JP2006351949A - Substrate mounting base, method for manufacturing the same and substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate mounting base capable of preventing processing unevenness such as etching unevenness due to projections themselves formed on the substrate mounting substrate, and to provide a method for manufacturing the same. <P>SOLUTION: The substrate mounting base 4 where a substrate G is mounted in a substrate processing apparatus 1 has a primary mounting base body 4a, a plurality of projections 7 formed projecting from the reference surface of the primary mounting base body 4a on the substrate mounting side, a peripheral edge base 6 which is formed projecting from the reference surface to surround the reference surface and come into contact with the peripheral edge of the substrate G when the substrate G is mounted. The reference surface and the top surface of the peripheral edge base 6 are smooth surfaces of ≤1.5 μm in surface roughness Ra (mathematical mean roughness), and top surfaces of the projections are rough surfaces of ≥8 μm in surface roughness Ry (maximum height). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate mounting table on which a substrate such as a glass substrate for manufacturing a flat panel display (FPD) is mounted, a method for manufacturing the same, and a process such as dry etching on the substrate using the substrate mounting table. The present invention relates to a substrate processing apparatus that applies

  For example, in the FPD manufacturing process, plasma processing such as dry etching, sputtering, and CVD (Chemical Vapor Deposition) is frequently used for a glass substrate that is a substrate to be processed.

  In such plasma processing, for example, a pair of parallel plate electrodes (upper and lower electrodes) are disposed in a chamber, a substrate to be processed is mounted on a susceptor (mounting table) that functions as a lower electrode, and a processing gas is supplied. While being introduced into the chamber, a high-frequency electric field is applied to at least one of the electrodes to form a high-frequency electric field between the electrodes, a plasma of a processing gas is formed by this high-frequency electric field, and the substrate to be processed is subjected to plasma processing.

  Since the surface of the susceptor is actually a gently curved surface, there is a small gap between the substrate and the susceptor, and deposits accumulate on the susceptor by repeatedly performing plasma treatment. To do. For this reason, a portion where the susceptor contacts the back surface of the substrate to be processed and a portion where deposits come into contact with each other, and the thermal conductivity and conductivity differ between these portions, resulting in uneven etching on the substrate (to be processed). In some cases, a portion having a high etching rate and a portion having a low etching rate are mixed in the processing substrate).

  Further, when the substrate to be processed is placed in surface contact with the susceptor, the substrate to be processed may be attracted to the susceptor due to the charging of the plasma processing.

  In order to prevent such uneven etching and adsorption of the substrate to be processed, a proposal has been made to form a convex pattern on the surface of the fired ceramic insulating layer covering the electrostatic electrode (for example, Patent Document 1). There has also been proposed a method in which a concavo-convex pattern is formed on the surface of the susceptor by photoetching to reduce electrostatic force (adhesion force) so that the wafer can be easily separated from the susceptor after plasma processing (Patent Document 2).

  Furthermore, the surface of an aluminum or aluminum alloy susceptor is shot blasted to form irregularities, and in order to prevent impurity contamination, the sharp convexities are removed by chemical polishing, electrolytic polishing, or buffing. The proposal to do is also made (patent document 3).

  Each of these conventional techniques has a drawback that dust generated by plasma processing is likely to accumulate because the top of the convex portion is flat. Further, when the top surface of the convex portion is flat and is in surface contact with the back surface of the substrate to be processed, the contour of the contact surface is transferred to the substrate to be processed as etching unevenness depending on the etching conditions. That is, the unevenness of the etching also occurs due to the protrusion itself, which causes a problem that the yield of the product is lowered. In addition, as a prior art in consideration of the shape of the convex portion, a proposal has been made to form the upper portion of the convex portion into a curved shape by spraying ceramics through an aperture plate (Patent Document 4).

In the case of a susceptor having a convex portion on the surface, there is a difference in height between the convex portion and a surface other than the convex portion, so that by repeating the plasma treatment, deposits accumulate on this portion, and etching unevenness is also caused. There is a concern that it may cause particle contamination of the substrate.
JP-A-60-261377 JP-A-8-70034 JP-A-10-340896 JP 2002-313898 A

  As described above, in the prior art, it has been proposed to form a convex portion on the mounting surface of the substrate mounting table, but the occurrence of etching unevenness caused by the convex portion itself or other than the convex portion and the convex portion There remains room for improvement in the problem of deposit formation due to surface elevation differences. In other words, in the prior art, little consideration has been given to the shape of the convex portion in consideration of etching unevenness and the shape of the surface other than the convex portion and the convex portion.

  When the susceptor has a function as an electrostatic adsorption electrode, a heat transfer medium gas is introduced between the substrate to be processed and the susceptor. At this time, in order to increase heat transfer efficiency, it is preferable to form a sealed space between the susceptor and the substrate to be processed. Therefore, in Patent Document 4, it is also proposed to provide a pedestal at the periphery of the susceptor, but details of the shape of the pedestal and the method of processing the susceptor surface including the pedestal are not shown.

  The present invention has been made in view of the above circumstances, and firstly provides a substrate mounting table and a method for manufacturing the same that can prevent processing unevenness such as etching unevenness caused by the convex portions themselves formed on the substrate mounting table. The challenge is to do. Secondly, it is an object of the present invention to prevent processing unevenness and substrate contamination caused by accumulation of deposits on the surface of the substrate mounting table. Thirdly, it is also an object to provide a substrate mounting table capable of improving the heat transfer efficiency by the heat transfer medium gas and a method for manufacturing the same.

