JP2008153249A - Plasma etching apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma etching apparatus which can apply a bias efficiently even to a substrate which is not a conductor and can perform double-side polishing without damaging a pattern formed on both sides of the substrate. <P>SOLUTION: The plasma etching apparatus comprises a substrate supporting member movable in the direction perpendicular to the surface of a substrate to be etched. Since the movable substrate supporting member holding a substrate to be etched is stuck to the electrode side outputting a bias voltage, a distance between the electrode to which the bias voltage is applied and the substrate is shortened and thereby the bias can be applied efficiently to the substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method of a magnetic recording medium in which a recording layer is formed in a concavo-convex pattern.

  A hard disk device rotates an annular magnetic recording medium at a high speed and records / reproduces a digital signal by a magnetic head. Conventionally, a magnetic recording medium has been obtained by depositing a magnetic material on an annular aluminum substrate having a very flat surface or a tempered glass substrate by sputtering or the like. As the recording density increases, the surface recording density of the recording medium is reduced by making the magnetic material composing the recording layer finer, changing the magnetic material, devising the laminated structure of the magnetic material, adopting the perpendicular recording method, etc. Improvements have been made. However, due to problems such as noise, crosstalk, and thermal fluctuation resistance caused by the medium, the limit of improvement in recording density has begun to appear with existing recording media. In view of this, magnetic recording media such as so-called discrete track media and patterned media that can realize further improvement in recording density by providing predetermined irregularities on the magnetic recording layer have been proposed (for example, see Patent Document 1). ).

  The process of providing the magnetic recording layer with unevenness can be roughly classified into two types. The first is a method in which a desired mask is applied to a substrate obtained by depositing a magnetic material, and the magnetic material in the non-mask portion is directly etched. The other is to apply a desired mask to the substrate itself or a non-magnetic film such as silicon nitride or silicon oxide deposited on the substrate (hereinafter referred to as the substrate including both of them), and etching the substrate by etching. In this method, a magnetic material is vapor-deposited on the applied material.

  Examples of a method for applying a mask to a substrate or a magnetic material include a nanoimprint method, photolithography, and electron beam lithography. In addition, as a method of etching a substrate or a magnetic material provided with a mask, dry etching such as wet etching, plasma etching, ion beam etching, ion milling, or neutral beam etching can be considered. In particular, plasma etching technology widely used in the manufacture of semiconductor devices can be expected to be applied to uneven processing of a substrate or a magnetic material in consideration of mass productivity.

  In plasma etching, a processing gas is introduced into a decompressed processing chamber, and the processing chamber is turned into plasma by supplying high-frequency power from a source power source to the processing chamber via a flat antenna, a coiled antenna, or the like. The process proceeds by irradiating the generated ions and radicals onto the substrate. There are various types of plasma sources, such as magnetic field microwave type, inductively coupled plasma (ICP) type, and capacitively coupled (CCP) type, depending on the method of generating plasma. Yes.

  Furthermore, by applying a high frequency bias to the electrode on which the substrate is placed, ions in the plasma can be actively drawn into the substrate, thereby improving the etching rate and improving the vertical workability. The high frequency bias often uses a frequency that is one to three orders of magnitude lower than the frequency of the source power supply used for plasma generation.

Japanese Unexamined Patent Publication No. 9-97419

  However, when an uneven process is applied to a magnetic recording medium using a conventional plasma etching apparatus, pattern damage on the back surface of the substrate and adhesion of foreign matter to the back surface of the substrate becomes a problem. The magnetic recording medium uses both front and back surfaces as recording layers in order to increase the recording capacity per medium. Therefore, the discrete track media and the patterned media also need to be processed with irregularities on both the front and back sides. If the back side of the substrate touches the electrode surface while processing the front side of the substrate, that is, the surface in contact with the plasma, the concavo-convex pattern on the back side of the substrate is damaged, or foreign matter adheres to the concavo-convex pattern on the back side of the substrate. Problems occur. This increases the possibility of causing serious defects in the concavo-convex pattern.

  In order to avoid this, a method is conceivable in which the substrate is not placed directly on the stage, but the substrate is held in plasma so that both surfaces of the substrate are in contact with the plasma, and the front and back surfaces of the substrate are etched together. However, such a double-sided batch processing method has a problem that it is difficult to apply a bias to a non-conductive substrate, the etching rate does not increase, and vertical processing becomes difficult.

