TW531466B - Mechanical polishing apparatus and method of cleaning a lower electrode of a plasma etcher - Google Patents

Abstract

A mechanical polishing apparatus and a method of cleaning a lower electrode of a plasma etcher are provided. The mechanical polishing apparatus includes a housing having a motor therein, a handle for a user's griping, a rotation disk disposed under a lower surface of the housing, a shaft for connecting the motor with the rotation disk, and a replaceable polishing pad pasted on the rotation disk. The motor can drive the shaft for rotating the rotation disk and the polishing pad so as to make the mechanical polishing apparatus polish the lower electrode. In addition, the method firstly utilizes the mechanical polishing apparatus to polish the lower electrode for a predetermined period so as to remove contaminations on the surface of the lower electrode. Then, a predetermined cleaning process is performed to remove the contaminations still remaining on the surface of the lower electrode.

Description

531466

V. Description of the invention (1) Field of the invention The present invention relates to a mechanical grinding device and method for cleaning electrodes under a plasma etching machine. % Background Description Plasma etching technology has been widely used in the remaining technology of semiconductor processes to remove the part of the surface of the semiconductor wafer that is not covered and protected by photo-resist. Turn the photomask to the surface of the semiconductor wafer. The electric engraving mainly refers to the excitation of the semiconductor gas field and the dissociation of the reaction gas molecules into agglomerates, including ions, atoms, or chemical reactions of reactive electrical membranes, i ί ί ί : f 4, use the thin layer on the semiconductor wafer to extract the volatile material from the semiconducting substance, and then use the vacuum system to $ 15 on the wafer surface. Please refer to Figure 1. As shown in FIG. 1, a laser etcher is a simplified plasma etching machine showing the upper electrode 20 and the lower one. The engraving machine 10 includes a cavity 12 and a wafer holder (not shown). 'And a holmium wafer 24 is provided on the upper surface of the lower electrode 22. The cavity 12 is a combination of two semiconductor side walls 18 for plasma etching, 7 walls 14, lower side walls 16, and left and right sides of the upper side wall of the cavity 12 4 The electrode 20 and the lower electrode 22 are respectively disposed on the I and the lower side wall 16. Plasma etching machine 1

531466 V. Description of the invention (2) Use radio waves of radio frequency (rad i 0f requency, RF) power provided by the upper electrode 20 and the lower electrode 22 to excite / dissociate the gas inside the cavity 12 and apply it to the cavity. A plasma environment is generated in 2 to facilitate the etching process. In addition, the plasma etching machine includes a gas inlet 26 that controls the flow of gas into the cavity 12 and a gas outlet 28 that controls the discharge of gas from the cavity 12 28 ° During the etching process, the cavity 1 The plasma gas in 2 often produces pollutants such as by-products or particles. After the etching process is completed, the inner side wall, the upper electrode 20, or the power-off is completed. The temperature of the lower electrode 20 will quickly drop to a suitable temperature, and the lower electrode 20, which is convenient for low temperature, will more easily cause the electric particles to be deposited on the lower electrode 20. In addition, in order to avoid damage to the electronic components on the semiconductor wafer 24, a cooling system is usually provided on the semiconductor wafer to cool the semiconductor wafer 24 during the etching process, but it also causes some contamination on the surface of the lower electrode 22. The object will be deposited on the cavity 1 2 pole 2 2. Especially when the remaining process speed drops, so that the semiconductor wafer 24 is taken out and then the next process is performed, and the plasma gas and etching by-products are slightly over the plasma etching machine design surface temperature during the plasma etching machine during the etching process The electrode 2 2 below the stage 10 has the crystal back of the semiconductor wafer 24 to have a lower temperature, but the problem of contamination such as adhesion is more serious.

