A method for transporting wafers after CMP cleaning

Abstract

The invention relates to a wafer post-CMP cleaning conveying method, comprising the following steps: step S01, a handover unit receives a wafer after CMP; step S02, a double robot conveys a first wafer in the handover unit to a first cleaning unit for a first cleaning; step S03, the double robot conveys the first wafer to a second cleaning unit for a second cleaning; step S04, the double robot conveys a second wafer in the handover unit to the first cleaning unit for a first cleaning; step S05, the second wafer is moisturized and waits after being cleaned in the first cleaning unit, and enters the second cleaning unit before the first wafer is cleaned for the second time; step S06, the double robot swaps the positions of the first wafer and the second wafer, the second wafer is cleaned in the second cleaning unit, and the first wafer is conveyed to a wafer box on a loading platform; step S07, steps S02 to S06 are repeated to sequentially put the wafers into the wafer box. The invention effectively reduces the conveying time of the wafer and improves the production capacity.

Description

Technical Field

[0001] The invention belongs to the relevant technical field of wafer cleaning, and in particular relates to a conveying method for wafer post-CMP cleaning. Background Art

[0002] Wafer cleaning is a very important step in the production process of semiconductor devices. Whether the cleaning is thorough directly affects the performance and yield of the device, so the wafer needs to be cleaned multiple times in the preparation process of semiconductor devices. In the existing semiconductor manufacturing process, the chemical mechanical polishing (CMP) method is generally used for planarization. However, a lot of residues will be generated during the CMP process, thus forming defects. Therefore, the wafer needs to be cleaned after CMP to reduce defects.

[0003] The existing cleaning method generally uses a robot to directly place the CMP wafer on a carrier, and then uses the robot to move the wafers one by one to each cleaning mechanism for direct cleaning. Although this can clean the wafers, after a long period of actual processing, it is found that this wafer transportation cleaning method has low transportation efficiency and long transportation time, resulting in the cleaning capacity not meeting high demand, which seriously restricts the further development of the wafer. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a wafer post-CMP cleaning conveying method that can improve the cleaning speed of wafers and meet the wafer production capacity requirements.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a wafer post-CMP cleaning conveying method, comprising the following steps:

[0006] Step S01, the handover unit receives the wafer after CMP and performs pre-cleaning;

[0007] Step S02, the dual manipulators transport the first wafer in the transfer unit to the first cleaning unit for first cleaning; wherein the first cleaning time is 110 to 130 seconds;

[0008] Step S03, the dual manipulators transport the first wafer after the first cleaning to the second cleaning unit for a second cleaning; wherein the second cleaning time is 170 to 190 seconds;

[0009] Step S04, the dual manipulators return to the transfer unit, and transport the second wafer in the transfer unit to the first cleaning unit for the first cleaning;

[0010] Step S05, the second wafer is moisturized and waits after the first cleaning unit completes cleaning, and then the second wafer enters the second cleaning unit before the first wafer completes cleaning for the second time;

[0011] Step S06: After the dual manipulators exchange the positions of the first wafer and the second wafer, the second wafer is cleaned in the second cleaning unit, and the first wafer is sent to the wafer box on the loading platform by the dual manipulators;

[0012] Step S07, repeating steps S02 to S06 in sequence, placing the wafers into the wafer box on the loading platform in sequence, and when the number of wafers reaches the requirement, the subsequent robot takes away the wafer box.

[0013] Furthermore, a temporary storage unit is provided between the second cleaning unit and the loading platform for temporarily storing the cleaned wafers that cannot be placed on the loading platform.

[0014] Furthermore, in step S01, the pre-cleaning is used to immerse the CMP wafers in ozone water in groups of two, and then perform ultrasonic cleaning to ensure that the wafers are in a wet state.

[0015] Furthermore, the cleaning process of the first cleaning unit is as follows: when the brush rotates, the wafer is brushed with pure water and alkaline solution in turn.

