JP2007258396A - Plasma treatment apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma treatment apparatus capable of automatically performing cleaning and conditioning in a required time, securing high productivity, and is capable of flexible production. <P>SOLUTION: The plasma treatment apparatus comprises: treatment chambers 2-4 for treating wafers; a conveyance chamber 5 in which a carrying means 6 for carrying wafers into and out of the treatment chambers 2-4 is installed; a load lock chamber 7 that is connected to the outside and the conveyance chamber 5 and can switch to atmospheric pressure and pressure in the conveyance chamber; a dummy wafer arrangement section that stores a dummy wafer used when performing the cleaning or conditioning of the treatment chambers 2-4, and is arranged in the load lock chamber 7 or a chamber connected to the conveyance chamber 5 so that the stored dummy wafer can be carried in and out by a carrying means; and a control unit 24 for performing the treatment operation control in the treatment chambers 2-4 and the operation control of the carrying means 6. A dummy treatment registration section for registering treatment timing using a dummy wafer and treatment conditions is provided in the control unit 24. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus and method, and more particularly, to a plasma processing apparatus and method that realizes high-quality processing with high productivity by automatically cleaning and conditioning a processing chamber when necessary.

  In a plasma processing apparatus, for example, a dry etching apparatus, if wafers are continuously processed, substances scattered during etching adhere to and accumulate on the inner wall surface of the processing chamber, and after a predetermined number of times or a predetermined time or more have been processed However, there is a risk that the deposits may be peeled off, and the peeled deposits adhere to the wafer and cause a wafer defect.

  Therefore, when a predetermined number of processing sheets or processing time has elapsed during wafer processing, the processing chamber is opened to the atmosphere to perform cleaning work, or a process using a dummy wafer made of an unetched material instead of the wafer. By performing the processing, cleaning is performed to remove the deposits on the inner wall surface of the processing chamber by etching. In addition, if processing in the processing chamber has not been performed for a certain time or longer, conditioning is performed to adjust the atmosphere in the processing chamber by performing an etching process using a dummy wafer of an appropriate material before processing the production lot. After that, the production lot is processed.

  Note that a dummy substrate is used so that dry cleaning and subsequent conditioning can be performed collectively, and a dummy removing gas for removing deposits in the processing chamber and a dummy having the ability to etch the dummy substrate are used. A plasma processing method for supplying a substrate etching gas to a processing chamber and performing a dry cleaning process is known (for example, see Patent Document 1).

Further, in order to prevent a decrease in throughput due to the operation of the dummy wafer, a loading chamber, a loading chamber, and a dummy wafer chamber are provided between the negative pressure transfer chamber connected to the processing chamber and the positive pressure transfer chamber connected to the outside. The dummy wafer chamber is provided with a temporary table for temporarily holding the dummy wafer, so that when the dummy wafer is stocked or replaced in the dummy wafer chamber, the dummy wafer can be placed without interrupting the normal operation in the processing chamber. It is known that the number of times of use of a dummy wafer can be managed by transferring the dummy wafer to an arbitrary processing chamber via a negative pressure transfer chamber.
JP 2004-172333 A JP 2004-304116 A

  By the way, in the conventional cleaning, usually, after the processing of all the wafers (production lot) in the wafer cassette carried in and installed in the apparatus is finished and the wafer cassette is taken out to the outside, the operator manually Since the dummy wafer is carried into the processing chamber and processing is performed, the processing production of the entire apparatus is interrupted each time the processing chamber is cleaned, resulting in low productivity. In addition, conditioning also has a problem that it takes time to process the production and lowers the productivity because it is necessary to manually process the wafer or process the dummy lot before processing the production lot. .

  The configuration described in Patent Document 1 prevents dry etching and conditioning from being reduced by performing dry cleaning and conditioning at the same time, and an operator manually loads a dummy substrate into the processing chamber. Thus, the problem of reduced productivity due to processing cannot be solved.

  Further, in the configuration described in Patent Document 2, it is not necessary to interrupt the operation of the processing chamber when transferring or exchanging dummy wafers, and only cleaning or conditioning is described to be performed regularly or irregularly. Actually, after processing the production lot or when the abnormality occurs, the processing is interrupted and the cleaning and conditioning are performed manually. Therefore, there is a plurality of types of wafers with different processes in one production lot because productivity is lowered and cleaning and conditioning are not automatically performed at an arbitrary timing during processing of the production lot. Even in this case, there is a problem that flexible production in which processing is continuously performed cannot be realized.

  In view of the above-described conventional problems, the present invention provides a plasma processing apparatus and method that can automatically perform cleaning and conditioning when necessary, ensure high productivity, and realize flexible production. With the goal.

