Plasma processing apparatus

Abstract

The invention provides a plasma processing apparatus, which can stabilize plasma by using a plurality of antennas and perform required plasma processing on a processed object in a processing chamber. A plasma processing apparatus (1) is provided with: a housing (2); a plurality of antennas (7) for generating a magnetic field for generating plasma inside the housing (2); at least two power sources (8) for supplying, to each of the plurality of antennas (7), a high-frequency current for generating a magnetic field; and a control unit (C). A power supply (8) supplies a high-frequency current for generating plasma during a first period of a required duty ratio in a period so as to intermittently generate plasma at a required period. The control unit (C) individually controls the duty ratios of the at least two power sources (8).

Description

Technical Field

[0001] The present disclosure relates to a plasma processing apparatus. Background Art

[0002] A plasma processing apparatus is known that generates inductively coupled plasma in a vacuum chamber using an antenna disposed therein. Depending on the type of plasma processing apparatus, the plasma processing apparatus performs a predetermined plasma treatment on an object to be processed using the generated plasma.

[0003] Furthermore, among plasma processing apparatuses, there is known an apparatus that provides a plurality of antennas in a vacuum chamber to perform plasma processing on an object to be processed.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-69653 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In a plasma processing apparatus, there is room for improvement in terms of performing desired plasma processing on an object to be processed within a processing chamber while stabilizing plasma using a plurality of antennas.

[0009] The present disclosure has been made in view of the above-mentioned problems, and an object thereof is to provide a plasma processing apparatus that can perform desired plasma processing on an object to be processed inside a processing chamber while stabilizing plasma using a plurality of antennas.

[0010] Technical means to solve the problem

[0011] In order to solve the above-mentioned problem, a plasma processing device according to one aspect of the present disclosure includes: a processing chamber; a plurality of antennas for generating a magnetic field for generating plasma inside the processing chamber; at least two power supplies for supplying a high-frequency current for generating the magnetic field to the plurality of antennas; and a control unit, wherein the power supply supplies the high-frequency current for generating the plasma during a first period of a required duty cycle in a cycle so as to intermittently generate the plasma according to the required cycle, and the control unit individually controls the duty cycles of the at least two power supplies.

[0012] Effects of the Invention

[0013] According to one embodiment of the present disclosure, a plasma processing apparatus can be provided that can perform desired plasma processing on an object to be processed inside a processing chamber while stabilizing plasma using a plurality of antennas. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] [ Figure 1 ] is a diagram illustrating the structure of the plasma processing device according to embodiment 1 of the present disclosure.

[0015] [ Figure 2 ]yes Figure 1 Cross-sectional view along line II-II.

[0016] [ Figure 3 ] is a diagram showing the main structure of the plasma processing device.

[0017] [ Figure 4 ] means Figure 1 Detailed operation example of the power supply shown in FIG.

[0018] [ Figure 5 ] is a graph showing a specific example of the change in the luminous intensity ratio when the duty cycle is changed in the plasma processing apparatus.

[0019] [ Figure 6 ] is a graph showing a specific example of the change in film formation speed when the duty cycle is changed in the plasma processing apparatus.

[0020] [ Figure 7 ] is a diagram illustrating the main structure of the plasma processing device of embodiment 2 of the present disclosure.

[0021] [ Figure 8 ] is right Figure 7 FIG. 1 is a graph showing an example of a specific relationship between the surface temperature and the film deposition rate when the duty ratio is changed in the plasma processing apparatus shown.

[0022] [ Figure 9 ] is correct Figure 7 1 and 2 are diagrams for explaining the main structure of a modified example of the plasma processing apparatus shown in FIG. DETAILED DESCRIPTION

[0023] [Implementation Method 1]

[0024] Below, use Figures 1 to 4 Embodiment 1 of the present disclosure will be described in detail. Figure 1 This is a diagram illustrating the structure of the plasma processing apparatus 1 according to the first embodiment of the present disclosure. Figure 2 yes Figure 1 Cross-sectional view along line II-II. Figure 3 1 is a diagram showing a main structure of the plasma processing apparatus 1 . Figure 4 Yes Figure 1 8 is a diagram showing a specific operation example of the power supply 8 shown in FIG.

[0025] In addition, in the following description, a plasma processing device 1 is used as an example for explanation. The plasma processing device 1 performs a film forming process as a predetermined plasma process. The film forming process forms a predetermined film on the surface of a processed sample W as a processed object by a plasma CVD (Chemical Vapor Deposition) method using an inductively coupled plasma.

[0026] However, the present disclosure can be applied to a plasma processing apparatus that performs, for example, a film-forming process for forming a predetermined film on a sample W to be processed by sputtering as the predetermined plasma processing. Furthermore, the present disclosure can be applied to a plasma processing apparatus that performs, as the predetermined plasma processing, a surface processing process for performing predetermined processing on the surface of the sample W to be processed using plasma, such as an etching process or an ashing process. Furthermore, in a plasma processing apparatus that performs sputtering, a target material is disposed, for example, within a plasma generation region HA described later.

[0027] <Structure of Plasma Processing Apparatus 1>

[0028] like Figure 1 As shown, the plasma processing apparatus 1 of the first embodiment includes a housing 2, a flange 3, a vacuum cover 4, an antenna cover 5, and a stage 6. Furthermore, the plasma processing apparatus 1 includes an antenna 7, a control unit C, a stage drive unit SD, and a plasma emission monitor PD. Furthermore, in the plasma processing apparatus 1, a sample W to be processed is transported between the stage 6 and a known load lock chamber by a transport mechanism (not shown).

