JP2005183865A - Vacuum treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum treatment device capable of preventing a decrease in the quality and yield of a product caused by a defective operation of an APC valve and having a function to promptly find the adherence of a by-product to the APC valve to accurately grasp maintenance timing. <P>SOLUTION: A vacuum gauge 13 for monitoring a degree of vacuum comprising a baratron gauge, a pirani gauge or the like is provided to a vacuum chamber 2 of the vacuum treatment device 1, and the degree of vacuum detected by the vacuum gauge 13 is inputted to the APC 14. The APC 14 controls the valve travel of an opening/closing valve 11a of a first APC valve 11 to adjust a degree of vacumm in the vacuum chmaber 2 to the predetermined degree of a vacuum on the basis of the degree of the detected vacuum. A new second APC valve 15 and a main valve 16 are further provided at the downstream side of the first APC valve 11 of an exhaust tube 9. The first APC valve 11 and the second APC valve 15 comprise butterfly valves or the like and both of them are switchable by the APC 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vacuum processing apparatus that performs predetermined processing on a semiconductor wafer (hereinafter referred to as a wafer) while automatically controlling the degree of vacuum in a vacuum chamber, and in particular, a reduction in product yield due to malfunction of an APC valve. It is related with the vacuum processing apparatus provided with the function which can grasp | ascertain accurately the maintenance time of an APC valve.

  Vacuum processing apparatuses used in semiconductor device manufacturing processes include CVD apparatuses and sputtering apparatuses that form a thin film on the surface of a wafer, and conversely, dry etching apparatuses that etch the surface of a wafer. No. 15378 (Patent Document 1).

  FIG. 4 is a diagram showing a schematic configuration of a conventional vacuum processing apparatus. As shown in FIG. 4, in a conventional vacuum processing apparatus 41, an upper electrode 43 and a lower electrode 44 on which a wafer W is placed are provided inside a vacuum chamber 42 so as to face each other vertically. A high frequency power supply 46 is connected to the upper electrode 43 via a matching unit 45 so that high frequency power is applied between the upper electrode 43 and the lower electrode 44. Further, a gas supply source 48 is connected to the upper electrode 43 via a gas supply valve 47, and a reaction gas is supplied into the vacuum chamber 42. A vacuum pump 52 such as a turbomolecular pump, a mechanical booster pump, or a rotary pump is connected to an exhaust pipe 49 below the vacuum chamber 42 via an APC valve 51 including main valves 50a and 50b and a butterfly valve. ing. Further, the vacuum chamber 42 is provided with a vacuum gauge 53 made of a Baratron gauge, a Pirani gauge or the like for monitoring the degree of vacuum, and the degree of vacuum detected by the vacuum gauge 53 is an APC (Automatic Pressure Controller) 54. To be input.

In the operation of the conventional vacuum processing apparatus 41, first, after placing the wafer W on the lower electrode 44 in the vacuum chamber 42, the vacuum chamber 52 is evacuated to a high vacuum. Next, the gas supply valve 47 is opened, a reaction gas having a predetermined flow rate is supplied from the gas supply source 48 into the vacuum chamber 42, and the pressure in the vacuum chamber 42 is increased from high vacuum to near the process vacuum. Next, the degree of vacuum in the vacuum chamber 42 is detected by the vacuum gauge 53, and the APC 54 controls the opening degree of the opening / closing valve 51 a of the APC valve 51 based on the detected degree of vacuum so that the inside of the vacuum chamber 42 has a predetermined level. Adjust to a vacuum level. Subsequently, high-frequency power is supplied from the high-frequency power source 46 to the upper electrode 43 while impedance is controlled by the matching unit 45, plasma of the reaction gas is generated, and the wafer W is processed.
Japanese Patent Laid-Open No. 10-15378 (2nd page, paragraphs 0002 to 0007, FIG. 1)

