Front-side-type image sensor

The invention relates to a front-side imager comprising in succession: -a semiconductor carrier substrate, a first electrically insulating separating layer, and a single-crystal semiconductor layer, called the active layer, comprising a matrix array of photodiodes, wherein the imager further comprises between the carrier substrate and the first electrically insulating layer: -a second electrically insulating separating layer, and -a second semiconductor or electrically conductive layer, called the intermediate layer, arranged between the second separating layer and the first separating layer, the second separating layer being thicker than the first separating layer.