JP2008159097A - Substrate holder, etching process of substrate and manufacturing method of magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently form a rugged pattern on recording layers of front and rear both surfaces of a magnetic recording medium. <P>SOLUTION: In a substrate holder provided with an insulating member provided with a recessed part holding a substrate to be etched and a through hole formed in a direct under part of the recessed part and a conductive body member provided with a projecting part engaged with the through hole, a gap part is formed between the surface of the projecting part and a bottom surface of the substrate in such a state that the substrate to be etched is placed in the recessed part, the gap part has 0.05 to 1 mm thickness and the insulating member has 1 to 15 mm thickness. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate holder, a substrate etching method, and a magnetic recording medium manufacturing method, and more particularly to a substrate holder and a substrate etching method suitable for manufacturing a magnetic recording medium in which a recording layer is formed in a concavo-convex pattern.

  A hard disk device rotates a disk-shaped magnetic recording medium at a high speed and records / reproduces a digital signal by a magnetic head. Conventionally, a magnetic recording medium is a disk-shaped aluminum substrate having a very flat surface or a tempered glass substrate on which a magnetic material is deposited 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 stage 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.

  Patent Document 2 discloses an example of a substrate holder that is suitable for dry etching a single substrate.

JP-A-9-97419 JP 2006-222127 A

  However, when the conventional plasma etching apparatus is used to perform uneven processing on the magnetic recording medium, the following two problems occur. First, as a first problem, when the material of the substrate is a non-conductor such as tempered glass, it is difficult to apply a high frequency bias to the substrate. When the substrate is a non-conductor, the high-frequency impedance from the stage to the plasma is remarkably increased only at the portion where the non-conductor substrate is placed. Therefore, it becomes difficult for a high-frequency current to flow through the substrate, and etching of the substrate does not proceed. Increasing the high-frequency bias power to compensate for this not only deteriorates the energy efficiency, but also etches parts other than the part where the substrate of the stage is placed, shortening the life of the stage parts and the like, and reducing the running cost There is a concern that it will increase or foreign matter will be generated due to scraping of stage parts.

  Next, as a second problem, pattern damage on the back surface of the substrate and adhesion of foreign matter to the back surface of the substrate can be mentioned. 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 surface of the stage while processing the front side of the substrate, that is, the surface in contact with the plasma, the uneven pattern on the back side of the substrate is damaged, or foreign matter adheres to the uneven pattern on the back side of the substrate. To occur. This increases the possibility of causing serious defects in the concavo-convex pattern.

  In order to avoid this, there may be a method 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 in that it is difficult to apply a bias to a non-conductive substrate, the etching rate does not increase, and vertical processing becomes difficult.

  Furthermore, in order to perform good uneven pattern processing on both sides of the substrate, attention must be paid not only during the etching process but also about the conveyance of the substrate. In an etching apparatus for manufacturing a normal semiconductor device, a transfer arm always comes into contact with the back surface of a silicon substrate when the silicon substrate is carried into and out of a processing chamber. Therefore, it is impossible to use a similar transport system when etching a magnetic recording medium that requires double-side processing.

  In Patent Document 1 and Patent Document 2, no consideration is given to such a problem.

  One of the objects of the present invention is to avoid damage to the pattern formed on the substrate to be processed during processing and transport of the substrate to be processed having both surfaces to be processed, and to efficiently apply the pattern to both the front and back surfaces of the substrate to be processed. The object is to provide a substrate holder suitable for forming.

  Another object of the present invention is to provide a low-cost substrate manufacturing apparatus and a method for manufacturing a magnetic recording medium, which are suitable for efficiently forming a magnetic recording medium in which recording layers are formed in an uneven pattern on both sides of a substrate. There is to do.

  The substrate holder of the present invention includes a plate-like insulator member provided with a plurality of through holes, and a conductive holding member provided with a convex portion that can be engaged with each through hole, and the convex portion is the through hole. The substrate mounting surface and a gap portion having a thickness in a direction perpendicular to the substrate mounting surface are formed in the through-hole in a state in which the through hole is engaged.

  Here, the thickness of the gap is set between 0.05 mm and 1 mm, the insulator member is set to a thickness of 1 mm to 15 mm, and the impedance of the insulator member viewed from a high frequency bias is It is characterized by being larger than the combined impedance of the gap and the substrate to be processed. Further, the substrate holder is configured to be able to place a plurality of substrates to be etched.

  The method of manufacturing a magnetic recording medium having recording layers on both front and back surfaces according to the present invention includes a step of etching a base resist with a gas-based plasma containing O2 or CO2 on both surfaces of a substrate to be processed, and a fluorocarbon-based method. It is characterized in that at least three steps of etching the insulator layer by plasma and removing the resist remaining on the insulator layer by O2 plasma are performed in the same processing chamber. To do.

  Furthermore, the plasma processing method according to the present invention is characterized in that a substrate holder itself, on which a substrate to be processed having processing surfaces on both sides is placed, is carried into a processing chamber of an etching apparatus, and the substrate holder is subjected to plasma processing. Here, the outer diameter of the substrate holder is desirably 200 mm or 300 mm, which is the same as the wafer size for semiconductor devices.

  In the substrate holder according to the present invention, since the gap portion is provided on the back surface of the substrate to be processed, it is possible to avoid damaging the pattern formed on the back surface of the substrate while the substrate surface is being etched. Further, since the entire substrate holder is transported, it is possible to avoid damaging the pattern formed on the back surface of the substrate during transport.

  In addition, the substrate holder according to the present invention is configured so that the impedance of the insulator member as viewed from the high frequency bias is larger than the combined impedance of the gap and the substrate to be processed. A high frequency bias can be applied only to the medium. As a result, only the magnetic recording medium can be efficiently etched, and the portion of the insulator member that is directly exposed to plasma can be suppressed from being consumed. Thereby, generation | occurrence | production of the foreign material resulting from the scraping of the said insulator member, and the raise of a running cost can be suppressed.