  However, the above-described conventional vacuum processing apparatus 41 has the following problems. By-products generated by the reaction gas generated in the vacuum chamber 42 are exhausted to the outside by the vacuum pump 52, but the temperature outside the vacuum chamber 42 is lower than that of the vacuum chamber 42. A large amount of by-products were condensed and adhered to the inside of 49 and the on-off valve 51a of the APC valve 51. In particular, when this by-product adheres to the opening / closing valve 51 a of the APC valve 51, it causes a malfunction of the APC valve 51. As a result, it becomes difficult to control the opening degree of the on-off valve 51a, the vacuum degree in the vacuum chamber 42 cannot be kept stable during the processing of the wafer W, and there is a problem that the product quality and the yield are lowered. It was.

  In order to prevent this, maintenance such as cleaning or replacement of the APC valve 51 is periodically performed to remove the attached by-products. During this period, the vacuum processing apparatus 41 is stopped for a long time. As a result, the apparatus operation rate was reduced.

  In addition, since the timing of performing this maintenance work is determined by the number of wafers W processed, the operating time of the vacuum processing apparatus 41, and the like, it does not necessarily correspond to the amount of by-product attached, I could not say. For example, if maintenance is frequently performed even though the amount of adhesion is small, the time and cost required for work increase, and the operation rate of the apparatus is significantly reduced. Conversely, if maintenance is overlooked despite the large amount of adhesion, the possibility of malfunction of the APC valve 51 increases, and the degree of vacuum cannot be stably controlled, resulting in product quality and yield. Will be reduced.

  The present invention has been conceived to solve the above-mentioned problems, and prevents the deterioration of the product quality and the yield due to the malfunction of the APC valve, and at the same time discovers the adhesion of by-products to the APC valve. An object of the present invention is to provide a vacuum processing apparatus having a function capable of accurately grasping the maintenance time.

  In order to achieve the above object, a vacuum processing apparatus according to a first aspect of the present invention provides a predetermined object to a target object while automatically controlling the degree of vacuum in a vacuum chamber using a vacuum gauge, an APC, and an APC valve. A vacuum processing apparatus that performs the above-described processing is characterized in that a plurality of APC valves connected in series are provided between the vacuum chamber and the vacuum pump, and the plurality of APC valves can be switched by APC. According to this configuration, even if one APC valve malfunctions during wafer processing, other APC valves connected in series can be operated immediately, so that the wafer can be stably processed to the end. Can do.

  The vacuum processing apparatus according to claim 2 is a vacuum processing apparatus that performs a predetermined process on a target object while automatically controlling the degree of vacuum in a vacuum chamber using a vacuum gauge, an APC, and an APC valve. A plurality of APC valves connected in parallel are provided between the vacuum chamber and the vacuum pump, and the plurality of APC valves can be switched by APC. With this configuration, even if one APC valve malfunctions during wafer processing, other APC valves connected in parallel can be operated immediately, so that the wafer can be stably processed to the end. it can. Furthermore, it is possible to perform maintenance of the APC valve that has malfunctioned during wafer processing.

  Further, the vacuum processing apparatus according to claim 3 is the vacuum processing apparatus according to claim 2, further comprising a maintenance time determination means for determining a maintenance time of the APC bubble based on a degree of vacuum in the vacuum chamber. It is characterized by that. According to this configuration, the maintenance of the APC valve is not performed periodically but only when it is determined to be necessary by the maintenance time determination means, so that maintenance efficiency can be greatly improved.

  The vacuum processing apparatus according to claim 4 is the vacuum processing apparatus according to claim 3, wherein the maintenance time determination means is stored in the storage unit that stores the degree of vacuum in the vacuum chamber and the storage unit. A comparison unit for comparing the degree of vacuum before and after the treatment, a determination unit for determining the presence or absence of by-products attached in the APC valve from the change in the degree of vacuum compared by the comparison unit, and a determination result of the determination unit It is characterized by comprising a display unit for displaying. According to this configuration, the presence or absence of by-products adhering to the APC valve is determined by comparing changes in the degree of vacuum before and after the treatment, so that the maintenance timing of the APC valve can be accurately grasped.