[0029] like Figure 2 and Figure 3 As shown, a plurality of, for example, three antennas 71, 72, and 73 (collectively referred to as "7") are provided in the plasma processing apparatus 1, and a vacuum cover 4 and an antenna cover 5 are provided for each antenna 7. These antennas 7 are arranged such that two adjacent antennas 7 are equally spaced from each other, for example, along Figure 2 and Figure 3 The shown arrangement direction is MH.

[0030] The sample W to be processed can be, for example, a glass substrate or a synthetic resin substrate used in liquid crystal panel displays or organic electroluminescence (EL) panel displays. Alternatively, the sample W to be processed can be a semiconductor substrate used for various applications. The plasma processing apparatus 1 forms a predetermined film, such as a barrier (moisture-proof) film, on the sample W to be processed through the predetermined plasma treatment, and also etches or modifies at least a portion of the surface or coating. Furthermore, in addition to the sample W to be processed, three-dimensional, relatively complex-shaped structures such as bolts or metal parts, such as fixtures, can also be used as the processed object.

[0031] <Case 2>

[0032] The housing 2 includes a housing body 2a, which forms a processing chamber for performing the prescribed plasma treatment on the sample W. A first opening 2b is provided at the top of the housing body 2a, connecting the interior of the processing chamber with the exterior. A flange 3 having a plurality of openings is airtightly attached to the top surface of the housing 2 (housing body 2a).

[0033] In plasma processing apparatus 1, when flange 3 is attached to housing body 2a, the opening of flange 3 is contained within first opening 2b, which connects the interior of the processing chamber to the exterior. In other words, when flange 3 and vacuum cover 4 are attached to the upper surface of housing 2, first opening 2b is blocked by flange 3 and vacuum cover 4.

[0034] Furthermore, the housing 2 includes a processing gas supply unit (not shown) corresponding to the predetermined plasma processing, and the plasma processing is performed under a processing gas atmosphere. The processing gas supply unit introduces a processing gas including a film-forming gas for the film into the plasma generation area HA (processing chamber) of the housing 2. The processing gas is, for example, argon, hydrogen, nitrogen, silane, or oxygen.

[0035] Furthermore, a temperature sensor (not shown) for detecting the temperature of the stage 6 is provided in the housing 2 , and the detection result of the temperature sensor is output to the control unit C. The control unit C then controls the stage 6 to a predetermined set temperature during the plasma processing by performing feedback control using the input detection result of the temperature sensor.

[0036] In addition, if Figure 1As shown, the housing 2 is provided with a stage drive unit SD for driving the stage 6. The stage drive unit SD includes a drive mechanism such as a motor (not shown), and is configured to perform predetermined driving operations on the stage 6 in accordance with instructions from the control unit C. Specifically, the stage drive unit SD causes the stage 6, with the sample W to be processed placed thereon, to swing, rotate, or raise or lower the stage 6 within the housing 2.

[0037] <Flange 3>

[0038] like Figure 2 As shown, the flange 3 includes, for example, a rectangular frame having two first sides 3a facing each other, and two second sides 3b ( Figure 1 The flange 3 may include, for example, a third side portion 3c and a fourth side portion 3d extending from one second side portion 3b to the other second side portion 3b on the inner side of the frame. In other words, the third side portion 3c and the fourth side portion 3d may be formed so as to be continuous with the second side portion 3b at both ends. The third side portion 3c and the fourth side portion 3d may be formed between the two first side portions 3a so as to be parallel to the first side portions 3a.

[0039] In addition, the first side 3a, the second side 3b, the third side 3c, and the fourth side 3d may respectively have a protrusion described later that protrudes toward the first opening 2b side. In addition, in the following description, the first side 3a, the second side 3b, the third side 3c, and the fourth side 3d are collectively referred to as side 3h.

[0040] <Vacuum cover 4>

[0041] In the plasma processing apparatus 1, the vacuum cover 4 that closes the first opening 2b is detachably mounted on the first opening 2b. Specifically, the vacuum cover 4 is airtightly mounted on the flange 3 to close the first opening 2b and is reversibly mounted to be detachable from the flange 3.

[0042] Here, the flange 3 may include a protrusion formed to gradually reduce the opening area of the first opening 2b in the direction from the outside of the processing chamber toward the inside of the processing chamber. For example, the first side 3a, the third side 3c, and the fourth side 3d may each include a first support portion protruding inside the first opening 2b to engage the peripheral edge of the vacuum cover 4. The first support portion may be a portion of the protrusion.

[0043] The vacuum cover 4 is an example of an outer cover and is supported by the upper surface of the second side 3b and the upper surfaces of the first supporting portions of the first side 3a, the third side 3c, and the fourth side 3d.

[0044] <Radome 5>

[0045] In addition, in the plasma processing apparatus 1, the antenna cover 5 is supported inside the first opening 2b in a manner that is detachable relative to the flange 3. Specifically, Figure 1 and Figure 2 As shown, the antenna cover 5 includes, for example, an antenna housing portion 5a having a U-shaped cross section. Furthermore, the antenna cover 5 includes a cover support portion 5b and a cover opening 5c. The cover support portion 5b is formed continuously from both ends of the U-shaped cross-section antenna housing portion 5a and is formed as a flange extending outward from the ends of the antenna housing portion 5a. In other words, the cover support portion 5b has an outwardly directed flange shape.

[0046] Here, for example, the edge 3h of the flange 3 may include a second support portion protruding from within the first opening 2b to engage the peripheral edge of the radome 5. This second support portion is a portion of the protruding portion, and protrudes further into the first opening 2b than the first support portion (protruding longer). When the radome 5 is supported within the first opening 2b, the radome support portion 5b is supported by (the second support portion of) the edge 3h of the flange 3. Furthermore, the radome 5 includes a radome opening 5c formed by the antenna housing 5a.

