A low voltage hybrid bulk/SOI CMOS active pixel image sensor

A hybrid bulk/silicon-on-insulator (SOI) complementary metal oxide semicond uctor (CMOS) active pixel image sensor has been fabricated and studied. The active pixel comprise of reset and source follow transistors on the SOI th in film while the photodiode is fabricated on the SOI handling substrate af ter removing the buried oxide. The hulk photo diode can be optimized for ef ficiency with the use of lightly doped SOI substrate without compromising B e circuit performance. On the other hand, the elimination of wells on the S OI thin-film allows the use of PMOSFET without increasing the pixel size, T he addition of a PMOSFET in the active pixel structure can reduce the minim um operating voltage of the circuit beyond that of conventional designs. Wi th the combination of the high quantum efficiency of bulk photodiode and th e low power advantage of SOI technology, the hybrid technology is attractiv e, for scaled low voltage imaging applications.