  As described above, according to the vacuum processing apparatus of the present invention, a plurality of APC valves connected in series are provided between the vacuum chamber and the vacuum pump, and the plurality of APC valves can be switched by APC. Even if one APC valve malfunctions during this process and the degree of vacuum control in the vacuum chamber becomes unstable, the other APC valves connected in series can be operated immediately. Thereby, the wafer can be stably processed to the end, and the quality and yield of the product can be improved.

  In addition, since the plurality of APC valves are connected in parallel, even if one APC valve malfunctions during wafer processing and the degree of vacuum control in the vacuum chamber becomes unstable, the other APC valves are connected in parallel. The APC valve can be operated immediately. Thereby, the wafer can be stably processed to the end, and the quality and yield of the product can be improved. Furthermore, since the APC valves that have become defective can be maintained while operating the APC valves connected in parallel, it is not necessary to stop the vacuum processing apparatus during the maintenance work, and the apparatus operating rate can be greatly improved.

  In addition, since the maintenance time determination means is newly provided, the maintenance time of the exhaust pipe and the APC valve can be accurately grasped. As a result, maintenance efficiency can be greatly improved, and failure of the APC valve can be prevented.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a vacuum processing apparatus according to a first embodiment of the present invention. As shown in FIG. 1, in the vacuum processing apparatus 1 of the present embodiment, an upper electrode 3 and a lower electrode 4 on which a wafer W is placed are provided inside a vacuum chamber 2 so as to face each other. A high frequency power source 6 is connected to the upper electrode 3 via a matching unit 5, and high frequency power is applied between the upper electrode 3 and the lower electrode 4. Further, the upper electrode 3 is connected to a gas supply source 8 via a gas supply valve 7, and a reaction gas is supplied into the vacuum chamber 2. A vacuum pump 12 such as a turbomolecular pump, a mechanical booster pump, or a rotary pump is connected to the exhaust pipe 9 below the vacuum chamber 2 via main valves 10 a and 10 b and a first APC valve 11. The vacuum chamber 2 is provided with a vacuum gauge 13 composed of a Baratron gauge, a Pirani gauge or the like for monitoring the degree of vacuum, and the degree of vacuum detected by the vacuum gauge 13 is input to the APC 14.

  Furthermore, in this embodiment, a second APC valve 15 and a main valve 16 are newly provided on the exhaust pipe 9 downstream of the first APC valve 11. Further, the first APC valve 11 and the second APC valve 15 are constituted by butterfly valves or the like, and both can be switched by the APC 14.

  Next, operation | movement of the vacuum processing apparatus 1 of a present Example is demonstrated. The degree of vacuum in the vacuum chamber 2 during wafer W processing is adjusted by the APC 14 controlling the opening degree of the opening / closing valve 11 a of the first APC valve 11 based on the degree of vacuum detected by the vacuum gauge 13. At this time, the on-off valve 15a of the second APC valve 15 is held in a fully open state. If the processing is repeated, a by-product of the reaction gas is trapped and attached to the on-off valve 11a of the first APC valve 11, but the on-off valve 15a of the second APC valve 15 is kept fully open, Hardly adheres. When a by-product adheres to the opening / closing valve 11a of the first APC valve 11 and the opening degree control of the opening / closing valve 11a becomes difficult and the control of the degree of vacuum in the vacuum chamber 2 becomes unstable, the APC 14 causes the first APC valve The opening / closing valve 15a of the second APC valve 15 is gradually closed while the opening / closing valve 11a of the eleventh valve 11 is gradually opened, and the vacuum chamber 2 is adjusted to have a predetermined degree of vacuum, and the processing of the wafer W is continued. After the processing is completed, the main valves 10a and 10b are closed and maintenance of the first APC valve 11 is performed.

