Electrostatic chuck device for wafer chemical mechanical polishing

Abstract

The invention provides an electrostatic chuck device for wafer chemical mechanical polishing, which comprises a wafer carrier and an electrostatic chuck, an adsorption surface is formed at the upper end of the wafer carrier, the electrostatic chuck is arranged at a position corresponding to the adsorption surface in the wafer carrier, and the electrostatic chuck is connected with a control module. The control module is used for controlling the electrostatic chuck to generate static electricity, so that the wafer is adsorbed on the adsorption surface, and chemical mechanical polishing operation is facilitated; therefore, the electrostatic chuck device for chemical mechanical polishing of the wafer can stably suck the wafer without being influenced by the thickness of the wafer, so that the yield is improved, the technological process is improved, a better thinning effect is achieved, the time and the cost of a gluing and film coating procedure for enhancing the strength of the wafer are saved, the procedures of degumming and film removing are eliminated, and the production efficiency is improved. And compared with an existing vacuum suction mode, the time and the cost for frequent maintenance are saved, and the overall implementation and use are more practical.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to an electrostatic chuck device for chemical mechanical polishing of wafers. Background Art

[0002] In recent years, the semiconductor industry has developed rapidly, and various semiconductor chips have been widely used. The research and development and production of semiconductor chips often affect many industries around the world. Wafer is the abbreviation of semiconductor crystal circular piece, which is a thin slice of cylindrical semiconductor crystal, used as a carrier substrate in the integrated circuit process and in the manufacture of solar cells. Due to its round shape, it is called a wafer. The most common one is silicon wafer, and there are also gallium nitride wafers, silicon carbide wafers, etc.

[0003] Among them, in each process flow of the wafer, if the wafer has uneven surface flatness and unevenness, it will affect the yield and production efficiency of the final product. Therefore, chemical etching and mechanical processing are usually used on the microcircuit formed by repeated exposure, development and etching. Chemical-Mechanical Polishing (CMP) refers to a process of using abrasives (Slurry) to thin or mirror the wafer. This process can reduce or remove the height errors caused by repeated process stacking of the wafer, and it is also a way to thin the surface thickness of the wafer substrate or coating material in the process flow. In addition to controlling the thickness of the wafer, the final surface polishing of the wafer is also a process of chemical mechanical polishing (CMP) to remove the surface residue of the wafer that has been polished to the target thickness (mirror processing) to prepare for the next semiconductor process flow.

[0004] When the wafer is subjected to the chemical mechanical polishing (CMP) process, the wafer is mainly sucked up by the suction cup of the wafer carrier and moved to the corresponding grinding pad, and the suction cup and the grinding pad of the wafer carrier are rotated to grind the wafer; however, the suction cup is generally a vacuum suction cup, and although the vacuum suction cup can achieve the expected effect of sucking the wafer, it is also found in the actual operation and use process that with the advancement of science and technology, the diameter of the wafer is getting larger and the thickness is getting thinner, causing the vacuum suction cup to suck the wafer with a larger diameter and thinner thickness. Due to the insufficient structural internal stress of the wafer, the wafer is easily affected by the suction force of the vacuum suction cup and damaged. Although the industry will coat the surface of the wafer with a glue layer to increase the structural internal stress of the wafer, after grinding, the process of removing the glue layer from the wafer is also likely to cause the wafer to be damaged, so the thickness of the wafer that can be sucked by the vacuum suction cup is limited.

[0005] In addition, those skilled in the art have also developed a method of using a ceramic suction cup to suck up the wafer and move it to a grinding pad for grinding. However, since the vacuum suction of the ceramic suction cup is to suck up the wafer through the tiny holes on the surface of the ceramic suction cup, during the grinding process of the wafer, the tiny particles contained in the grinding liquid used can easily block the tiny holes on the surface of the ceramic suction cup, resulting in the need to frequently clean the ceramic suction cup to maintain sufficient suction, making the ceramic suction cup extremely inconvenient in overall operation and use. Summary of the invention

[0006] The main purpose of the present invention is to provide an electrostatic chuck device for wafer chemical mechanical polishing, so as to solve the problem that the existing chuck limits the wafer thickness and the ceramic chuck is inconvenient to clean. The present invention mainly utilizes an electrostatic chuck to suck the wafer for chemical mechanical polishing (CMP) operation, so that the electrostatic chuck can stably suck the wafer regardless of the thickness of the wafer, which can improve the yield and improve the process flow, and achieve a better wafer thinning effect. It can also eliminate the time and cost of the corresponding glue and film application procedures before the wafer process flow to enhance the wafer strength, and can avoid the glue debonding and film removal procedures after the process flow, thereby reducing the cost and risk of fragmentation, saving the time and cost of frequent maintenance required under the current vacuum suction method, and having a more practical effect in the overall implementation and use of the present invention.

[0007] The main purpose and effect of the electrostatic chuck device for wafer chemical mechanical polishing provided by the present invention are achieved by the following specific technical means:

[0008] An electrostatic chuck device for wafer chemical mechanical polishing includes: a wafer carrier and an electrostatic chuck; wherein:

[0009] The wafer carrier has an adsorption surface formed on its upper end;

[0010] The electrostatic chuck is arranged at a position corresponding to the adsorption surface in the wafer carrier, and is connected with a control module for controlling the electrostatic chuck to generate static electricity by the control module so as to adsorb the wafer on the adsorption surface.

