Ceramic dielectric window surface processing method for semiconductor etching machine

Abstract

The invention discloses a surface processing method of a ceramic dielectric window for a semiconductor etching machine, which comprises the following steps of: S1, carrying out sand blasting treatment on the surface of a ceramic substrate to form a rough surface; s2, yttrium oxide meltallizing is conducted on the rough surface, and a meltallizing coating is formed; s3, the meltallizing coating is ground to be flat, and a flat face is formed; and S4, progressive polishing is carried out on the flat surface. By means of the mode of polishing the ceramic matrix before meltallizing the yttrium oxide coating, the roughness degree of the contact surface between the ceramic matrix and the meltallizing coating is increased, then the connection tightness between the ceramic matrix and the meltallizing coating can be improved, and therefore the situation that in the subsequent polishing process, the meltallizing coating falls off due to the fact that the meltallizing coating is subjected to external force, and the service life of the meltallizing coating is prolonged is avoided. The polishing quality is guaranteed, and the rework rate is reduced; furthermore, a progressive polishing mode is adopted, and different polishing materials are adopted in each polishing process, so that the polishing precision degree is improved, and the disc polishing quality is improved.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a surface processing method for a ceramic dielectric window used in a semiconductor etcher. Background Art

[0002] The etcher is a key equipment in the etching process of the semiconductor manufacturing process. The wafer is bombarded by plasma gas in the equipment to etch a predetermined pattern on the surface of the wafer. Since the process gas is mainly fluorine-containing plasma gas, it will corrode the cavity material, the most important of which is the equipment top cover - the ceramic dielectric window. The ceramic dielectric window is made of high-purity alumina ceramic material. Alumina itself is not resistant to fluoride ion corrosion, and it is usually necessary to spray corrosion-resistant yttrium oxide ceramic material on the surface. Since the surface roughness of the sprayed material reaches Ra3~7μm, the etching speed is increased during use and particles are very likely to fall off. The yttrium oxide coating material is loose and has poor bonding strength. It is very easy to fall off and difficult to polish during the polishing process.

[0003] For example, the publication number "CN118280902A" discloses "an electrostatic chuck", including: a substrate, the substrate is made of metal material; a first insulating layer, the first insulating layer is arranged on the substrate, and the first insulating layer has an electrode layer for generating static electricity inside; a second insulating layer, the second insulating layer is arranged on the first insulating layer. By providing the first insulating layer and the second insulating layer, while having an appropriate dielectric constant for forming static electricity, the volume resistance will increase, thereby suppressing leakage current, suppressing arc generation, improving static electricity, improving electrical properties, and significantly increasing the service life.

[0004] However, in actual applications, the yttrium oxide coating is loose and easily falls off, resulting in low polishing quality and high rework rate. Summary of the invention

[0005] In view of the problem of low polishing quality in the prior art mentioned in the background technology, the present invention provides a surface processing method for a ceramic dielectric window for a semiconductor etcher, which can improve the connection strength of the yttrium oxide spray coating, improve the polishing quality, and increase the service life of the yttrium oxide coating.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions.

[0007] A method for processing the surface of a ceramic dielectric window for a semiconductor etching machine comprises the following steps: S1. Sandblasting the surface of the ceramic substrate to form a rough surface; S2, performing yttrium oxide spraying on the rough surface to form a spraying coating; S3, grinding the spray coating to form a flat surface; S4. Perform progressive polishing on the flat surface.

[0008] In the present application, by polishing the ceramic substrate before spraying the yttrium oxide coating, the roughness of the contact surface between the ceramic substrate and the sprayed coating is increased, thereby improving the tightness of the connection with the sprayed coating, thereby preventing the sprayed coating from falling off due to external force during the subsequent polishing process, thereby ensuring the polishing quality and reducing the rework rate; further, the present application adopts a progressive polishing method, and polishing materials of different materials are used in each polishing process, thereby improving the polishing precision and improving the disc polishing quality.

