Growth mechanism and inhibition technologies of a contamination on the surface of photomask for longtime LCD-TFT lithography process

Recently, the progressive contamination of photomasks has become a major concern for long-term LCD-TFT manufacturing, as it is the cause of significant defects. We have deciphered the chemical structure and growth mechanism of progressive contamination, and have devised an accelerated test procedure which simulates 2 years of TFT processes in order to determine how best to inhibit its growth (UG Series). By using the photomask with a new type of pellicle (UG series), we were able to inhibit the growth of progressive contamination to the extent that no contamination was confirmed on the photomask for approximately two years.