Patent ID: 7253019

Claim:
A method of making a CMOS active pixel structure, comprising: providing a semiconductor substrate with dopants of a first conductivity type at a first concentration density, and with an insulating layer at a surface region of the semiconductor substrate; forming a collection region by introducing dopants of a second conductivity type which is opposite the first conductivity type at a second concentration density region into the surface region of the semiconductor substrate; forming a detection region not bordering the collection region which defines a barrier region between the detection region and the collection region by introducing dopants of the second conductivity type at a third concentration density into the surface region of the semiconductor substrate; forming a barrier region of the first conductivity type in the substrate, with a concentration density of dopants being higher than the concentration density of dopants in the substrate; forming a dual-purpose electrode on the insulating layer with the dual-purpose electrode extending over the surface of at least part of the collection region, and over at least part of the substrate, the dual-purpose electrode being intended to be driven by a first voltage that causes an electrostatic potential which collects in an area of the collection region beneath the dual-purpose electrode charges generated by electromagnetic radiation and by a second voltage, which is higher than the first voltage, for transferring the charges from the collection region into a detection region; and forming an amplifier integrated in the active pixel structure that is coupled to the detection region to amplifying the collected charge.