Photoresist keys and depth indicator
Abstract
Abstract A METHOD IS DISCLOSED FOR PROVIDING MEANS FOR ORIENTING AND POSITIONING A PHOTORESIST MASK ON A SEMICONDUCTOR WAFER AND FOR INDICATING THE DEPTH OF AN EPITAXIAL DEPOSIT. THIS MEANS COMPRISES FILLED HOLES CALLED KEYS WHICH ARE EASILY NOTED EVEN THOUGH THE SURFACE OF THE WAFER IS CAREFULLY POLISHED. SINCE THE DEPTH OF THE KEYS IS LESS BY A PREDETERMINED AMOUNT THAN THE DEPTH OF THE EPITAXIAL DEPOSIT, PRESENCE OF THE DEYS AFTER THE POLISHING STEP INDICATES THAT THE REMAINING DEPTH OF THE DEPOSIT IS GREAT ENOUGH TO MAKE APPLICATION OF OTHER PROCESS STEPS TO THE WAFER ADVISALBE AND THE KEYS THEMSELVES ARE USED FOR POSITIONING AND ORIENTING SUCH FIXTURES AS MASKING DEVICES ON THE SURFACE OF THE WAFER. D R A W I N G
Inventors
- 👤 E Cheskis
- 👤 J Price
Bibliographic Details
Claims Analysis
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