[0009] Preferably, in step S3, the thermal spray coating is subjected to grinding wheel calendering treatment to remove the ups and downs on the surface of the thermal spray coating. Before polishing, the grinding wheel calendering treatment can remove the ups and downs on the thermal spray coating, thereby forming a flat surface, so that the subsequent polishing process can polish all areas of the thermal spray coating, avoiding polishing dead angles, and at the same time improving the polishing efficiency and the smoothness of the polishing.

[0010] Preferably, in step S4, pre-polishing is included, followed by rough polishing, and then fine polishing is performed. The three segmented polishing steps can improve the polishing quality, and different polishing materials can be flexibly changed, so that the spray coating can form a mirror polishing during the segmented polishing process.

[0011] Preferably, diamond media is used in pre-polishing, 3 μm diamond is used in pre-polishing, and copper disk is used for polishing in pre-polishing.

[0012] Preferably, diamond media is used in the rough polishing, 1 μm diamond is used in the rough polishing, and a copper disk is used for polishing in the rough polishing.

[0013] Preferably, an aluminum oxide medium is used in the fine polishing, 1 μm aluminum oxide is used in the fine polishing, and resin is used for polishing in the fine polishing.

[0014] Preferably, in step S1, the roughness of the sandblasting treatment is Ra2-3 μm, and the sandblasting removal amount of the ceramic substrate is 0.02 mm. By controlling the roughness within this range, the adhesion of the thermal spray coating to the ceramic substrate can be significantly improved, and the shedding caused by the radial force generated on the surface of the thermal spray coating during the grinding and polishing process can be avoided.

[0015] Preferably, in step S4, a polishing liquid of corresponding concentration is used, dispersed with a dispersant and set aside.

[0016] Preferably, in step S2, a shielding plate is sleeved on the non-melting side of the ceramic substrate, and the axial height of the shielding plate is higher than the rough surface of the ceramic substrate. A shielding plate is arranged on the non-melting side of the ceramic substrate, so that the coating will not be sprayed onto the non-spraying area of ​​the ceramic substrate during the spraying process, ensuring the accuracy of the spraying, and at the same time, the axial height of the shielding plate is set higher than the rough surface, so that after the spraying is completed, the sprayed coating is not only in contact with the ceramic substrate, but also the side of the sprayed coating is in contact with the shielding plate. In the subsequent grinding and polishing process, axial force and radial force will be generated on the surface of the sprayed coating, wherein the axial force is supported by the connection with the ceramic substrate, and the radial force received by the sprayed coating during the grinding and polishing process is carried out by the strong connection between the friction surface between the sprayed coating and the ceramic substrate and the shielding plate and the radial limit, so that the radial deviation tendency of the sprayed coating can be shared, and the sprayed coating is prevented from falling off.

[0017] Preferably, in step S3, the shielding side plate is ground or cut synchronously, and the shielding side plate is kept flush with the edge of the thermal spray coating; in step S4, the progressive polishing range covers the flat surface and the shielding side plate. Since the shielding side plate is provided, and the shielding side plate is higher than the rough surface, the edge of the thermal spray coating will be connected to the shielding side plate during the thermal spraying process. In step S3, the thermal spray coating and the shielding side plate are ground synchronously, or the shielding side plate is directly cut to the extent that it is flush with the flat surface. In the process of grinding the thermal spray coating, since the thermal spray coating always maintains the connection with the shielding side plate, it can form a protective constraint on the thermal spray coating to avoid separation from the ceramic base during the grinding process. In this way, in the subsequent polishing process, the shielding side plate can be synchronously with the thermal spray coating in the polishing coverage range, thereby avoiding the generation of polishing dead angles at the edge position of the thermal spray coating, and at the same time, each area in the axial direction of the thermal spray coating can obtain the same radial support, thereby ensuring the uniformity of the radial support.

[0018] The beneficial effects of the present invention are as follows: (1) It can improve the bonding force between the spray coating and the ceramic substrate, thereby ensuring the firmness of the spray coating during the polishing process and improving the polishing quality; (2) It can disperse the radial force exerted on the spray coating during the polishing process and ensure the connection stability between the spray coating and the ceramic substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of Example 2.

