JP4361835B2 - Plasma processing apparatus, plasma control member, and plasma processing method - Google Patents

Description

  The present invention relates to a plasma processing apparatus, a plasma control member, and a plasma processing method for performing predetermined processing such as etching processing on a substrate such as a semiconductor wafer using plasma.

  In the manufacturing process of a semiconductor device, for example, in order to separate capacitors and elements, or to form a contact hole, a substrate such as a semiconductor wafer (hereinafter referred to as “wafer”) is subjected to plasma dry etching or film formation processing. Has been done. As one of apparatuses for performing these processes, a single-wafer type parallel plate type plasma processing apparatus that generates plasma by applying a high-frequency voltage between an upper electrode and a lower electrode is used.

  FIG. 11 shows a schematic view of this type of plasma apparatus. Briefly explaining the outline of the apparatus, an upper electrode 11 that also serves as a gas shower head and a lower electrode 12 that also serves as a substrate mounting table are provided vertically inside an airtight container 1 that forms a vacuum chamber. Further, a focus ring 13 made of quartz, for example, is provided so as to surround the periphery of the wafer 100 placed on the lower electrode (mounting table) 12. In the figure, reference numeral 14 denotes an electrostatic chuck for electrostatically adsorbing the wafer 100, and a foil-like electrode 15 to which a chuck voltage from a power source (not shown) is applied is provided inside the electrostatic chuck 14. . A predetermined processing gas selected according to the type of processing is injected from the gas shower head (upper electrode) 11 toward the wafer 100 and evacuated by the vacuum pump 16 so that the inside of the hermetic container 1 has a predetermined pressure. When a high-frequency voltage is applied between the upper electrode 11 and the lower electrode 12 by the high-frequency power source 17 in the state maintained in this state, a predetermined process such as etching is performed on the wafer 100 by converting the processing gas into plasma.

  Here, since the processing gas sprayed from the gas shower head (upper electrode) 11 and has reached the vicinity of the surface of the wafer 100 is exhausted from the periphery of the wafer 100 outward and downward, the periphery of the wafer 100 (near the periphery). The gas flow of the processing gas is different between the region near the center and the region near the center, so that the balance of the predetermined component ratio in the processing gas is lost at the peripheral portion of the wafer 100, and the region where the wafer 100 is placed The impedance component, conductance component, and the like between the plasma and the lower electrode 12 are different from the outside. Specifically, the dissociation degree of the processing gas is higher on the peripheral side of the wafer 100 near the exhaust space than the region near the center, and thus the plasma density in the vicinity of the peripheral portion is increased, resulting in the wafer. When viewed in the plane of 100, the etching rate at the peripheral edge portion may be larger than the etching rate at the central portion.

  On the other hand, in order to increase the utilization rate of the wafer 100, there is a strong demand for forming a device as close to the periphery of the wafer 100 as possible. There is a need. For this reason, a focus ring 13 made of, for example, a conductor, a semiconductor, or a dielectric is disposed so as to surround the periphery of the wafer 100, and the plasma density above the peripheral edge of the wafer 100 is adjusted. Specifically, the material of the focus ring 13 is selected according to the type of processing gas, the material of the film to be etched, etc., and the focus ring 13 suitable for the processing is installed. For example, in Patent Document 1, when etching a refractory metal and its silicide (silicon compound) with chlorine radicals generated by plasma formation, the adsorptivity of chlorine radicals is strong and the chlorine radical concentration jumps around the periphery of the wafer 100. It is described that SiC is preferable as the material of the focus ring 13 because it can be relaxed.

  It is also known that when a quartz ring is used as the insulator focus ring 13, the surface of the quartz ring is coated with, for example, polyimide in order to suppress the release of oxygen that affects the etching characteristics from the surface. (For example, see Patent Document 2).