  In addition, since the substrate holder according to the present invention is configured so that a plurality of substrates to be processed can be mounted, a significant improvement in throughput can be expected as compared with the case where the substrates to be processed are processed one by one. Furthermore, by setting the outer diameter of the substrate holder to 200 mm or 300 mm, it is possible to carry out processing using an etching apparatus widely used for manufacturing semiconductor devices, and to suppress the investment cost for the etching apparatus. .

  Further, according to the method for manufacturing a magnetic recording medium according to the present invention, it is possible to efficiently form an uneven pattern on the recording layers on both the front and back surfaces of the magnetic recording medium at a low cost.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a best mode for carrying out an etching apparatus and a processing method for a substrate to be processed according to the invention will be described with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view schematically showing a substrate holder according to the first embodiment of the present invention. 2 shows a cross-sectional view taken along the line OA of FIG.

  The substrate holder 101 is composed of a plate-like insulator member 1, a central insulator member 2, a ring-like conductor member 4, and a disk-like conductor member 5. The disc-shaped plate-like insulator member 1 is provided with a plurality of through-holes 3 at equal intervals from the center thereof. Each through hole is formed with a step portion serving as a substrate mounting surface at the top thereof. The central insulator member 2, the ring-shaped conductor member 4, and the disk-shaped conductor member 5 are integrated to form a conductive holding member. In this conductive holding member, the central insulator member 2 is located at a position corresponding to the central portion of each through-hole 3, and the ring-shaped conductive member 4 is fitted to the central insulator member 2 at the central portion and the outer peripheral portion is penetrated. It is configured to engage with the hole 3. That is, the central insulator member 2 and the ring-shaped conductor member 4 constitute a convex portion that can be engaged with the through hole 3, and the substrate holder 101 is in a state in which the convex portion is engaged with the through hole 3. A substantially ring-shaped recess for holding the substrate to be etched 12 is formed on the upper surface of the substrate.

  FIG. 1 shows a state in which a plurality of substantially ring-shaped substrates to be etched 12 are supported on a substrate holder 101. That is, the outer diameter of the upper end of each through hole 3 is slightly larger than the outer diameter of the substrate 12 to be etched, and the substantially ring-shaped substrate 12 to be etched is formed in each through hole 3 of the plate-like insulator member 1. The structure just fits in the recess, and the substrate to be etched 12 is held on the substrate mounting surface at the periphery of the recess. In addition, each substrate to be etched is held in the vicinity of the central portion by the central insulator member 2 in a substantially ring-shaped recess. As shown in FIG. 2, in a state where the plate-like insulator member 1 is held on the conductive holding member and the convex portion is engaged in the through hole 3, the bottom surface of each substrate to be etched, that is, the substrate mounting surface, In other words, a gap 6 having a thickness in a direction perpendicular to the substrate mounting surface is formed between the surface of the convex portion and the upper surface of the ring-shaped conductor member 4.

  FIG. 1 shows a state in which six substrates to be processed are placed on the substrate holder, but actually, it is preferable from the viewpoint of throughput that a larger number of substrates to be processed are placed. For example, when the substrate holder has an outer diameter of 300 mm and a substrate to be processed having an outer diameter of φ2.5 inches is placed thereon, it is possible to place about 12 to 14 substrates to be processed. It goes without saying that a larger number of substrates to be processed can be placed on a substrate to be processed having an outer diameter of φ2 inches or an outer diameter of φ1.8 inches. In this case, the positions of the through holes 3 provided in the plate-like insulator member 1 are not limited to the example in which the through holes 3 are arranged at equal intervals on a single circle, and the through holes 3 are alternately arranged on two inner and outer concentric circles. It goes without saying that various positions can be taken according to the size of the substrate and processing conditions, such as placement.

Here, it is desirable that the material of the plate-like insulator member 1 and the central insulator member 2 is difficult to change even when exposed to plasma. That is, materials such as quartz (SiO ₂ ), alumina (Al ₂ O ₃ ), aluminum nitride (AlN), and Pyrex (registered trademark) are desirable. Among them, quartz having a small relative dielectric constant is preferable in terms of preventing a high frequency bias from being applied to the plate-like insulator member 1 and the central insulator member 2.

  The plate-like insulator member 1 is provided with a positioning mark 7 for positioning when the substrate 12 to be processed is placed on the substrate holder 101 or when the substrate holder and the substrate to be processed are carried into the etching apparatus. It has been. The positioning mark 7 is created by physically providing a recess in the plate-like insulator member 1 or by embedding a metal, a magnetic material or the like in the plate-like insulator member 1. The orientation of the substrate holder 101 can be detected by detecting the position of the positioning mark 7 of the substrate holder 101 by detecting means such as light, eddy current, and magnetic field.

  Furthermore, the substrate can be processed using an existing semiconductor etching apparatus. That is, by setting the outer diameter of the plate-like insulator member 1 to φ200 mm or φ300 mm, the plate-like insulator member 1 having a diameter of 300 mm, for example, instead of a wafer having a diameter of 300 mm is placed on the lower electrode (stage) of the existing semiconductor etching apparatus. It is possible to process a large number of substrates to be processed at the same time.

  As the material of the conductive holding member, that is, the ring-shaped conductor member 4 and the disk-shaped conductor member 5, conductive materials such as aluminum, various aluminum alloys, titanium alloys, stainless steel, and boron-doped silicon are preferable. Furthermore, the ring-shaped conductor member 4 and the disk-shaped conductor member 5 are preferably integrated by means such as brazing or welding.

