METHOD AND APPARATUS FOR CLEANING SEMICONDUCTOR WAFER

• US 20150332940A1
• Filed: 11/28/2012
• Published: 11/19/2015
• Est. Priority Date: 11/28/2012
• Status: Active Grant

• Current Assignee: ACM Research (Shanghai), Inc.
• Original Assignee: ACM Research (Shanghai), Inc.
• Inventors: Wang, Hui, Chen, Fuping, Xie, Liangzhi, Wang, Xi, Jia, Shena, Zhang, Xiaoyan
• Granted Patent: US 10,297,472 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/67051 using mainly spraying means, e.g. nozzles
• CPC Class Codes: H01L 21/67057 with the semiconductor substrates being dipped in baths or vessels
• CPC Class Codes: H01L 21/67781 Batch transfer of wafers

Abstract

A method and apparatus (100) for cleaning semiconductor wafer are provided, combining batch cleaning and single wafer cleaning together. The method includes the following steps: tacking at least two wafers from a cassette in a load port (110) and putting said wafers into a first tank (137) filled with chemical solution; after said wafers have been processed in the first tank (137), taking said wafers out of the first tank (137) and keeping said wafers in wet status; putting said wafers into a second tank (138) filled with liquid; after said wafers have been processed in the second tank (138), taking said wafers out of the second tank (138) and keeping said wafers in wet status; putting one of said wafers on a chuck inside a single wafer cleaning module (150); rotating the chuck while applying chemical solution on said wafer; applying deionized water on said wafer; drying said wafer; taking said wafer out of the single wafer cleaning module (150) and then putting said wafer back to the cassette in the load port (110).

Claims

1. A method for cleaning semiconductor wafer, comprising:

taking at least two wafers from a cassette in a load port and putting said wafers into a first tank filled with chemical solution;

after said wafers have been processed in the first tank, taking said wafers out of the first tank and keeping said wafers in wet status;

putting said wafers into a second tank filled with liquid;

after said wafers have been processed in the second tank, taking said wafers out of the second tank and keeping said wafers in wet status;

putting one of said wafers on a chuck inside a single wafer cleaning module;

rotating the chuck while applying chemical solution on said wafer;

applying deionized water on said wafer;

drying said wafer; and

taking said wafer out of the single wafer cleaning module and then putting said wafer back to the cassette in the load port.

2. The method as claimed in claim 1, wherein the chemical solution in the first tank is hot SPM at an elevated temperature higher than 20°

C. and lower than 250°

C.

3. The method as claimed in claim 1, wherein the chemical solution in the first tank includes a solvent, temperature of which is an elevated temperature higher than 20°

C. and lower than 250°

C.

4. The method as claimed in claim 3, wherein the solvent in the first tank is TMAH.

5. The method as claimed in claim 1, wherein the liquid in the second tank is deionized water.

6. The method as claimed in claim 5, wherein the deionized water in the second tank is heated to an elevated temperature higher than 20°

C. and lower than 100°

C.

7. The method as claimed in claim 1, wherein the step of rotating the chuck while applying chemical solution on said wafer includes applying diluted hydrogen chloride, SC1, SC2 or ozone solution on said wafer.

8. The method as claimed in claim 1, wherein the step of rotating the chuck while applying chemical solution on said wafer includes applying functional water doped by gas and NH₄OH on said wafer.

9. The method as claimed in claim 8, wherein the gas is hydrogen gas with concentration of 1.6 ppm, and concentration of NH₄OH is less than 100 ppm.

10. The method as claimed in claim 1, further comprising applying chemical solution on said wafer prior to the step of drying said wafer.

11. The method as claimed in claim 10, wherein the chemical solution is diluted hydrogen chloride, SC1, or SC2 solution.

12. The method as claimed in claim 1, wherein the step of drying said wafer includes rotating the chuck while applying IPA solution on said wafer to dry said wafer.

13. The method as claimed in claim 1, further comprising applying megasonic wave to clean said wafer in the single wafer cleaning module.

14. The method as claimed in claim 1, wherein applying chemical solution and deionized water on said wafer by using a spray nozzle.

15. An apparatus for cleaning semiconductor wafer, comprising:

a first cassette located in a load port for loading a plurality of wafers;

at least one first tank filled with chemical solution;

a second tank filled with liquid;

at least two single wafer cleaning modules for cleaning and drying single wafer;

two turnover mechanisms for turning the wafers put therein, one turnover mechanism disposed adjacent to the first tank and the other turnover mechanism disposed adjacent to the second tank;

a first robot equipped with at least two wafer loading arms for taking at least two wafers from the first cassette and putting the at least two wafers in the turnover mechanism adjacent to the first tank;

a second robot taking the at least two wafers from the turnover mechanism and, putting the at least two wafers into the first tank and the second tank successively, after the at least two wafers are immersed into the first tank and the second tank respectively for a period of time, the second robot taking the at least two wafers out of the second tank and putting the at least two wafers in the turnover mechanism adjacent to the second tank;

a third robot equipped with at least two wafer loading arms for taking the at least two wafers out of the turnover mechanism adjacent to the second tank and putting one of the at least two wafers into one of the single wafer cleaning modules for performing single wafer cleaning and drying processes, wherein the at least two wafers are kept in wet status all the time before single wafer cleaning and drying processes are performed;

the first robot is further adaptive to take the wafer out of the single wafer cleaning module and put the wafer back to the first cassette.