  The present invention is for solving the above-described problems, and includes an evacuation unit, a gas supply unit, two opposing electrodes, two high-frequency power sources connected to the respective electrodes, a substantially annular substrate to be etched, In a plasma etching apparatus having a movable substrate support member for holding an annular substrate to be etched, the substrate to be etched clamped in the movable substrate support member is movable in a direction perpendicular to the surface of the substrate to be etched. Device.

  The outermost peripheral portion of the movable substrate support member that supports the substrate to be etched protrudes in a range of more than 0 mm and less than 3 mm from the surface of the substrate to be etched clamped in the movable substrate support member. I am doing.

  Further, both of the opposing two electrode surfaces are provided with a central insulator member, and the central insulator member can fill a hole in the center of the substantially annular substrate to be etched.

  Further, by inserting a stretchable material into the movable substrate support member, the stretchable material absorbs an impact generated when the electrode and the movable substrate support member come into contact with each other, and the electrode, the movable substrate support member, and the substrate to be etched are absorbed. Such impact can be reduced.

  In addition, the high-frequency power source can select and output one of two types of high-frequency voltages: a bias voltage for applying a bias to the substrate and a source voltage for generating plasma.

  Since the substrate to be etched clamped to the movable substrate support member moves in the vertical direction of the substrate to be etched, the movable substrate support member on which the substrate to be etched is attached can be brought into close contact with the electrode side to which the bias voltage is applied. It is possible to efficiently apply a bias to the substrate to be etched.

  And the outermost peripheral part supporting the substrate of the movable substrate support member has a structure that protrudes within a range of less than 3 mm larger than 0 mm than the front and back surfaces of the substrate to be etched clamped in the movable substrate support member. When the electrode and the substrate to be etched come close to each other, the protrusion of the movable substrate support member comes into contact with the electrode, so that a gap is generated between the electrode and the substrate to be etched in the range of more than 0 mm and less than 3 mm. The gap can prevent the electrode and the surface of the substrate to be etched from coming into contact with each other, and damage to the pattern formed on the back surface of the substrate can be avoided while the substrate surface is being etched.

  Further, the central insulator member provided on the surface of the electrode closes the hole at the center of the substantially annular substrate to be etched, so that plasma or process gas is opposite to the processing surface from the hole at the center of the substantially annular substrate to be etched. It is possible to prevent the surface opposite to the processing surface from being contaminated.

  Furthermore, by inserting an elastic material into the substrate support member, the impact applied to the movable substrate support member, the substrate, and the electrode is reduced, and damage to the movable substrate support member, the substrate, and the electrode can be prevented. Further, in order to reduce the pressure applied to the electrode, the movable substrate support member, and the substrate to be etched by the stretchable material, the movable substrate support member is pressed against the electrode side with a certain pressure, that is, the movable substrate support member and the electrode. It is possible to perform processing with improved adhesion. By increasing the adhesion, it is possible to prevent the plasma or process gas from flowing from the side surface of the substrate to the surface opposite to the processing surface, and to prevent the surface opposite to the processing surface from being contaminated.

  In addition, a high-frequency power source capable of selecting and outputting one of two types of high-frequency voltages, ie, a bias voltage and a source voltage, is connected to two opposing electrodes, and one electrode in close contact with the movable substrate support member is biased. By applying a voltage to the other electrode at the opposite position, a source voltage is applied, so that plasma processing can be performed in a state where a bias is efficiently applied to the substrate. After the surface of the substrate to be etched is processed by the above method, the movable substrate support member is brought into close contact with the opposite electrode using the movable substrate support member, and the bias is applied to the electrode that is in close contact with the movable substrate support member. By applying a voltage and a source voltage to the other electrode, the back surface of the substrate can be processed. Thus, it becomes possible to process both the front and back surfaces of the substrate by sequentially etching the front surface and the back surface of the substrate.

Embodiments of the invention will be described below with reference to the drawings.
A schematic diagram best representing an embodiment of the invention is shown in FIG. A first electrode 2 is disposed in the evacuated conductive vacuum vessel 1, and a second electrode 3 is vertically disposed in the vacuum vessel 1 at a position facing the first electrode 2. Between the two electrodes, there is a movable substrate support member 4 and a substrate to be etched 5 clamped in the movable substrate support member, and the movable substrate support member is movable between the two electrodes. In conjunction with the movement, the substrate to be etched can also move between the two electrodes. The first electrode 2 is integrated with the fixed electrode table 6, and the second electrode 3 is integrated with the movable electrode table 7. The first electrode 2 is connected to the first high-frequency power source 8, and the second electrode 3 is connected to the second high-frequency power source 9. The fixed electrode base 6 and the movable electrode base 7 support both the electrodes described above, and also have a role of insulating both the electrodes and the vacuum vessel 1.