  As shown in FIG. 3, the substrate holder 101 has a conductive holding member, that is, a central insulating member 2, a ring-shaped conductive member 4, and a disk-shaped conductive pair member 5 in the vertical direction with respect to the plate-shaped insulating member 1. It has a structure that can be separated. Further, the central insulator member 2 and the through-hole 3 protrude from the central portion in the axial direction, so that step portions are formed on the upper and lower sides, respectively. The upper step portion 21 of the central insulator member and the upper step portion 31 of the through hole 3 are the plate-like insulator member 1, the central insulator member 2, the ring-like conductor member 4, and the disk-like conductive pair member 5. In the state of FIG. 2 where the two are coupled, the height is substantially the same, and the step 21 and the step 31 constitute a substrate mounting surface in the recess. Note that the stepped portion 31 may be slightly raised and the substrate mounting surface may be configured only by this. The lower step portion of the central insulator member 2 corresponds to the step portion of the central hole of the ring-shaped conductor member 4. The step portion 41 on the outer periphery of the ring-shaped conductor member 4 is engaged with the step portion 32 on the lower side of the through hole 3. Further, the disk-shaped conductor member 5 engages with a recess formed on the lower surface of the plate-shaped insulator member 1.

  As shown in FIG. 2, a gap 6 is formed between the mounting surface of the substrate 12 to be processed and the upper surface 40 of the ring-shaped conductor member 4. In other words, in a state where the substrate 12 to be processed is placed on the substrate holder 101, the distance between the substrate 12 to be processed and the upper surface 40 of the ring-shaped conductor member 4 is 0. 0 in the direction perpendicular to the substrate placement surface. A gap 6 having a thickness of about 05 mm to 1 mm is formed. In the substrate holder according to the present invention, by providing this gap portion 6, the substrate to be processed can be etched without damaging the pattern formed on the back surface thereof.

  Next, a substrate transfer mechanism corresponding to the substrate holder according to the present invention will be described with reference to FIG. The transport mechanism includes a push-up mechanism 8, a first substrate holding mechanism 9, and a second substrate holding mechanism 15. The first substrate holding mechanism 9 can transport the substrate 12 to be processed while holding the inner peripheral portion. The second substrate holding mechanism 15 is used to hold the outer peripheral portion of the substrate 12 to be processed and to reverse the vertical direction of the substrate.

  When placing the substrate to be processed on the substrate holder 101, first, the plate-like insulator member 1 is pushed up by the push-up mechanism 8, whereby the central insulator member 2 and the ring-like conductor member are placed against the plate-like insulator member 1. 4. Separate the disk-shaped conductive pair member 5. In this state, the substrate 12 to be processed held by the first substrate holding mechanism 9 is successively placed on the placement surface, that is, the concave portion in the through hole 3 of the plate-like insulator member 1. After placing the substrate to be processed in all of the plurality of through holes 3 provided in the plate-like insulator member 1, the push-up mechanism 8 is lowered.

  Next, an etching apparatus and a transport mechanism for processing a substrate using the substrate holder according to the first embodiment of the present invention will be described. FIG. 4 is a plan view schematically showing an etching apparatus for semiconductor. The semiconductor etching apparatus shown below is merely an example, and may be in any form. In the following description, “a substrate holder in which a plurality of substrates to be processed are installed” is referred to as a “substrate holder”.

  In FIG. 4, reference numeral 102 denotes a hoop containing a plurality of substrate holders 101 on which a plurality of substrates to be processed 12 are placed, and is installed in an atmospheric transfer part of an etching apparatus for semiconductor processing.

  The substrate holder 101 stored in the FOUP 102 is taken out of the FOUP by the transfer arm 104 of the atmospheric transfer robot and then placed on the aligner 105 of the atmospheric transfer unit. The aligner plays a role of fine adjustment of the position of the substrate holder in the horizontal plane and positioning in the circumferential direction.

  Next, a configuration example of the processing chamber 109 of the etching apparatus suitable for processing a substrate to be processed using the substrate holder of the present invention will be described with reference to FIG. FIG. 5 is a longitudinal sectional view showing an outline of an etching apparatus for a semiconductor.

  An insulator top plate 202 and a shower plate 203 are provided above the vacuum chamber 201 that is evacuated and grounded. The process gas supplied from the gas supply system 204 is uniformly introduced into the processing chamber by the shower plate. A stage 207 that is temperature-controlled by a temperature adjustment mechanism 212 is provided at the lower part of the processing chamber, and the substrate holder 101 is placed on the stage 207. A waveguide 205 is provided in the upper portion of the processing chamber, and microwaves are supplied to the processing chamber from a plasma source power source (not shown) via the waveguide. Two or three solenoid coils 208 and a yoke 209 are provided outside the processing chamber 201, and an arbitrary direct current is passed through the solenoid coil to generate a magnetic field having an arbitrary shape in the processing chamber. be able to. The process gas introduced into the processing chamber can be turned into plasma by the interaction between the magnetic field and the microwave. Furthermore, the plasma density and the plasma distribution can be controlled in detail by adjusting the source power, the magnetic field arrangement, the processing pressure, and the like.

  A high-frequency power source 21 is connected to the stage 207 via a matching unit 210 so that a high-frequency bias can be applied to the substrate to be processed installed in the substrate holder 101. The high frequency bias can positively attract ions in the plasma to the substrate to be processed, and realize a vertical processing shape and a high processing speed.

  Further, the wafer stage is provided with a dipole electrostatic chuck so that the disk-shaped conductor member 5 of the substrate holder can be held on the wafer stage by electrostatic attraction when processing the substrate to be processed. Also good.

  According to this embodiment, since the gap is provided on the back surface of the substrate to be processed in the substrate holder, damage to the pattern formed on the back surface of the substrate can be avoided while the substrate surface is being processed. Furthermore, since a high frequency bias can be applied only to the magnetic recording medium, only the magnetic recording medium can be efficiently etched.

