Back-illuminated sensor process

Abstract

The present disclosure provides methods and apparatus for reducing dark current in a backside illuminated semiconductor device. In one embodiment, a method of fabricating a semiconductor device includes providing a substrate having a frontside surface and a backside surface, and forming a plurality of sensor elements in the substrate, each of the plurality of sensor elements configured to receive light directed towards the backside surface. The method further includes forming a dielectric layer on the backside surface of the substrate, wherein the dielectric layer has a compressive stress to induce a tensile stress in the substrate. A backside illuminated semiconductor device fabricated by such a method is also disclosed.

Description

[0001] priority date [0002] This application claims priority to US Provisional Application Serial No. 61 / 353,951 (Attorney No. 24061.1524), filed June 11, 2010, the entire contents of which are incorporated herein by reference. technical field [0003] The invention relates to a back-illuminated sensor technology. Background technique [0004] In semiconductor technology, backside illuminated (BSI) sensors are used to sense a certain amount of exposure light that hits the back surface of a substrate or sensing layer. A backside illuminated sensor can be formed on a substrate, and light irradiated onto the back surface of the substrate can reach the sensor. However, it is well known that the stress on the substrate or sensing layer will affect the leakage current or dark current during the processing of BSI sensors. In particular, stress on the device substrate or sensing layer can be caused by subsequent color filter processing and / or device packaging after leaving the m...

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Problems solved by technology

However, it is well known that stress on the substrate or sensing layer during BSI sensor processing can affect the leakage current or dark current

In particular, stress on the device substrate or sensing layer can be caused by subsequent color filter processing and / or device packaging after leaving the manufacturing facility, which can cause changes in dark current and the resulting negative impact on device performance or may even cause device degradation

[0005] Thus, while existing methods of fabricating semiconductor devices have been generally adequate for their intended purposes, they have not been satisfactory in every respect

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