A In order to avoid that the machine management staff inside the cavity 12 cleans the cavity 12 after a period of time to clean the contaminants in the cavity 12 to affect the etching process, we will perform a wet cleaning ’sidewall, upper electrode 2 or

I% pole U 531466 V. Description of the invention (3) The pollutants attached to the invention (3), that is, the inside of the cavity 12 is cleaned by using a cleaning solvent (such as isopropyl alcohol, thallium, etc.). However, the wet cleaning process cannot remove all the contaminants in the cavity 12, so personnel must use a scraper, (b 1 a d e) to scrape the harder contaminants in the cavity 12. In addition, the upper surface of the lower electrode 22 is used to place the semiconductor wafer 24, so the surface of the lower habitat 22 must be kept fairly flat, so that the lower electrode 22 can provide a stable voltage and temperature to the semiconductor wafer 24, but due to the operator Improper operation or uneven application of force when using a scraper will often cause the surface of the lower electrode 22 to be scratched or scratched, which will cause the life of the lower electrode 22 to be shortened and must be often Replace the lower electrode 22, or the phamber r: covery rate) becomes low, so it must be cleaned again. Therefore, it is necessary for Brother to seek an effective and proper method for cleaning the lower electrode 22. SUMMARY OF THE INVENTION The object of the present invention is to provide a mechanical grinding device and method for cleaning electrodes under a plasma etching machine to solve the aforementioned problems. According to the purpose of the present invention, in a preferred embodiment of the present invention, a mechanical grinding device is first used to grind the lower electrode for a predetermined time to grind off the contamination of the lower electrode and the surface, and then a predetermined cleaning process is performed. Divide the contaminants still attached to the surface of the lower electrode by $. The mechanical grinding device includes a housing with a motor, a handle for a user to grasp, and a rotation

Page 7 531466 The five discs of the mill, description of the invention (4)-connected to the lower surface of the housing, a connection between the motor and the bearing, and a replaceable polishing pad adhered to the rotating disc, disc The motor can drive the bearing to rotate the rotating disk and the grinding pad, wherein the pad grinds the lower electrode. As a result of this research, the present invention is to use a mechanical polishing device to remove the surface of the lower electrode, the -1 object 'because the surface of the polishing pad of the mechanical polishing device is rough / defective. Come, i :; To grind the surface of the lower electrode with such force. In addition, since the surface of U is scratched, thereby extending the life of the lower electrode, a comprehensive grinding machine = the polishing device uses a polishing pad to feed the lower electrode. This can shorten the time period of subsequent cleaning procedures. Detailed description of the invention Referring to the square electrode of the lower electrode of the second JSj, the second figure is a plasma etching machine 2 shown in FIG. This method is not limited to cleaning the machine in Figure 1. The lower electrodes of the second i can also be applied, and other different types of plasma etching. This method first goes one by one to clean the lower electrode structure. As shown in FIG. 2, the surface of the electrode 22 is approximately jg in step 30, and a mechanical polishing device is used to grind off the pollutants that are removed, so that the harder grinding time on the surface of the lower electrode 22 is also different. Depending on the contamination, the grinding time required for step 30 is generally about 2 to 3 minutes. Next, proceed—also step 32, using a predetermined cleaning procedure to attach