In order to solve the above problems, a first aspect of the present invention is a substrate mounting table for mounting a substrate in a substrate processing apparatus,
A mounting table body;
A plurality of protrusions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body,
Surrounding the reference surface, and a peripheral base portion formed so as to protrude from the reference surface so as to contact the peripheral portion of the substrate when the substrate is placed;
Have
The top surface of the convex part is a rough surface, and the top surface of the peripheral base part is a smooth surface.

  In the first aspect, the plurality of convex portions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body and the reference surface are surrounded and contacted with the peripheral portion of the substrate when the substrate is mounted. In this way, in the substrate mounting table having the peripheral base portion protruding from the reference surface, the top surface of the convex portion is a rough surface and the top surface of the peripheral base portion is a smooth surface. It is possible to improve processing non-uniformity such as uneven etching, and to form a sealed space on the back side of the substrate by bringing the peripheral base part into close contact with the substrate. For example, a heat transfer medium is introduced into this space When the temperature is adjusted, the heat transfer efficiency can be increased.

A second aspect of the present invention is a substrate mounting table for mounting a substrate in a substrate processing apparatus,
A mounting table body;
A plurality of protrusions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body,
Have
The substrate mounting table is characterized in that the reference surface is a smooth surface and the top surface of the convex portion is a rough surface.

  In the second aspect, in the substrate mounting table having a plurality of convex portions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body, the reference surface is a smooth surface and the top surface of the convex portion is a rough surface. Therefore, it is possible to improve non-uniform processing such as uneven etching due to protrusions, and even when reaction products or particles adhere to the reference surface to form deposits, simple cleaning, etc. Easy to remove. Therefore, non-uniform processing such as uneven etching due to deposits and substrate contamination can be reduced.

A third aspect of the present invention is a substrate mounting table for mounting a substrate on a substrate processing apparatus,
A mounting table body;
A plurality of protrusions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body,
Surrounding the reference surface, and a peripheral base portion formed so as to protrude from the reference surface so as to contact the peripheral portion of the substrate when the substrate is placed;
Have
Provided is a substrate mounting table, wherein the reference surface and the top surface of the peripheral base portion are smooth surfaces.

  In the third aspect, the plurality of convex portions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body and the reference surface are surrounded and contacted with the peripheral portion of the substrate when the substrate is mounted. In this way, in the substrate mounting table having the peripheral pedestal formed so as to protrude from the reference surface, the top surface of the reference surface and the peripheral pedestal is a smooth surface, so that reaction products or particles adhere to the reference surface. It is possible to prevent uneven deposition such as uneven etching due to deposits and substrate contamination, and to form a sealed space on the back side of the substrate by bringing the peripheral base portion into close contact with the substrate. For example, when the temperature is adjusted by introducing a heat transfer medium into this space, the heat transfer efficiency can be increased.

A fourth aspect of the present invention is a substrate mounting table for mounting a substrate in a substrate processing apparatus,
A mounting table body;
A plurality of protrusions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body,
Surrounding the reference surface, and a peripheral base portion formed so as to protrude from the reference surface so as to contact the peripheral portion of the substrate when the substrate is placed;
Have
Provided is a substrate mounting table, wherein the reference surface and the top surface of the peripheral base portion are smooth surfaces, and the top surface of the convex portion is a rough surface.

  In the fourth aspect, the plurality of convex portions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body and the reference surface are surrounded, and contact the peripheral edge of the substrate when the substrate is mounted. In this way, in the substrate mounting table having the peripheral pedestal formed so as to protrude from the reference surface, the top surface of the convex portion is made rough, so that uneven processing such as uneven etching due to the convex portion is improved. be able to. In addition, since the reference surface and the top surface of the peripheral pedestal are smooth surfaces, reaction products and particles are prevented from adhering to the reference surface, and are prevented from depositing and sticking. Uniformity and substrate contamination can be reduced by simple cleaning, and it becomes possible to form a sealed space on the back side of the substrate by bringing the peripheral base part into close contact with the substrate. For example, a heat transfer medium is introduced into this space to adjust the temperature. The heat transfer efficiency can be increased when performing the above.

  In the substrate mounting table according to the first, second, or fourth aspect, the surface roughness Ry (maximum height) of the top surface of the convex portion is preferably 8 μm or more.

  In the substrate mounting table according to any one of the second to fourth aspects, it is preferable that a surface roughness Ra (arithmetic mean roughness) of the reference surface is 1.5 μm or less.

  In the substrate mounting table according to the first, third, or fourth aspect, it is preferable that the surface roughness Ra (arithmetic average roughness) of the top surface of the peripheral pedestal is 1.5 μm or less. In this case, it is preferable that the substrate mounting table functions as an electrostatic adsorption electrode, and the mounting table main body includes a base material, a first dielectric material film formed on the base material, and the first dielectric material. A conductive layer laminated on the conductive material film and a second dielectric material film laminated on the conductive layer may be included. Furthermore, a heat transfer medium channel provided through the substrate mounting table and supplying a heat transfer medium toward the back surface of the substrate may be provided.

  According to a fifth aspect of the present invention, there is provided a substrate processing apparatus including the substrate mounting table according to any one of the first to fourth aspects. The substrate processing apparatus may be used for manufacturing a flat panel display, and may be a plasma etching apparatus that performs a plasma etching process on a substrate.