  The plasma processing apparatus of the present invention includes a processing chamber for processing a wafer, a transfer chamber that is connected to the processing chamber and has transfer means for loading and unloading the wafer into and from the processing chamber, and an external and transfer chamber. A load lock chamber that can be switched between atmospheric pressure and pressure in the transfer chamber, and a dummy wafer used for cleaning or conditioning the processing chamber, and the stored dummy wafer can be loaded and unloaded by the transfer means A dummy process registration unit that includes a dummy wafer placement unit and a control unit that performs processing operation control in the processing chamber and operation control of the transfer means, and registers the processing timing and processing conditions using the dummy wafer in the control unit. Is provided.

  According to this configuration, each wafer in the wafer cassette loaded into the load lock chamber is sequentially loaded into each processing chamber by the transfer means of the transfer chamber, processed after being processed in each processing chamber, and stored in the wafer cassette. In the process of successively and sequentially processing each wafer, when the timing registered in advance in the dummy process registration unit is reached, the dummy wafer is taken out from the dummy wafer placement unit and loaded into the corresponding processing chamber. Since the control unit controls the cleaning or conditioning process in the processing chamber automatically under the registered processing conditions, the cleaning and conditioning can be performed automatically when necessary to ensure high productivity. In addition, each processing chamber can be cleaned and conditioned even for each wafer in accordance with the change in wafer type. It is possible to perform the grayed, it can be realized flexible manufacturing in the production lot.

  Further, the plasma processing method of the present invention includes a step of pre-registering timing and processing conditions for cleaning or conditioning the processing chamber before continuously processing the wafer in the processing chamber, and carrying the wafer into the processing chamber, Performs wafer processing and continuously carries out the processing of unloading the processed wafer, and loads the dummy wafer into the processing chamber instead of the wafer at the registered timing, and cleans the processing chamber under the registered processing conditions. Alternatively, the method includes a step of performing a conditioning process and a step of returning to the wafer processing process after the cleaning or conditioning process.

  According to this configuration, as described above, cleaning and conditioning can be performed automatically as needed, ensuring high productivity and realizing flexible production.

  According to the plasma processing apparatus and method of the present invention, when the timing registered in advance in the dummy process registration unit is reached, the dummy wafer is taken out from the dummy wafer placement unit and loaded into the corresponding processing chamber, and in the processing chamber under the pre-registered processing conditions. Since the cleaning or conditioning process is automatically performed, cleaning and conditioning can be performed automatically when necessary, ensuring high productivity, and for each wafer according to changes in the type of wafer. However, since each processing chamber can be conditioned, flexible production can also be realized.

  Hereinafter, an embodiment of a dry etching apparatus to which a plasma processing apparatus of the present invention is applied will be described with reference to FIGS.

  In the dry etching apparatus 1 of the present embodiment, as shown in FIG. 1, a transfer chamber 5 in which an etching process chamber 2, a rinse process chamber 3, an ashing process chamber 4, and a double arm type transfer means 6 are arranged. And a load lock chamber 7 that is configured to be switchable between an atmospheric pressure state and an arbitrary vacuum state and that transfers the wafer cassette 10 containing the wafer 11 to and from the outside. The processing chambers 2, 3, 4 and the load lock chamber 7 are arranged in four directions with the transfer chamber 5 in the center, and a gate 8 provided between the processing chambers 2-4 and the load lock chamber 7. The wafer 11 can be loaded into and unloaded from the respective chambers by the transfer means 6. The load lock chamber 7 is provided with a gate 9 for carrying in / out the wafer cassette 10 to / from the outside, and transfer means (not shown) such as the wafer cassette 10 outside the gate 9. Etc. are arranged.

  As shown in FIG. 2, the load lock chamber 7 is provided with a support base 12 that supports the wafer cassette 10. In the wafer cassette 10, a plurality of (usually several to about 20) wafers 11 are accommodated in a stacked state with a space in the vertical direction. The support table 12 is configured to be moved up and down and rotated by the lifting and rotating means 13, whereby the orientation of the wafer cassette 10 on the support table 12 is arbitrarily adjusted, and when the arbitrary wafer 11 is transferred by the transfer means 6. It is configured so that it can be adjusted to a predetermined height position required. Further, a dummy wafer placement section 14 for storing a plurality of dummy wafers 15 used for cleaning or conditioning the processing chamber is provided below the support table 12. The up-and-down rotation means 13 is configured to be adjusted to a predetermined height at which an arbitrary dummy wafer 15 in the dummy wafer placement unit 14 can be carried in and out by the transfer means 6.