[0016] Furthermore, the cleaning process of the second cleaning unit is as follows: the nozzle sprays ozone and acid solution on the wafer in sequence, and finally spins the wafer dry.

[0017] Furthermore, the dual manipulator is provided with two clamping claws arranged upper and lower, which are used to clamp the wafers in wet state and dry state respectively.

[0018] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0019] The wafer post-CMP cleaning conveying method of the present invention adopts dual manipulators to clamp the wafers, so that the latter wafer can be moved to the cleaning position of the former wafer before the former wafer is cleaned. After the positions of the two wafers are interchanged, the former wafer is sent to the subsequent workstation, which can effectively reduce the wafer conveying time, thereby improving production capacity and cleaning efficiency, and meeting the batch cleaning requirements of wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The technical solution of the present invention is further described below in conjunction with the accompanying drawings:

[0021] Attached Figure 1This is a schematic diagram of the state in which the dual manipulators transport the first wafer after the first cleaning to the second cleaning unit in step S03 of the first embodiment;

[0022] Attached Figure 2 This is a schematic diagram of a state in which the dual manipulators transport the second wafer to the first cleaning unit in step S04 of the first embodiment;

[0023] Attached Figure 3 This is a schematic diagram of the state in which the dual manipulators transport the second wafer 10 after the first cleaning to the second cleaning unit in step S05 of the first embodiment;

[0024] Attached Figure 4 This is a schematic diagram of the transport process of the transport method in Example 2;

[0025] Among them: 1. Handover unit; 2. First cleaning unit; 3. Second cleaning unit; 4. Dual manipulators; 5. Temporary storage unit; 6. Loading unit; 10. First wafer; 20. Second wafer. DETAILED DESCRIPTION

[0026] In order to make the contents of the present invention more clear and understandable, the contents of the present invention are further described below in conjunction with the drawings of the specification. Of course, the present invention is not limited to this specific embodiment, and general replacements known to those skilled in the art are also covered within the scope of protection of the present invention.

[0027] Embodiment 1

[0028] Please refer to the attached Figure 1 In the wafer post-CMP cleaning conveying method described in an embodiment of the present invention, a transfer unit 1, a first cleaning unit 2, a second cleaning unit 3, a dual robot 4 and a loading platform 6 are included.

[0029] Specifically, the handover unit 1 mainly serves to hand over the wafers after CMP in the previous process, accept the wafers after CMP processing, and pre-clean these wafers; wherein, the pre-cleaning operation process is to immerse the wafers in ozone water and clean them by ultrasound. Here, the wafers are immersed in ozone water in groups of two, and at the same time, the wafers can be kept in a moist state.

[0030] Among them, the cleaning process of the first cleaning unit is as follows: when the brush rotates, it brushes the wafer with pure water and alkaline solution in turn; the cleaning process of the second cleaning unit is as follows: the nozzle sprays ozone and acid solution on the wafer in turn, and finally the wafer is spun dry.

[0031] The dual robot 4 includes two clamps arranged upper and lower. The upper clamp is used to clamp wafers in a dry state, and the lower clamp is used to clamp wafers in a wet state. The dual robot 4 is used to transport wafers between the handover unit 1, the first cleaning unit 2, the second cleaning unit 3 and the loading platform 6. Only the wafers cleaned in the second cleaning unit 3 need to be clamped with the clamp in a dry state.

[0032] The loading platform 6 is located at the rear end of the second cleaning unit. A wafer box is provided on the loading platform 6 for placing cleaned wafers. In this embodiment, one wafer box can hold 23 wafers. When there are 23 wafers, they are taken away by the robot of the next process.

[0033] This embodiment discloses a method for transporting wafers after CMP cleaning.

[0034] Please refer to the attached Figure 1 , step S01, the handover unit receives the wafers after CMP, and the wafers are immersed in ozone water in groups of two, and are cleaned by ultrasonic waves to ensure that the wafers are in a wet state.