A sixth aspect of the present invention is a method for manufacturing a substrate mounting table for mounting a substrate when processing the substrate,
A dielectric material film forming step of forming a dielectric material film on the substrate surface;
A polishing step of polishing the surface of the dielectric material film;
Cutting the surface of the dielectric material film after polishing, leaving a peripheral edge, and forming a recess;
A protrusion forming step of forming a plurality of protrusions made of ceramics by spraying ceramics on the recesses through an opening plate having a plurality of openings;
A method for manufacturing a substrate mounting table is provided.

  According to the sixth aspect, by a thermal spraying method using an aperture plate as a mask, a substrate mounting table in which the top surface of the convex portion is a rough surface and the surface other than the convex portion is a smooth surface can be obtained with a short processing time and low processing cost Can be manufactured.

In the sixth aspect, the protrusion forming step includes
Placing an aperture plate having a plurality of apertures on the dielectric material film; and
Blasting the dielectric material film exposed in the opening of the opening plate;
Spraying ceramics on the dielectric material film through the aperture plate;
Removing the aperture plate;
Can be included.
Thus, after blasting the dielectric material film through the aperture plate, further spraying ceramics on the dielectric material film through the aperture plate, the dielectric material film of the portion forming the convex portion The convex surface and the dielectric material film can be adhered by roughening the surface by the anchor effect, and the substrate surface other than the portion forming the convex portion is left as a smooth surface by mechanical polishing or machining. Can do.

In the sixth aspect, the dielectric material film forming step includes
Forming a first dielectric material film on a substrate;
Forming a conductive layer on the first dielectric material film;
Forming a second dielectric material film on the conductive layer;
Can be included.

  In the sixth aspect, it is preferable that polishing is performed until the surface roughness Ra (arithmetic average roughness) is 1.5 μm or less in the polishing step. In the cutting step, it is preferable to perform cutting or polishing so that the surface roughness Ra (arithmetic average roughness) of the bottom surface of the recess is 1.5 μm or less. Furthermore, it is preferable that in the convex part forming step, the thermal spraying is performed so that the surface roughness Ry (maximum height) of the surface of the convex part by the thermal spraying is 8 μm or more.

  According to the present invention, it is possible to prevent inconveniences such as uneven processing such as etching unevenness due to the substrate mounting table and substrate contamination due to deposits.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a plasma etching apparatus as an example of a processing apparatus provided with a susceptor as a substrate mounting table according to an embodiment of the present invention. The plasma etching apparatus 1 is a cross-sectional view of an apparatus for performing a predetermined process on an FPD glass substrate G, and is configured as a capacitively coupled parallel plate plasma etching apparatus. Here, as the FPD, a liquid crystal display (LCD), a light emitting diode (LED) display, an electro luminescence (EL) display, a fluorescent display tube (VFD), a plasma display panel (PDP), and the like. Illustrated. The processing apparatus of the present invention is not limited to a plasma etching apparatus.

  This plasma etching apparatus 1 has a chamber 2 formed into a rectangular tube shape made of aluminum, for example, whose surface is anodized (anodized). A prismatic insulating plate 3 made of an insulating material is provided at the bottom of the chamber 2, and a susceptor for placing an LCD glass substrate G, which is a substrate to be processed, on the insulating plate 3. 4 is provided. In addition, an insulating member 8 is provided on the outer periphery of the base material 4a of the susceptor 4 and the peripheral edge of the upper surface where the dielectric material film 5 is not provided.

  A power supply line 23 for supplying high frequency power is connected to the susceptor 4, and a matching unit 24 and a high frequency power supply 25 are connected to the power supply line 23. For example, high frequency power of 13.56 MHz is supplied from the high frequency power supply 25 to the susceptor 4.

  Above the susceptor 4, a shower head 11 that functions as an upper electrode is provided in parallel with the susceptor 4. The shower head 11 is supported on the upper portion of the chamber 2, has an internal space 12 inside, and has a plurality of discharge holes 13 for discharging a processing gas on the surface facing the susceptor 4. The shower head 11 is grounded and forms a pair of parallel plate electrodes together with the susceptor 4.

A gas inlet 14 is provided on the upper surface of the shower head 11, and a processing gas supply pipe 15 is connected to the gas inlet 14. A valve 16 and a mass flow controller 17 are connected to the processing gas supply pipe 15. A processing gas supply source 18 is connected to the via. A processing gas for etching is supplied from the processing gas supply source 18. As the processing gas, a gas usually used in this field, such as a halogen-based gas, an O ₂ gas, or an Ar gas, can be used.

  An exhaust pipe 19 is connected to the bottom of the side wall of the chamber 2, and an exhaust device 20 is connected to the exhaust pipe 19. The exhaust device 20 includes a vacuum pump such as a turbo molecular pump, and is configured so that the inside of the chamber 2 can be evacuated to a predetermined reduced pressure atmosphere. Further, a substrate loading / unloading port 21 and a gate valve 22 for opening and closing the substrate loading / unloading port 21 are provided on the side wall of the chamber 2, and a load lock chamber adjacent to the substrate G with the gate valve 22 opened. (Not shown).

