 54, a plurality of on-off devices 55 and a plurality of fiber optic signal lines 56, the plurality of on-off devices 55 are connected one-to-one with the plurality of parallel branches, the plurality of fiber optic signal lines 56 are connected one-to-one with the plurality of on-off devices 55, and the fiber optic control module 54 is signal-connected to the plurality of fiber optic signal lines 56, respectively, for sending control signals to the plurality of on-off devices 55 one-to-one through the plurality of fiber optic signal lines 56, so as to control the on and off of the plurality of parallel branches one-to-one through the plurality of on-off devices 55.

[0070] For example, the on-off device 55 may optionally include a reed relay. The reed relay is low level effective, that is, when the optical fiber control module 54 sends a low level (0V) control signal to the corresponding on-off device 55 through the optical fiber signal line 56, the reed relay can control the corresponding parallel branch to be connected, and when the optical fiber control module 54 sends a high level (24V) control signal to the corresponding on-off device 55 through the optical fiber signal line 56, the reed relay can control the corresponding parallel branch to be disconnected.

[0071] Compared with traditional cables, optical fiber signal lines 56 have higher stability in radio frequency environments, natural isolation and anti-electromagnetic interference capabilities, higher transmission bandwidth, and lower signal-to-noise ratio. Therefore, transmitting control signals via optical fiber signal lines 56 can make circuit control more efficient and precise.

[0072] Since the parasitic capacitance of the reed relay is relatively small (usually less than 10 pF), the influence of the on-off device 55 on the adjustment accuracy of the variable impedance component can be reduced, thereby improving the adjustment accuracy of the variable impedance component.

[0073] Optionally, the variable impedance component 5 may further include a substrate, and the variable impedance component and the control component may both be disposed on the substrate.

[0074] Optionally, the substrate may be a printed circuit board (PCB).

[0075] Optionally, the variable impedance component 5 may further include a voltage boosting component. This is because the high-level signal sent by the optical fiber control module 54 may be 5V, and the voltage boosting component can boost the 5V high-level signal to a 24V high-level signal to act on the reed relay, so that the reed relay can control the corresponding parallel branch to disconnect.

[0076] In actual applications, the control signals sent by the optical fiber control module 54 to each on-off device 55 can be manually written into a signal table in advance. The independent variable of the signal table can be the total etching time, and the dependent variable can be the high-level signal or low-level signal of the optical fiber control module 54 received by each on-off device 55.

[0077] like Figure 4 and Figure 5 As shown, in one embodiment of the present invention, the lower electrode structure may further include a radio frequency feeding electrode 3 , which is disposed inside the supporting component 1 and can be electrically connected to the lower radio frequency source 91 .

[0078] In practical applications, the lower RF source 91 can load RF power to the RF feeding electrode 3 , and the RF power loaded to the RF feeding electrode 3 can be coupled to the middle of the wafer 100 supported by the supporting component 1 through the RF feeding electrode 3 to generate a bias voltage.

[0079] like Figure 4 and Figure 5 As shown, in one embodiment of the present invention, the variable impedance component 5 can be electrically connected to the lower RF source 91 through the RF feeding electrode 3 .

[0080] In practical applications, the lower RF provided by the lower RF source 91 can be first loaded to the RF feeding electrode 3, then loaded to the variable impedance component 5 through the RF feeding electrode 3, and then loaded to the annular electrode 4 through the variable impedance component 5. Such a design can make the lower RF source 91 not need to be electrically connected to the variable impedance component 5 through a separate circuit, and the variable impedance component 5 and the RF feeding electrode 3 can be both arranged inside the bearing component 1, which can facilitate the electrical connection between the variable impedance component 5 and the lower RF source 91. Moreover, such a design can make the lower RF source 91 electrically connected to the RF feeding electrode 3 and the lower RF source 91 electrically connected to the annular electrode 4 the same lower RF source, so there is no need to set up a separate lower RF source 91 to be electrically connected to the annular electrode 4, thereby avoiding the lower RF phase difference caused by different lower RF sources 91 and reducing costs.

