Helium leak rate was 0.6 for 2 wafers and it jumped back to
5.9 for the next 4 wafers and on the 3rd one, the back side of silicon wafer was burned black!
And for all of the wafer, it's consistent that the left side of the wafer has higher etch rate and the right edge of the wafer had ZERO etch rate.
Also, the etch rate when there was 0.6 helium leak was 30% faster than that of 5.9 helium leak.
No comments:
Post a Comment