[0047] The antenna cover 5 is formed of a dielectric material such as alumina and serves as a dielectric inner cover. Furthermore, the antenna cover 5 includes an antenna housing portion 5a formed to correspond to the shape of the antenna 7. The antenna housing portion 5a is shaped so as to partially cover the outer circumference of the antenna 7 when the antenna 7 is mounted.

[0048] In addition, the radome 5 has a radome support portion 5b detachably supported by the edge portion 3h of the flange 3. Furthermore, the radome 5 has a radome opening 5c provided so as to open toward the vacuum cover 4. This radome opening 5c is an example of a second opening that constitutes a portion of the antenna accommodation space AK, described later.

[0049] Furthermore, the housing 2 includes an antenna housing space AK enclosed by at least a vacuum cover 4 and a radome 5. In the plasma processing apparatus 1 of this embodiment, the antenna housing space AK is also enclosed by the inner wall surface of the flange 3. The antenna housing space AK is an example of an enclosed space and houses an antenna 7 for generating inductively coupled plasma. However, the antenna housing space AK is designed to be too large to sustain the plasma generated by the antenna 7, and therefore functions as a plasma non-generating region.

[0050] Specifically, in the housing 2, a radome 5 is installed within the first opening 2b, thereby defining the interior space of the housing 2 and forming a plasma generation area HA within the housing body 2a. A stage 6 and a sample W to be processed supported on the stage 6 are disposed within the plasma generation area HA, essentially forming the processing chamber. In other words, within the housing 2, the radome 5 separates the plasma generation area HA from the plasma non-generation area.

[0051] Furthermore, in the housing 2, the flange 3 and the vacuum cover 4 are airtightly mounted on the housing body 2a and the flange 3, respectively, to form a vacuum container including the processing chamber. Figure 1 As shown, in the housing 2, a vacuum pump PO is connected to the housing body 2a, and the control unit C controls the vacuum pump PO, whereby the interior of the plasma generation area HA is brought into a predetermined vacuum degree at least during plasma processing.

[0052] Specifically, the plasma generation area HA is depressurized by evacuating the housing 2 using the vacuum pump PO, and the antenna accommodation space AK is also depressurized. This is because the portion where the radome 5 and the housing 2 meet is not vacuum-sealed, and the plasma generation area HA and the antenna accommodation space AK are connected to each other via a gap.

[0053] In addition, the antenna housing space AK is narrower than the plasma generation area HA and becomes an area where it is difficult to generate and maintain plasma (plasma non-generation area). When the antenna 7 is energized and plasma is generated in the plasma generation area HA, the gas pressure in the antenna housing space AK can be the same as that in the plasma generation area HA, for example, 1Pa to 100Pa.

[0054] In addition, if Figure 1 As shown, the housing 2 and the stage 6 are electrically grounded. Furthermore, a pressure gauge (not shown) is provided in the housing 2 to detect the pressure (vacuum level) inside the plasma generation area HA. The control unit C uses the detection result of the pressure gauge to control the vacuum level inside the plasma generation area HA.

[0055] Antenna 7

[0056] The antenna 7 is cylindrical, for example, and is made of a metal material such as copper. In addition, the antenna 7 has a direction TH ( Figure 3 ) A linear antenna 7 having a linear portion arranged parallel to the linear portion.

[0057] Furthermore, one end and the other end of the antenna 7 are placed in the vacuum cover 4 in a state of being electrically insulated from the vacuum cover 4 via the antenna insulating portion 13A and the antenna insulating portion 13B, respectively, and are airtightly drawn out to the outside of the housing 2. In other words, in the antenna 7, as shown in FIG. Figure 1 As shown, both ends of the linear portion are bent approximately 90 degrees, whereby one end and the other end of the antenna 7 extend upwards toward the housing 2 .

[0058] Furthermore, a cooler 12 is connected to the antenna 7. The antenna 7 is cooled to a predetermined temperature by a cooling medium, such as cooling water, circulated through the cooler 12. Specifically, the cooler 12 includes a cooler body 12a, which includes a drive unit (not shown), such as a pump, for circulating the cooling water, and a pipe 12b airtightly connected to the cooler body 12a.

[0059] In addition, the piping 12b is also arranged in the internal space of the antenna 7, and is configured so that the internal space of the antenna 7 is used as a circulation path for cooling water. Figure 1 As indicated by arrows R1 and R2 , the antenna 7 is cooled by causing cooling water to flow through the inner space of the antenna 7 .

[0060] <Power supply 8, etc.>

[0061] Furthermore, an impedance adjusting unit 9 and an impedance adjusting unit 10 are electrically connected to one end and the other end of the antenna 7, respectively. Figure 1 The device shown includes a matching circuit (matching device) having a variable capacitor, and one end of the antenna 7 is connected to the power supply 8 via the matching circuit. In addition, the impedance adjustment unit 10 includes a variable capacitor, and the other end of the antenna 7 is electrically grounded via the variable capacitor.

[0062] Power supply 8 supplies, for example, 13.56 MHz high-frequency power to one end of antenna 7 via impedance adjuster 10. In plasma processing apparatus 1, controller C controls the efficient supply of high-frequency power to antenna 7 by varying the capacitance of the variable capacitor of impedance adjuster 10.

[0063] In the first embodiment, the power supply 8, the impedance adjuster 9, and the impedance adjuster 10 are provided for each antenna 7. In other words, the plasma processing apparatus 1 of the first embodiment includes a high-frequency circuit including the power supply 8, the impedance adjuster 9, the antenna 7, and the impedance adjuster 10 for each antenna 7.