JP-A-62-47130 JP 11-317393 A

  However, with the progress of pattern miniaturization, further in-plane uniformity is required for the in-plane processing of the wafer 100. Therefore, the method of Patent Document 1 focusing on adsorption of chlorine radicals cannot cope with the current specifications. That is, the situation is that the jumping of the etching rate at the peripheral portion cannot be sufficiently suppressed. Therefore, the inventors have studied to select carbon as the material of the focus ring 13. When the focus ring 13 is formed of carbon, when exposed to plasma during process processing, for example, carbon radicals are dissociated from the carbon, and if the carbon radicals react with the chlorine radicals, the chlorine radicals are consumed. In addition, the effect of lowering the chlorine radical density near the periphery of the wafer 100 is expected. However, since the carbon is damaged by the plasma, the ring has to be periodically replaced, for example, in about 1000 hours. However, since the carbon ring is expensive, there is a concern that the manufacturing cost may be increased. is there.

  Further, as in Patent Document 2, when a polyimide layer is provided on the surface of the focus ring 13 by coating, for example, when the wafer 100 is repeatedly processed and the polyimide deteriorates, the focus ring 13 is removed from the apparatus. There is a problem that maintenance work is frequent because it is necessary to remove the once deteriorated polyimide and perform coating again.

  The present invention has been made under such circumstances, and an object of the present invention is to provide a plasma processing apparatus and method for easily replacing a member provided so as to surround a substrate in order to control plasma. is there.

The plasma processing apparatus of the present invention is a plasma processing apparatus that converts a processing gas into a plasma with a high-frequency power in a processing container, and performs processing on the substrate placed on the mounting table with plasma.
A ring portion provided to surround the periphery of the substrate on the mounting table,
A groove formed on the surface of the ring portion along the circumferential direction of the ring portion;
A plasma control sheet provided in the groove;
An adhesive layer is provided between the ring portion and the plasma control sheet, and allows the plasma control sheet to be attached to and detached from the ring portion.

  The pressure-sensitive adhesive layer may be formed of an adhesive applied to the back surface of the plasma control sheet. The plasma control sheet may include a material that dissociates components that react with active species that mainly contribute to plasma processing. Further, the plasma may contain chlorine radicals, and the plasma control sheet may be composed of an organic resin, and the sheet may be a polyimide sheet. Furthermore, the present invention may be applied to a process of etching tungsten or tungsten silicide on the surface layer portion of the substrate by the plasma.

The plasma control member of the present invention is a plasma control member provided in a plasma processing apparatus that converts a processing gas into plasma with high-frequency power in a processing container and performs processing on the substrate mounted on the mounting table with plasma.
A ring portion provided to surround the periphery of the substrate on the mounting table,
A groove formed along the circumferential direction of the ring portion to the surface of the ring portion,
A plasma control sheet provided in the groove ;
Interposed between the sheets for the plasma control and the ring portion, and the adhesive layer to removably seat for plasma control over the ring section,
It is provided with.

  The adhesive layer may be formed of an adhesive applied to the back surface of the plasma control sheet. The plasma control sheet may be composed of an organic resin, and the sheet may be a polyimide sheet.

In the plasma processing method of the present invention, a ring portion is provided so as to surround a mounting table in a processing container, and a groove is formed on a surface of the ring portion along a circumferential direction of the ring portion, and the groove is formed in the groove. Using a plasma processing apparatus in which a sheet for plasma control is attached via an adhesive layer,
A step of placing the substrate on the mounting table;
Next, supplying a processing gas into the processing container, converting the processing gas into plasma with high-frequency power and processing the substrate with plasma,
Separating the plasma control sheet from the ring portion and replacing the plasma control sheet with a new plasma control sheet.

  The plasma control sheet may include a material that dissociates components that react with active species that mainly contribute to plasma processing. The plasma contains chlorine radicals, and the plasma control sheet may be made of an organic resin or a polyimide sheet. Furthermore, the present invention may be applied to a process of etching tungsten or tungsten silicide on the surface layer portion of the substrate by the plasma.