  Next, as a second embodiment, a substrate etching method using the substrate holder according to the present invention will be described with reference to FIGS. First, the substrate 12 to be processed is placed on the substrate holder 101. At this point, it is assumed that mask patterns have already been formed on both the front and back surfaces of the substrate to be processed.

  First, as shown in FIG. 3, the plate-like insulator member 1 is pushed up by the push-up mechanism 8, and the substrate to be processed 12 holding the inner peripheral portion by the first substrate holding mechanism 9 is replaced with the plate-like insulator. The members 1 are successively placed in the recesses that are the substrate placement surfaces. After placing the substrate to be processed on all of the plurality of substrate placement surfaces provided in the plate-like insulator member 1, the push-up mechanism 8 is lowered. Here, it is important to place the substrate 12 to be processed on the substrate holder without contacting the front and back pattern portions of the substrate.

  The substrate holder after setting a plurality of substrates to be processed is set in a wafer cassette or hoop for a semiconductor etching apparatus.

  Next, as shown in FIG. 4, a hoop containing a plurality of substrate holders on which a plurality of substrates to be processed 12 are installed is installed in the atmospheric transfer part of an etching apparatus for semiconductor processing. The substrate holder 101 stored in the hoop 102 is taken out from the hoop by the atmospheric transfer arm 104 and then placed on the aligner 105. The substrate holder whose position and direction are adjusted by the aligner is carried into the lock chamber 106. Next, after the lock chamber is evacuated by a pump (not shown), the substrate holder 101 is carried into the buffer chamber 107 by the vacuum transfer arm 108. Thereafter, the substrate holder 101 is carried into the processing chamber 109 and subjected to a predetermined etching process. That is, the substrate 12 to be processed is transferred into the etching apparatus together with the substrate holder 101, and is subjected to the etching process with respect to the substrate holder. At this time, as described above, by using the substrate holder according to the present invention, only the substrate to be processed 12 can be efficiently etched, and the plate-like insulating member 1 is hardly damaged by the plasma. Furthermore, the gap 6 provided on the back side of the substrate 12 to be processed does not damage the pattern on the back surface of the substrate 12 to be processed.

  Next, the substrate holder 101 on which the substrate 12 to be processed that has undergone the processing on one side is unloaded from the processing chamber 109 by the vacuum transfer arm 108 and is loaded into the lock chamber 106. The lock chamber is then purged with nitrogen gas or dry air. After the pressure in the lock chamber rises to atmospheric pressure, the substrate holder 101 is unloaded from the lock chamber by the atmospheric transfer arm and collected in the FOUP 102.

  After the processing of all the substrate bases 12 to be processed is completed by the procedure described so far and the substrate holder 101 on which all the substrate bases 12 to be processed are recovered, the hoop is recovered from the etching apparatus. The

  Next, a procedure for inverting the front and back of the substrate 12 to be processed will be described with reference to FIG. 3 again. First, the plate-like insulator member 1 is pushed up by the push-up mechanism 8, the inner peripheral portion of the substrate to be processed 12 is held by the first substrate holding mechanism 9, and the substrate to be processed 12 is removed from the plate-like insulator member 1. lift. Next, after holding the outer peripheral portion of the substrate 12 to be processed by the second substrate holding mechanism 15, the first substrate holding mechanism 9 is opened. Next, the second substrate holding mechanism 15 is rotated 180 ° in the θ direction in the figure to reverse the vertical direction of the substrate, and then the inner peripheral portion of the substrate 12 to be processed is again formed by the first substrate holding mechanism 9. And the second substrate holding mechanism 15 is opened. Finally, the first substrate holding mechanism 9 is lowered, and the substrate 12 to be processed whose front and back are reversed is placed on the plate-like insulator member 1. These series of operations are performed for the number of substrates 12 to be processed.

  The substrate holder 101 after setting the plurality of substrates to be processed 12 whose front and back sides are reversed is set again in the hoop for the semiconductor etching apparatus. The hoop is again installed in the etching apparatus and performs an etching process on a surface that has not been processed yet. Since this processing is performed in the same procedure as described above, description thereof is omitted.

  Finally, after the hoop in which the substrate holder on which the substrate 12 to be processed on which both sides have been processed is placed is stored is recovered from the etching apparatus, the substrate 12 to be processed is recovered from the substrate holder 101.

  First, the plate-like insulator member 1 is pushed up by the push-up mechanism 8, and the substrate to be processed 12 holding the inner peripheral portion by the substrate holding mechanism 9 is sequentially collected from the concave portion of the plate-like insulator member 1. After the substrate to be processed is collected from all of the plurality of recesses provided in the plate-like insulator member 1, the push-up mechanism 8 is lowered.

  In the above description, the plate-like insulator member 1 is pushed up by the push-up mechanism 8 to place and collect the substrate to be processed. As a modification of the first embodiment, the central insulator member 2 is The substrate to be processed can also be placed and recovered by pushing it up. In this case, an opening is provided immediately below the central insulator member 2 of the disk-shaped conductor member 5, and a push-up mechanism 8 for pushing up the central insulator member 2 through the opening is provided for the number of substrates to be processed. Install it. Even in this case, the bottom surface of each substrate to be etched in a state where the convex portion constituted by the central insulator member 2 and the ring-shaped conductor member 4 is engaged in the through hole 3 of the plate-like insulator member 1. Then, a gap portion 6 having a thickness in a direction perpendicular to the substrate mounting surface is formed between the substrate mounting surface and the surface of the convex portion, in other words, the upper surface of the ring-shaped conductor member 4. The central insulator member 2 is configured to be movable up and down with respect to the ring-shaped conductor member 4 and the disk-shaped conductor member 5. In this case, the substrate holding mechanism 9 may be configured to hold the outer peripheral portion of the substrate to be processed.

  According to the present invention, it is possible to efficiently apply a high-frequency bias to the substrate 12 to be processed by setting the thickness of the gap 6 and the thickness of the plate-like insulator member 1 as shown below. Become.