[0020] In the figure: 1 ceramic substrate, 2 spray coating, 3 shielding side plate. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0022] Embodiment 1: A method for processing the surface of a ceramic dielectric window for a semiconductor etching machine comprises the following steps: S1. Sandblasting is performed on the surface of the ceramic substrate to form a rough surface; the roughness of the sandblasting is Ra2-3 μm, and the amount of sandblasting removed from the ceramic substrate is 0.02 mm; S2, performing yttrium oxide spraying on the rough surface to form a spraying coating; S3, grinding the spray coating to form a flat surface; performing grinding wheel calendering on the spray coating to remove the ups and downs on the surface of the spray coating; S4, performing progressive polishing on the flat surface; including pre-polishing, rough polishing after pre-polishing, and fine polishing after rough polishing; using a polishing liquid of corresponding concentration, dispersing with a dispersant and setting aside; Diamond media was used in pre-polishing, 3μm diamond was used in pre-polishing, and copper disk was used for polishing in pre-polishing;

[0023] Diamond media was used in the rough polishing, 1 μm diamond was used in the rough polishing, and copper disk was used for polishing in the rough polishing;

[0024] Alumina media is used in fine polishing, 1μm alumina is used in fine polishing, and resin is used for polishing in fine polishing.

[0025] In the present application, by polishing the ceramic substrate before spraying the yttrium oxide coating, the roughness of the contact surface between the ceramic substrate and the sprayed coating is increased, thereby improving the tightness of the connection with the sprayed coating, thereby preventing the sprayed coating from falling off due to external force during the subsequent polishing process, thereby ensuring the polishing quality and reducing the rework rate; further, the present application adopts a progressive polishing method, and polishing materials of different materials are used in each polishing process, thereby improving the polishing precision and improving the disc polishing quality.

[0026] Before polishing, the undulations on the spray coating can be removed by grinding wheel calendering to form a flat surface, so that the subsequent polishing process can polish all areas of the spray coating to avoid polishing dead corners, while improving polishing efficiency and polishing fluency.

[0027] Through three segmented polishing steps, the polishing quality can be improved, and different polishing materials can be flexibly changed, so that the spray coating can form a mirror polishing in the segmented polishing process.

[0028] By controlling the roughness within this range, the adhesion of the spray coating to the ceramic substrate can be significantly improved, avoiding shedding caused by radial force on the surface of the spray coating during the grinding and polishing process.

[0029] The specific polishing process in this embodiment is as follows (the polishing method in this embodiment is set to the standard group): In the first step, the material of the ceramic matrix is ​​selected to be high-purity alumina ceramic, and the material purity of the high-purity alumina ceramic is above 99.7%. After the ceramic matrix is ​​processed according to the size required by the customer, the surface that needs to be sprayed is sandblasted; Among them, the roughness of the sandblasting treatment is Ra2~3μm, the sandblasting removal amount is 0.02mm, and after the spraying is completed, a rough surface is formed on the ceramic substrate; In the second step, the substrate after sandblasting is subjected to yttrium oxide spraying treatment to form a spraying coating on the rough surface; Among them, the thickness of the spray coating is 1mm; In the third step, the spray coating needs to be ground to remove the undulations of the surface material; Among them, a high-precision surface grinder is used in the grinding process of the re-melting spray coating; Among them, the high-precision surface grinder uses 800# resin grinding wheel Among them, the processing parameters of high-precision surface grinders are between 0.005 and 0.01 mm for a single feed; Among them, the roughness of the spray coating after grinding reaches less than Ra1μm; The fourth step is to perform pre-polishing, rough polishing and fine polishing in sequence after the thermal spray coating is ground; Among them, the pre-polishing polishing medium uses 3μm diamond; The concentration of the 3-micron polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of pre-polishing polishing liquid is 3s added every 30s, and the flow rate is 3ml / s; Among them, the pre-polishing time is 60 to 120 minutes, and the roughness after polishing is less than Ra0.5μm; Among them, the rough polishing medium uses 1μm diamond; The concentration of the 3-micron polishing liquid is 2-3%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of rough polishing polishing liquid is added for 3s every 40s, and the flow rate is 5ml / s; Among them, the rough polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.2μm; Among them, the polishing medium used for fine polishing is 1μm aluminum oxide; The concentration of 1 micron aluminum oxide polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; The polishing equipment uses a double-station LAP machine, the polishing disc is made of polyurethane material, and the rotation speed of the polishing disc is 25-35R / min; the frequency of fine polishing polishing liquid is added for 1s every 10s, and the flow rate is 3ml / s; Among them, the fine polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.1μm.