  According to the present invention, the plasma control sheet is configured such that the plasma control sheet is detachably provided on the surface of the ring portion provided so as to surround the periphery of the substrate, with the adhesive layer interposed therebetween. Can be easily performed, and the plasma control member can be easily replaced, reducing the burden on the operator and operating rate of the apparatus. It leads to improvement. By using an organic resin such as a polyimide sheet that dissociates a component that reacts with active species that mainly contribute to plasma treatment, such as a polyimide sheet that dissociates carbon, the active species is present in the vicinity of the peripheral edge of the substrate. For example, since radicals are consumed, it is possible to suppress the density of plasma in the vicinity of the peripheral edge of the substrate from becoming higher than the plasma density in the inner region. As a result, plasma processing with high in-plane uniformity can be performed on the substrate.

  An embodiment in which a plasma processing apparatus according to the present invention is applied to an etching apparatus will be described with reference to FIG. In the figure, 2 is a hermetically formed processing container made of a conductive member such as aluminum. An exhaust port 21 is provided at the bottom of the processing container 2, and the exhaust port 21 is connected to a vacuum pump 22 such as a vacuum molecular pump or a dry pump through an exhaust path 21 a. Further, a wafer transfer port 24 having a gate valve 23 that can be opened and closed is provided on the side wall of the processing chamber 2.

  An upper electrode 3 that also serves as a gas shower head, which is a gas supply unit for introducing a predetermined processing gas, for example, an etching gas, is provided inside the processing container 2. A large number of gas diffusion holes 31 are formed on the lower surface side of the upper electrode 3, and the processing gas sent from the processing gas supply source 32 through the supply path 33 is supplied to the wafer 100 located on the lower side. It is configured to be able to supply over the entire surface. Further, an insulating member 34 made of, for example, quartz is provided so as to surround the upper electrode 3, so that the upper electrode 3 is in an electrically floating state.

  Further, a substrate mounting table 4 is provided inside the processing container 2 so as to face the upper electrode 3, and the substrate mounting table 4 is electrically sufficient with respect to the processing container 2 by an insulating member 40. It is in a floating state. The substrate mounting table 4 is provided with a columnar support portion 41 made of a conductive member such as aluminum, and a mounting plate 42 on which the wafer 100 is placed is provided on the upper end surface of the support portion 41. The mounting plate 42 is formed as a dielectric plate made of a dielectric material such as ceramics such as aluminum nitride, and a foil-like electrode (lower electrode) 43 is provided on the upper surface side, and further on the lower surface side. A mesh heater 44 as a heating unit is provided. Reference numeral 45 in the drawing denotes an exhaust ring having a large number of through holes formed on the surface thereof so that the processing gas is uniformly exhausted from the peripheral portion of the wafer 100 in the circumferential direction. Although not shown, substrate support pins that can be raised and lowered in a state where the wafer 100 is supported from the back surface side are provided so as to be able to protrude and retract from the surface of the mounting table 4, and the wafer transfer that enters from the outside of the apparatus is carried out. The wafer 100 is transferred to the mounting table 4 by the cooperative action of the arm and the substrate support pins.

  One end of a power supply rod 50 is connected to the lower electrode 43, the other end of the power supply rod 50 is connected to the high frequency power source 5, and a matching circuit 51 is provided in the middle thereof. Further, the power feeding rod 50 is branched, for example, before the matching circuit 51. The tip of this branching path is connected to a DC power source 52 for electrostatic chuck, and a switch 53 is provided in the middle. That is, the lower electrode 43 serves as both an electrode for applying a high frequency voltage and an electrode for an electrostatic chuck. Therefore, the lower electrode 43 and the upper dielectric portion are used for electrostatically adsorbing the wafer 100. Configure an electrostatic chuck. Furthermore, the heater 44 is connected to a heater power supply 55 via a conductive rod 54.