[0035] Step S02 : The dual manipulators transport the first wafer 10 in the transfer unit to the first cleaning unit for cleaning with a brush, pure water and alkaline solution for 110 seconds.

[0036] Step S03: The dual manipulators transport the first wafer 10 after the first cleaning to the second cleaning unit for spray cleaning with ozone and acidic liquid by the nozzle and then drying. This process takes 170 seconds.

[0037] Please refer to the attached Figure 2 :

[0038] In step S04 , the dual manipulators return to the transfer unit and transport the second wafer 20 in the transfer unit to the first cleaning unit for a first cleaning for 110 seconds. At this time, the first wafer 10 is cleaned in the second cleaning unit.

[0039] Please refer to the attached Figure 3 : In step S05, because the first wafer 10 is cleaned in the second cleaning unit for a longer time than the second wafer 20, the second wafer 20 continues to be moisturized in the first cleaning unit after being cleaned in the first cleaning unit, and then the second wafer 20 enters the second cleaning unit before the first wafer 10 is cleaned for the second time.

[0040] Step S06: After the dual manipulators exchange the positions of the first wafer and the second wafer, they use the clamps in the dry state to take out the first wafer 10 in the second cleaning unit, and then use the clamps in the wet state to put the second wafer 20 into the second cleaning unit for cleaning. The first wafer 10 is sent to the wafer box on the loading platform.

[0041] Step S07, repeating steps S02 to S06 in sequence, placing the cleaned wafers into the wafer box on the loading platform in sequence, and when the number of wafers in the wafer box reaches 23, the subsequent robot will take away the wafer box filled with 23 wafers.

[0042] Embodiment 2

[0043] The present invention discloses a method for transporting multiple wafers after CMP cleaning, comprising the following steps:

[0044] Step S01: The handover unit receives the wafer after CMP and moisturizes it.

[0045] Step S02: The dual manipulators transfer the first wafer 10 in the transfer unit to the first cleaning unit for cleaning with a brush, pure water and alkaline solution for 130 seconds.

[0046] Step S03, the dual manipulators transport the first wafer 10 after the first cleaning to the second cleaning unit for spray cleaning with ozone and acid solution by the nozzle and then drying. This process takes 190 seconds.

[0047] Step S04 , the dual manipulators return to the transfer unit, and transport the second wafer 20 in the transfer unit to the first cleaning unit for a first cleaning for 130 seconds. At this time, the first wafer 10 is cleaned in the second cleaning unit.

[0048] Step S05 , after the second wafer 20 is cleaned in the first cleaning unit, it continues to be moisturized in the first cleaning unit, and then the second wafer 20 enters the second cleaning unit before the first wafer 10 is cleaned for the second time.

[0049] Step S06: After the dual robots exchange the positions of the first wafer 10 and the second wafer 20, they use the clamps in the dry state to take out the first wafer 10 in the second cleaning unit, and then use the clamps in the wet state to put the second wafer 20 into the second cleaning unit for cleaning. The first wafer 10 is sent to the wafer box on the loading platform.

[0050] Step S07, repeating steps S02 to S06 in sequence, placing the cleaned wafers into the wafer box on the loading platform in sequence, and when the number of wafers in the wafer box reaches 21, the subsequent robot will take away the wafer box filled with 21 wafers.

[0051] Embodiment 3

[0052] Please refer to the attached Figure 4 The difference between this embodiment and the first embodiment is that a temporary storage unit 5 is installed between the loading platform and the second cleaning unit for storing wafers that cannot be placed in the second cleaning unit 4 after cleaning.

[0053] The present invention discloses a method for transporting multiple wafers after CMP cleaning, comprising the following steps:

[0054] Step S01: The handover unit receives the wafer after CMP and moisturizes it.

[0055] Step S02: The dual manipulators transport the first wafer in the transfer unit to the first cleaning unit for cleaning with a brush, pure water and alkaline solution for 120 seconds.