[0081] like Figure 5 As shown, in one embodiment of the present invention, the RF feeding electrode 3 may be provided with a connecting protrusion 31 , and the variable impedance component 5 may be electrically connected to the RF feeding electrode 3 via the connecting protrusion 31 .

[0082] Optionally, the connecting protrusion 31 may be provided with a threaded hole, and the substrate of the variable impedance component 5 may be provided with a through hole. By passing a bolt through the through hole of the substrate and threadably engaging with the threaded hole of the connecting protrusion 31, the connecting protrusion 31 can be electrically connected to the variable impedance component 5, thereby electrically connecting the variable impedance component 5 to the RF feeding electrode 3 through the connecting protrusion 31.

[0083] Optionally, the connection protrusion 31 may be electrically connected to the input end 51 of the variable impedance component, so that the variable impedance component 5 is electrically connected to the RF feeding electrode 3 through the connection protrusion 31 .

[0084] Optionally, the connecting protrusion 31 may be made of a metallic conductive material.

[0085] like Figure 5 and Figure 8As shown, in one embodiment of the utility model, the lower electrode structure may also include an electrical connection component, and the variable impedance component 5 may be electrically connected to the annular electrode 4 through the electrical connection component; the electrical connection component may include a first electrical connector 61, a converter 62 and a second electrical connector 63, the first electrical connector 61 is electrically connected to the variable impedance component 5, the second electrical connector 63 is electrically connected to the annular electrode 4, and the first electrical connector 61 is electrically connected to the second electrical connector 63 through the converter 62.

[0086] That is to say, the lower radio frequency loaded to the variable impedance component 5 can be loaded to the annular electrode 4 through the electrical connection component. Specifically, the lower radio frequency loaded to the variable impedance component 5 can be loaded to the annular electrode 4 through the first electrical connector 61, the adapter 62 and the second electrical connector 63 in sequence.

[0087] Optionally, the output end 52 of the variable impedance component may be electrically connected to the first electrical connector 61 via a wire 65 , so as to achieve electrical connection between the first electrical connector 61 and the variable impedance component 5 .

[0088] like Figure 8 As shown, optionally, the first electrical connector 61 may include a first cluster plug, the second electrical connector 63 may include a second cluster plug and a feeding column, the wire 65 may be electrically connected to the adapter 62 through the first cluster plug, the feeding column may be electrically connected to the ring electrode 4, and may be electrically connected to the adapter 62 through the second cluster plug.

[0089] Optionally, the material of the feed column may include at least one of stainless steel and aluminum, because stainless steel and aluminum have good electrical conductivity.

[0090] Optionally, the surface of the feed column may have an anti-corrosion layer, which can prevent active particles in the plasma from corroding the feed column.

[0091] Optionally, the material of the anti-corrosion layer may include at least one of nickel, gold and silver. In practical applications, the anti-corrosion layer may be formed by nickel plating or silver plating and then gold plating the surface of the feed column.

[0092] like Figure 4 and Figure 5 As shown, in one embodiment of the utility model, the lower electrode structure may also include a base ring 71 and an insulating ring 72, and the insulating ring 72, the base ring 71 and the focusing ring assembly are stacked in sequence on the supporting component 1, and the first electrical connector 61, the adapter 62 and the second electrical connector 63 are respectively arranged inside the base ring 71 and the insulating ring 72.

[0093] That is, the insulating ring 72 is arranged on the bearing component 1, the base ring 71 is arranged on the insulating ring 72, and the focusing ring assembly is arranged on the base ring 71. Figure 5As shown, optionally, the first electrical connector 61 can be disposed inside the insulating ring 72 , the adapter 62 can be disposed inside the insulating ring 72 , a portion of the second electrical connector 63 can be disposed inside the insulating ring 72 , and another portion can be disposed inside the base ring 71 .

[0094] like Figure 8 As shown, in one embodiment of the utility model, the electrical connection assembly may also include a seal 64. The seal 64 may be arranged on a side of the adapter 62 that is electrically connected to the first electrical connector 61, and / or the seal 64 may be arranged on a side of the adapter 62 that is electrically connected to the second electrical connector 63. The seal 64 is used to seal the gap between the adapter 62 and the insulating ring 72 and / or the base ring 71.