  In addition, a focus ring 6 that is a ring portion for plasma control is provided so as to surround the entire periphery of the wafer 100 sucked and held on the surface of the mounting plate 42 described above. The focus ring 6 includes a ring member 61 made of, for example, an insulating member such as quartz, alumina, yttrium oxide and the like, for example, having a top surface width of 55 mm. Further, on the upper surface of the ring member 61, as will be described in detail later, a material that reacts with plasma active species such as chlorine radicals when exposed to plasma, such as a material that dissociates carbon such as carbon radicals, such as an organic resin such as polyimide. For example, a ring-shaped plasma control sheet 62 having a thickness of, for example, 0.5 to 1 mm, which covers the entire upper surface of the ring member 61 or is set to a width of, for example, 10 to 20 mm, is attached or detached via the adhesive layer 63 It is provided freely. FIG. 1 shows an example in which a plasma control sheet 62 is provided so as to cover the entire upper surface of the ring member 61.

  In detail, in this example, the plasma control sheet 62 and the adhesive layer 63 are formed as a pressure-sensitive adhesive sheet by applying an adhesive to the back side of the plasma control sheet 62 to give adhesiveness. The adhesive member can be attached to the surface of the ring member 61 and can be peeled off from the ring member 61 together with the adhesive, for example, by an operator's hand. Specifically, a polyimide sheet formed as a pressure-sensitive adhesive sheet with an adhesive applied to the back side can be used, and the inventors have actually tested it, for example, “(No. 5413) “Polyimide tape (trade name)” is confirmed to be applicable. Strictly speaking, the adhesive layer 63 does not necessarily have to be formed over the entire back surface of the plasma control sheet 62. For example, an adhesive is applied only to the peripheral edge portions on the outer peripheral edge side and the inner peripheral edge side, and the adhesive layer 63 is partially adhered. The layer 63 may be formed.

  Here, in this type of process processing in which the processing gas is processed into plasma by high-frequency power, the inside of the processing container 2 is set to a vacuum state in order to promote the generation of plasma, and further, the inside of the processing container 2 is set during processing. High temperature, for example, 300 ° C. may occur. Therefore, in order to prevent the plasma control sheet 62 from being peeled off from the ring member 61 under such severe conditions, the adhesive forming the adhesive layer 63 does not change in quality at a high temperature and has a certain level of adhesive action. It is necessary to have. The inventors have actually tested and confirmed that a silicone-based adhesive mainly composed of Si is applicable.

  The plasma control sheet 62 is preferably provided as close to the outer peripheral edge of the wafer 100 as possible, and is provided within 1 mm from the outer peripheral edge of the wafer 100, for example. Further, the surface of the ring member 62 is set to the same height as the surface of the wafer 100 or a position higher than the surface of the wafer 100 by, for example, 0.5 to 0.7 mm. That is, the plasma control sheet 62 is set at a position higher than the surface of the wafer 100.

Next, a method of etching the substrate, for example, the wafer 100 using, for example, a chlorine-based processing gas using the above-described etching apparatus will be described. FIG. 2 is a diagram showing how the barrier metal layer (cap layer) 7 of the gate electrode is etched. 70a is a silicon layer, 70b is a gate insulating film made of, for example, a SiO ₂ film, 70c is a polysilicon layer which is a gate electrode layer, and the barrier metal layer 7 is laminated on the upper surface of the polysilicon layer, for example, tungsten (W) Alternatively, it is formed of a tungsten silicide (WSi) layer. Reference numeral 71 denotes a mask pattern made of, for example, a resist formed in a predetermined circuit pattern.

  Here, an example of generation of the gate electrode is given as an example of etching of the barrier metal layer 7 formed of the W layer or the WSi layer. However, the present invention is a barrier metal interposed between the wiring layer and the interlayer insulating film. This is also applied to the case of etching a W layer or a WSi layer forming a layer. However, the etching target of the present invention is not limited to the W layer or the WSi layer, and can be applied to, for example, etching of polysilicon or photoresist.

