METHOD FOR MAKING AN ACTIVE PIXEL SENSOR

摘要

A plurality of active pixel sensors are formed on the surface of a semiconductor wafer. The semiconductor wafer comprises a P-type substrate, an active pixel sensor region and a periphery circuit region. A first active pixel sensor block mask (APSB mask) is formed to cover the active pixel sensor region, then at least one N-well on the surface of the semiconductor wafer not covered by the first APSB mask is formed. A second APSB mask and at least one N-well mask are formed to cover the active pixel sensor region and the region outside the P-well region. At least one P-well on the surface of the semiconductor wafer not covered by the second APSB mask and the N-well mask is formed. Finally, at least one photodiode and at least one complementary metal-oxide semiconductor (CMOS) transistor are formed on the surface of the active pixel sensor region.