Semiconductor Manufacturing Tour
Table of Contents
Slide 7 of 22
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The wafer with patterned photoresist is then put into an oxide etch process to remove the oxide where there is no pattern. This has the effect of transferring the pattern to the oxide, creating barriers of oxide where we do not want subsequent processes to impact the silicon below. The etch may be either a classic wet chemistry or a "dry" etch which uses gas excited by a radio frequency generator to and excited plasma state.
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At this point, the photoresist has served its useful purpose and must be removed. This process is called "strip". The stripping of photoresist must beentirely complete since this is an organic material which, if left on the wafer surface, would cause defects. To do this effectively, chipmakers often use both "wet" and "dry" strippers.