  As shown in FIG. 1, a susceptor 4 that is a substrate mounting table according to an embodiment of the present invention includes a base material 4a and a dielectric material film 5 provided on the base material 4a. A step is provided on the periphery of the upper surface of the dielectric material film 5 to form a base 6. A plurality of convex portions 7 are formed in a protruding shape on the upper surface of the dielectric material film 5, and these convex portions 7 are surrounded by a base portion 6. In addition, between the base material 4a and the dielectric material film 5, it has an intermediate thermal expansion coefficient for the purpose of relaxing the thermal stress due to the difference in the thermal expansion coefficient between the base material 4a and the dielectric material film 5. One or more intermediate layers made of a material may be provided.

  2 is a plan view of the susceptor 4, and FIG. 3 is a cross-sectional view taken along the line III-III ′ of FIG. FIG. 4 is an essential part cross-sectional view showing an enlarged structure near the surface of the susceptor 4. The convex portions 7 are uniformly distributed in the substrate G placement region on the dielectric material film 5, and the substrate G is placed on the convex portions 7. As a result, the convex portion 7 functions as a spacer that separates the susceptor 4 and the substrate G from each other, and the deposits adhered on the susceptor 4 are prevented from adversely affecting the substrate G.

  As schematically shown in FIG. 4, in the susceptor 4 of this embodiment, the convex portion 7 is formed in a trapezoidal shape, for example, in cross section, and the top surface 7 a is roughened. Can be contacted.

  More specifically, the surface roughness Ry of the top surface 7a of the convex portion 7 is 8 μm or more and preferably 9 μm or more and 15 μm or less. Here, Ry is the maximum height specified in JIS B0601-1994. The reference length is determined from the roughness curve in the direction of the average line, and the highest peak height and the lowest height within this reference length. The sum of the bottom of the valley is expressed in micrometers (μm). By setting the surface roughness Ry of the top surface 7a of the convex portion 7 to 8 μm or more, the top surface 7a of the convex portion 7 comes into point contact with the back surface of the substrate G, thereby preventing uneven etching during etching. can do.

The height h ₁ of the convex part 7 is preferably 30 to 80 μm. This is because when the amount of deposits adhering to the susceptor 4 is taken into account, the height of the convex portions 7 can be set to 30 μm or more to sufficiently prevent the deposits from adversely affecting the substrate G. On the other hand, when the height h ₁ of the convex portion 7 exceeds 80 μm, the electrostatic attraction force decreases, the strength of the convex portion 7 decreases, and the etching rate of the substrate G decreases. Further, there is also a disadvantage that the spraying time becomes long when the convex portion 7 is formed by spraying.

  Moreover, it is preferable that the diameter D of the top surface 7a of the convex part 7 is 0.5-1 mm, and it is preferable that the space | interval (distance which connects the center points of two adjacent convex parts 7) shall be 5-20 mm. . For example, 6000 or more such convex portions 7 are preferably formed on the surface of the dielectric material film 5. However, since the convex part 7 should just be formed in the space | interval which the board | substrate G does not contact the reference surface 5a, the said number is a standard to the last. Moreover, there is no restriction | limiting in particular in the arrangement pattern of the convex part 7, For example, a staggered arrangement may be sufficient.

The convex part 7 is comprised with the ceramics generally known as a material with high durability and corrosion resistance. The ceramic constituting the convex portion 7 is not particularly limited, and typically includes insulating materials such as Al ₂ O ₃ , Zr ₂ O ₃ , and Si ₃ N _4, but to some extent like SiC. It may have conductivity. The convex part 7 is preferably formed by thermal spraying as will be described later.

  Further, the top surface 6a of the pedestal 6 which is a portion other than the convex portion on the upper surface of the susceptor 4 and the reference surface 5a of the dielectric material film 5 are both smooth surfaces. Specifically, the surface roughness Ra of the top surface 6a of the base 6 and the reference surface 5a of the dielectric material film 5 is 1.5 μm or less, preferably 0 or more and 1.5 μm or less. Here, Ra is an arithmetic average roughness defined in JIS B0601-1994, and a reference length is determined from the roughness curve in the direction of the average line, and measured from the average line within the reference length. The absolute value of the deviation up to the roughness curve is summed, and the average value is expressed in micrometers (μm).

  By setting the surface roughness Ra of the top surface 6a of the pedestal 6 to 1.5 μm or less, the peripheral edge of the substrate G is brought into close contact with the top surface 6a of the pedestal 6 when the substrate G is placed on the susceptor 4. Can do. Therefore, a sealed space can be formed between the substrate G and the reference surface 5 a of the susceptor 4. Thereby, especially when the heat transfer medium gas is supplied to the back surface of the substrate G to perform temperature control, the heat transfer medium gas can be confined in the space on the back surface side of the substrate G, so that the heat transfer efficiency can be improved. it can.

Further, by setting the surface roughness Ra of the reference surface 5 a of the dielectric material film 5 to 1.5 μm or less, it is possible to prevent deposits from being deposited on the reference surface 5 a lower than the convex portion 7.
That is, if the reference surface 5a is rough in the susceptor 4, the etching process is repeated, so that substances etched from the substrate G adhere to, accumulate, and accumulate on the reference surface 5a of the dielectric material film 5. However, in this embodiment, since the reference surface 5a is a smooth surface, reaction products and particles due to etching are difficult to adhere, and deposits are difficult to form. In addition, even if a deposit is formed, the convex portion 7 serves as a spacer, so that the deposit is difficult to contact the substrate G, uneven etching occurs in the substrate G, or the substrate G is adsorbed to the susceptor 4. Inconveniences such as being prevented are prevented.