[0011] In a preferred embodiment of the electrostatic chuck device for wafer chemical mechanical polishing of the present invention, a quick-release unit combined with the machine platform is provided at the bottom of the wafer carrier.

[0012] Compared with the prior art, the technical solution of the present invention has the following characteristics and advantages:

[0013] The electrostatic suction cup device for wafer chemical mechanical polishing provided by the present invention can be independent of the thickness of the wafer and can stably absorb the wafer, and can improve the yield and improve the process flow to achieve a better thinning effect. It can also eliminate the time and cost of the gluing and filming procedures performed before the wafer process flow to enhance the wafer strength, and can also avoid the procedures of degumming and film removal after the process flow, thereby reducing the cost and risk of breakage, saving the time and cost of frequent maintenance required under the current vacuum suction method, and having a more practical effect in its overall implementation and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic structural diagram of an electrostatic chuck device for wafer chemical mechanical polishing of the present invention;

[0015] Figure 2 A schematic diagram of the use state of the electrostatic chuck device for wafer chemical mechanical polishing of the present invention;

[0016] Figure 3 It is a schematic diagram of the use status of the quick-release unit of the electrostatic chuck device for wafer chemical mechanical polishing of the present invention.

[0017] Description of Figure Numbers:

[0018] 1. Wafer carrier; 11. Adsorption surface; 12. Quick release unit;

[0019] 2. Electrostatic chuck; 21. Control module;

[0020] 3. Wafer;

[0021] 4. Abrasive pad. DETAILED DESCRIPTION

[0022] In order to make the technical content, invention purpose and effect achieved by the present invention more complete and clear, please refer to the disclosed drawings and figure numbers, and the detailed description is as follows:

[0023] First, see Figure 1 As shown in the structural schematic diagram of the electrostatic chuck device for wafer chemical mechanical polishing of the present invention, the electrostatic chuck device for wafer chemical mechanical polishing provided by the present invention comprises: a wafer carrier 1 and an electrostatic chuck 2; wherein:

[0024] The wafer carrier 1 has an adsorption surface 11 formed on its upper end, and a quick-release unit 12 is provided at the bottom of the wafer carrier 1 for combining with a machine.

[0025] The electrostatic chuck 2 is disposed at a position corresponding to the adsorption surface 11 in the wafer carrier 1, and the electrostatic chuck 2 is connected to a control module 21, so that the electrostatic chuck device for wafer chemical mechanical polishing provided by the present invention can use the control module 21 to control the electrostatic chuck 2 to generate static electricity.

[0026] Specifically, in the operation and use of the present invention, the control module 21 can control the electrostatic chuck 2 to generate static electricity, so that the wafer 3 is attracted by the electrostatic attraction of the electrostatic chuck 2 and is adsorbed on the adsorption surface 11 of the wafer carrier 1, and the wafer carrier 1 is moved to the corresponding polishing pad 4 by the machine. Please refer to Figure 2 The schematic diagram of the use status of the electrostatic chuck device for wafer chemical mechanical polishing of the present invention is shown, the polishing pad 4 is in contact with the wafer 3 adsorbed on the adsorption surface 11 of the wafer carrier 1, and the wafer carrier 1 and the polishing pad 4 are rotated to perform chemical mechanical polishing (CMP) operation on the wafer 3.

[0027] Please also refer to Figure 3 The schematic diagram of the use status of the quick-release unit of the electrostatic chuck device for wafer chemical mechanical polishing of the present invention is shown. Since the bottom of the wafer carrier 1 is combined with the machine through the quick-release unit 12, after the wafer 3 is adsorbed on the adsorption surface 11 of the wafer carrier 1 by the electrostatic chuck 2 and polished, the wafer 3 can directly use the quick-release unit 12 to separate the wafer carrier 1 from the state of being combined with the machine, so that the wafer 3 can maintain the state of being adsorbed on the adsorption surface 11 of the wafer carrier 1 by the electrostatic chuck 2, so that when the wafer 3 is moved to the next process flow, the wafer 3 does not need to be separated from the adsorption surface 11 of the wafer carrier 1, so as to reduce the probability of damage to the wafer 3.

[0028] From the above description, it can be seen that compared with the prior art, the present invention has the following advantages:

[0029] 1. The yield of wafer 3 can be improved and the process flow can be improved.

[0030] 2. Achieve better thinning effect.

[0031] 3. Eliminates the time and cost of the corresponding glue and film coating procedures to enhance the wafer strength before the wafer process.

[0032] 4. It avoids the process of debonding and film removal after the process flow, reducing costs and the risk of fragmentation.

[0033] 5. Saves the time and cost of frequent maintenance required under the current vacuum suction method.

[0034] However, the above embodiments or drawings do not limit the product structure or usage of the present invention. Any appropriate changes or modifications that can be made by technicians in the relevant technical field should be deemed to be within the scope of patent protection of the present invention.

Claims

1. An electrostatic chuck device for wafer chemical mechanical polishing, characterized in that: include: Wafer carrier and electrostatic chuck; including: The wafer carrier has an adsorption surface formed on its upper end; The electrostatic chuck is arranged at a position corresponding to the adsorption surface in the wafer carrier, and is connected to a control module for controlling the electrostatic chuck to generate static electricity to adsorb the wafer on the adsorption surface.

2. The electrostatic chuck device for wafer chemical mechanical polishing as claimed in claim 1, characterized in that: The bottom of the wafer carrier is provided with a quick-release unit combined with the machine platform.

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