[0064] Specifically, in this embodiment 1, Figure 3As shown, three power supplies 81 , 82 and 83 (collectively referred to as “ 8 ”) are provided corresponding to the three antennas 71 , 72 and 73 , respectively. Each power supply 8 supplies a high-frequency current to the corresponding antenna 7 using an impedance adjuster 9 and an impedance adjuster 10 .

[0065] Plasma luminescence monitor PD

[0066] In addition, if Figures 1 to 3 As shown, in the plasma processing apparatus 1 of the present embodiment 1, a plurality of plasma emission monitors PD are provided for monitoring the emission of plasma generated inside the housing (processing chamber) 2. Specifically, as shown in FIG. Figure 3 As shown, a plurality of, for example, three, plasma light emission monitors PD are provided along the arrangement direction MH of the antennas 7. In addition, a plurality of, for example, two, plasma light emission monitors PD are provided along the orthogonal direction TH.

[0067] In other words, if Figure 3 As shown, three plasma emission monitors PD are provided in the orthogonal direction TH of the antenna 7 so as to face the antenna 7 , and two plasma emission monitors PD are provided so as to face the linear portions in the longitudinal direction of the three antennas 7 .

[0068] Specifically, the plasma emission monitor PD includes, for example, a light receiving element for detecting light from the plasma within the housing 2, and a spectrometer (not shown) for splitting the detection light detected by the light receiving element. Furthermore, the spectrometer in the plasma emission monitor PD obtains the wavelength spectrum of the light received by the light receiving element (i.e., the emission spectrum of the plasma) and outputs it to the control unit C.

[0069] <Control Unit C>

[0070] The control unit C is a functional block that includes, for example, a central processing unit (CPU), random access memory (RAM), and read-only memory (ROM), and controls various components of the plasma processing apparatus 1 based on information processing. Specifically, the control unit C performs predetermined control processing for the plasma processing of the sample W in the plasma generation area HA.

[0071] Furthermore, in this first embodiment, the control unit C can control the generation of plasma generated by each antenna 7 by controlling the power supply 8 (i.e., the high-frequency circuit) of each antenna 7. Thus, in this first embodiment, the control unit C can more appropriately operate the antenna 7, thereby reliably suppressing the generation of plasma in the antenna-accommodating space AK. As a result, in this first embodiment, damage to the antenna 7 caused by unnecessary plasma in the antenna-accommodating space AK can be more reliably suppressed.

[0072] Furthermore, in the control unit C of the first embodiment, each power supply 8 periodically increases or decreases the magnitude of the high-frequency current supplied to the corresponding antenna 7 in accordance with instructions from the control unit C. This supplies a high-frequency current for generating plasma during a first period of a desired duty cycle within the cycle, thereby intermittently generating plasma generated by the antenna 7 at a predetermined period. In other words, the control unit C of the first embodiment individually controls the duty cycles of the three power supplies 8.

[0073] Specifically, if Figure 4 As illustrated, the control unit C individually controls the duty ratio of the power supply 8 by adjusting the on period (the first period) and the off period for a set of antennas 7 and power supply 8. Furthermore, in this first embodiment, as described in detail later, the control unit C uses the detection results of a plurality of plasma emission monitors PD to individually control the duty ratios of the plurality of power supplies 8.

[0074] Furthermore, when the cycle is, for example, 1 millisecond (msec), the on-period and off-period are, for example, values within the range of 0.9 msec to 0.1 msec and values within the range of 0.1 msec to 0.9 msec, respectively. Specifically, for example, a plasma on-period of 0.8 msec and a plasma off-period of 0.2 msec may be set.

[0075] Furthermore, the control unit C uses the detection results from the five plasma emission monitors PD to individually control the duty ratios of the three power supplies 8. Specifically, upon receiving the detection results from the five plasma emission monitors PD, the control unit C obtains the emission intensity of the plasma generated within the housing 2 based on the desired spectral intensity (the intensity within the desired wavelength band within the wavelength spectrum). The control unit C then determines the duty ratio of each power supply 8 based on the obtained emission intensity of the plasma within the housing 2, and controls the driving of the corresponding power supply 8 according to the determined duty ratio.

[0076] The control unit C also functions as an optical emission spectrometer (optical emission spectrometer), configured to perform predetermined spectroscopic analysis on the detection light from the light receiving element of each plasma emission monitor PD. Thus, when plasma is generated within the housing 2, the control unit C can detect the elements and their concentrations contained in the plasma based on the spectroscopic analysis results. The plasma emission intensity and spectroscopic analysis results are detection results of the plasma emission monitor PD and are specific examples of predetermined emission data related to the plasma.

[0077] <Function>

[0078] The plasma processing apparatus 1 of the first embodiment, configured as described above, includes a housing 2; three antennas 7 for generating a magnetic field for generating plasma within the housing 2; three power supplies 8 for supplying high-frequency current to each of the three antennas 7 for generating a magnetic field; and a control unit C. The three power supplies 8 supply the high-frequency current for generating plasma during a first period of a desired duty ratio in a cycle, thereby intermittently generating plasma at a desired cycle.

[0079] The control unit C individually controls the duty ratios of the three power supplies 8. Thus, in the plasma processing apparatus 1 of the first embodiment, the plasma can be stabilized using the three antennas 7 while performing the desired plasma processing on the sample W to be processed within the housing (processing chamber) 2. The desired plasma processing described herein refers to, for example, uniform film formation on the surface of the sample W to be processed.