[0030] The polishing method of the control group 1 set in this embodiment is as follows: In the first step, the material of the ceramic matrix is ​​selected to be high-purity alumina ceramic, and the material purity of the high-purity alumina ceramic is above 99.7%. After the ceramic matrix is ​​processed according to the size required by the customer, the surface that needs to be sprayed is sandblasted; Among them, the roughness of the sandblasting treatment is Ra1.5μm, the sandblasting removal amount is 0.02mm, and after the spraying is completed, a rough surface is formed on the ceramic substrate; In the second step, the substrate after sandblasting is subjected to yttrium oxide spraying treatment to form a spraying coating on the rough surface; Among them, the thickness of the spray coating is 1mm; In the third step, the spray coating needs to be ground to remove the undulations of the surface material; Among them, a high-precision surface grinder is used in the grinding process of the re-melting spray coating; Among them, the high-precision surface grinder uses 800# resin grinding wheel Among them, the processing parameters of high-precision surface grinders are between 0.005 and 0.01 mm for a single feed; Among them, the roughness of the spray coating after grinding reaches less than Ra1μm; The fourth step is to perform pre-polishing, rough polishing and fine polishing in sequence after the thermal spray coating is ground; Among them, the pre-polishing polishing medium uses 3μm diamond; The concentration of the 3-micron polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of pre-polishing polishing liquid is 3s added every 30s, and the flow rate is 3ml / s; Among them, the pre-polishing time is 60 to 120 minutes, and the roughness after polishing is less than Ra0.5μm; Among them, the rough polishing medium uses 1μm diamond; The concentration of 1 micron polishing liquid is 2-3%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of rough polishing polishing liquid is added for 3s every 40s, and the flow rate is 5ml / s; Among them, the rough polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.2μm; Among them, the polishing medium used for fine polishing is 1μm aluminum oxide; The concentration of 1 micron aluminum oxide polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; The polishing equipment uses a double-station LAP machine, the polishing disc is made of polyurethane material, and the rotation speed of the polishing disc is 25-35R / min; the frequency of fine polishing polishing liquid is added for 1s every 10s, and the flow rate is 3ml / s; Among them, the fine polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.1μm.

[0031] Difference: In this control group, the roughness of the sandblasting process was set to Ra1.5μm.

[0032] The polishing method of the control group 2 set in this embodiment is as follows: In the first step, the material of the ceramic matrix is ​​selected to be high-purity alumina ceramic, and the material purity of the high-purity alumina ceramic is above 99.7%. After the ceramic matrix is ​​processed according to the size required by the customer, the surface that needs to be sprayed is sandblasted; Among them, the roughness of the sandblasting treatment is Ra2~3μm, the sandblasting removal amount is 0.02mm, and after the spraying is completed, a rough surface is formed on the ceramic substrate; In the second step, the substrate after sandblasting is subjected to yttrium oxide spraying treatment to form a spraying coating on the rough surface; Among them, the thickness of the spray coating is 1mm; In the third step, the spray coating needs to be ground to remove the undulations of the surface material; Among them, a high-precision surface grinder is used in the grinding process of the re-melting spray coating; Among them, the high-precision surface grinder uses 800# resin grinding wheel Among them, the processing parameters of high-precision surface grinders are between 0.005 and 0.01 mm for a single feed; Among them, the roughness of the spray coating after grinding reaches less than Ra1μm; The fourth step is to perform pre-polishing, rough polishing and fine polishing in sequence after the thermal spray coating is ground; Among them, the pre-polishing polishing medium uses 3μm diamond; The concentration of the 3-micron polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of pre-polishing polishing liquid is 3s added every 30s, and the flow rate is 3ml / s; Among them, the pre-polishing time is 60 to 120 minutes, and the roughness after polishing is less than Ra0.5μm; Among them, the rough polishing medium uses 1μm diamond; The concentration of 1 micron polishing liquid is 2-3%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of rough polishing polishing liquid is added for 3s every 40s, and the flow rate is 5ml / s; Among them, the rough polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.2μm; Among them, the polishing medium used for fine polishing is 1μm aluminum oxide; The concentration of 1 micron aluminum oxide polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 25-35R / min; Among them, the frequency of fine polishing polishing liquid is added for 1 second every 10 seconds, and the flow rate is 3ml / s; Among them, the fine polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.1μm.