  FIG. 6 shows a schematic view when etching is performed using the substrate holder 101 according to the present invention. Plasma 20 generated using CCP, ICP, or a magnetic field microwave plasma source is present above the substrate holder 101, and the disk-shaped conductor member 5 and the ring-shaped conductor member 4 of the substrate holder. A high frequency bias having a frequency of about 100 kHz to 13.56 MHz is applied from the high frequency power source 21. An ion sheath 23 is formed on the upper surface of the plasma, the substrate holder, and the substrate to be processed by applying a bias.

  The applied high-frequency bias current flows into the plasma 20 via the plate-like insulator member 1-sheath 23 (path b), and via the gap 6-substrate 12-sheath 23 (path c). Therefore, it can be considered to be decomposed into the amount that flows into the plasma 20.

  FIG. 7 shows this state as an electrical equivalent circuit. Here, the plate-like insulator member 1, the gap 6, and the substrate to be processed 12 can all be regarded as capacitance components with respect to the high frequency bias, and the sheath 23 can be regarded as a nonlinear element having a certain impedance.

  In FIG. 7, Z 1 b represents the high frequency impedance per unit area of the plate-like insulator member 1, and Zsb represents the high-frequency impedance per unit area of the sheath formed on the plate-like insulator member 1. Z6c represents the high-frequency impedance per unit area of the gap portion 6, Z3c represents the substrate 12 to be processed, and Zsc represents the sheath formed on the substrate 12 to be processed. Ib indicates the current density of the high-frequency current flowing through the path b, and Ic indicates the current density of the high-frequency current flowing through the path c.

  Here, consider a case where the combined impedance (Z6c + Z3c) created by the gap 6 and the substrate 12 to be processed is equal to the impedance Z1b of the plate-like insulator member 1. This state is referred to as Case 1. In this case, the voltage Vsc applied to the sheath on the substrate 12 to be processed and the voltage Vsb applied to the sheath on the plate-like insulator member 1 are naturally equal. Further, the current density Ic flowing through the path c and the current density Ib flowing through the path b are also equal. That is, the power density IcVsc consumed by the sheath on the substrate 12 to be processed is equal to the power density IbVsb consumed by the sheath on the plate-like insulator member 1.

  Next, consider a case where the thickness of the plate-like insulator member 1 is slightly increased from the above-described state and the impedance Z1b formed by the plate-like insulator member 1 is increased. This state is referred to as Case 2. In this case, the following phenomenon occurs.

  (1) Considering the voltage applied to each element in the path b, since the voltage V1b divided by Z1b increases, the voltage Vsb applied to the sheath decreases conversely.

  (2) Considering the current density divided into the path b and the path c, since Z1b> Z3c + Z6c, the current density Ib of the bias current flowing in the path b becomes small.

  (3) Due to the synergistic effect of the above (1) and (2), the electric power Vsb × Ib consumed by the sheath formed on the upper part of the plate-like insulator member 1 is greatly reduced.

  Thus, by slightly increasing the thickness of the plate-like insulator member 1, the power consumed by the sheath on the plate-like insulator member 1 is greatly reduced. As a result, the sheath on the substrate 12 to be processed is reduced. The electric power consumed in will greatly increase. That is, the input bias power efficiently contributes to the etching of the substrate 12 to be processed.

  On the contrary, when the thickness of the plate-like insulator member 1 is slightly reduced from the case 1, a phenomenon completely opposite to that described in the case 2 occurs. That is, the power consumed by the sheath on the substrate to be processed 12 is greatly reduced, and the input bias power hardly contributes to the etching of the substrate to be processed 12.

  As apparent from what has been described so far, the critical state in which the bias power is more efficiently applied to the substrate 12 to be processed than the plate-like insulator member 1 is the case 1, that is, the gap 6 and the object to be processed. It can be seen that the combined impedance (Z6c + Z3c) produced by the substrate 12 is equal to the impedance Z1b of the plate-like insulator member 1. Further, in the case 1, it has been shown that the substrate 12 to be processed can be efficiently etched by increasing the thickness of the plate-like insulator member 1. However, if the same idea is used, the thickness of the gap 6 is reduced. That is, it can be seen that the same effect can be expected by reducing Z6c.

  Next, when the gap portion 6 is set to a certain thickness t6, to what extent the thickness t1 of the supporting dielectric member 1 is increased, a high frequency bias is efficiently applied to the substrate 12 to be processed. I specifically estimated.

  The solid line in FIG. 8 indicates the critical thickness t1c of the supporting dielectric member 1 with respect to the thickness t6 of the gap 6 and is a line that satisfies the relationship Z1b = Z6c + Z3c. Here, the relative dielectric constant of the supporting dielectric member 1 is 4 (quartz), the relative dielectric constant of the gap 6 is 1 (vacuum), the relative dielectric constant of the substrate to be processed is 6 (glass), and the thickness of the substrate to be processed is Is estimated as 0.65 mm. In FIG. 8, when a combination of the values of t1 and t6 existing in the region above the solid line is used, more bias is applied to the substrate to be processed than the supporting dielectric member.

  Furthermore, the broken line in FIG. 8 indicates T1c, which is a line that satisfies the relationship Z1b = 1.5 × (Z6c + Z3c). If a combination of t1 and t6 existing in the region above the broken line in FIG. 8 is used, a high frequency bias can be applied to the substrate 12 to be processed more efficiently. Here, the broken line in FIG. 8 can be represented by a straight line of T1c = 0.65 + 6 × t6 using the critical thickness t1c and the thickness t6 of the gap 6. Further, the intercept value 0.65 in the straight line expression representing the broken line corresponds to the thickness of the substrate to be processed of 0.65 mm. That is, when the thickness of the substrate 12 to be processed is set to t3, the thickness t1c of the supporting dielectric member 1 satisfies the relationship of t1c> (t3 + 6 × t6) with respect to the thickness t6 of the gap 6. It is only necessary to determine.