  The first electrode 2 and the second electrode 3 are used in two applications. One is used to emit electromagnetic waves for generating and maintaining plasma, and the other is used to apply a bias to the substrate to be etched. If the area of the two electrodes is equal to or larger than the area of the processed surface of the substrate 5 to be etched, the shape is not particular, but in order to generate a uniform plasma on the substrate or to apply a uniform bias to the substrate In this case, it is desirable to have a vertically and horizontally symmetrical structure. An example of a vertically and horizontally symmetrical electrode structure is a circular or rectangular electrode structure. The two electrodes are preferably made of a material that has high conductivity and plasma resistance and does not cause foreign matter or contamination even when exposed to plasma for a long time. That is, aluminum, various aluminum alloys, titanium alloys, stainless steel, boron-doped silicon and the like are preferable. Alternatively, a material obtained by subjecting a metal surface such as aluminum to an alumite treatment or forming a sprayed film such as alumina, titania or yttria is also preferable. For example, when one of the two electrodes is used for plasma generation, the other is used to apply a bias to the substrate, and a method of processing one side of the substrate or both are used for plasma generation. The usage method can be selected according to the purpose, for example, as a method for processing both sides of the film.

  The movable electrode table 4 and the fixed electrode table 6 are provided with a conductor for applying a high-frequency voltage to the electrodes and a gas introduction path for introducing a process gas into the vacuum vessel.

  The movable substrate support member 4 includes members such as a substrate lower surface support holder and a substrate upper surface support holder. The substrate to be etched is installed between the substrate lower surface support holder and the substrate upper surface support holder, and the substrate lower surface support holder and the substrate are arranged. A function of mechanically clamping the substrate to be etched by the upper surface support holder is provided. The substrate to be etched 5 clamped to the movable substrate support member 4 is interlocked with the movable substrate support member 4 moving on the first support member base 10 in the direction perpendicular to the substrate surface, that is, in the direction of the arrow a. The substrate to be etched can also move between the electrodes. In this figure, the movable substrate support member 4 has a structure that can move on the first support member base 10, but if a mechanism that can move between the electrodes is provided, the structure is not particularly concerned. The movable substrate support member 4 and the side wall are provided with a first positioning mechanism 11 using a detecting means such as light, and between the substrate to be etched 5 and the first electrode 2 installed on the fixed electrode table 6. It is possible to accurately measure and adjust the distance.

  The movable electrode table 7 has a structure that protrudes out of the vacuum vessel through the vacuum bellows 12, and the movable electrode table support member 13 moves on the second support member table 14 in the vertical direction of the substrate surface, that is, the arrow b Can move in conjunction with moving in the direction of. Thereby, the distance between two electrodes facing each other can be set to an optimum distance according to a desired condition. The movable electrode base 7 and the side wall are provided with a second positioning mechanism 15 using detection means such as light, and the distance between the two electrodes facing each other can be accurately measured and adjusted.

  The high frequency power supplies 8 and 9 can select and output one of a frequency of 100 kHz to 13.56 MHz as a high frequency bias and a frequency of 10 MHz to 1 GHz as a plasma source, and can be selectively used depending on the application. For example, when the movable substrate support member 4 is operated and the substrate to be etched 5 is brought close to the first electrode 2, the first high-frequency power source 8 is used as a bias power source, Used to apply a bias to the etched substrate. At this time, the second high-frequency power source 9 is used as a source power source, and is used to emit electromagnetic waves from the second electrode 3 to generate plasma. By doing so, plasma etching can be performed in a state where a bias is efficiently applied to the substrate to be etched.

  When processing a substantially annular substrate having a hole in the center like a magnetic disk substrate, a center made of an insulating material such as heat resistant glass, quartz, alumina, zirconia, silicon nitride, polyimide resin on the two electrodes. By providing the insulator member 16, it is possible to close the holes in the substantially annular substrate and prevent the plasma and process gas from flowing from the holes to the surface opposite to the processing surface. As a result, when plasma processing is performed on the surface of one of the substrates to be etched, the plasma or process gas circulates from the holes to the opposite surface, that is, the surface that is not desired to be in direct contact with the plasma. It is possible to prevent the surface pattern from being damaged or contaminated.