[0080] Specifically, in the plasma processing apparatus 1 of the first embodiment, by individually controlling the duty cycle of the power supply 8, the plasma generated by each antenna 7 can be maintained in a stable state without changing the impedance of the high-frequency circuit corresponding to each antenna 7 (for example, the capacitance of the variable capacitor of the matching circuit). As a result, in the plasma processing apparatus 1 of the first embodiment, the flux ratio of active species such as radicals and ions contained in the plasma directed to the sample W to be processed can be appropriately controlled on an antenna 7 basis, thereby easily performing the desired plasma treatment on the sample W to be processed.

[0081] Furthermore, in the plasma processing apparatus 1 of the first embodiment, since the duty cycle is controlled for each antenna 7, the density of the plasma generated by each antenna 7 can be locally adjusted. As a result, the plasma processing apparatus 1 of the first embodiment can perform desired plasma processing under different conditions on the sample W to be processed for each antenna 7. In other words, in the plasma processing apparatus 1 of the first embodiment, for example, a film with different characteristics can be formed on the sample W to be processed, or etching can be performed under different conditions for each antenna 7.

[0082] In addition, in the plasma processing apparatus 1 of the present embodiment 1, as Figure 3 As shown, three plasma emission monitors PD and two plasma emission monitors PD are respectively provided along the arrangement direction MH and the orthogonal direction TH. In the plasma processing apparatus 1 of the first embodiment, the control unit C uses the detection results of the five plasma emission monitors PD to individually control the duty ratios of the three power supplies 8.

[0083] Thus, in the plasma processing apparatus 1 of the first embodiment, the control unit C can grasp the state of the plasma generated by each of the three antennas 7. As a result, in the plasma processing apparatus 1 of the first embodiment, the control unit C can easily perform high-precision plasma processing on the sample W to be processed while ensuring a stable plasma state.

[0084] Specifically, in the plasma processing apparatus 1 of the first embodiment, the control unit C uses the detection results of the five plasma luminescence monitors PD. Thus, the control unit C distinguishes the flux of the active species directed to the processed sample W by the plasma luminescence intensity corresponding to the dissociated state of free radicals or ions, even with the same molecular weight, and detects the luminescence intensity in real time. As a result, in the plasma processing apparatus 1 of the first embodiment, the control unit C can perform plasma treatment on the processed sample W at a desired active species flux ratio per antenna 7.

[0085] In other words, in the plasma processing device 1 of this embodiment 1, the control unit C controls the duty cycle of each antenna 7 so that the luminous intensity contained in each detection result of the five plasma luminescence monitors PD is uniform, thereby making the flux ratio for the processed sample W uniform, so that the film quality distribution of the formed film can be uniform.

[0086] Furthermore, in the plasma processing apparatus 1 of the first embodiment, since the control unit C individually controls the duty cycle of the power supply 8, it is possible to easily set an off period (i.e., a period other than the first period) during which no high-frequency current flows to each antenna 7. Thus, in the plasma processing apparatus 1 of the first embodiment, the control unit C can increase the temperature of the processed sample W and reduce the sheath electric field caused by the plasma during the off period, thereby suppressing damage to the processed sample W caused by ion bombardment.

[0087] <Action Example>

[0088] Here, also refer to Figure 5 and Figure 6 , the effects produced by the control operation of the control unit C in the plasma processing apparatus 1 according to the first embodiment will be described in detail. Figure 5 This is a graph showing a specific example of changes in the emission intensity ratio when the duty ratio is changed in the plasma processing apparatus 1 . Figure 6 This is a graph showing a specific example of a change in film formation speed when the duty ratio is changed in the plasma processing apparatus 1 .

[0089] In addition, when using Figure 5 In the description of the plasma processing apparatus 1 of the present embodiment 1, the results of a first verification test in which a silicon nitride film is formed on a processed sample W using silicon fluoride gas (SiF 4 ), nitrogen gas, and hydrogen gas as the processing gases are illustrated.

[0090] In addition, Figure 5 In the experiment, the wavelength spectra of the plasma, as detected by the plasma emission monitor (PD), were calculated using 253 nm for silicon, 295 nm for silicon fluoride (SiF), 316 nm for nitrogen, and 657 nm for hydrogen to determine the following emission intensity ratios. Furthermore, in the first verification test, the duty cycle was varied to, for example, 1 msec for the on / off period.

[0091] like Figure 5 As shown in the horizontal axis of FIG, when the control unit C changes the duty cycle of the antenna 7, the luminous intensity ratio of nitrogen / silicon fluoride is obtained according to the duty cycle. Figure 5 The values indicated by △ in the figure are shown. Furthermore, the results of the verification test showed that, in the processed sample W, the smaller the duty cycle, the more long-lived nitrogen radicals were present near the processed sample W. Therefore, it was confirmed that nitridation was promoted in the processed sample W, resulting in the formation of a high-quality silicon nitride film.

[0092] In addition, when the control unit C changes the duty ratio of the antenna 7, the luminous intensity ratio of silicon / silicon fluoride is obtained according to the duty ratio. Figure 5 The values indicated by circle (○) are shown in the figure. Furthermore, the results of the verification test indicate that the presence of silicon radicals is considered to be an excess of plasma reaction relative to the decomposition of silicon fluoride gas using plasma. Furthermore, silicon radicals contain many dangling bonds, which are the main cause of defects in the silicon nitride film. Therefore, it was confirmed that the fewer silicon radicals, that is, the smaller the duty cycle, the higher the quality of the silicon nitride film formed on the processed sample W.