  Moreover, in FIG. 8, the one-dot broken line which shows a process limit, and the two-dot broken line which shows a conveyance limit are shown. The processing limit is limited by the accuracy with which the dielectric support member 1 is formed by machining, and indicates the minimum value of the thickness of the gap 6, which is approximately 0.05 mm. The transport limit indicates the maximum thickness t1c of the supporting dielectric member 1 that can be transported by a general semiconductor etching apparatus, which is usually about 7-8 mm. Therefore, a region indicated by hatching is a preferable region. The support dielectric member 1 is desirably thicker from the viewpoint of efficiently applying a bias to the substrate to be processed. However, if the support dielectric member 1 is too thick, there is a concern that the support dielectric member 1 may come into contact with a part of the etching apparatus through the transport path. Although this concern can be resolved by making a slight modification to the semiconductor etching apparatus, when considering the cost of the insulator member and the increase in the weight of the insulator member, the thickness of t1c is limited to about 15 mm. I think.

  According to the present embodiment, the substrate holder is configured so that the impedance of the insulator member viewed from the high frequency bias is larger than the combined impedance of the gap and the substrate to be processed. A high frequency bias can be applied only to the magnetic recording medium. As a result, only the magnetic recording medium can be efficiently etched, and the portion of the insulator member that is directly exposed to plasma can be suppressed from being consumed. Thereby, generation | occurrence | production of the foreign material resulting from the scraping of the said insulator member, and the raise of a running cost can be suppressed.

  Next, FIG. 9 shows an example of a substrate processing process using the substrate holder 101 according to the present invention. The substrate in this case is a magnetic recording medium such as a discrete track medium, for example. A discrete track medium is a recording medium that is physically and magnetically separated by a groove in which each data track is formed. The discrete track medium leaves only the track portion necessary for recording, removes the magnetic material between the tracks unnecessary for recording, and fills it with a nonmagnetic material. As a manufacturing process, first, a pattern is transferred to a resist resin on a recording medium, and a groove is formed on the surface of the recording medium by dry etching using the transferred resin pattern as a mask material. In order to ensure the flying stability of the magnetic head, a nonmagnetic material is again buried in the groove once formed and planarized, and then a protective film or the like is formed. In order to refill the groove once formed and finish the surface of the recording medium into a mirror surface, a nano-order fine processing technique is required. Hereinafter, a description will be given based on the drawings.

  In FIG. 9, (a1) shows the state of the substrate to be processed that is carried into the etching chamber together with the substrate holder 101. In other words, the insulator layer 302 is formed on the tempered glass substrate 303, and a desired pattern ( That is, a resist mask portion 301 (dot pattern, groove pattern, servo pattern) is formed. Here, the insulator layer 303 is made of a material such as silicon nitride or silicon oxide. The mask portion 301 is formed using an imprint method, light, or electron beam lithography.

  First, as shown in (a2), the base resist portion is removed by dry etching in an etching chamber as a first step. In this first step, it is necessary to remove the base resist layer while suppressing the amount of side etching, and selectivity with the underlying insulating film layer 302 is required, so O 2 or CO 2 is used. Further, by diluting these gases with a gas having a low reactivity such as N 2 or Ar, it is possible to further suppress the side etch amount.

  Next, in the second step, the insulator layer 302 is etched as shown in (a3). In this step, the vertical processability of the insulator layer and the selection ratio of the resist material that is the mask are required. In many cases, these fluorocarbon-based gases are diluted with a less reactive gas such as Ar, N2, or Xe, and O2 or the like is added. In addition, if the oxygen atmosphere in the first step remains, the resist selectivity may be lowered. Therefore, it is desirable to interrupt the discharge between the first step and the second step.

  Next, in the third step, as shown in (a4), the resist material remaining on the upper part of the pattern is removed by ashing with O2 plasma. Further, in the present invention, the above-described first to third steps can be consistently processed in one etching processing chamber.

  The fluorocarbon-based gas used in the second step described above is highly depositable, and CF-based polymer is deposited on the walls of the processing chamber. As a result, the etching characteristics may change with time and the polymer may peel off from the wall and become a foreign substance, but the third process not only removes the resist material remaining on the pattern, but also CF deposited on the wall. It also serves as a cleaning agent to remove the polymer. That is, by performing the first process to the third process in a single etching process chamber, it is possible to always keep the process chamber in a constant state, and a stable treatment can be expected for a long time with low foreign matters. . By performing the steps from the first step to the third step, the portions for performing the processes (a1) to (a4) in FIG. 9 are the features of the substrate holder and the etching method using the substrate holder according to the present invention. It is. Note that it goes without saying that the same effect can be obtained when another process is added to the above three processes and integrated processing is performed in one etching chamber.

  After the etching of the insulating layer 302 is completed, a wet cleaning process is performed by a wet processing apparatus, and then a plurality of layers of magnetic bodies 304 made of an alloy such as Co, Ni, Fe, and Pt are deposited by a sputtering apparatus. The magnetic material as shown in (a5) of 9 is patterned. Furthermore, by filling the pattern recess with an insulator by sputtering or SOG (Spin On Glass) coating, and performing planarization by CMP (Chemical Mechanical Polyshing) method, etch back, milling, etc., the surface is very smooth and A magnetic recording medium such as a discrete track medium patterned with a magnetic material can be produced.

  According to the present embodiment, since a plurality of substrates to be processed can be placed, a significant improvement in throughput can be expected compared to the case where the substrates to be processed are processed one by one. Furthermore, by setting the outer diameter of the substrate holder to 200 mm or 300 mm, it is possible to carry out processing using an etching apparatus widely used for manufacturing semiconductor devices, and to suppress the investment cost for the etching apparatus. .