The height h ₂ of the pedestal 6 is substantially the same as or slightly higher than the height of the convex portion 7 from the viewpoint of forming a sealed space between the substrate G and the reference surface 5a while surrounding the convex portion 7. For example, it can be formed by machining or polishing.

The dielectric material film 5 is not limited to any material as long as it is made of a dielectric material, and includes not only a highly insulating material but also a material having conductivity sufficient to permit charge transfer. Such a dielectric material film 5 is preferably made of ceramics from the viewpoint of durability and corrosion resistance. In this case, the ceramic is not particularly limited, and as in the case of the convex portion 7, typically, an insulating material such as Al ₂ O ₃ , Zr ₂ O ₃ , Si ₃ N ₄ can be cited. It may have some conductivity like SiC. Such a dielectric material film 5 can be formed by thermal spraying, for example.

  The base material 4a supports the dielectric material film 5, and is made of, for example, a metal such as aluminum or a conductor such as carbon.

Next, referring to FIG. 1 again, the processing operation in the plasma etching apparatus 1 will be described.
First, after the gate valve 22 is opened, the substrate G, which is the object to be processed, is loaded into the chamber 2 from the load lock chamber (not shown) via the substrate loading / unloading port 21, and on the susceptor 4, that is, the susceptor 4. It is placed on the convex part 7 and the base part 6 of the dielectric material film 5 formed on the surface. In this case, the transfer of the substrate G is performed through a lifter pin (not shown) provided so as to be able to protrude from the susceptor 4 through the inside of the susceptor 4. Thereafter, the gate valve 22 is closed, and the inside of the chamber 2 is evacuated to a predetermined vacuum level by the exhaust device 20.

  Thereafter, the valve 16 is opened, and the flow rate of the processing gas from the processing gas supply source 18 is adjusted by the mass flow controller 17, while passing through the processing gas supply pipe 15 and the gas inlet 14 to the internal space 12 of the shower head 11. Then, the pressure is uniformly discharged to the substrate G through the discharge holes 13, and the pressure in the chamber 2 is maintained at a predetermined value.

  In this state, high frequency power is applied from the high frequency power supply 25 to the susceptor 4 through the matching unit 24, and a high frequency electric field is generated between the susceptor 4 as the lower electrode and the shower head 11 as the upper electrode, and the processing gas is dissociated. As a result, the substrate G is subjected to an etching process.

  After performing the etching process in this manner, the application of the high frequency power from the high frequency power supply 25 is stopped, the gas introduction is stopped, and then the pressure in the chamber 2 is reduced to a predetermined pressure. Then, the gate valve 22 is opened, and the substrate G is unloaded from the chamber 2 to the load lock chamber (not shown) via the substrate loading / unloading port 21, thereby completing the etching process for the substrate G.

  Next, a method for forming the base 6 and the convex 7 on the dielectric material film 5 will be described with reference to FIGS. In the present embodiment, the top surface 7a of the convex portion 7 is a rough surface, and the reference surface 5a of the dielectric material film 5 that is a portion other than the convex portion 7 and the top surface 6a of the base portion 6 are smooth surfaces. The following manufacturing method was adopted.

First, a substrate in which the dielectric material film 5 is formed on the upper surface of the substrate 4a is prepared. The dielectric material film 5 is formed by spraying the ceramic material, and the sprayed surface 5b is exposed. Note that pores may be formed when the dielectric material film 5 is formed by thermal spraying. In that case, it is preferable to perform a sealing treatment in order to ensure a withstand voltage performance.
As shown in FIG. 6 (a), the exposed surface 5b is mechanically polished by using a polishing means 100 such as a portal type polishing machine to be uniformly smoothed (step S11). In this polishing step, polishing is performed until the surface roughness Ra of the exposed surface 5b is 1.5 μm or less.

  Next, as shown in FIG. 6B, the periphery of the smoothed dielectric material film 5 is left, and the inside is cut using a cutting means 101 such as a portal cutting machine (step S12). . By this cutting process, the central portion of the dielectric material film 5 is cut into a concave shape, the reference surface 5a is exposed at the bottom of the concave portion, and the base portion 6 is formed at the periphery. The reference surface 5a is a smooth surface obtained by cutting and has a surface roughness Ra of 1.5 μm or less. On the other hand, the top surface of the pedestal 6 has a surface roughness Ra of 1.5 μm or less because the polished surface of FIG. 6A remains as it is.

  Next, as shown in FIG. 6C, an opening plate 102 having a plurality of circular openings is set on the dielectric material film 5 (step S13). A through hole is formed in the opening plate 102 as a mask member so as to correspond to the size and arrangement of the plurality of convex portions 7. As such an opening plate 102, for example, a metal plate having a thickness of about 0.3 to 0.5 mm, specifically, a stainless plate can be used. Blasting is performed with the aperture plate 102 set, and the smooth surface of the dielectric material film 5 exposed in the aperture of the aperture plate 102 is roughened (step S14). This roughening is performed in order to give an anchor effect during the thermal spraying of the next process and to firmly bond the projection 7 formed by thermal spraying to the dielectric material film 5.

  In FIG. 6D, the ceramic material is sprayed from above the aperture plate 102 by the spray gun 103. Thereby, the convex part 7 is formed in the opening of the opening plate 102 (step S15). When spraying the projection 7, the surface roughness Ry of the top surface 7 a can be roughened to 8 μm or more by selecting the spraying conditions such as the spraying particle size and the number of spraying passes. Moreover, if the material of the dielectric material film 5 and the material of the convex part 7 are the same, since both will couple | bond firmly, it is suitable. However, the materials of both may be different as long as they are sufficiently bonded in the temperature range during processing.