  As described above, in the vacuum processing apparatus 1 of the present embodiment, in addition to the conventional first APC valve 11, the second APC valve 15 is newly connected in series and both 11 and 15 can be switched by the APC 14. Even if the control of the degree of vacuum by the first APC valve 11 becomes unstable due to adhesion of by-products, the second APC valve 15 connected in series can be operated immediately. As a result, the degree of vacuum in the vacuum chamber 2 during the processing of the wafer W is stabilized, so that product quality and yield can be improved.

  Next, another preferred embodiment will be described with reference to the drawings. FIG. 2 is a diagram showing a schematic configuration of a vacuum processing apparatus according to the second embodiment of the present invention. In FIG. 2, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  In the vacuum processing apparatus 21 of this embodiment, the difference from the first embodiment described above is that the exhaust pipe 9 is connected to the sub exhaust pipe 22 that bypasses the main valve 10a, the first APC valve 11 and the main valve 10b, This is because a second APC valve 23 and main valves 24 a and 24 b are newly provided in the sub exhaust pipe 22. Further, similarly to the first embodiment described above, the first APC valve 11 and the second APC valve 23 can be switched by the APC 14.

  Next, operation | movement of the vacuum processing apparatus 21 of a present Example is demonstrated. The vacuum degree in the vacuum chamber 2 during the wafer W process is adjusted by the APC 14 controlling the opening degree of the opening / closing valve 11 a of the first APC valve 11 based on the vacuum degree detected by the vacuum gauge 13. At this time, the main valves 10a and 10b are kept open, the main valves 24a and 24b are closed, and the second APC valve 23 is kept fully closed. By repeated processing, reaction gas by-products adhere to the on-off valve 11a of the first APC valve 11, making it difficult to control the opening degree of the on-off valve 11a, and the control of the degree of vacuum in the vacuum chamber 2 becomes unstable. The main valves 24a and 24b are immediately opened, and the open / close valve 23a of the second APC valve 23 is gradually opened while the open / close valve 11a of the first APC valve 11 is gradually closed by the APC 14, and the vacuum chamber 2 is opened. Is adjusted to a predetermined degree of vacuum. Thereafter, the main valves 10a and 10b are immediately closed and the processing of the wafer W is continued.

  Thus, in the vacuum processing apparatus 21 of the present embodiment, in addition to the conventional first APC valve 11, the second APC valve 23 is newly connected in parallel and both 11 and 23 can be switched by the APC 14. Even if the control of the degree of vacuum by the first APC valve 11 becomes unstable due to adhesion of gas by-products, the second APC valve 23 connected in parallel can be operated immediately. As a result, the degree of vacuum in the vacuum chamber 2 during the processing of the wafer W is stabilized, so that product quality and yield can be improved. Furthermore, according to the present embodiment, the first APC valve 11 and the second APC valve 23 are provided in the separate exhaust pipes 9 and 22, and are separated by the main valves 10a, 10b, 24a, and 24b. During the operation, the first APC valve 11 can be maintained. Thereby, it is not necessary to stop the vacuum processing apparatus 21 during the maintenance work of the first APC valve 11, and the apparatus operating rate can be greatly improved.

  Next, another preferred embodiment will be described with reference to the drawings. FIG. 3 is a diagram showing a schematic configuration of a vacuum processing apparatus according to a third embodiment of the present invention. In FIG. 3, the same components as those in the second embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  In the vacuum processing apparatus 31 of the present embodiment, the difference from the second embodiment described above is that a maintenance time determination means 32 for determining the maintenance time of the first APC bubble 11 based on the degree of vacuum in the vacuum chamber 2 is newly provided. It is provided. This maintenance time determination means 32 is compared by the comparison unit 34 with a storage unit 33 that stores the degree of vacuum in the vacuum chamber 2, a comparison unit 34 that compares the degree of vacuum before and after processing stored in the storage unit 33. It is comprised from the determination part 35 which determines the presence or absence of the by-product adhering in the APC valve | bulb 11 from the degree of vacuum degree which changed, and the display part 36 which displays the determination result of the determination part 35. The maintenance time determination means 32 is composed of a well-known CPU, memory, etc., and is connected to the vacuum gauge 13 so that the output signal of the vacuum gauge 13 is processed.