16. The apparatus as claimed in claim 15, wherein the chemical solution in the first tank is hot SPM at an elevated temperature higher than 20°

C. and lower than 250°

C.

17. The apparatus as claimed in claim 15, wherein the liquid in the second tank is deionized water which is heated to an elevated temperature higher than 20°

C. and lower than 100°

C.

18. The apparatus as claimed in claim 15, wherein the number of the first tank is two, the two first tanks are filled with hot SPM at an elevated temperature higher than 20°

C. and lower than 250°

C.

19. The apparatus as claimed in claim 15, wherein the single wafer cleaning process is performed by using diluted hydrogen chloride and/or SC1 solution.

20. The apparatus as claimed in claim 15, wherein the single wafer drying process is performed by using IPA solution.

21. The apparatus as claimed in claim 15, wherein the first robot includes five independent wafer loading arms, and every wafer loading arm is equipped with one end effector for taking one wafer out of one single wafer cleaning module and putting the wafer back to the first cassette.

22. The apparatus as claimed in claim 15, wherein the first robot includes one independent wafer loading arm with five end effectors for taking five wafers from the first cassette and putting the five wafers in the turnover mechanism adjacent to the first tank.

23. The apparatus as claimed in claim 15, wherein the second robot has five pairs of wafer hands, each pair of wafer hands is independent and capable to be opened or closed to grip five wafers every time.

24. The apparatus as claimed in claim 15, wherein the third robot includes five independent wafer loading arms, every wafer loading arm is equipped with one end effector for taking one wafer out of the turnover mechanism adjacent to the second tank and putting the wafer into the single wafer cleaning module.

25. The apparatus as claimed in claim 15, wherein every wafer loading arm of the third robot has a shower head and a nozzle connecting with the shower head for spraying deionized water onto the wafer held by the wafer loading arm.

26. The apparatus as claimed in claim 15, wherein the first robot takes twenty five wafers from the first cassette and puts the twenty five wafers in the turnover mechanism every time.

27. The apparatus as claimed in claim 15, wherein the first robot takes five wafers from the first cassette and puts the five wafers in the turnover mechanism every time.

28. The apparatus as claimed in claim 15, wherein the first tank or the second tank is made of quartz material.

29. The apparatus as claimed in claim 15, wherein the first tank includes a pair of wafer sustainers connected together by a pair of connecting members, two lifting members are respectively connected to the connecting members and cylinders used for driving the lifting members to rise or drop and correspondingly, the wafer sustainers are lifted or descended along with the lifting members.

30. The apparatus as claimed in claim 15, wherein the first tank includes a pair of wafer sustainers connected together by a pair of connecting members, two lifting members are respectively connected to the wafer sustainers and cylinders used for driving the lifting members to rise or drop and correspondingly, the wafer sustainers are lifted or descended along with the lifting members.

31. The apparatus as claimed in claim 15, wherein the second tank is divided into five independent areas, every area of the second tank has a pair of wafer sustainers connected together by a pair of connecting members, two lifting members are respectively connected to the connecting members and cylinders used for driving the lifting members to rise or drop and correspondingly, the wafer sustainers are lifted or descended along with the lifting members.

32. The apparatus as claimed in claim 15, wherein the at least two wafers are immersed into the first tank for 30 to 600 seconds.

33. The apparatus as claimed in claim 15, wherein every turnover mechanism has a pedestal used for receiving the at least two wafers, opposite sides of the pedestal respectively protrude inwardly to form a pair of leading pillars, each side of the pedestal flexibly connects with a side wall by using a revolving shaft, the side wall protrudes inwardly to form a stack of supporting portions for supporting the at least two wafers correspondingly, a wafer holder is disposed in the pedestal and is capable to slide along the leading pillars, the wafer holder defines grooves for holding the at least two wafers, two cylinders are provided to connect with the side walls respectively for driving the side walls turning around the revolving shafts, so the side walls will be unfolded or folded, an axle passes through the pedestal and is fixed with the pedestal, a tip end of the axle which is exposed outside of the pedestal connects with another cylinder for driving the pedestal turning.