[0093] In addition, when the control unit C changes the duty ratio of the antenna 7, the luminous intensity ratio of nitrogen / hydrogen is obtained according to the duty ratio. Figure 5 The values indicated by squares are shown in the figure. Furthermore, the results of the verification test showed that, in the processed sample W, the smaller the duty cycle, the more long-lived nitrogen radicals were present near the processed sample W. Therefore, it was confirmed that nitridation was promoted in the processed sample W, resulting in the formation of a high-quality silicon nitride film.

[0094] As described above, it was confirmed that in the plasma processing apparatus 1 of the first embodiment, the control unit C can perform plasma processing at a desired active species flux ratio on the sample W by using the detection results of the five plasma emission monitors PD.

[0095] Next, use Figure 6 An example of results of a second verification test in the plasma processing apparatus 1 of Embodiment 1 will be described. In the second verification test, the same processing gas as in the first verification test was used to measure the film formation rate when a silicon nitride film was formed on a processed sample W.

[0096] like Figure 6 As shown by the middle dashed line 70, in the second verification test, it was confirmed that the control unit C could control (change) the film formation rate of the silicon nitride film on the processed sample W by changing the duty ratio of the antenna 7. In other words, it was confirmed that in the plasma processing apparatus 1 of the first embodiment, the control unit C could selectively perform film formation processing of a high-quality film in accordance with the processing time of the plasma processing.

[0097] Furthermore, the duty cycle and film formation speed are not in a purely proportional relationship; even with a shorter on-period, the film formation speed increases. Therefore, it was confirmed that by controlling the duty cycle, a high film formation speed can be achieved while suppressing the temperature rise on the surface of the processed sample W0 (a phenomenon proportional to the on-period).

[0098] In addition, in a comparative example in which the increase or decrease of the power supplied by a power supply to multiple antennas or the amplitude modulation of the high-frequency current is controlled simultaneously, unlike in the first embodiment, the impedance of the high-frequency circuit changes significantly, and the capacitance of the variable capacitor in the matching circuit also changes, causing the plasma to become unstable.

[0099] In other words, in the comparative example, if the capacitance of the variable capacitor changes, it takes time for the matching circuit to achieve matching when the plasma is ignited, resulting in unstable processing and other problems such as degradation of the sliding portion of the variable capacitor. Furthermore, in the comparative example, unlike the first embodiment, it is difficult to locally adjust (control) the plasma density within the housing (processing chamber). Unlike the first embodiment, it is difficult to perform plasma processing under different conditions within a single processing chamber.

[0100] [Implementation Method 2]

[0101] use Figure 7 Embodiment 2 of the present disclosure will be described in detail. Figure 7 1 is a diagram illustrating the main structure of the plasma processing apparatus 1 according to the second embodiment of the present disclosure. In addition, for the sake of convenience, the same symbols are attached to the components having the same functions as those described in the first embodiment, and their descriptions are not repeated. Figure 7 In order to simplify the drawings, the Figure 1 The diagram of the stage driving unit SD is shown.

[0102] The main differences between the second embodiment and the first embodiment are that a transport mechanism M1 is provided inside the housing 2 to transport the processed sample W0 along the arrangement direction MH, and temperature detectors S1 and S2 are provided to detect the temperature of the processed sample W0.

[0103] like Figure 7 As shown, in the plasma processing apparatus 1 of the second embodiment, a sample W0 to be processed as a processed object is placed on a stage 61. The stage 61 is provided with not only Figure 1 The stage drive unit SD shown in FIG. 1 is also provided with a transport mechanism M1 for reciprocating the stage 61 along the arrangement direction MH. The transport mechanism M1 includes a driving member such as a motor (not shown) and moves the stage 61 carrying the sample W0 to be processed from the stage 61 to the stage 61 in accordance with the instruction from the control unit C. Figure 7 The status shown is along the Figure 7 The materials are transported in the direction indicated by the middle arrow SH (i.e., the arrangement direction MH).

[0104] In other words, in the plasma processing apparatus 1 of the second embodiment, the sample W0 is transported so as to sequentially pass under the three antennas 7 , that is, the region where local plasma is generated by each antenna 7 , as the stage 61 moves due to the operation of the transport mechanism M1 .

[0105] In the plasma processing apparatus 1 of the second embodiment, a plurality of, for example, two, temperature detection units S1 and S2 are provided along the arrangement direction MH. Specifically, Figure 7 As shown, the temperature detector S1 is disposed on the third side 3c between the antennas 71 and 72, and the temperature detector S2 is disposed on the fourth side 3d between the antennas 72 and 72. Furthermore, the temperature detectors S1 and S2 each detect the surface temperature of the processed sample W0 as the temperature of the processed sample W0 passing thereunder, and output the detection results to the control unit C.

[0106] In the plasma processing apparatus 1 of the second embodiment, the control unit C receives detection results from each of the five plasma emission monitors PD, similar to the control unit C of the first embodiment. Furthermore, the control unit C uses the detection results from each plasma emission monitor PD and the detection results from the two temperature detectors S1 and S2 to individually control the duty ratio for each of the three antennas 7.

[0107] With the above configuration, the plasma processing apparatus 1 of the second embodiment achieves the same effects as those of the plasma processing apparatus 1 of the first embodiment.

[0108] In addition, in the plasma processing device 1 of this embodiment 2, the processed sample W0 is transported along the arrangement direction MH of the three antennas 7 by the transport mechanism M1. Therefore, the processed sample W0 can be subjected to plasma treatment using plasma generated by different antennas 7, thereby easily performing plasma treatment under different conditions.

[0109] In other words, in this embodiment 2, compared with embodiment 1, the density of the plasma generated by each antenna 7 can be adjusted locally and more easily, so the processed sample W0 can be formed in sequence by stacking multiple films with different properties, for example, or stacked films with different hardness can be etched in sequence under different conditions.