  First, the gate valve 23 is opened, and the wafer 100 is loaded into the processing container 2 from the load lock chamber (not shown) via the wafer transfer port 24 and heated to a predetermined temperature by the heater 44 via a substrate lift pin (not shown). The wafer 100 is placed on the placed mounting plate 42. Thereafter, the switch 53 is turned on to apply a DC voltage, which is a chuck voltage, to the lower electrode 43, thereby electrostatically attracting the wafer 100 to the surface of the mounting plate 42. On the other hand, the gate valve 23 is closed to make the processing container 2 airtight.

Subsequently, for example, an etching gas containing chlorine (Cl ₂ ) and oxygen (O ₂ ), for example, having flow rates set to 150 sccm and 10 sccm, respectively, is sprayed toward the surface of the wafer 100 through the gas diffusion holes 31. On the other hand, the inside of the processing container 2 is evacuated by the vacuum pump 22, and the inside of the processing container 2 is maintained at a vacuum degree of, for example, 5 to 10 mTorr. The etching gas sprayed toward the wafer 100 through the gas diffusion holes 31 forms an air flow that flows radially outward along the surface of the wafer 100 and is dispersed using the ventilation resistance of the exhaust ring 45. Due to the action, the air is exhausted uniformly from around the mounting table 4.

  Subsequently, when a high frequency voltage for plasma generation of 100 MHz, for example, is applied to the lower electrode 43 through the matching circuit 51 from the high frequency power source 5 at 250 W, for example, the wafer 100 on the upper electrode 3 and the mounting plate 42 is applied. A high-frequency voltage (high-frequency power) is applied between them, and the etching gas is turned into plasma, thereby generating plasma active species that are etchants, such as chlorine radicals. Also, a bias voltage of 13.56 MHz, for example, is applied to the lower electrode 43 at 200 W, for example, so that the plasma active species is incident with high perpendicularity toward the surface of the wafer 100, and the resist 71 in the barrier metal film 7. The exposed portion that is not covered with is etched (see FIG. 2B). On the other hand, at the interface between the surface of the plasma control sheet 62 and the plasma sheath, a component that reacts with the plasma active species from the surface of the plasma control sheet 62 when exposed to plasma, for example, polyimide. Carbon radicals dissociate, and the carbon radicals react with chlorine radicals in the vicinity of the upper side thereof, that is, in the vicinity of the peripheral portion of the wafer 100, for example, chlorides having no etching action, such as CClx (x = 1, 2, 3, 4). ) Is generated. The produced chloride is discharged out of the apparatus together with the exhaust stream.

  Thereafter, for example, when a predetermined time elapses, the application of the high-frequency voltage from the high-frequency power source 5 and the introduction of the etching gas are stopped, and an inert gas such as nitrogen is introduced into the processing container 2 from, for example, an air supply means (not shown). At the same time, evacuation of the vacuum pump 22 is stopped. Thereafter, the switch 53 is switched to stop the application of the chucking voltage to release the wafer 100 from the attracted state, the gate valve 23 is opened, the wafer 100 is carried out of the apparatus, and the etching process is completed. In the case where a large number of wafers 100 are repeatedly processed, another wafer 100 is carried into the apparatus and the same process as described above is performed. By repeating this process, a large number of wafers 100 are processed. For example, when the operation time of the apparatus exceeds 1000 hours, the ceiling of the processing container 2 is opened and the apparatus is opened to the atmosphere for maintenance. In accordance with this timing, the plasma control sheet 62 is peeled off from the ring member 61 by the operator's hand, and a new plasma control sheet 62 is attached.

  According to the above-described embodiment, the plasma control sheet 62 is configured to be detachable by interposing the adhesive layer 63 between the ring member 61 and the plasma control sheet 62. Since the attaching operation of the sheet 62 and the removing operation of the deteriorated plasma control sheet 62 can be easily performed, for example, it is easy to replace at the time of maintenance, and as a result, the burden on the operator can be reduced. In addition, the operating rate of the apparatus can be improved. Furthermore, it is inexpensive because it is in the form of a sheet.

