ion implantation in one embodiment the n si region 145 is implanted with a doping concentration similar to the doping concentration of the extension regions 130 a and 130 b and deeper than the extension regions 130 a and 130 b the n si region 145 and the p substrate 110 form a pn junction therefore can be collectively referred to as a photo diode 110 145 next with reference to fig1 h in one embodiment a drain region 150 is formed in the substrate 110 by illustratively ion implantation in one embodiment the drain region 150 also called a floating diffusion region 150 is heavily doped with n type dopants and deeper than the extension regions 130 a and 130 b it should be noted that the gate dielectric region 120 the gate electrode region 125 the extension regions 130 a and 130 b and the floating diffusion region 150 can be collectively referred to as a transfer gate 155 next with reference to fig1 in one embodiment a nitride layer 160 is formed on top of the structure 100 of fig1 h illustratively the nitride layer 160 can be formed by pecvd plasma enhanced chemical vapor deposition of silicon nitride on top of the dielectric layer 135 and the nitride spacers 140 a and 140 b next with reference to fig1 j in one embodiment a charge pushing region 165 is formed by cvd of a transparent and conducting material on top of the nitride layer 160 followed by a lithographic and etching step the lithographic and etching step is performed such that the charge pushing region 165 is only formed to the left and on top of a part of the gate electrode region 125 as shown in fig1 j in one embodiment the.