  As the transfer means 6 in the transfer chamber 5, the double arm type transfer means previously proposed by the present applicant (see Japanese Patent Laid-Open No. 7-221157) is applied. As shown in FIG. 3 (a), the conveying means 6 has an upper arm 16a and a lower arm 16b driven by a single arm drive motor 17 via a cam box 18, as shown in FIG. 3 (b). In addition, while the cam shaft (not shown) in the cam box 18 makes one rotation, the upper arm 16a and the lower arm 16b move back and forth, so that the wafer 11 can be loaded and unloaded in one operation step. It is something that can be done. In FIG. 3A, arm drive shafts 19 a and 19 b that drive the upper and lower arms 16 a and 16 b from a cam box 18 disposed outside the transfer chamber 5 penetrate the lower wall surface of the transfer chamber 5. A vacuum seal portion 20 is provided on the lower wall surface of the transfer chamber 5 for vacuum-sealing the through portions of the arm drive shafts 19a and 19b in a rotatable manner. A revolving shaft 21 rotates the cam box 18 around the same axis as the shaft center of the vacuum seal portion 20 to change the direction of the upper and lower arms 16a and 16b. Driven.

  Next, the control configuration of the dry etching apparatus 1 will be described. As shown in FIG. 1, each of the process chambers 2 to 4 is provided with process control units 2a, 3a, and 4a for controlling the respective process operation steps. In addition, a control device 24 is provided for overall control of the processing control units 2 a, 3 a, 4 a, the conveying means 6, and the lifting / lowering rotating means 13 of the load lock chamber 7.

  As shown in FIG. 4, the control device 24 commands the processing conditions in the processing chambers 2 to 4 to the processing control units 2 a, 3 a, and 4 a and monitors the processing state. 25, a wafer processing condition registration unit 26 for registering the processing conditions for each type of wafer, a transfer unit control unit 27 for controlling the operation of the transfer unit 6, and an operation control of the lifting and rotating unit 13 in the load lock chamber 7. Load lock chamber control unit 28, dummy process registration unit 29 for registering control data for processing using dummy wafers, input means 30 for inputting various control data such as processing conditions, and processing in each processing chamber 2-4 An output means 31 for displaying a state, a state at the time of occurrence of an abnormality, and the like, and a CPU 32 for comprehensively controlling these are provided. The dummy process registration unit 29 is provided with a process timing registration unit 33 for registering timing for performing processes such as dry cleaning and conditioning, and a process condition registration unit 34 for registering the process conditions.

  Next, the processing operation of the wafer 11 by the dry etching apparatus 1 having the above configuration will be described with reference to FIG. First, prior to the start of processing, processing conditions for various wafers to be processed are input from the input means 30 and registered in the wafer processing condition registration unit 26 (step S1), and cleaning in each processing chamber 2 to 4 is performed. Alternatively, the conditioning timing and processing conditions are input from the input unit 30 and registered in the processing timing registration unit 33 and the processing condition registration unit 34 of the dummy process registration unit 29 (step S2).

  Next, the wafer cassette 10 containing the wafer 11 to be processed is loaded and placed on the support base 12 of the load lock chamber 7, and processing is started (step S3). Then, when the wafer 11 to be processed is first taken out of the wafer cassette 10 from the wafer cassette 10, the wafer 11 is recognized (step S4), and the processing conditions of the wafer 11 to be processed are read from the wafer processing condition registration unit 26 (step S4). S5), based on this, processing conditions are instructed from the processing condition command / state monitoring unit 25 to the corresponding processing control units 2a-4a of the corresponding processing chambers 2-4, and the required processing is performed in each of the processing chambers 2-4. At the same time, the processing state is monitored (step S6).

  When the necessary processing in the processing chambers 2 to 4 is completed for each wafer 11 recognized in step S4, the wafer 11 processed by the transfer means 6 is loaded into the wafer cassette 10 and the next wafer 11 is taken out. It is. At that time, it is determined whether or not the processing of all the wafers 11 has been completed (step S7). When the processing is completed, the processing operation is ended. On the other hand, if the process has not been completed, the dummy process for performing the cleaning or conditioning process using the dummy wafer 15 in any one of the process chambers 2 to 4 with reference to the process timing registration unit 33 of the dummy process registration unit 29. If it is not the timing of the dummy process, the process returns to step S4 to recognize the wafer 11 to be processed and repeat the above operation. On the other hand, at the timing of the dummy process, the dummy wafer 15 is taken out from the dummy wafer placement unit 14 by the transfer means 6 and is transferred to the target process chambers 2 to 4 under the process conditions read from the process condition registration unit 34. Then, the necessary cleaning and conditioning processes are performed (step S9). When the processes are completed, the transfer means 6 returns the dummy wafer 15 to the dummy wafer placement section 14, and then returns to step S4 to perform the processing operation of the wafer 11. Return to.