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i. Description of the invention (5) In the example, the diffuse wave was washed and the contaminants on the surface of the lower electrode 22 were completely removed. In the comparative example p of the present invention, the predetermined cleaning program first performs a step 32a, and applies a power-down to a supersonic cleaner by using. ^ Shake to remove contaminants still attached to the surface of the lower electrode 2 2. In step 32b, the lower electrode 22 is immersed in a main tank containing a cleaning solution for several minutes. Finally, in step 32c, the lower electrode 22 is dried, and the lower electrode 22 is washed. Please refer to the second diagram '. The third diagram is a schematic diagram of the machine and device used by the method of the present invention. As shown in FIG. 3, a mechanical grinding device 40 includes an opera body 42 in which a motor (not shown) is installed, and the housing 42 includes an upper surface 44 and a lower surface 46. In order to facilitate the user to grasp the mechanical grinding device 40, the upper surface 44 of the housing 42 is provided with a handle 48. In addition, the mechanical polishing device 40 also includes a rotating disk 50 provided on the lower surface 46 of the housing 42, a replaceable polishing pad 5 2 adhered to the outer surface of the rotating disk 50, and 4 is used to connect the motor with the rotary disk 50. Among them, in this embodiment, the shape of the rotary disk 50 is a circle, but in fact other shapes such as oval, rectangular, and even irregular shapes can be used. It depends on the user's decision. In a better case, the user can select a more suitable shape of the rotating disk according to the shape of the lower electrode and the place where the by-products are gathered. In addition, the polishing pad 5 2 has a rough surface for removing the contaminants on the surface of the lower electrode 22. It is recommended that sandpaper with different roughness can be used as the material of the polishing pad 52 according to actual needs

531466

V. Description of the invention (6) /, the appearance shape and size are the same as those of the rotating disk 50. In this embodiment, the rotating disk 50 and the polishing pad 52 are both circular, and the diameter is about 6 inches. 2. When the lower electrode 22 is ground by the mechanical grinding device 40, the motor in the housing 42 can drive the bearing 54 to rotate the rotating disk 50 and the polishing pad 52 so that the rotating disk 50 and the polishing pad 52 rotate at a fixed frequency, and then the polishing pad is rotated. 52 contacts the power-down 22, and the grinding pad 52 grinds the lower electrode 22 to remove the contaminants on the surface of the lower electrode 22. Compared with the conventional method, the user of the present invention uses a surface of a mechanical grinding device electrode 2 2 to uniformly remove it from the mechanical grinding device 40. It can provide an average rotation speed, so it can not only effectively remove but avoid the lower electrode 2 The surface of 2 was scratched and 'increased the recovery rate of cavity 12. In addition, the polishing pad 52 is used to perform a shortening of the lower electrode 22 when the subsequent cleaning of the lower electrode 22 is performed to scrape off the contaminants of the lower electrode 22, and 40 to provide a uniform force for polishing the surface of the lower electrode 22. . The surface roughness of the sentence and the contamination on the surface of the lower electrode 22 are more stable, and the life of the lower electrode 22 can be prolonged. The mechanical grinding device 40 is a two-sided grinding, so it can be used by a lifting machine. rate.

The above are just the equivalent changes and modifications made to the patent scope of the preferred implementation of the present invention, and the scope of application is covered by the present invention. … Baiying belongs to the invention patent

Page 10 531466 Simple illustration of the diagram Simple illustration of the diagram Figure 1 is a schematic diagram of a simplified plasma etching machine. FIG. 2 is a flowchart of a method for cleaning electrodes under a plasma etching machine according to the present invention. FIG. 3 is a schematic diagram of a mechanical grinding device used in the method of the present invention. Symbol description

10 Plasma etching machine 12 Cavity 14 Upper side wall 16 Lower side wall 18 Side wall 20 Upper electrode 22 Lower electrode 24 Semiconductor wafer 26 Gas inlet 28 Gas outlet 30 Step 30 32 Step 32 32a Step 32a 32b Step 32b 32c Step 32c 40 Mechanical Grinding device 42 Housing 44 Upper surface 46 Lower surface 48 Handle 50 Rotating disc 52 Grinding pad 54 Bearing Page 11

Claims (1)

