SOLUTION
Electronics
Foreign matter adhesion on cleaned wafers reduced by 90% or more
Case study at a semiconductor wafer manufacturer
| At a manufacturing plant for semiconductor wafers used in telecommunication devices, errors were often detected in the inspection process due to foreign matter adhering to the wafers. During the transfer of wafers that had been cleaned in the cleaning process to the subsequent inspection process, other foreign matter had adhered to the wafers. Of course, all operations were carried out in a cleanroom and the utmost care was taken to prevent foreign matter from adhering to the wafers, but error detections were still unavoidable, and the customer was very troubled. |
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The solution to this problem was the dust prevention effect of space ionizing. TRINC’s PHASED ARRAY IONIZERs (TAS-821 SFS) were installed between the cleaning and inspection processes to make the transfer area an ionized space. This prevents foreign matter from adhering to the wafer during transfer and has succeeded in drastically reducing the number of error detection in the inspection process.
When the adhesion of foreign matter on a vertically standing wafer was measured with and without static elimination, it was reduced by more than 85%. Based on these results, 10 sets were installed and operated on the production line, and the same dust prevention effect as in the test results was obtained, and the number of defects in the inspection process was reduced by more than 90%.
The situation improved to the point where the number of foreign matter defects in the inspection process was reduced to zero on some days, and it was determined that the dust prevention effect of space ionizing was extremely effective in preventing foreign matter between processes.
When the adhesion of foreign matter on a vertically standing wafer was measured with and without static elimination, it was reduced by more than 85%. Based on these results, 10 sets were installed and operated on the production line, and the same dust prevention effect as in the test results was obtained, and the number of defects in the inspection process was reduced by more than 90%.
The situation improved to the point where the number of foreign matter defects in the inspection process was reduced to zero on some days, and it was determined that the dust prevention effect of space ionizing was extremely effective in preventing foreign matter between processes.