  Then, as shown in FIG. 6E, the base plate 6 and the convex portion 7 are formed on the surface of the dielectric material film 5 by removing the opening plate 102 (step S16). The top surface 7a of the projection 7 thus formed is a sprayed surface, and the surface roughness Ry is roughened to 8 μm or more. On the other hand, the top surface 6a of the pedestal 6 is a smooth surface formed by mechanical polishing, and the reference surface 5a is a smooth surface formed by cutting, both having a surface roughness Ra of 1.5 μm or less. . According to the above manufacturing method, the susceptor 4 in which the top surface 7a of the convex portion 7 is roughened and the top surface 6a of the base 6 and the reference surface 5a are smooth surfaces is manufactured with a short processing time and a low processing cost. can do.

FIG. 7 shows a cross-sectional curve showing the surface roughness of the convex portion formed on the surface of the susceptor 4.
Samples A to C in FIG. 7 are cross-sectional curves when the convex portion 7 (and the base portion 6) is formed by a conventional manufacturing method. First, the sample A is a sample in which the opening plate 102 is placed on the surface of the dielectric material film 5 that is laminated and sprayed on the surface of the base material 4a, and the convex portions 7 are formed by thermal spraying. Since the sample A is a sprayed surface in which both the top surface 7a of the convex portion 7 and the reference surface 5a are formed by thermal spraying, both are roughened as shown by a cross-sectional curve. Therefore, although etching unevenness due to the convex portion 7 is difficult to occur, there is a problem that reaction products and particles are likely to adhere to the rough reference surface 5a by repeatedly performing plasma etching, and deposits are easily formed.

  Sample B is a sample in which convex portions 7 are formed on the surface of the dielectric material film 5 laminated and sprayed on the surface of the substrate 4a by direct cutting. In this case, since the reference surface 5a is a smooth surface obtained by machining, deposits are difficult to be formed, but as can be seen from the cross-sectional curve, the surface 7a of the convex portion 7 has a substantially complete trapezoidal shape, and its top surface 7a. Is smooth, and etching unevenness is likely to occur.

  Sample C is an improved example of Sample B. After forming the convex portions 7 on the dielectric material film 5 by cutting, the surface is sprayed by, for example, one pass with a thermal spraying device, and the surface is thinly sprayed. It is a sample in which a film is formed. Since the sample C is also a sprayed surface in which both the top surface 7a of the convex portion 7 and the reference surface 5a are formed by thermal spraying, the sample C is roughened as shown by a cross-sectional curve. Accordingly, etching unevenness due to the convex portions 7 does not occur, but there is a problem that reaction products and particles are likely to adhere to the rough reference surface 5a by repeatedly performing plasma etching, and deposits are easily formed.

  Sample D in FIG. 7 is a cross-sectional curve when the base portion 6 and the convex portion 7 are formed by the manufacturing method shown in FIGS. 5 and 6, and the top surface 7 a of the convex portion 7 is roughened. On the other hand, it can be seen that the top surface 6a of the base 6 and the reference surface 5a of the dielectric material film 5 are smooth surfaces. Therefore, the occurrence of uneven etching due to the convex portion 7 is suppressed, and the generation of deposits on the reference surface 5a can be avoided. Furthermore, since the smooth top surface 6a of the base 6 can be in close contact with the back surface of the substrate G, the temperature control efficiency when the heat transfer medium gas is introduced into the back space of the substrate G can be enhanced.

  As described above, in the sample D according to the manufacturing method of the present embodiment, the shapes of the top surface 7a of the convex portion 7, the top surface 6a of the base portion 6 and the reference surface 5a are taken into consideration, so that etching unevenness and deposits Problems are less likely to occur, and the reliability of the etching process in the plasma etching apparatus 1 can be ensured. On the other hand, in the samples A to C of the comparative example by the conventional manufacturing method, in any case, the top surface 7a of the convex portion 7, the top surface 6a of the base portion 6 and the shape of the reference surface 5a (rough surface, It is understood that problems such as uneven etching and generation of deposits are likely to occur because the combination of whether the surface is smooth or not is inappropriate.

  Next, the relationship between the surface roughness of the top surface 7a of the protrusion 7 and the occurrence of etching unevenness will be described. The surface roughness was evaluated by three methods of Ra (arithmetic average roughness), Rz (ten-point average roughness), and Ry (maximum height). Here, Rz is a ten-point average roughness defined in JIS B0601-1994. A reference length is determined from the roughness curve in the direction of the average line, and within the reference length, from the highest peak. The sum of the average value of the absolute values of the elevations up to the fifth summit and the average value of the absolute values of the altitudes of the bottom from the lowest valley to the fifth, expressed in micrometers (μm).

  FIG. 8 shows the results of examining the surface roughness and the occurrence of uneven etching in the plasma etching process for five types of susceptors (samples 1 to 5) having different surface roughnesses on the top surface 7a of the convex portion 7. ◯ below each sample number indicates the presence or absence of occurrence of etching unevenness, ○ means “etching unevenness does not occur”, and X means “etching unevenness occurs”.

