Method for photomask processing
A method for photomask processing including the formation of a photoresist pattern for a P-Well. The method further includes implanting ions for the P-well using the photoresist pattern as an ion implantation mask, coating another photoresist for the N-well that has a higher etch resistance than that of the photoresist for the P-well, removing the photoresist for the P-well, implanting ions for the N-well, and removing the photoresist. The method reduces the number of photomask processes for ion implantation, so the total processing cost can be reduced.
1 . A method for photomask processing, comprising:
forming a photoresist pattern for a P-Well;
implanting ions for the P-well using the photoresist pattern as an ion implantation mask;
coating another photoresist for the N-well that has a higher etch resistance than that of the photoresist for the P-well;
removing the photoresist for the P-well;
implanting ions for the N-well; and
removing the photoresist.
2 . The method of claim 1 , wherein the photoresist for the N-well has an etch resistance that is at least three times higher than the photoresist for the P-well.
3 . The method of claim 1 , wherein, in removing the photoresist for the P-well, an etchant having a removing rate that is at least three times higher for the photoresist for the P-well than for the photoresist for the N-well is used for wet-etching the photoresist.
4 . The method of claim 1 , wherein the photomask processing is also adopted for forming an N channel and a P channel.
5 . The method of claim 1 , wherein the photomask processing is also adopted for forming an N-type source/drain region and a P-type source/drain region.