[0033] Difference: In this control group, the fine polishing material was changed to a copper plate.

[0034] The polishing method of the control group 3 set in this embodiment is as follows: In the first step, the material of the ceramic matrix is ​​selected to be high-purity alumina ceramic, and the material purity of the high-purity alumina ceramic is above 99.7%. After the ceramic matrix is ​​processed according to the size required by the customer, the surface that needs to be sprayed is sandblasted; Among them, the roughness of the sandblasting treatment is Ra2~3μm, the sandblasting removal amount is 0.02mm, and after the spraying is completed, a rough surface is formed on the ceramic substrate; In the second step, the substrate after sandblasting is subjected to yttrium oxide spraying treatment to form a spraying coating on the rough surface; Among them, the thickness of the spray coating is 1mm; In the third step, the spray coating needs to be ground to remove the undulations of the surface material; Among them, a high-precision surface grinder is used in the grinding process of the re-melting spray coating; Among them, the high-precision surface grinder uses 800# resin grinding wheel Among them, the processing parameters of high-precision surface grinders are between 0.005 and 0.01 mm for a single feed; Among them, the roughness of the spray coating after grinding reaches less than Ra1μm; The fourth step is to perform pre-polishing, rough polishing and fine polishing in sequence after the thermal spray coating is ground; Among them, the pre-polishing polishing medium uses 9μm diamond; The concentration of the 9-micron polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of pre-polishing polishing liquid is 3s added every 30s, and the flow rate is 3ml / s; Among them, the pre-polishing time is 60 to 120 minutes, and the roughness after polishing is less than Ra0.5μm; Among them, the rough polishing medium uses 3μm diamond; The concentration of the 3-micron polishing liquid is 2-3%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of rough polishing polishing liquid is added for 3s every 40s, and the flow rate is 5ml / s; Among them, the rough polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.2μm; Among them, the polishing medium used for fine polishing is 1μm aluminum oxide; The concentration of 1 micron aluminum oxide polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; The polishing equipment uses a double-station LAP machine, the polishing disc is made of polyurethane material, and the rotation speed of the polishing disc is 25-35R / min; the frequency of fine polishing polishing liquid is added for 1s every 10s, and the flow rate is 3ml / s; Among them, the fine polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.1μm.

[0035] Difference: In the control group, the polishing medium in the pre-polishing process was changed to 9 μm diamond, and the polishing medium in the rough polishing process was changed to 3 μm diamond.

[0036] The polishing method of the control group 4 set in this embodiment is as follows: In the first step, the material of the ceramic matrix is ​​selected to be high-purity alumina ceramic, and the material purity of the high-purity alumina ceramic is above 99.7%. After the ceramic matrix is ​​processed according to the size required by the customer, the surface that needs to be sprayed is sandblasted; Among them, the roughness of the sandblasting treatment is Ra2~3μm, the sandblasting removal amount is 0.02mm, and after the spraying is completed, a rough surface is formed on the ceramic substrate; In the second step, the substrate after sandblasting is subjected to yttrium oxide spraying treatment to form a spraying coating on the rough surface; Among them, the thickness of the spray coating is 1mm; In the third step, the spray coating needs to be ground to remove the undulations of the surface material; Among them, a high-precision surface grinder is used in the grinding process of the re-melting spray coating; Among them, the high-precision surface grinder uses 800# resin grinding wheel Among them, the processing parameters of high-precision surface grinders are between 0.005 and 0.01 mm for a single feed; Among them, the roughness of the spray coating after grinding reaches less than Ra1μm; The fourth step is to perform pre-polishing, rough polishing and fine polishing in sequence after the thermal spray coating is ground; Among them, the pre-polishing polishing medium uses 3μm diamond; The concentration of the 3-micron polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of pre-polishing polishing liquid is 3s added every 30s, and the flow rate is 3ml / s; Among them, the pre-polishing time is 60 to 120 minutes, and the roughness after polishing is less than Ra0.5μm; Among them, the rough polishing medium uses 1μm diamond; The concentration of 1 micron polishing liquid is 2-3%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of rough polishing polishing liquid is added for 3s every 40s, and the flow rate is 5ml / s; Among them, the rough polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.2μm; Among them, the polishing medium used in the fine polishing process is 1μm diamond; The concentration of the 1 micron polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; The polishing equipment uses a double-station LAP machine, the polishing disc is made of polyurethane material, and the rotation speed of the polishing disc is 25-35R / min; the frequency of fine polishing polishing liquid is added for 1s every 10s, and the flow rate is 3ml / s; Among them, the fine polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.1μm.