  From FIG. 8, the surface roughness in which a difference is clearly seen in the group of the sample in which the etching unevenness occurred (sample 2 and sample 3) and the sample in which the etching unevenness did not occur (sample 1, sample 4, sample 5). It can be seen that the amount is Ry. Further, in the sample with Ry of 8 μm or more, etching unevenness did not occur. Accordingly, it was shown that Ry is suitable as an evaluation index of the surface roughness of the top surface 7a of the convex portion 7, and that Ry should be 8 μm or more in order to prevent etching unevenness.

  Next, another embodiment will be described with reference to FIGS. 9 and 10. The susceptor 40 of the present embodiment has an electrostatic chuck function. As shown in an enlarged view in FIG. 10, the first dielectric material film 51 and a conductive material such as a metal are formed on the substrate 4a. The susceptor 40 is configured by laminating a conductive layer 52 functioning as an electrostatic electrode layer and a second dielectric material film 53 in this order. On the surface of the second dielectric material film 53, a plurality of convex portions 7 and a base portion 6 are formed so as to protrude with respect to the reference surface 53a. And it is comprised so that the board | substrate G can be electrostatically adsorbed by Coulomb force, for example by applying a DC voltage to the conductive layer 52 from the DC power supply which is not shown in figure. The first dielectric material film 51, the conductive layer 52, and the second dielectric material film 53 may be formed by any method, but all may be formed by thermal spraying.

  Further, a plurality of air outlets are formed on the reference surface 53 a of the second dielectric material film 53 through the base material 4 a, the first dielectric material film 51, the conductive layer 52, and the second dielectric material film 53. The heat transfer medium flow path 41 is formed. As a result, the space between the convex portions 7 on the back side of the substrate G can be filled with a heat transfer medium such as helium gas to uniformly cool the substrate G, and the temperature of the substrate G can be made uniform. Therefore, plasma processing such as etching is also performed uniformly over the entire surface of the substrate. Moreover, it is possible to suppress the heat transfer gas from diffusing into a region other than the susceptor and to improve the heat transfer efficiency by the base 6 formed at the peripheral edge.

Similarly to the susceptor 4 in the first embodiment, also in the susceptor 40 of the present embodiment, the top surface 7a of the convex portion 7 is a rough surface, and the surface roughness Ry is 8 μm or more and 9 μm or more and 15 μm or less. Is preferred.
Further, the top surface 6a of the base 6 which is a portion other than the convex portion on the upper surface of the susceptor 40 and the reference surface 53a of the second dielectric material film 53 are both smooth surfaces. Specifically, the surface roughness Ra of the top surface 6a of the base 6 and the reference surface 53a of the second dielectric material film 53 is 1.5 μm or less, preferably 0 or more and 1.5 μm or less.

As with the dielectric material film 5, the first dielectric material film 51 and the second dielectric material film 53 may be any material as long as they are made of a dielectric material. From the viewpoint of durability and corrosion resistance, it is preferable to use a ceramic material including those having conductivity sufficient to permit movement of the metal. The ceramic material is not particularly limited and typically includes an insulating material such as Al ₂ O ₃ , Zr ₂ O ₃ , Si ₃ N _4, etc., but has some conductivity like SiC. It may be. The first dielectric material film 51 and the second dielectric material film 53 may be the same material or different. Further, in order to relieve the thermal stress due to the difference in thermal expansion coefficient between the base material 4a and the first dielectric material film 51, an intermediate between them is provided between the base material 4a and the first dielectric material film 51. One or more intermediate layers made of a material having a coefficient of thermal expansion can also be provided.

  The function and manufacturing method of the convex part 7 and the base part 6 are the same as in the first embodiment. In the present embodiment, the substrate G can be electrostatically attracted by the electrostatic chuck, and the substrate G can be processed with high accuracy, for example, while the temperature is adjusted by the heat transfer medium. In addition, even if it does not take such a structure, it can be made to function as an electrostatic chuck by making the base material 4a of the susceptor 4 shown in FIG. 1 into the electrostatic electrode of an electrostatic chuck.

  The susceptor 40 shown in FIG. 9 can be provided in a plasma etching apparatus having the same configuration as the plasma etching apparatus 1 shown in FIG.

In addition, this invention is not restrict | limited to the said embodiment, A various deformation | transformation is possible.
For example, in FIG. 1, the RIE type capacitively coupled parallel plate plasma etching apparatus that applies high-frequency power to the lower electrode has been described as an example. However, the present invention is not limited to the etching apparatus, and other plasma processing such as ashing and CVD film formation is performed. The present invention can be applied to a device, and can be a type that supplies high-frequency power to the upper electrode, or is not limited to a capacitive coupling type, and may be an inductive coupling type.

Further, the substrate to be processed is not limited to the FPD glass substrate G but may be a semiconductor wafer.
Further, the size, number, arrangement, and the like of the convex portions 7 are not limited and can be appropriately selected according to the processing content.

Sectional drawing which shows the plasma etching apparatus which is an example of the processing apparatus provided with the susceptor as a substrate mounting base concerning one Embodiment of this invention. The top view of a susceptor. Sectional drawing of the III-III 'line | wire arrow in FIG. The principal part enlarged view of a susceptor cross section. The flowchart which shows an example of the manufacturing process of a susceptor surface shape. Sectional drawing for demonstrating the manufacturing process of susceptor surface shape. Drawing which shows the section curve of the susceptor surface according to a manufacturing method. The result of having tested the relationship between the surface roughness of the top face of a convex part, and etching nonuniformity is shown, (a) is Ra, (b) is Rz, (c) is the graph evaluated by Ry. The susceptor which concerns on other embodiment which provided the electrostatic chuck is shown, (a) is sectional drawing, (b) is a principal part top view. The expanded sectional view of the principal part of the susceptor which concerns on embodiment of FIG.