  Furthermore, according to the above-described embodiment, the plasma control sheet is composed of the polyimide that dissociates the component that reacts with the chlorine radical, which is the etchant that controls the rate of etching of tungsten or tungsten silicide, so that it is dissociated from this polyimide. Since the carbon radicals to consume consume chlorine radicals, it is possible to suppress the difference in density of chlorine radicals between the vicinity of the peripheral edge of the wafer W and its inner region. As a result, the wafer 100 can be etched at an etching rate with high in-plane uniformity.

  In a plasma apparatus exposed to the harsh conditions of a high-temperature plasma atmosphere, parts are likely to deteriorate, and the surface may be deposited. Therefore, as described above, maintenance is performed at a predetermined cycle, for example, every 1000 hours. It is the actual situation. Furthermore, in an actual apparatus, a processing system is often constructed by incorporating a plurality of plasma apparatuses. Therefore, as described above, the fact that the plasma control sheet 62, which is a consumable material, can be easily replaced is extremely effective in reducing the burden on the operator during maintenance. I can say that. However, since the thickness of the plasma control sheet 62 gradually decreases when a component that reacts with plasma, such as carbon, is dissociated, it must be set to a thickness that can withstand the maintenance cycle. The present inventors have grasped by simulation that the required thickness is 1 mm when the apparatus is operated for 1000 hours.

  Furthermore, since the amount of carbon radical dissociation depends on the surface area of the plasma control sheet 62, if the surface area of the plasma control sheet 62 is too large, the plasma density at the peripheral edge will be reduced. The internal uniformity may deteriorate. Therefore, the plasma control sheet 62 is set to an appropriate surface area, and in this case, the width is set to 10 to 20 mm, thereby finely controlling the plasma density in the vicinity of the periphery of the wafer 100. Can do.

  Further, in the present invention, the pressure-sensitive adhesive layer 63 is not limited to the structure formed by the adhesive, and for example, the surface of the ring member 61 is subjected to surface modification treatment, for example, a photochemical method, and vacuum ultraviolet light (130 nm to 260 nm) and water are supplied. It is possible to improve the adhesive action by substituting the polyimide surface from a hydrophobic C—H bond to a hydrophilic group. Similarly, the laser application method is also possible. In this case, the same effect as in the above case can be obtained.

  In the present invention, the configuration is not limited to the configuration in which the plasma control sheet 62 is provided over the entire circumference in the circumferential direction of the ring member 61. For example, as shown in FIG. The sheets 62 may be arranged at intervals in the circumferential direction. Even in this case, since the component that reacts with the plasma, for example, the carbon radical, dissociates from the plasma control sheet 62, the same effect as in the above case can be obtained. When the plasma control sheet 62 is attached with a gap, a surface portion of the ring member 61 exposed to the plasma is formed, but carbon radicals dissociated from the plasma control sheet 62 are formed on the surface portion. The ring member 61 is less likely to deteriorate because it reacts with the chlorine radicals that are directed.

  Further, it is not necessary to provide the plasma control sheet 62 so as to cover the entire upper surface of the ring member 61. For example, as shown in FIG. 4, the plasma control sheet 62 is provided only on the inner peripheral side of the ring member 61. You may do it. In this case, the same effect as in the above case can be obtained.

  Furthermore, the present invention is not limited to the configuration in which the plasma control sheet 62 is attached to the flat surface of the ring member 62. For example, as shown in FIG. It is also possible to form a groove 8 corresponding to this length along the circumferential direction and attach a plasma control sheet 62 in the groove 8. Even in this case, the same effect as in the above case can be obtained. Further, according to this example, when the processing container 2 is in a vacuum state, the peripheral edge portion of the plasma control sheet 62 is rolled. Can be suppressed more reliably. Although an example of the ring-shaped plasma control sheet 62 has been described here as an example, the present invention can also be applied to a configuration in which the plasma control sheet 62 is attached in a radial pattern as shown in FIG.