[0110] Furthermore, in the plasma processing apparatus 1 of the second embodiment, the control unit C, similar to the control unit C of the first embodiment, uses the detection results of the five plasma light emission monitors PD to individually control the duty ratios of the three power supplies 8. Thus, in the plasma processing apparatus 1 of the second embodiment, the control unit C can grasp the state of the plasma generated by each of the three antennas 7. The control unit C can easily perform high-precision plasma processing on the sample W being processed while ensuring a stable plasma state.

[0111] Furthermore, in the plasma processing apparatus 1 of the second embodiment, the control unit C uses the detection results of the two temperature detectors S1 and S2 to individually control the duty ratios of the three power supplies 8. Thus, in the plasma processing apparatus 1 of the second embodiment, the control unit C can grasp the temperature of the sample W0 to be processed, thereby easily performing plasma processing on the sample W0 with higher precision while ensuring a stable plasma state.

[0112] Here, use Figure 8 An example of results of a third verification test in the plasma processing apparatus 1 according to the second embodiment will be described. Figure 8 Yes Figure 7 Graph illustrating an example of a specific relationship between the surface temperature and the film formation rate when the duty ratio is changed in the plasma processing apparatus 1. In the third verification test, a silicon nitride film was formed on the processed sample W0 using the same process gas as in the first verification test.

[0113] In the third verification test, the temperature of the stage 61 detected by the temperature sensor is set to, for example, 150° C. ( Figure 8 ) or 240°C ( Figure 8 The following describes the situation (shown by dotted lines 92 and 93). Figure 8 In the figure, the vertical axes correspond to the left and right axes. The dashed line 93 and the solid line 94 correspond to the left vertical axis, and the solid line 91 and the dashed line 92 correspond to the right vertical axis. The film formation speed on the left vertical axis is obtained based on the film thickness and film formation time measured by an ellipsometer, for example.

[0114] like Figure 8 As shown by the solid line 91 and the dashed line 92, the temperature of the processed sample W0 decreases linearly with decreasing duty cycle, regardless of the stage 61 temperature. This indicates that the temperature of the processed sample W0 is proportional to the length of the on-period, regardless of the duty cycle. On the other hand, the film deposition rate remains higher than when it decreases linearly with decreasing duty cycle, regardless of the stage 61 temperature.

[0115] This indicates that reducing the duty cycle increases the film deposition rate per unit length of the on-time. This is because even when the plasma is extinguished, residual radicals contribute to the plasma process. Consequently, reducing the duty cycle of the high-frequency current during plasma processing shortens the on-time required for plasma processing, thereby lowering the temperature of the processed sample W0.

[0116] In addition, it was confirmed that when the surface temperature of the processed sample W0 is below 300°C, when the control unit C changes the duty cycle of each antenna 7, the surface temperature of the processed sample W0 and the film formation speed of the silicon nitride film for the processed sample W0 also change regardless of the temperature of the carrier 61.

[0117] In addition, confirm that Figure 8 As shown by the solid line 94 and the dashed line 93, when the surface temperature of the processed sample W0 is between 300°C and 500°C, and the duty ratio of each antenna 7 is changed by the control unit C, the surface temperature of the processed sample W0 and the film formation rate of the silicon nitride film on the processed sample W0 change regardless of the temperature of the stage 61. Furthermore, it was confirmed that when the surface temperature of the processed sample W0 is high, the increase in the surface temperature and the increase in the film formation rate increase as the duty ratio of each antenna 7 is increased, compared to when the surface temperature of the processed sample W0 is low.

[0118] [Variation]

[0119] use Figure 9 Modifications of the present disclosure will be described in detail. Figure 9 Yes Figure 7 1 and 2. For convenience of description, members having the same functions as those described in the second embodiment are denoted by the same reference numerals, and their description will not be repeated.

[0120] The main difference between the modification and the second embodiment is that a transport mechanism M2 is provided on the stage 6 to transport the processed sample W0 along the arrangement direction MH instead of the transport mechanism M1. Figure 9 As shown, in the plasma processing apparatus 1 of this modification, a transport mechanism M2 is provided for reciprocating along the arrangement direction MH on the stage 6 in a state of sandwiching the sample W0 to be processed.

[0121] The conveying mechanism M2 includes a driving member such as a motor (not shown) and operates according to an instruction from the control unit C. Figure 9 The status shown is along the Figure 9The processed sample W0 is transported in the direction indicated by the arrow SH (ie, the arrangement direction MH). With the above configuration, the plasma processing apparatus 1 of this modification achieves the same effects as the plasma processing apparatus 1 of the second embodiment.

[0122] In the above description, a linear antenna 7 is used. However, the present disclosure is not limited to any method as long as a magnetic field for generating plasma inside the processing chamber (housing 2) is generated. For example, a helical antenna may also be used.

[0123] Furthermore, while the above description describes a case where three power sources 8, equal in number to the number of antennas 7, are used as the at least two power sources 8, the present disclosure is not limited to this number of power sources 8, as long as the control unit C individually controls the duty ratios of the at least two power sources 8. Specifically, for example, when four antennas 7 are provided, by connecting two antennas 7 in parallel or in series with one power source 8, the control unit C can individually control the duty ratios of the three power sources 8, namely, the one power source 8 and the two power sources 8 connected in series with the remaining two antennas 7.

[0124] 〔Summarize〕

[0125] In order to solve the above-mentioned problem, the plasma processing apparatus of the first embodiment of the present disclosure includes: a processing chamber; a plurality of antennas for generating a magnetic field for generating plasma inside the processing chamber; at least two power supplies for supplying a high-frequency current for generating the magnetic field to the plurality of antennas; and a control unit, wherein the power supply supplies the high-frequency current for generating the plasma during a first period of a required duty cycle in a cycle so as to intermittently generate the plasma according to the required cycle, and the control unit individually controls the duty cycles of the at least two power supplies.