  Next, operation | movement of the vacuum processing apparatus 31 of a present Example is demonstrated. First, the initial opening degree X1 of the first APC valve 11 and the initial vacuum degree Y1 of the vacuum chamber 2 when the new (or immediately after maintenance) first APC valve 11 is attached to the vacuum processing apparatus 31 are respectively determined as the APC 14 and the maintenance time. Store in the storage unit 33 of the means 32. At this time, the main valves 10a and 10b are kept open, the main valves 24a and 24b are closed, and the second APC valve 15 is kept fully closed. Next, the opening degree X2 of the first APC valve 11 and the degree of vacuum Y2 of the vacuum chamber 2 after processing a certain number of wafers W are similarly stored in the storage unit 33 of the APC 14 and the maintenance determination means 32.

  Next, after closing the main valves 10a and 10b and opening the main valves 24a and 24b, the second APC valve 23 is set to the initial opening X1, and the vacuum degree Y3 in the vacuum chamber 2 at this time is set to the vacuum gauge 13. Measure with The degree of vacuum Y3 at this time is stored in the storage unit 33 of the maintenance time determination unit 32 and then output to the comparison unit 34 together with the initial degree of vacuum Y1 stored in advance. In the comparison unit 34, the degree of vacuum Y3 and the initial degree of vacuum Y1 are compared, and the result is output to the determination unit 35. If the degree of vacuum Y3 is the same as the initial degree of vacuum Y1, it is determined that no by-product is attached to the exhaust pipe 9, and if the degree of vacuum Y3 is worse than the initial degree of vacuum Y1, the by-product is attached to the exhaust pipe 9. It is judged that there is. When the degree of vacuum (Y3-Y1) is equal to or higher than a predetermined value set in advance, it is displayed on the display unit 36 that it is time to perform maintenance in the exhaust pipe 9. The by-product of the reaction gas adheres not only to the first APC valve 11 but also to the exhaust pipe 9, gradually reducing the inner diameter of the exhaust pipe 9, and causing the vacuum degree in the vacuum chamber 2 to decrease. With the above operation, first, the presence or absence of by-product adhesion in the exhaust pipe 9 is determined.

  Next, the second APC valve 23 is set to the opening degree X2, and the degree of vacuum in the vacuum chamber 2 at this time is measured by the vacuum gauge 13. The degree of vacuum Y4 at this time is stored in the storage unit 33 of the maintenance time determination unit 32 and then output to the comparison unit 34 together with the degree of vacuum Y2 stored in advance. In the comparison unit 34, the degree of vacuum Y4 and the degree of vacuum Y2 are compared, and the result is output to the determination unit 35. If the degree of vacuum Y4 is the same as the degree of vacuum Y2, it is determined that no by-product is attached to the first APC valve 11. If the degree of vacuum Y4 is better than the degree of vacuum Y2, there is a by-product attached to the first APC valve 11. It is judged. When the degree of vacuum (Y2-Y4) is equal to or greater than a predetermined value set in advance, it is displayed on the display unit 36 that it is time to perform maintenance in the first APC valve 11. At this time, an alarm may be issued as necessary. With the above operation, the presence or absence of by-product adhesion in the first APC valve 11 is determined.