  Next, FIG. 10 shows an example of another substrate processing process using the substrate holder 101 according to the present invention. The processing process of FIG. 9 is a method in which a substrate is patterned in advance and a magnetic material is deposited thereon by sputtering. Example 4 described below is a method of directly processing a magnetic material.

  FIG. 10B1 shows a state in which a magnetic material 304 is deposited on a tempered glass substrate 303 and a resist mask portion 301 having a desired pattern is formed thereon. Here, the magnetic body 304 usually has a multilayer structure in order to improve the magnetic characteristics and the stability of the magnetic film, but is shown in a single layer structure for the sake of simplicity of the drawings and description. .

  First, as shown in (b2) as the first step, the base resist portion is removed by dry etching in the etching processing chamber. For this, it is necessary to remove the base resist layer while suppressing the amount of side etching, and since selectivity with the underlying insulating film layer 302 is required, O 2 or CO 2 is used. Further, by diluting these gases with a gas having a low reactivity such as N 2 or Ar, it is possible to further suppress the side etch amount.

  Next, as shown in (b3) as a second step, the magnetic body 304 is directly etched. For this, a gas system such as CO + NH3 is often used. Since the magnetic material is poor in volatility, the etching hardly proceeds unless a bias is applied. However, by using the substrate holder according to the present invention, it is possible to efficiently apply a bias, and high throughput processing can be expected. .

  Next, as shown in (b4) as a third step, the resist material remaining on the upper portion of the pattern is removed by ashing with O2 plasma. Thus, the part which performs the processing from (b1) to b4 is another etching method using the substrate holder and the substrate holder according to the present invention. Further, after that, an insulator is embedded in the pattern recess and the surface is flattened, whereby a magnetic recording medium can be produced.

  By consistently performing the first to third steps in one etching chamber, the state of the chamber can be kept constant, and stable treatment can be expected for a long time with low foreign matters. Note that it goes without saying that the same effect can be obtained when another process is added to the above three processes and integrated processing is performed in one etching chamber.

  According to the present embodiment, since a plurality of substrates to be processed can be placed, a significant improvement in throughput can be expected compared to the case where the substrates to be processed are processed one by one.

  Although the etching method using the substrate holder according to the present invention has been described above, the cost of the etching apparatus itself can be reduced by diverting the one for semiconductor manufacturing. As for the etching apparatus, an etching apparatus using any method other than the inductive coupling type, the parallel plate type, and the magnetic field microwave type may be used.

  Further, in the etching method using the substrate holder according to the present invention described so far, when the substrate 12 to be processed is placed on the substrate holder, an apparatus for placing, inverting and collecting the substrate on the holder is necessary. However, the mechanism can be provided in the etching apparatus itself.

  Next, other embodiments for carrying out the present invention will be described. A cross-sectional view of this embodiment is shown in FIG. The description of the parts described in the first embodiment is omitted. FIG. 11 shows a state in which the substrate holder according to the present invention is placed on the stage 207 in the etching apparatus. The stage 207 is provided with a temperature control mechanism 212 and a cooling gas introduction mechanism 213, and a high frequency power supply 211 is connected via a matching unit 210. In addition, the outer periphery of the electrode is also provided with a susceptor 214 made of quartz or alumina in order to prevent leakage of the bias power to the part other than the upper part of the electrode.

  In this embodiment, a gas introduction mechanism 10 for introducing a gas such as helium, argon, or nitrogen into the gap 6 between the substrate to be processed 12 and the ring-shaped conductor member 5 is provided. Further, a substrate chucking mechanism 11 to be processed is provided.

  The gas introduction mechanism 10 prevents the lower surface of the substrate to be processed 12 from being damaged by purging the gap 6 when the upper surface of the substrate to be processed 12 is etched. Etching proceeds when ions or radicals generated by the plasma are incident on the substrate. However, radicals may enter the gap 6 while the upper surface of the substrate 12 is being etched.

  The radical that has entered the gap portion 6 may damage the mask pattern on the lower surface of the substrate 12 to be processed and the pattern that has already been etched. By purging the gap 6 with the gas introduction mechanism 10 during the etching process and keeping the pressure in the gap 6 higher than the processing pressure, it is possible to prevent radicals from entering the gap 6.

  The processing pressure is usually about 0.2 Pa to 20 Pa, but radicals can be completely prevented from entering the gap 6 by setting the purge pressure to the gap 6 to about 0.3 kPa to 3 kPa. Furthermore, by performing a gas purge to the gap 6, it becomes possible to adjust the temperature of the substrate to be processed, so that more precise processing can be performed. Further, the substrate to be processed 12 can be prevented from being lifted by the substrate chucking mechanism 11 when the pressure in the gap 6 is made higher than the processing pressure.

  Gas supply to the substrate holder itself is performed from a cooling gas introduction mechanism 213 that is usually provided in a wafer stage of an etching apparatus. At this time, the concern that the substrate holder may float from the wafer stage is that a wafer stage equipped with a dipole electrostatic chuck is used to electrically chuck the disk-shaped conductor member 5 of the substrate holder on the stage. Can be avoided.

  As described above, by using this embodiment, it is possible to prevent damage to the back surface of the substrate to be processed, and furthermore, the temperature of the substrate to be processed can be controlled, so that more precise processing can be performed. it can.

It is a perspective view which shows the outline of 1st embodiment of the board | substrate holder by this invention. It is sectional drawing which shows the OA cross section in FIG. It is a figure which shows the method of mounting, reversing, and collect | recovering the to-be-processed substrates. It is a top view which shows the outline of the etching apparatus for semiconductors. It is sectional drawing which shows the outline of the etching process chamber of the etching apparatus for semiconductors. It is a schematic diagram at the time of etching using the substrate holder by this invention. It is the figure which showed FIG. 6 with the electrical equivalent circuit. It is a figure which shows the critical thickness of the plate-shaped insulator member 1 with respect to the thickness of the clearance gap part 6. FIG. It is a conceptual diagram which shows the multi-step etching process using the substrate holder by this invention. It is a conceptual diagram which shows the multistep etching process which becomes another embodiment using the substrate holder by this invention. It is a figure which shows other embodiment of the board | substrate holder by this invention.