  FIG. 2 schematically shows the circuit configuration of the first high-frequency power source 8 and the second high-frequency power source 9. The two high-frequency power sources have the same structure, and both are hereinafter collectively referred to as a dual-mode high-frequency power source. The dual-mode high-frequency power supply consists of a bias power supply 19 that applies a high-frequency bias and a source power supply 20 that supplies high-frequency power. The bias power supply 19 is used to efficiently draw ions into the substrate to be etched, and the ions can follow 100 kHz or higher. The frequency of 13.56 MHz or less is desirable, and the source power supply 20 is used to generate and maintain plasma, and the frequency of 10 MHz to 1 GHz that accelerates electrons and efficiently generates plasma is desirable. The bias power source 19 and the source power source 20 can select and output one of them by a switch 21.

  In this figure, the bias power source and the source power source are described in different frequency regions. However, when the frequency region is 1 MHz to 100 MHz, the bias power source and the source power source can be used at the same frequency. At this time, it is desirable that the phase of the voltage output from the bias power supply and the voltage output from the source power supply are shifted by 180 °. This is to make it easier to confine plasma between the opposing electrodes by shifting the phase by a half period. Further, when the bias power source and the source power source are used at the same frequency, the internal structure of the high frequency power source may be only one of the bias power source and the source power source, and no switch is required, leading to cost reduction.

  An example of the structure of the movable substrate support member 4 is shown in FIG. 3A, an enlarged view of the encircling line X is shown in FIG. 3B, and a schematic diagram when the movable substrate support member is brought into close contact with the movable substrate support member is shown. Shown in 3C. The movable substrate support member includes a substrate lower surface support holder 22, a substrate upper surface support holder 23, and a substrate support rod 24, and has a structure that holds and holds the substrate 5 to be etched from both sides as shown in FIG. 3A. Hereinafter, the substrate lower surface support holder and the substrate upper surface support holder are collectively referred to as a substrate support holder. The outermost periphery supporting the substrate of the substrate support holder has a structure protruding 0.5 mm from the substrate surface. As shown in FIG. 3C, when the movable substrate support member 4 is brought into close contact with the electrode 2, a gap is formed between the substrate 5 and the electrode 2 so that they are not in contact with each other. This is to prevent damage.

  A structure in which a gap is formed between the substrate and the electrode and the both are brought into contact with each other as long as the electrode is partially protruded and the gap is formed between the substrate and the electrode may be employed. At this time, the protrusion on the electrode must be in a position where the protrusion does not contact the pattern formed on the substrate to be etched when the movable substrate support member is brought into close contact with the electrode. Further, when the movable substrate member and the electrode are brought into close contact with each other, it is desirable that the electrode surface and the surface of the substrate to be etched are parallel to each other, and it is desirable that all the protruding portions are aligned at the same height.

  The movable substrate support member is preferably an insulating material such as heat resistant glass, quartz, alumina, zirconia. This is because the bias power consumed by the substrate support holder is reduced, and most of the applied bias power is consumed by the plasma formed on the substrate. In order to prevent damage to the substrate 5, the substrate support member, and the electrode inside the substrate support member due to the pressure applied to both of the movable substrate support member and the electrode, as shown in FIG. It is desirable to insert a stretchable material 25 that is resistant to plasma and heat, such as a stainless spring, into the support holder. Even if the substrate support member on which the substrate is installed is moved to the electrode side at a high speed by the elastic material 25 and the substrate support member and the electrode collide, the impact can be mitigated and the substrate, the substrate support member, and the electrode can be prevented from being damaged. In addition, since the elastic material reduces the pressure applied to the substrate, it can be processed while pressing the substrate support member toward the electrode with a constant pressure, and it is possible to perform etching with increased adhesion between the substrate support member and the electrode. is there. This can reduce the amount of plasma and process gas that flows from the side surface of the substrate to the surface opposite to the processing surface.

  Although this figure shows a state in which one substrate to be etched is held in the substrate support holder, a structure in which two or more substrates to be etched are held in the substrate support holder may be employed. In this case, as a matter of course, the number of substrates that can be processed by one etching increases, leading to an improvement in throughput.