  In the above description of the operation, the principle operation process during the processing of the wafer 11 has been simplified so that it can be easily understood. Therefore, the processing of each wafer 11 in the processing chambers 2 to 4 has been completed. Thereafter, it may be understood that the next wafer 11 is taken out from the wafer cassette 10 and processed in each of the processing chambers 2 to 4, but in order to ensure high productivity as a matter of course, The next wafer 11 is carried into the other processing chambers 2 to 4 during processing in any of the processing chambers 2 to 4 and is simultaneously performed in the plurality of processing chambers 2 to 4 in consideration of a rational processing order so as not to interfere with each other. Operation control is performed so as to perform processing in parallel.

  According to the above embodiment, since cleaning and conditioning can be performed automatically as needed, high productivity can be ensured in the wafer etching process. Further, since the processing chambers 2 to 4 can be cleaned and conditioned even for every single wafer in accordance with the change in the type of the wafer 11, the contents of the processing are stored in the wafer cassette 10 which is a unit of the production lot. It is also possible to realize flexible production in which a plurality of different types of wafers 11 are accommodated and necessary processing is performed on each wafer 11.

  In the above embodiment, the example in which the dummy wafer placement unit 14 is disposed below the support 12 of the load lock chamber 7 has been described. However, as illustrated in FIG. An independent dummy wafer chamber 35 can be arranged around each of the processing chambers 2 to 4 and the load lock chamber 7, and the dummy wafer placement portion 14 can be placed in the dummy wafer chamber 35. In short, the dummy wafer placement portion 14 is arranged. May be arranged in a chamber in which the carrying means 6 can carry in and out.

  Further, in the above embodiment, the dummy wafer 15 for cleaning and conditioning is arranged in the dummy wafer arrangement unit 14, but the measurement chambers 2 to 4 are periodically arranged by arranging measurement dummy wafers as necessary. It can also be measured.

  In the above description of the embodiment, only an example in which the present invention is applied to a dry etching apparatus has been described. However, the present invention is not limited to dry etching, but also to various plasma processing apparatuses that perform surface modification, thin film deposition, and the like. It is obvious that it is possible to apply and that the same effect can be obtained by applying, without needing to be described in detail.

  According to the plasma processing apparatus and method of the present invention, cleaning and conditioning can be performed automatically when necessary, ensuring high productivity, and for each wafer in accordance with changes in wafer types. However, since each processing chamber can be cleaned and conditioned, flexible production can be realized, and it can be effectively used in various plasma processing apparatuses.

The top view which shows the whole structure of the dry etching apparatus of one Embodiment of this invention 1 is a longitudinal sectional view taken along the line AA in FIG. 1 showing the load lock chamber of the embodiment. The conveyance chamber and conveyance means of the same embodiment are shown, (a) is a longitudinal sectional view, (b) is an operation timing diagram of the upper arm and lower arm of the conveyance means. The block diagram which shows the structure of the control apparatus of the embodiment Flow chart of processing operation of the embodiment A plan view showing a modified configuration example of the embodiment

Explanation of symbols

1 Dry etching equipment (plasma processing equipment)
DESCRIPTION OF SYMBOLS 2 Etching processing chamber 3 Rinse processing chamber 4 Ashing processing chamber 5 Transfer chamber 6 Transfer means 7 Load lock chamber 11 Wafer 14 Dummy wafer arrangement | positioning part 15 Dummy wafer 24 Control apparatus (control part)
29 Dummy Process Registration Unit 33 Processing Timing Registration Unit 34 Processing Condition Registration Unit

Claims (2)

  A processing chamber for processing wafers, a transfer chamber disposed in connection with the processing chamber and provided with transfer means for loading / unloading wafers into / from the processing chamber, and connected to an external transfer chamber and at atmospheric pressure. A load lock chamber that can be switched to the pressure in the transfer chamber, a dummy wafer placement section that houses a dummy wafer used when cleaning or conditioning the processing chamber, and is arranged so that the stored dummy wafer can be loaded and unloaded by the transfer means; And a control unit for controlling the processing operation in the processing chamber and the transport unit, and the control unit is provided with a dummy processing registration unit for registering processing timing and processing conditions using a dummy wafer. Plasma processing equipment.   Before the wafer is continuously processed in the processing chamber, a process for pre-registering the timing and processing conditions for cleaning or conditioning the processing chamber, a wafer is loaded into the processing chamber, the wafer is processed, and the processed wafer is processed. A wafer processing step for continuously carrying out the unloading operation, a step of loading a dummy wafer into the processing chamber in place of the wafer at a registered timing, and cleaning or conditioning the processing chamber under the registered processing conditions; And a step of returning to the wafer processing step after the conditioning processing.

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