Explanation of symbols

1: plate-like insulator member, 2: central insulator member, 4: ring-like conductor member, 5: disc-like conductor member, 6: gap portion, 7: positioning mark, 8: push-up mechanism, 9: first One substrate holding mechanism, 10: gas introduction mechanism, 11: substrate to be processed chucking mechanism, 12: substrate to be processed, 15: second substrate holding mechanism, 21: high frequency power supply 101: substrate holder, 102: hoop, 104 : Atmospheric transfer arm, 105: aligner, 106: lock chamber, 107: buffer chamber, 108: vacuum transfer arm, 109: processing chamber, 201: vacuum chamber, 202: insulator top plate, 203: shower plate, 204: process Gas supply system, 205: Waveguide, 207: Stage, 208: Coil, 209: Yoke, 210: Matching device, 211: High frequency power supply, 212: Temperature control mechanism, 213: Cooling gas supply Structure, 301: mask portion, 302: insulating layer, 303: tempered glass substrate, 304: magnetic body.

Claims (11)

A plate-like insulator member provided with a plurality of through holes, and a conductive holding member provided with a convex portion that can be engaged with each through hole;
The substrate mounting surface and a gap having a thickness in a direction perpendicular to the substrate mounting surface are formed in the through hole in a state where the convex portion is engaged with the through hole. Substrate holder. In claim 1,
A substrate holder, wherein the gap portion has a thickness of 0.05 mm or more and 1 mm or less, and the plate-like insulator member has a thickness of 1 mm or more and 15 mm or less. In claim 1,
When the thickness of the substrate to be processed held on the substrate mounting surface is t3, the gap portion of thickness t6 is formed between the convex surface and the bottom surface of the substrate, A thickness t6 of the gap is 0.05 mm or more and 1 mm or less, a thickness t1c of the insulator member is 1 mm or more and 15 mm or less, and satisfies a relationship of t1c> (t3 + 6 × t6) Substrate holder. In Claim 1, the plate-like insulator member and the conductive holding member are formed of a disk-like member,
The substrate holder, wherein the plate-like insulator member and the conductive holding member are separable in a direction perpendicular to the substrate mounting surface. In claim 1,
A substrate holder comprising a mechanism for introducing gas into the gap. An etching processing apparatus that includes an atmospheric transfer robot, a lock chamber, a vacuum transfer robot, and a vacuum processing chamber, and performs an etching process on a substrate to be processed having a surface to be processed on both sides.
An atmospheric transfer robot for transferring the substrate holder between the lock chamber and a hoop capable of storing a plurality of substrate holders on which a plurality of the substrates to be processed are placed;
A vacuum transfer robot for transferring the substrate holder between the lock and the vacuum processing chamber;
The vacuum processing chamber has a stage for placing the substrate holder and etching one substrate surface of the substrate to be processed,
The substrate holder includes a plate-like insulator member provided with a plurality of through holes, and a conductive holding member provided with a convex portion that can be engaged with each through hole, and the convex portion of the conductive holding member is In a state where the plate-like insulator member is engaged with the through hole, a substrate placement surface and a gap portion having a thickness in a direction perpendicular to the substrate placement surface are formed in the through hole, and The plate-like insulator member and the conductive holding member are configured to be separable,
After reversing the substrate surface in the substrate holder where one substrate surface of the substrate to be processed has been processed, the substrate holder is placed on the stage and the other surface of the substrate to be processed An etching processing apparatus characterized by being configured to perform etching processing. A method for producing a magnetic recording medium having recording layers on both front and back surfaces,
Etching the base resist with a gas-based plasma containing O2 or CO2 on both surfaces of the substrate to be processed, etching the insulator layer with a fluorocarbon-based plasma, and the insulator layer with an O2-based plasma. A method of manufacturing a magnetic recording medium, wherein at least three steps of removing a resist remaining on the upper portion are subjected to an integrated process in the same processing chamber.   8. The method of manufacturing a magnetic recording medium according to claim 7, wherein the discharge is interrupted between the steps. In an etching processing apparatus provided with an atmospheric transfer unit, a lock, a vacuum transfer robot and a vacuum processing chamber, an etching method for etching both surfaces of a substrate to be processed using a substrate holder,
The substrate holder includes a plate-like insulator member provided with a plurality of through holes, and a conductive holding member provided with a convex portion that can be engaged with each through hole, and the convex portion of the conductive holding member is In a state where the plate-like insulator member is engaged with the through hole, a substrate placement surface and a gap portion having a thickness in a direction perpendicular to the substrate placement surface are formed in the through hole,
An etching method characterized by consistently performing a plurality of processing steps on the substrate to be processed placed on the substrate holder in the same vacuum processing chamber. The plasma etching method according to claim 9,
For the substrate to be processed placed on the substrate holder,
Etching the base resist with a gas-based plasma containing O 2 or CO 2;
Etching the insulator layer with fluorocarbon plasma;
Etching method characterized in that at least three steps of removing the resist remaining on the upper part of the insulator layer by O2 plasma are consistently processed on the substrate to be processed in the same vacuum processing chamber. . The plasma etching method according to claim 9,
For the substrate to be processed placed on the substrate holder,
Etching the base resist with a gas-based plasma containing O2 or CO2, etching the magnetic layer with a CO + NH3-based plasma, and removing the resist remaining on the magnetic body with the O2-based plasma. An etching method characterized in that at least three steps are performed consistently in the same vacuum processing chamber.

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