Is it all mask stram out or only matel revision stream out, in case of metal revision it may be mask check. what does they do they will X-or new layers with old one and provide results back to layout ebineer for review.
thanks sachin_kirdat, since I saw the tapeout chip got the "Reliability Qualification Approval ", and it is said "XXX has achieved MC qual." , so is it means the Mask Check ?