  FIG. 7 shows a schematic diagram when etching is performed using the present invention. In this schematic diagram, the movable substrate supporting member 4 with the substrate to be etched is brought into close contact with the electrode 2, the first high frequency power source 8 is used as a bias power source, the second high frequency power source 9 is used as a source power source, and etching is performed. It shows how it is going. When the movable substrate support member mounted with the substrate to be etched is brought into close contact with the electrode 3 and the second high frequency power source 9 is used as a bias power source and the first high frequency power source 8 is used as a source power source, the schematic diagram of FIG. In the same way, the high frequency power supply 8 is replaced with the high frequency power supply 9 and the electrode 2 is replaced with the electrode 3.

  A gap 201 is provided between the substrate to be etched 4 and the electrode 2, and by making the substrate to be etched 4 and the electrode 2 non-contact, damage to the pattern formed on the substrate to be etched can be prevented. Further, the plasma 203 generated by the electromagnetic wave radiated from the electrode 3 exists on the substrate 5 to be etched, and a bias having a frequency of 100 kHz to 13.56 MHz is applied to the electrode 2 from a high frequency bias power source. An ion sheath 202 is formed between the plasma 203 formed on the substrate to be etched and the substrate 4 to be etched by applying a bias to the substrate 4 to be etched. FIG. 8 shows this state as an electrical equivalent circuit. Here, the gap 201 can be regarded as a capacitance component with respect to the high-frequency bias, and the sheath 203 can be regarded as a non-linear element having a certain impedance.

  In FIG. 8, Z201 represents a high-frequency impedance per unit area of the gap 201, and Z202 represents a high-frequency impedance per unit area of the sheath 202 formed on the upper portion of the substrate 4 to be etched. In this equivalent circuit, the substrate to be etched 4 and the plasma 203 are regarded as conductors and omitted.

FIG. 9 shows the applied voltage dependence of the power density consumed by the high-frequency impedance Z202 that simulates the sheath when the thickness of the gap d, that is, the high-frequency impedance Z201 is changed, using the equivalent circuit of FIG. This is the estimated result. The vertical axis in FIG. 9 indicates the power density consumed by the high frequency impedance Z202 when the thickness d of the gap 201 is changed, and the horizontal axis indicates the amplitude of the output voltage from the first high frequency power supply 8. Here, the frequency of the bias voltage output from the first high-frequency power supply 8 is 800 kHz, the relative permittivity of the gap 202 is 1, the plasma density is 1.0 × 10 ¹⁰ (/ cm ³ ), and the plasma electron temperature is 2 eV. It is.

From the result of FIG. 9, the power density consumed by the high-frequency impedance Z202 simulating the sheath from the thickness of the gap d of 3 mm or more is less than 0.1 (W / cm ² ), and almost no power is consumed in the sheath, It becomes difficult to apply a bias to the substrate to be etched. For this reason, the thickness of the gap d must be less than 3 mm. The gap d is the distance of the space formed between the substrate to be etched and the electrode when the electrode is brought into close contact with the working substrate support member holding the substrate to be etched, and can be regarded as the same as the height of the protrusion of the substrate support holder. That is, the height of the protrusion of the substrate support holder must be less than 3 mm. In this figure, the plasma density is estimated to be 1.0 × 10 ¹⁰ (/ cm ³ ). However, when the plasma density becomes higher, the substrate to be etched is less likely to be biased. For this reason, in order to efficiently apply a bias to the substrate to be etched, the height of the protruding portion is preferably 1 mm or less.

  In order to efficiently apply a bias to the substrate to be etched, it is desirable that the substrate to be etched is not in contact with the electrode, that is, as long as the thickness of the gap d exceeds 0 mm, the smaller the smaller. However, if the height of the protruding portion is less than 0.05 mm, the processing accuracy is less than 10% of the dimensional error, and it becomes difficult to manufacture the protruding portion of the substrate support holder. For this reason, when the height of the protruding portion is less than 0.05 mm, when the movable substrate support member and the electrode are brought into close contact with each other, the gap between the substrate to be etched and the electrode has a variation of more than 10%, and the in-plane distribution is good. It becomes difficult to process the etching substrate. Therefore, the height of the protruding portion of the substrate support holder is desirably 0.05 mm or more.