[0126] With this configuration, it is possible to perform desired plasma processing on an object to be processed in the processing chamber while stabilizing plasma using a plurality of antennas.

[0127] The second embodiment of the present disclosure is based on the plasma processing apparatus of the first embodiment, and may further include a plurality of plasma luminescence monitors, which monitor the luminescence of the plasma generated inside the processing chamber. The control unit uses the detection results of the plurality of plasma luminescence monitors to individually control the duty cycles of the at least two power supplies.

[0128] With this configuration, the control unit can grasp the state of plasma generated by each of the plurality of antennas, thereby stabilizing the plasma using the plurality of antennas and performing desired plasma processing on the workpiece inside the processing chamber with higher precision.

[0129] According to a third embodiment of the present disclosure, the plasma processing apparatus of the second embodiment may be configured such that the plurality of antennas are arranged along a predetermined arrangement direction, and the plurality of plasma luminescence monitors include a plurality of plasma luminescence monitors arranged along the arrangement direction and in directions orthogonal to the arrangement direction.

[0130] With the above structure, since multiple plasma emission monitors are arranged along the arrangement direction of multiple antennas and directions orthogonal to the arrangement direction, high-precision plasma processing of the workpiece can be easily performed while ensuring the stability of the plasma.

[0131] The fourth embodiment of the present disclosure is a plasma processing device according to any one of the first to third embodiments, wherein the plurality of antennas are arranged along a prescribed arrangement direction, and the plasma processing device further comprises a conveying mechanism for conveying the object to be processed along the arrangement direction inside the processing chamber.

[0132] With this configuration, since the object to be processed is transported by the transport mechanism along the arrangement direction of the plurality of antennas, the object to be processed can be subjected to plasma treatment using plasma generated by different antennas, thereby facilitating plasma treatment under different conditions.

[0133] The fifth embodiment of the present disclosure is based on the plasma processing apparatus of the fourth embodiment, and may further include a plurality of plasma luminescence monitors, which monitor the luminescence of the plasma generated inside the processing chamber. The plurality of plasma luminescence monitors are arranged along the arrangement direction, and the control unit uses the detection results of the plurality of plasma luminescence monitors to individually control the duty cycles of the at least two power supplies.

[0134] Through the above structure, the control unit can grasp the state of the plasma generated by multiple antennas, so that higher-precision plasma processing using plasma generated by different antennas can be performed on the workpiece, thereby easily performing higher-precision plasma processing under different conditions.

[0135] The sixth embodiment of the present disclosure may be a plasma processing device according to any one of the first to fifth embodiments, which may further include a plurality of temperature detection units, which detect the temperature of the processed object, and the plurality of temperature detection units are arranged along the arrangement direction. The control unit uses the detection results of the plurality of temperature detection units to individually control the duty cycles of the at least two power supplies.

[0136] With this configuration, the control unit can grasp the temperature of the object to be processed, and thus can easily perform plasma processing on the object to be processed with higher precision while ensuring a stable state of plasma.

[0137] The present disclosure is not limited to the above-described embodiments and modifications, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments and modifications are also included in the technical scope of the present disclosure.

[0138] Explanation of Figure Numbers

[0139] 1: Plasma treatment device

[0140] 2: Shell (processing chamber)

[0141] 7, 71, 72, 73: Antenna

[0142] 8, 81, 82, 83: Power supply

[0143] C: Control Department

[0144] PD: Plasma Luminescence Monitor

[0145] S1, S2: Temperature detection unit

[0146] M1, M2: transport mechanism

Claims

1. A plasma processing apparatus, comprising: processing room; a plurality of antennas for generating a magnetic field for generating plasma inside the processing chamber; at least two power supplies for supplying high-frequency currents to the plurality of antennas for generating the magnetic field; as well as Control Department, The power supply is a power supply that supplies a high-frequency current for generating the plasma during a first period of a desired duty ratio in a cycle, so as to intermittently generate the plasma in the desired cycle. The control unit controls the duty ratios of the at least two power supplies individually.

2. The plasma processing apparatus according to claim 1, further comprising a plurality of plasma emission monitors for monitoring emission of plasma generated inside the processing chamber. The control unit controls the duty ratios of the at least two power supplies individually using detection results of the plurality of plasma emission monitors.

3. The plasma processing apparatus according to claim 2, wherein: The plurality of antennas are arranged along a predetermined arrangement direction, The plurality of plasma emission monitors include a plurality of plasma emission monitors provided along each of the arrangement direction and a direction orthogonal to the arrangement direction.

4. The plasma processing apparatus according to claim 1, wherein The plurality of antennas are arranged along a predetermined arrangement direction, The plasma processing apparatus further includes a transport mechanism configured to transport the processed object along the arrangement direction within the processing chamber.

5. The plasma processing apparatus according to claim 4, further comprising a plurality of plasma emission monitors for monitoring emission of plasma generated inside the processing chamber. The plurality of plasma luminescence monitors are arranged along the arrangement direction, The control unit controls the duty ratios of the at least two power supplies individually using detection results of the plurality of plasma emission monitors.

6. The plasma processing apparatus according to claim 4 or 5, further comprising a plurality of temperature detection units for detecting the temperature of the object to be processed. The plurality of temperature detection parts are arranged along the arrangement direction, The control unit controls the duty ratios of the at least two power supplies individually using detection results of the plurality of temperature detectors.

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