Method and apparatus providing CMOS imager device pixel with transistor having lower threshold voltage than other imager device transistors

摘要

A transistor of a pixel cell for use in a CMOS imager with a low threshold voltage of about 0.3 V to less than about 0.7 V is disclosed. The transistor is provided with high dosage source and drain regions around the gate electrode and with the halo implanted regions and/or the lightly doped LDD regions and/or the enhancement implanted regions omitted from at least one side of the gate electrode. The low threshold transistor is electrically connected to a high voltage transistor with a high threshold voltage of about 0.7 V.