34. The apparatus as claimed in claim 15, further comprising a pair of horizontal guiding rails and a pair of vertical guiding rails, the vertical guiding rails being perpendicular to the horizontal guiding rails and capable of moving along the horizontal guiding rails, a supporting plate disposed on the vertical guiding rails and being capable of moving up and down along the vertical guiding rails, a supporting arm fixed on the supporting plate and being perpendicular to the supporting plate, the second robot disposed on the supporting arm and being capable of moving along the supporting arm.

35. The apparatus as claimed in claim 34, wherein the second robot swings around the supporting arm.

36. The apparatus as claimed in claim 15, further comprising exhaust devices disposed at sides of the first tank for exhausting acid mist produced in the first tank.

37. The apparatus as claimed in claim 15, further comprising spray tubes arranged beside the turnover mechanism adjacent to the second tank, every spray tube having nozzles for spraying deionized water on the wafers in the turnover mechanism to keep the wafers in wet status all the time before the wafers are put in the single wafer cleaning modules to be processed.

38. The apparatus as claimed in claim 15, further comprising a trough filled with deionized water, a lifting apparatus disposed in the trough and a frame fixed on the lifting apparatus for holding a third cassette which receives the at least two wafers therein, the third cassette with the at least two wafers being put in the frame and immersed in the deionized water in the trough after the at least two wafers taken out of the second tank, the lifting apparatus raising the frame and making the frame on the lifting apparatus upright for taking the at least two wafers from the third cassette.

39. The apparatus as claimed in claim 38, wherein the deionized water in the trough will be drained every time after the same batch of wafers is processed and the fresh deionized water is supplied to the trough to process the next batch of wafers.

40. The apparatus as claimed in claim 15, further comprising another first tank, another second tank, another two turnover mechanisms and another second robot, all of which are disposed opposite to the first tank, the second tank, the two turnover mechanisms and the second robot.

41. The apparatus as claimed in claim 15, wherein the first tank and the second tank are divided into five independent areas, every area processes five wafers every time.

42. An apparatus for cleaning semiconductor wafer, comprising:

a first cassette located in a load port for loading a plurality of wafers;

at least one first tank filled with chemical solution;

a second tank filled with liquid;

at least two single wafer cleaning modules for cleaning and drying single wafer;

two turnover mechanisms for turning the wafers put therein, one turnover mechanism disposed adjacent to the first tank and the other turnover mechanism disposed adjacent to the second tank;

a buffer area for temporarily receiving the wafers;

a first robot equipped with at least two wafer loading arms for taking at least two wafers from the first cassette and putting the at least two wafers into the buffer area;

a third robot equipped with at least two wafer loading arms for taking the at least two wafers out of the buffer area and putting the at least two wafers in the turnover mechanism adjacent to the first tank;

a second robot taking the at least two wafers from the turnover mechanism and putting the at least two wafers into the first tank and the second tank successively, after the at least two wafers are immersed into the first tank and the second tank respectively for a period of time, the second robot taking the at least two wafers out of the second tank and putting the at least two wafers in the turnover mechanism adjacent to the second tank;

the third robot further taking the at least two wafers out of the turnover mechanism adjacent to the second tank and putting one of the at least two wafers into one of the single wafer cleaning modules for performing single wafer cleaning and drying processes, wherein the at least two wafers are kept in wet status all the time before single wafer cleaning and drying processes are performed;

the first robot further taking the wafer out of the single wafer cleaning module and putting the wafer back to the first cassette.

43. An apparatus for cleaning semiconductor wafer, comprising:

a first cassette located in a load port for loading a plurality of wafers;

at least one first tank filled with chemical solution;

a second tank filled with liquid;

at least two single wafer cleaning modules for cleaning and drying single wafer;

two turnover mechanisms for turning the wafers put therein, one turnover mechanism disposed adjacent to the first tank and the other turnover mechanism disposed adjacent to the second tank;

a first robot equipped with at least three wafer loading arms, one of which takes at least two wafers from the first cassette and puts the at least two wafers in the turnover mechanism adjacent to the first tank;

a second robot taking the at least two wafers from the turnover mechanism and putting the at least two wafers into the first tank and the second tank successively, after the at least two wafers are immersed into the first tank and the second tank respectively for a period of time, the second robot taking the at least two wafers out of the second tank and putting the at least two wafers in the turnover mechanism adjacent to the second tank;

one of the wafer loading arms of the first robot taking the at least two wafers out of the turnover mechanism adjacent to the second tank and putting one of the at least two wafers into one of the single wafer cleaning modules for performing single wafer cleaning and drying processes, wherein the at least two wafers are kept in wet status all the time before single wafer cleaning and drying processes are performed;

one of the wafer loading arms of the first robot taking the wafer out of the single wafer cleaning module and putting the wafer back to the first cassette.