  FIG. 10 shows the experimental results of measuring the etching rate of the photoresist material when the Si substrate coated with the photoresist material is disposed on the glass member and when the Si substrate coated with the photoresist material is disposed as it is. In the experiment, a mixed gas of argon and oxygen was used as the process gas. Further, the d value in FIG. 11 represents a converted film thickness in which the relative permittivity of the glass is 4, and the vacuum layer having the relative permittivity of 1, that is, the thickness of the gap d used in FIG. It is known that the sheath power consumption and the etching rate have a corresponding relationship, and the experimental result of FIG. 10 shows the same tendency as the calculation result of d = 0.25 mm in FIG. This shows that the estimate in FIG. 9 is correct.

  From the above, the height of the protruding portion of the substrate support holder must be greater than 0 mm and less than 3 mm, and a bias is efficiently applied to the substrate to be etched and the substrate to be etched is processed with good in-plane distribution. For this purpose, it is desirable that the height of the protruding portion be 0.05 mm or more and 1 mm or less.

  An example of the structure of the electrode is shown in FIG. 4A, and an OX sectional view of FIG. 4A is shown in FIG. 4B. The process gas introduced from the gas introduction path 26 is ejected from a large number of gas ejection holes 27 having a diameter of 0.1 mm to 5 mm in the electrode to make the process gas concentration on the substrate surface uniform. The electrode base 28 is a schematic representation of both the fixed electrode base 6 and the movable electrode base 7, and the electrode 29 is a schematic representation of both the first electrode 2 and the second electrode 3. Indicates.

  The electrode 29 includes a cooling path 30, and the electrode can be cooled by flowing a refrigerant. In this figure, a cooling path is provided in the electrode 29, but a cooling path may be provided in the electrode base 29 as long as the electrode can be efficiently cooled. When using an electrode as a bias source, purging a gas having good thermal conductivity, such as He, from the gas introduction path 26 into the gap between the electrode and the substrate, the thermal conductivity between the substrate and the electrode is improved, and the electrode is supplied. It is also possible to cool the substrate.

  In addition, as described above, the central insulator member 16 provided on the electrode surface closes the hole in the center of the substantially annular substrate to be etched, so that plasma or process gas is emitted from the hole in the center of the substantially annular substrate to be etched. It has a structure that goes around the surface opposite to the processing surface and prevents contamination of the surface opposite to the processing surface.

  Next, a method for etching both the front and back surfaces of the substrate to be etched 5 will be described with reference to FIG. 5 showing an operation diagram of the movable substrate support member. Here, the front surface refers to the substrate surface on the movable electrode table side, and the back surface refers to the substrate surface on the fixed electrode table side.

  In the case of processing the surface, the movable substrate support member 4 on which the substrate 5 is mounted is brought into close contact with the first electrode 2 to form the configuration shown in FIG. Thereafter, the second high frequency power source 9 is used as a source power source and the first high frequency power source 8 is used as a bias power source to etch the surface of the substrate. That is, the high frequency output from the second high frequency power source is emitted from the second electrode 3 as an electromagnetic wave, and the process gas introduced from the first gas introduction path 31 is turned into plasma. At the same time, the first high-frequency power supply 8 is used as a bias power supply, and a bias voltage can be efficiently applied to the substrate to be etched 5 adjacent to the first electrode 2. At this time, by purging a gas having good thermal conductivity such as He from the second gas introduction path 32 into the gap between the first electrode 2 and the substrate to be etched 5, the substrate can be processed while being cooled.

  Similarly, when processing the back surface, the movable substrate support member 4 on which the substrate 5 is mounted is brought into close contact with the second electrode 3 to form the configuration shown in FIG. 5 (B). Thereafter, the first high frequency power supply 8 is used as a source power supply, and the second high frequency power supply 9 is used as a bias power supply, and the back surface of the substrate is etched. That is, the first electrode 2 emits the high frequency output from the first high frequency power source as an electromagnetic wave, and the process gas introduced from the second gas introduction path 32 is turned into plasma. At the same time, the second high frequency power supply can be used as a bias power supply, and a bias voltage can be efficiently applied to the substrate to be etched 5 adjacent to the second electrode 3. At this time, by purging a gas having good thermal conductivity such as He from the first gas introduction path 31 into the gap between the second electrode 3 and the substrate to be etched 5, the substrate can be processed while being cooled.