[0037] Difference: In this control group, the polishing medium in the fine polishing process was changed to 1μm diamond.

[0038] The polishing method of the control group 5 set in this embodiment is as follows: In the first step, the material of the ceramic matrix is ​​selected to be high-purity alumina ceramic, and the material purity of the high-purity alumina ceramic is above 99.7%. After the ceramic matrix is ​​processed according to the size required by the customer, the surface that needs to be sprayed is sandblasted; Among them, the roughness of the sandblasting treatment is Ra2~3μm, the sandblasting removal amount is 0.02mm, and after the spraying is completed, a rough surface is formed on the ceramic substrate; In the second step, the substrate after sandblasting is subjected to yttrium oxide spraying treatment to form a spraying coating on the rough surface; Among them, the thickness of the spray coating is 1mm; In the third step, the spray coating needs to be ground to remove the undulations of the surface material; Among them, a high-precision surface grinder is used in the grinding process of the re-melting spray coating; Among them, the high-precision surface grinder uses 800# resin grinding wheel Among them, the processing parameters of high-precision surface grinders are between 0.005 and 0.01 mm for a single feed; Among them, the roughness of the spray coating after grinding reaches less than Ra1μm; The fourth step is to perform pre-polishing, rough polishing and fine polishing in sequence after the thermal spray coating is ground; Among them, the pre-polishing polishing medium uses 9μm diamond; The concentration of the 9-micron polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of pre-polishing polishing liquid is 3s added every 30s, and the flow rate is 3ml / s; Among them, the pre-polishing time is 60 to 120 minutes, and the roughness after polishing is less than Ra0.5μm; Among them, the rough polishing medium uses 3μm diamond; The concentration of the 3-micron polishing liquid is 2-3%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 30-45R / min; Among them, the frequency of rough polishing polishing liquid is added for 3s every 40s, and the flow rate is 5ml / s; Among them, the rough polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.2μm; Among them, the polishing medium used for fine polishing is 1μm aluminum oxide; The concentration of 1 micron aluminum oxide polishing liquid is 1-2%, and it is dispersed with a dispersant and then used for later use; Among them, the polishing equipment uses a double-station LAP machine, the polishing disc is a copper disc, and the speed of the polishing disc is 25-35R / min; Among them, the frequency of fine polishing polishing liquid is added for 1 second every 10 seconds, and the flow rate is 3ml / s; Among them, the fine polishing time is 120 to 240 minutes, and the roughness after polishing is less than Ra0.1μm.

[0039] Difference: In this control group, the polishing medium in the pre-polishing process was changed to 9 μm diamond, and the polishing medium in the rough polishing process was changed to 3 μm diamond, and the fine polishing material was changed to a copper disk.

[0040] Design the following experimental control groups according to the experimental parameters: After the test, the following results were obtained

[0041] Embodiment 2: like Figure 1 As shown, different from Example 1, in this embodiment, in step S2, the shielding side plate 3 is sleeved on the non-melting side of the ceramic substrate 1, and the axial height of the shielding side plate 3 is higher than the rough surface of the ceramic substrate 1. In step S3, the shielding side plate 3 is simultaneously ground or cut, and the shielding side plate 3 is kept flush with the edge of the thermal spraying coating 2; in step S4, the progressive polishing range covers the flat surface and the shielding side plate 3.