[0095] Such a design is due to the fact that the first electrical connector 61, the adapter 62, and the second electrical connector 63 are respectively arranged inside the base ring 71 and the insulating ring 72, therefore, it is necessary to open an assembly space inside the base ring 71 and the insulating ring 72 for assembling the first electrical connector 61, the adapter 62, and the second electrical connector 63. One side of the adapter 62 is electrically connected to the first electrical connector 61, and the first connector is electrically connected to the variable impedance component 5 inside the bearing component 1, and the inside of the bearing component 1 corresponds to the atmospheric environment in the process chamber 8 of the semiconductor device, while the other side of the adapter 62 is electrically connected to the second electrical connector 63, and the second connector is electrically connected to the annular electrode 4 at the bottom of the focusing ring body 2, and the bottom of the focusing ring body 2 corresponds to the vacuum environment in the process chamber 8 of the semiconductor device. In other words, the two sides of the adapter 62 are the transition between the atmospheric environment and the vacuum environment in the process chamber 8 of the semiconductor device. Therefore, by sealing the gap between the adapter 62 and the insulating ring 72 and / or the base ring 71 with the help of the seal 64, the connection between the atmospheric environment and the vacuum environment can be avoided, so that the semiconductor process can be carried out stably.

[0096] The embodiment of the present invention further provides a semiconductor device, including a process chamber 8 and a lower electrode structure provided in the embodiment of the present invention, wherein the lower electrode structure is arranged at the bottom of the process chamber 8 .

[0097] like Figure 5 As shown, the semiconductor device provided by the embodiment of the utility model sets the lower electrode structure provided by the embodiment of the utility model at the bottom of the process chamber 8, so that the direction and speed of plasma bombarding the edge of the wafer 100 are the same as the direction and speed of plasma bombarding the middle of the wafer 100, thereby improving the etching uniformity of the wafer 100.

[0098] like Figure 5As shown, optionally, the semiconductor device may further include a lower RF source 91 and a lower matching component 92 , both of which are arranged outside the bottom of the process chamber 8 , and the lower RF source 91 is electrically connected to the RF feeding electrode 3 through the lower matching component 92 .

[0099] like Figure 5 As shown, optionally, the semiconductor device may further include an upper electrode coil 93, an upper RF source 94 and an upper matching component 95. The upper electrode coil 93 may be arranged outside the top of the process chamber 8, and the upper RF source 94 is electrically connected to the upper electrode coil 93 through the upper matching component 95. In practical applications, the upper RF source 94 loads RF power to the upper electrode coil 93 to generate an alternating electromagnetic field through the energy in the upper electrode coil 93, so that the gas in the process chamber 8 forms plasma.

[0100] In summary, the focusing ring assembly, lower electrode structure and semiconductor equipment provided by the embodiments of the present invention can make the direction and speed of plasma bombarding the edge of the wafer 100 the same as the direction and speed of plasma bombarding the middle of the wafer 100, thereby improving the etching uniformity of the wafer 100.

[0101] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A focusing ring assembly, characterized in that: include: A focusing ring body, which can be arranged on a bearing component for bearing a wafer, and can be arranged around a bearing surface of the bearing component for bearing the wafer, and a ring-shaped receiving groove is arranged at the bottom of the focusing ring body; The annular electrode is accommodated in the accommodating groove and can be electrically connected to a lower radio frequency source for providing a lower radio frequency.

2. The focusing ring assembly according to claim 1, characterized in that: The side of the accommodating groove facing the bottom surface of the focusing ring body and the side of the accommodating groove facing the inner edge of the focusing ring body are both openings.

3. The focusing ring assembly according to claim 2, characterized in that: The inner edge of the annular electrode is flush with the inner edge of the focusing ring body, and / or the bottom surface of the annular electrode is flush with the bottom surface of the focusing ring body, and / or the outer diameter of the annular electrode is smaller than the outer diameter of the focusing ring body.