  Furthermore, in the present invention, the configuration is not limited to the configuration in which the plasma control sheet 62 is attached only to the upper end surface of the ring member 61. For example, as shown in FIG. The sheet may be folded over the side peripheral surface. Even in this case, the same effect as described above can be obtained. Further, according to this example, when the processing container 2 is put in a vacuum state by being pasted across a plurality of surfaces having different directions, In addition, it is possible to more reliably suppress the plasma control sheet 62 from being peeled off.

  Furthermore, the present invention can be applied to various processes such as plasma processing other than etching, such as CVD and ashing.

Next, examples performed to confirm the effects of the present invention will be described.
Example 1
In this example, a focus ring 6 is configured by attaching a plasma control sheet 62 made of a polyimide sheet formed as an adhesive plasma control sheet to the surface of a ring member 61 made of quartz. This is an embodiment in which the wafer 100 is etched using an incorporated etching apparatus. Detailed process conditions are listed below. About the film thickness of the wafer 100 before and after the etching process, the film thickness is measured at intervals along each axis of the diameter axis (X axis, Y axis, V axis and W axis) allocated equally from the center of the wafer W. And the result of having calculated | required the etching rate in each measurement point by calculation is shown in FIG. FIG. 8 shows the result of measuring the distribution of chlorine radicals (the intensity ratio of Cl and argon in the wafer W plane) using the plasma emission measurement method.
Etching object: tungsten silicide Etching gas: Cl ₂ (150 sccm) and O ₂ (10 sccm)
・ Pressure: 5 mTorr
Input power (for plasma generation / bias); 250 W (100 MHz) / 200 W (13.56 MHz)
・ Magnetic field: 56G
Temperature: 80 ° C. (processing vessel ceiling surface) / 70 ° C. (processing vessel side wall surface) / 60 ° C. (mounting plate)

(Comparative Example 1)
This example is a comparative example in which the same processing as in Example 1 was performed using a focus ring 6 made of a carbon ring. The calculation result of the etching rate is shown in FIG. The results of measuring the distribution of chlorine radicals are also shown in FIG.

(Comparative Example 2)
This example is a comparative example in which the same processing as in Example 1 was performed using a focus ring 6 made of a quartz ring without a polyimide sheet. The calculation result of the etching rate is shown in FIG. The results of measuring the distribution of chlorine radicals are also shown in FIG.

(Results and discussion of Example 1, Comparative Example 1 and Comparative Example 2)
As is apparent from the results shown in FIGS. 7 to 10, in Comparative Example 1 using a focus ring made of a quartz ring, the density of chlorine radicals near the periphery of the wafer 100 is extremely high, and the etching rate is also higher than that in the center. The periphery is much larger. On the other hand, in Example 1 using a polyimide sheet and Comparative Example 1 using a carbon ring, the jump in the density of chlorine radicals in the peripheral part is small, and the jump in the etching rate in the peripheral part is also small. However, in Comparative Example 1, the deviation of EE 3 mm is ± 10.6%, and the deviation of EE 30 mm is ± 10.6%. On the other hand, in Example 1, the deviation of EE 3 mm is ± 10.2% and the deviation of EE 30 mm is ± 7.6%, and the jumping of the peripheral edge is smaller than that of Comparative Example 1. Note that EE 3 mm means an average value of a measured value in a region extending from the edge portion of the wafer 100 to the inner side 3 mm, and EE 30 mm means an average value of a measured value in a region extending from the edge portion of the wafer 100 to the inner side 30 mm.

  From the above results, by sticking the polyimide sheet to the surface of the ring member 61 made of quartz, it is possible to suppress the density of chlorine radicals in the vicinity of the peripheral portion of the wafer 100 from being increased, thereby increasing the etching rate of the peripheral portion. It was confirmed that jumping up can be suppressed. The reason why the density of chlorine radicals in the vicinity of the peripheral edge of the wafer 100 is suppressed from jumping is presumed to be that carbon radicals dissociated from the polyimide sheet (carbon in Comparative Example 1) reacted with chlorine radicals.

