Patent ID: 7335546

Claim:
A method for making an image sensor, the method comprising: forming a first well and a second well in a substrate, the first well and the second well being different; forming a gate oxide layer on the substrate; depositing a first gate region and a second gate region on the gate oxide layer, the first gate region being associated with the first well, the second gate region being associated with the second well; forming a third well in the substrate; implanting a first plurality of ions to form a first lightly doped source region and a first lightly doped drain region in the first well; implanting a second plurality of ions to form at least a second lightly doped drain region in the second well; implanting a third plurality of ions to form a source in the second well; wherein: the first well and the second well are associated with a CMOS; the third well is associated with a photodiode; the implanting a second plurality of ions and the implanting a third plurality of ions are two separate processes; the implanting a third plurality of ions is associated with a first implant energy ranging from 40 KeV to 80 KeV and a first implant dose ranging from 10 3 cm −2 to 10 5 cm −2 .