4. A lower electrode structure, characterized in that: It comprises a carrying component and a focusing ring assembly as described in any one of claims 1 to 3, wherein the carrying component is used to carry a wafer, and the focusing ring assembly is arranged on the carrying component and surrounds a carrying surface of the carrying component for carrying the wafer.

5. The lower electrode structure according to claim 4, characterized in that: The lower electrode structure further includes a variable impedance component, and the annular electrode is electrically connected to the lower radio frequency source via the variable impedance component.

6. The lower electrode structure according to claim 5, characterized in that: The variable impedance component includes a variable impedance component and a control component. The variable impedance component is electrically connected to the lower RF source and the annular electrode respectively. The control component is signal-connected to the variable impedance component for controllably changing the impedance value of the variable impedance component.

7. The lower electrode structure according to claim 6, characterized in that: The variable impedance component includes a plurality of fixed impedance elements, and the plurality of fixed impedance elements are connected in parallel. The control component is respectively connected to a plurality of parallel branches formed by the plurality of fixed impedance elements in parallel, and is used to control the number of the fixed impedance elements electrically connected to the lower RF source and the annular electrode respectively by respectively controlling the on and off of the plurality of parallel branches.

8. The lower electrode structure according to claim 7, characterized in that: The control component includes a fiber optic control module, multiple on-off devices and multiple fiber optic signal lines. The multiple on-off devices are connected to the multiple parallel branches in a one-to-one correspondence, and the multiple fiber optic signal lines are connected to the multiple on-off devices in a one-to-one correspondence. The fiber optic control module is signal-connected to the multiple fiber optic signal lines respectively, and is used to send control signals to the multiple on-off devices in a one-to-one correspondence through the multiple fiber optic signal lines, so as to control the on and off of the multiple parallel branches in a one-to-one correspondence through the multiple on-off devices.

9. The lower electrode structure according to claim 7, characterized in that: The impedance values ​​of the plurality of fixed impedance elements are binary increasing, and / or the fixed impedance elements are all fixed capacitors, and the minimum capacitance of the plurality of fixed impedance elements is 1 pF.

10. The lower electrode structure according to claim 5, characterized in that: The lower electrode structure further includes a radio frequency feeding electrode, which is disposed inside the supporting component and can be electrically connected to the lower radio frequency source.

11. The lower electrode structure according to claim 10, characterized in that: The variable impedance component is electrically connected to the lower RF source through the RF feeding electrode.

12. The lower electrode structure according to claim 11, characterized in that: The RF feeding electrode is provided with a connecting protrusion, and the variable impedance component is electrically connected to the RF feeding electrode through the connecting protrusion.

13. The lower electrode structure according to any one of claims 5 to 12, characterized in that: The lower electrode structure further comprises an electrical connection component, and the variable impedance component is electrically connected to the annular electrode via the electrical connection component; The electrical connection component includes a first electrical connection member, an adapter and a second electrical connection member, the first electrical connection member is electrically connected to the variable impedance component, the second electrical connection member is electrically connected to the ring electrode, and the first electrical connection member is electrically connected to the second electrical connection member through the adapter.

14. The lower electrode structure according to claim 13, characterized in that: The lower electrode structure also includes a base ring and an insulating ring. The insulating ring, the base ring and the focusing ring assembly are stacked in sequence on the supporting component, and the first electrical connector, the adapter and the second electrical connector are respectively arranged inside the base ring and the insulating ring.

15. The lower electrode structure according to claim 14, characterized in that: The electrical connection assembly also includes a seal, which is arranged on a side of the adapter that is electrically connected to the first electrical connector, and / or the seal is arranged on a side of the adapter that is electrically connected to the second electrical connector, and the seal is used to seal the gap between the adapter and the insulating ring and / or the base ring.

16. A semiconductor device, characterized in that: It comprises a process chamber and a lower electrode structure as described in any one of claims 4 to 15, wherein the lower electrode structure is arranged at the bottom of the process chamber.

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