METHOD OF MANUFACTURING AN IMAGE SENSOR AND IMAGE SENSOR

A method of manufacturing a back-side ( 14 ) illuminated image sensor ( 1 ) is disclosed, comprising the steps of: starting with a wafer ( 2 ) having a first ( 3 ) and a second surface ( 4 ), providing light sensitive pixel regions ( 5 ) extending into the wafer ( 2 ) from the first surface ( 3 ), securing the wafer ( 2 ) onto a protective substrate ( 7 ) such that the first surface ( 3 ) faces the protective substrate, the wafer comprising a substrate of a first material ( 8 ) with an optical transparent layer ( 9 ) and a layer of semiconductor material ( 10 ), wherein the substrate ( 8 ) is selectively removed from the layer of semiconductor material by using the optical transparent layer ( 9 ) as stopping layer. For back-side illuminated image sensors, light has to transmit through the semiconductor layer and enter into the light sensitive pixel regions ( 5 ). In order to reduce absorption losses, it is very advantageous that the semiconductor layer ( 10 ) can be made relatively thin with a good uniformity. Because of the reduced thickness of the semiconductor layer, more light can enter into the light sensitive regions, resulting in an improved efficiency of the image sensor.