  In addition, when it is not necessary to apply a bias voltage to the substrate, the configuration shown in FIG. 5C is used, and both the first high-frequency power source and the second high-frequency power source are used as source power sources, and the first gas introduction path and A process gas is simultaneously introduced from the second gas introduction path to generate symmetrical plasma in contact with both the front and back surfaces of the substrate to be etched. By doing so, both front and back surfaces of the substrate to be etched can be processed at a time.

  FIG. 6 shows a second embodiment of the present invention. When the electrode 2, the electrode 3, and the substrate to be etched 5 are arranged horizontally in the vacuum vessel, the structure of FIG. 7 is also used, and the electrode 2, the electrode 3, and the substrate to be etched 5 are vertically arranged in the vacuum vessel as in FIG. It can be etched.

1 is a schematic diagram of a first embodiment of an apparatus configuration according to the present invention. It is a schematic diagram which shows an example of the high frequency power supply used by this invention. It is a schematic diagram which shows an example of the structure of the movable board | substrate support member used by this invention. It is a schematic diagram which shows an example of the structure of the conductor member used by this invention. It is an operation | movement figure which shows the method of processing both surfaces of a substrate by this invention. It is a figure which shows the outline of 2nd embodiment of an apparatus form by this invention. It is a schematic diagram at the time of performing etching using the present invention. It is the figure which represented FIG. 8 with the electrical equivalent circuit. FIG. 6 is a diagram in which changes in sheath power consumption with respect to the thickness of a gap 201 are estimated. It is the result of experimenting the change of the etching rate with respect to the thickness of the gap 201.

Explanation of symbols

1: vacuum container, 2: first electrode, 3: second electrode, 4: movable substrate support member, 5: substrate to be etched, 6: fixed electrode table, 7: movable electrode table, 8: first 9: second high frequency power supply, 10: first support member base, 11: first positioning mechanism, 12: vacuum bellows, 13: movable electrode base support member, 14: second support member 15: Second positioning mechanism 16: Center insulator member 19: Bias power source 20: Source power source 21: Switch 22: Substrate lower surface support holder 23: Substrate upper surface support holder 24: Substrate support rod 25: stretchable material, 26: gas introduction path, 27: gas ejection hole, 28: electrode base, 29: electrode, 30: cooling path, 31: first gas introduction path, 32: second gas introduction path.

Claims (6)

Plasma etching for generating plasma by applying a high-frequency voltage to an electrode opposed to the substrate to be etched held in a vacuum vessel, and etching the substrate to be etched using the plasma In the device
The substrate to be etched, a movable substrate support member that supports the substrate,
After the electrode and the substrate to be etched are etched on one side of the substrate to be etched, the movable substrate support member is moved in the vertical direction with respect to the substrate to be etched, and the surface opposite to the one side of the substrate to be etched A plasma etching apparatus characterized by etching. A plasma is generated by applying a high frequency voltage to an electrode disposed opposite to the substrate to be etched with respect to an annular substrate to be etched having a hole in the center held in the vacuum vessel, and using the plasma In the plasma etching apparatus for etching the substrate to be etched,
A plasma etching apparatus comprising an insulator member provided in the electrode and filling a hole of the annular substrate to be etched. The plasma etching apparatus according to claim 1 or 2,
The outermost peripheral part supporting the substrate to be etched of the movable substrate support member protrudes from the surface of the substrate to be etched held by the movable substrate in a range of 0 mm to less than 3 mm, and the movable substrate support member A plasma etching apparatus characterized in that a contact between the substrate to be etched and the electrode is prevented by contacting the electrode with the protruding portion, thereby preventing contact between the substrate to be etched and the electrode.   The movable substrate support member that supports the electrode, the substrate to be etched, and the substrate to be etched according to any one of claims 1 to 3, wherein the stretch material is inserted into the substrate support member so that the stretch material is A plasma etching apparatus that absorbs an impact applied to an electrode, a substrate to be etched, and a movable substrate support member, and prevents the electrode, the substrate to be etched, and the movable substrate support member from being damaged by the impact. The plasma etching apparatus according to claim 1 or 2,
The plasma etching apparatus characterized in that the high-frequency power source can select and output one of two types of high-frequency voltages: a bias voltage for applying a bias to the substrate and a source voltage for generating plasma.   An etching method for etching a substrate to be etched using the plasma etching apparatus according to claim 1.

Images