Explanation of symbols

1 Processing equipment (plasma etching equipment)
2 Chamber (Processing room)
DESCRIPTION OF SYMBOLS 3 Insulation board 4 Susceptor 5 Dielectric material film 5a Reference surface 6 Base part 6a Top surface 7 Convex part 7a Top surface 11 Shower head (gas supply means)
20 Exhaust device 25 High frequency power supply (plasma generating means)
40 susceptor 41 heat transfer medium flow path 51 first dielectric material film 52 conductive layer 53 second dielectric material film

Claims (19)

A substrate mounting table for mounting a substrate in a substrate processing apparatus,
A mounting table body;
A plurality of protrusions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body,
Surrounding the reference surface, and a peripheral base portion formed so as to protrude from the reference surface so as to contact the peripheral portion of the substrate when the substrate is placed;
Have
The top surface of the convex portion is a rough surface, and the top surface of the peripheral base portion is a smooth surface. A substrate mounting table for mounting a substrate in a substrate processing apparatus,
A mounting table body;
A plurality of protrusions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body,
Have
The substrate mounting table, wherein the reference surface is a smooth surface and the top surface of the convex portion is a rough surface. A substrate mounting table for mounting a substrate in a substrate processing apparatus,
A mounting table body;
A plurality of protrusions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body,
Surrounding the reference surface, and a peripheral base portion formed so as to protrude from the reference surface so as to contact the peripheral portion of the substrate when the substrate is placed;
Have
The substrate mounting table, wherein the reference surface and the top surface of the peripheral base portion are smooth surfaces. A substrate mounting table for mounting a substrate in a substrate processing apparatus,
A mounting table body;
A plurality of protrusions formed to protrude from the reference surface on the substrate mounting side of the mounting table main body,
Surrounding the reference surface, and a peripheral base portion formed so as to protrude from the reference surface so as to contact the peripheral portion of the substrate when the substrate is placed;
Have
The substrate mounting table, wherein the reference surface and the top surface of the peripheral base portion are smooth surfaces, and the top surface of the convex portion is a rough surface.   5. The substrate mounting table according to claim 1, wherein a surface roughness Ry (maximum height) of a top surface of the convex portion is 8 μm or more.   5. The substrate mounting table according to claim 2, wherein a surface roughness Ra (arithmetic mean roughness) of the reference surface is 1.5 μm or less.   5. The substrate mounting table according to claim 1, wherein a surface roughness Ra (arithmetic average roughness) of a top surface of the peripheral base portion is 1.5 μm or less.   The substrate mounting table according to claim 7, which functions as an electrostatic adsorption electrode.   The mounting table main body includes a base material, a first dielectric material film formed on the base material, a conductive layer laminated on the first dielectric material film, and a top surface of the conductive layer. The substrate mounting table according to claim 8, further comprising: a second dielectric material film laminated on the substrate.   10. The heat transfer medium channel according to claim 7, further comprising a heat transfer medium flow path that is provided through the substrate mounting table and supplies a heat transfer medium toward a back surface of the substrate. Substrate mounting table.   The substrate processing apparatus provided with the substrate mounting base as described in any one of Claims 1-10.   The substrate processing apparatus of Claim 11 used for manufacture of a flat panel display.   13. The substrate processing apparatus according to claim 11, wherein the substrate processing apparatus is a plasma etching apparatus that performs a plasma etching process on a substrate. A substrate mounting table manufacturing method for mounting a substrate when processing the substrate,
A dielectric material film forming step of forming a dielectric material film on the substrate surface;
A polishing step of polishing the surface of the dielectric material film;
Cutting the surface of the dielectric material film after polishing, leaving a peripheral edge, and forming a recess;
A protrusion forming step of forming a plurality of protrusions made of ceramics by spraying ceramics on the recesses through an opening plate having a plurality of openings;
A method for manufacturing a substrate mounting table, comprising: The convex portion forming step includes
Placing an aperture plate having a plurality of apertures on the dielectric material film; and
Blasting the dielectric material film exposed in the opening of the opening plate;
Spraying ceramics on the dielectric material film through the aperture plate;
Removing the aperture plate;
The method for manufacturing a substrate mounting table according to claim 14, comprising: The dielectric material film forming step includes:
Forming a first dielectric material film on a substrate;
Forming a conductive layer on the first dielectric material film;
Forming a second dielectric material film on the conductive layer;
The method for manufacturing a substrate mounting table according to claim 14, wherein:   The substrate mounting table according to any one of claims 14 to 16, wherein, in the polishing step, polishing is performed until a surface roughness Ra (arithmetic average roughness) is 1.5 µm or less. Manufacturing method.   The cutting or polishing is performed in such a manner that the surface roughness Ra (arithmetic mean roughness) of the bottom surface of the concave portion is 1.5 μm or less in the cutting step. 2. A method for manufacturing a substrate mounting table according to item 1.   19. The thermal spraying is performed so that the surface roughness Ry (maximum height) of the projecting portion of the projecting portion is 8 μm or more in the projecting portion forming step. The manufacturing method of the substrate mounting base of any one of Claims 1.

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