531466 6. Scope of patent application 1 · A mechanical grinding device for removing contaminants on electrodes under a plasma etching machine, the mechanical grinding device includes: a casing, a motor is installed therein, and the casing It includes an upper surface and a lower surface; a handle connected to the upper surface of the casing for a user to grasp; a rotation disk connected to the lower surface of the casing; a bearing (sha ft) To connect the motor and the 'rotating disk'; and a replaceable polishing pad adhered to the rotating disk; wherein the motor can drive the bearing to rotate the rotating disk and the polishing pad to make the polishing pad grind the The lower electrode effectively removes residual contaminants on the surface of the lower electrode for a predetermined time. 2. The mechanical grinding device according to item 1 of the scope of patent application, wherein the external shape of the rotating disk and the grinding pad may be circular. 3. The mechanical polishing device according to item 1 of the patent application scope, wherein the polishing pad is a sandpaper. 4. The mechanical grinding device according to item 1 of the patent application scope, wherein the predetermined time for the mechanical grinding device to grind the lower electrode is 2 to 3 minutes. 5. The mechanical grinding device according to item 1 of the scope of patent application, wherein the Page 12 531466 6. Scope of patent application Pollutants are formed by the deposition of plasma gas on the surface of the lower electrode when the internal temperature of the plasma etching machine drops. 6. A method for removing contaminants on an electrode below a plasma etching machine, comprising: grinding the lower electrode with a mechanical grinding device for a predetermined time to remove contaminants on the surface of the lower electrode; and A cleaning procedure is scheduled to remove contaminants still attached to the surface of the lower electrode. 7. The method according to item 6 of the scope of patent application, wherein the mechanical grinding device includes: a housing in which a motor is installed, and the housing includes an upper surface and a lower surface; a handle connected to the housing The upper surface of the body for grasping by a user; a rotation disk provided on the lower surface of the housing; a shaft connecting the motor and the rotating disk; and a replaceable A polishing pad is adhered to the rotating disk; wherein the motor can drive the bearing to rotate the rotating disk and the polishing pad, so that the polishing pad grinds the lower electrode. 8. The method according to item 6 of the scope of patent application, wherein the predetermined cleaning procedure includes the following steps: performing an ultrasonic vibration step to remove the surface still attached to the surface of the lower electrode. 531466 6. Scope of patent application Pollutants; perform a soaking step, soak the lower electrode in a washing tank containing a cleaning solution for several minutes; and dry the lower electrode. 9. The method according to item 7 of the scope of patent application, wherein the abrasive pad is a sandpaper. r 1 0. The method according to item 6 of the scope of patent application, wherein the predetermined time for the mechanical grinding device to grind the lower electrode is 2 to 3 minutes. 11. The method according to item 6 of the scope of patent application, wherein the pollutants are formed by the deposition of plasma gas on the surface of the lower electrode when the internal temperature of the plasma etching machine decreases. 12. A method for removing contaminants on an electrode below a plasma etching machine, the method includes: grinding a lower electrode with a grinding device for a predetermined time to remove the pollutants on the surface of the lower electrode, and The grinding device includes: a casing, in which a motor is installed, and the casing includes an upper surface and a lower surface; a handle connected to the upper surface of the casing for a user to grasp; a rotating disk (Rotation disk), located on the lower surface of the shell; Page 14 531466 VI. Patent application A bearing is used to connect the motor and the rotating disk; and a replaceable polishing pad is adhered to the rotating disk; and a predetermined cleaning program is performed to remove Contaminants still attached to the surface of the lower electrode; wherein the motor can drive the bearing to rotate the rotating disk and the polishing pad, so that the polishing pad grinds the lower electrode for the predetermined time. 13. The method according to item 12 of the scope of patent application, wherein the predetermined cleaning procedure includes the following steps: performing an ultrasonic vibration step to remove contaminants still attached to the surface of the lower electrode; and performing an immersion step , Soaking the lower electrode in a washing tank containing a cleaning solution for several minutes; and drying the lower electrode. 14. The method according to item 12 of the scope of patent application, wherein the abrasive pad is a sandpaper. Wherein the grinding device 15. The predetermined time for grinding the lower electrode according to the method described in item 12 of the patent application scope is 2 to 3 minutes Ψ 1 6. The method described in item 12 of the patent application scope, wherein The pollutant is formed due to the deposition of plasma gas on the surface of the lower electrode when the internal temperature of the plasma etching machine decreases. Page 15