It is a longitudinal cross-sectional view which shows the plasma processing apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the surface of the wafer etched using said plasma processing apparatus. It is explanatory drawing which shows the other example of the said focus ring. It is explanatory drawing which shows the other example of the said focus ring. It is explanatory drawing which shows the other example of the said focus ring. It is explanatory drawing which shows the other example of the said focus ring. It is a characteristic view which shows the result of the Example performed in order to confirm the effect of this invention. It is a characteristic view which shows the result of the Example performed in order to confirm the effect of this invention. It is a characteristic view which shows the result of the Example performed in order to confirm the effect of this invention. It is a characteristic view which shows the result of the Example performed in order to confirm the effect of this invention. It is explanatory drawing which shows the conventional plasma processing apparatus.

Explanation of symbols

2 Processing Container 22 Vacuum Pump 3 Upper Electrode 4 Mounting Table 42 Mounting Plate 43 Lower Electrode 6 Focus Ring 61 Ring Member 62 Plasma Control Sheet

Claims (15)

In a plasma processing apparatus that converts a processing gas into plasma with high-frequency power in a processing container and performs processing on the substrate mounted on the mounting table with plasma,
A ring portion provided to surround the periphery of the substrate on the mounting table,
A groove formed on the surface of the ring portion along the circumferential direction of the ring portion;
A plasma control sheet provided in the groove ;
A plasma processing apparatus comprising: an adhesive layer that is interposed between the ring portion and the plasma control sheet, and allows the plasma control sheet to be attached to and detached from the ring portion.   The plasma processing apparatus according to claim 1, wherein the adhesive layer is an adhesive applied to a back surface of a plasma control sheet.   The plasma processing apparatus according to claim 1, wherein the plasma control sheet includes a material that dissociates a component that reacts with active species that mainly contribute to plasma processing.   The plasma processing apparatus according to claim 1, wherein the plasma contains chlorine radicals, and the plasma control sheet is made of an organic resin.   The plasma processing apparatus according to claim 4, wherein the plasma control sheet is a polyimide sheet.   6. The plasma processing apparatus according to claim 1, wherein tungsten or tungsten silicide on a surface layer portion of the substrate is etched by the plasma. In a plasma control member provided in a plasma processing apparatus that converts a processing gas into plasma with high-frequency power in a processing container and performs processing on the substrate mounted on the mounting table with plasma,
A ring portion provided to surround the periphery of the substrate on the mounting table,
A groove formed along the circumferential direction of the ring portion to the surface of the ring portion,
A plasma control sheet provided in the groove ;
Interposed between the sheets for the plasma control and the ring portion, and the adhesive layer to removably seat for plasma control over the ring section,
A plasma control member comprising:   The plasma control member according to claim 7, wherein the adhesive layer is an adhesive applied to the back surface of the plasma control sheet.   The plasma control member according to claim 7 or 8, wherein the plasma control sheet is made of an organic resin.   The plasma control member according to claim 9, wherein the plasma control sheet is a polyimide sheet. A ring portion is provided so as to surround the mounting table in the processing container, and a groove is formed on the surface of the ring portion along the circumferential direction of the ring portion. The groove is used for plasma control via an adhesive layer in the groove. Using a plasma processing device with a sheet of
A step of placing the substrate on the mounting table;
Next, supplying a processing gas into the processing container, converting the processing gas into plasma with high-frequency power and processing the substrate with plasma,
Peeling off the plasma control sheet from the ring portion and replacing the plasma control sheet with a new plasma control sheet.   The plasma processing method according to claim 11, wherein the plasma control sheet includes a material that dissociates a component that reacts with active species that mainly contribute to the plasma processing.   The plasma processing method according to claim 11 or 12, wherein the plasma contains chlorine radicals, and the plasma control sheet is made of an organic resin.   The plasma processing method according to claim 13, wherein the plasma control sheet is a polyimide sheet.   15. The plasma processing method according to claim 11, wherein tungsten or tungsten silicide on a surface layer portion of the substrate is etched by the plasma.

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