  Thus, in the vacuum processing apparatus 31 of the present embodiment, after processing a certain number of wafers W, the degree of vacuum in the vacuum chamber 2 obtained when the first APC valve 11 and the second APC valve 23 are operated is compared. Accordingly, it is possible to easily determine whether or not by-products are attached to the exhaust pipe 9 and the first APC valve 11. Then, by carrying out this determination operation periodically, it is possible to grasp the exact maintenance timing of the exhaust pipe 9 and the first APC valve 11, so that the maintenance efficiency of both 9 and 11 can be greatly improved.

  In each of the above-described embodiments, the case where there are two APC valves has been described. However, the present invention can be applied to a case where there are three or more APC valves. Further, the present invention can be applied to any vacuum processing apparatus as long as it uses an APC valve. For example, the present invention can be applied to a CVD apparatus, a sputtering apparatus, a dry etching apparatus, and the like.

  By providing a plurality of APC valves connected in series or in parallel between the vacuum chamber and the vacuum pump, and enabling the plurality of APC valves to be switched by APC, one APC valve malfunctions during wafer processing. Even when the degree of vacuum control in the vacuum chamber becomes unstable, other APC valves connected in series or in parallel can be operated immediately. Thereby, the wafer can be stably processed to the end, and the quality and yield of the product can be improved.

The figure which shows schematic structure of the vacuum processing apparatus of 1st Example of this invention. The figure which shows schematic structure of the vacuum processing apparatus of 2nd Example of this invention. The figure which shows schematic structure of the vacuum processing apparatus of 3rd Example of this invention. The figure which shows schematic structure of the conventional vacuum processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum processing apparatus of 1st Example of this invention 2 Vacuum chamber 3 Upper electrode 4 Lower electrode 5 Matching device 6 High frequency power supply 7 Gas supply valve 8 Gas supply source 9 Exhaust pipe 10a, 10b Main valve 11 1st APC valve 11a On-off valve 12 Vacuum pump 13 Vacuum gauge 14 APC
DESCRIPTION OF SYMBOLS 15 2nd APC valve 15a On-off valve 16 Main valve 21 Vacuum processing apparatus of 2nd Example of this invention 22 Sub exhaust pipe 23 2nd APC valve 23a On-off valve 24a, 24b Main valve 31 Vacuum processing apparatus of 3rd Example of this invention 32 Maintenance time determination means 33 Storage unit 34 Comparison unit 35 Determination unit 36 Display unit 41 Conventional vacuum processing device 42 Vacuum chamber 43 Upper electrode 44 Lower electrode 45 Matching unit 46 High frequency power supply 47 Gas supply valve 48 Gas supply source 49 Exhaust pipe 50a 50b Main valve 51 APC valve 51a On-off valve 52 Vacuum pump 53 Vacuum gauge 54 APC

Claims (4)

  In a vacuum processing apparatus that performs a predetermined process on an object to be processed while automatically controlling the degree of vacuum in a vacuum chamber using a vacuum gauge, an APC, and an APC valve, the vacuum chamber is connected in series between the vacuum chamber and the vacuum pump. A vacuum processing apparatus, comprising a plurality of connected APC valves, wherein the plurality of APC valves can be switched by APC.   In a vacuum processing apparatus that performs a predetermined process on an object to be processed while automatically controlling the degree of vacuum in a vacuum chamber using a vacuum gauge, an APC, and an APC valve, the vacuum chamber and the vacuum pump are arranged in parallel. A vacuum processing apparatus, comprising a plurality of connected APC valves, wherein the plurality of APC valves can be switched by APC.   The vacuum processing apparatus according to claim 2, further comprising a maintenance time determination unit that determines a maintenance time of the APC bubble based on a degree of vacuum in the vacuum chamber.   The maintenance time determination unit includes a storage unit that stores the degree of vacuum in the vacuum chamber, a comparison unit that compares the degree of vacuum before and after processing stored in the storage unit, and a change in the degree of vacuum compared by the comparison unit. The vacuum processing apparatus according to claim 3, further comprising: a determination unit that determines the presence or absence of a by-product attached in the APC valve; and a display unit that displays a determination result of the determination unit.

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