[0042] A shielding side plate 3 is arranged on the non-melting side of the ceramic substrate 1, so that the coating will not be sprayed onto the non-sprayed area of ​​the ceramic substrate 1 during the spraying process, thereby ensuring the accuracy of the spraying. At the same time, the axial height of the shielding side plate 3 is set higher than the rough surface, so that after the spraying is completed, the sprayed coating 2 is not only in contact with the ceramic substrate 1, but also the side of the sprayed coating 2 is in contact with the shielding side plate 3. In the subsequent grinding and polishing process, axial force and radial force will be generated on the surface of the sprayed coating 2, wherein the axial force is supported by the connection with the ceramic substrate 1, and the radial force received by the sprayed coating 2 during the grinding and polishing process is carried out through the strong connection between the friction surface between the sprayed coating 2 and the ceramic substrate 1 and the radial limitation of the shielding side plate 3, thereby being able to share the radial deviation tendency of the sprayed coating 2 and avoiding the falling off of the sprayed coating 2.

[0043] Since the shielding side plate 3 is provided and the shielding side plate 3 is higher than the rough surface, the edge of the sprayed coating 2 will be connected to the shielding side plate 3 during the spraying process. In step S3, the sprayed coating 2 and the shielding side plate 3 are ground synchronously, or the shielding side plate 3 is directly cut to the level of being flush with the flat surface. In the process of grinding the sprayed coating 2, since the sprayed coating 2 always maintains the connection with the shielding side plate 3, it can form a protective constraint on the sprayed coating 2 to avoid separation from the ceramic base during the grinding process. In this way, in the subsequent polishing process, the shielding side plate 3 can be synchronously in the polishing coverage range with the sprayed coating 2, thereby avoiding the generation of polishing dead angles at the edge position of the sprayed coating 2, and at the same time, each area in the axial direction of the sprayed coating 2 can obtain the same radial support, thereby ensuring the uniformity of the radial support.

Claims

1. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher, characterized in that: The following steps are included: S1. Sandblasting the surface of the ceramic substrate to form a rough surface; S2, performing yttrium oxide spraying on the rough surface to form a spraying coating; S3, grinding the spray coating to form a flat surface; S4. Perform progressive polishing on the flat surface.

2. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to claim 1, characterized in that: In step S3, the thermal spray coating is subjected to a grinding wheel calendering treatment to remove the unevenness on the surface of the thermal spray coating.

3. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to claim 1, characterized in that: In step S4, pre-polishing is included, rough polishing is performed after the pre-polishing, and finish polishing is performed after the rough polishing.

4. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to claim 3, characterized in that: Diamond media was used in pre-polishing, 3 μm diamond was used in pre-polishing, and copper disk was used for polishing in pre-polishing.

5. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to claim 3, characterized in that: Diamond media was used in the rough polishing, 1 μm diamond was used in the rough polishing, and copper disk was used for polishing in the rough polishing.

6. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to claim 3, characterized in that: Alumina media is used in fine polishing, 1μm alumina is used in fine polishing, and resin is used for polishing in fine polishing.

7. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to any one of claims 1 to 6, characterized in that: In step S1, the roughness of the sandblasting treatment is Ra2-3 μm, and the sandblasting removal amount of the ceramic substrate is 0.02 mm.

8. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to any one of claims 1 to 6, characterized in that: In step S4, a polishing liquid of corresponding concentration is used and dispersed with a dispersant for later use.

9. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to any one of claims 1 to 6, characterized in that: In step S2, a shielding edge plate is sleeved on the non-melting side edge of the ceramic substrate, and the axial height of the shielding edge plate is higher than the rough surface of the ceramic substrate.

10. A method for processing the surface of a ceramic dielectric window for a semiconductor etcher according to claim 9, characterized in that: In step S3, the shielding side plate is grinded or cut synchronously, and the shielding side plate is kept flush with the edge of the spray coating; in step S4, the progressive polishing range covers the flat surface and the shielding side plate.

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