[0056] Step S03: The dual manipulators transport the first wafer after the first cleaning to the second cleaning unit for spray cleaning with ozone and acidic solution using a nozzle and then drying. This process takes 180 seconds.

[0057] Step S04, the dual manipulators return to the handover unit, and transport the second wafer in the handover unit to the first cleaning unit for a first cleaning for 120 seconds. At this time, the first wafer is cleaned in the second cleaning unit.

[0058] Step S05 , after the second wafer is cleaned in the first cleaning unit, it continues to be moisturized in the first cleaning unit, and then the second wafer enters the second cleaning unit before the first wafer is cleaned for the second time.

[0059] Step S06: After the dual manipulators exchange the positions of the first wafer and the second wafer, they use the clamping claws in the dry state to take out the first wafer in the second cleaning unit, and then use the clamping claws in the wet state to put the second wafer into the second cleaning unit for cleaning. The first wafer is sent to the wafer box on the loading platform.

[0060] Step S07, repeating steps S02 to S06 in sequence, placing the cleaned wafers into the wafer box on the loading platform in sequence, and when the number of wafers in the wafer box reaches 25, the subsequent robot will take away the wafer box filled with 25 wafers.

[0061] Step S08: When the wafer cannot be placed in the wafer box after cleaning, it is temporarily stored in the temporary storage unit for moisturizing so as to be subsequently sent to the loading platform.

[0062] The wafer post-CMP cleaning conveying method of the present invention adopts dual manipulators to clamp the wafers, so that the latter wafer can be moved to the cleaning position of the former wafer before the former wafer is cleaned. After the positions of the two wafers are interchanged, the former wafer is sent to the subsequent workstation, which can effectively reduce the wafer conveying time, thereby improving the production capacity and the cleaning efficiency, and meets the batch cleaning requirements of the wafers.

[0063] The above are only specific application examples of the present invention and do not constitute any limitation on the protection scope of the present invention. Any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the present invention.

Claims

1. A method for transporting wafers after CMP cleaning, characterized in that: The steps include: Step S01, the handover unit receives the wafer after CMP and performs pre-cleaning; Step S02, the dual manipulators transport the first wafer in the transfer unit to the first cleaning unit for first cleaning; wherein the first cleaning time is 110 to 130 seconds; Step S03, the dual manipulators transport the first wafer after the first cleaning to the second cleaning unit for a second cleaning; wherein the second cleaning time is 170 to 190 seconds; Step S04, the dual manipulators return to the transfer unit, and transport the second wafer in the transfer unit to the first cleaning unit for the first cleaning; Step S05, the second wafer is moisturized and waits after the first cleaning unit completes cleaning, and then the second wafer enters the second cleaning unit before the first wafer completes cleaning for the second time; Step S06: After the dual manipulators exchange the positions of the first wafer and the second wafer, the second wafer is cleaned in the second cleaning unit, and the first wafer is sent to the wafer box on the loading platform by the dual manipulators; Step S07, repeating steps S02 to S06 in sequence, placing the wafers into the wafer box on the loading platform in sequence, and when the number of wafers reaches the required number, the subsequent robot takes the wafer box away; The cleaning process of the first cleaning unit is as follows: when the brush rotates, it brushes the wafer with pure water and alkaline solution in turn; the cleaning process of the second cleaning unit is as follows: the nozzle sprays ozone and acid solution on the wafer in turn, and finally the wafer is spun dry; the dual manipulator is provided with two upper and lower clamps, which are respectively used to clamp the wafer in a wet state and a dry state.

2. The wafer post-CMP cleaning transport method according to claim 1, characterized in that: A temporary storage unit is also provided between the second cleaning unit and the loading platform, for temporarily storing the cleaned wafers that cannot be placed on the loading platform.

3. The wafer post-CMP cleaning transport method according to claim 1, characterized in that: In step S01, the pre-cleaning is to immerse the CMP wafers in ozone water in groups of two, and then perform ultrasonic cleaning to ensure that the wafers are in a wet state.

Images