Semiconductor device and method of making

A semiconductor device, comprising:

• one or more dielectric layers over a photodiode in a substrate;
• a radiation channeling structure extending through the one or more dielectric layers, wherein the radiation channeling structure overlies the photodiode;
• and
• a lens overlying the radiation channeling structure,
• wherein:
• a first portion of the radiation channeling structure is a first distance from the photodiode;
• a second portion of the radiation channeling structure is a second distance from the photodiode;
• the first distance is less than the second distance;
• and
• the first portion of the radiation channeling structure has a first tapered sidewall with which a first tapered sidewall of a first dielectric layer of the one or more dielectric layers is aligned.

A method for forming a semiconductor device, comprising:

• forming a plurality of dielectric layers over a substrate;
• forming a trench through one or more dielectric layers of the plurality of dielectric layers, wherein:
• the trench overlies a photodiode in the substrate;
• a bottom of the trench is defined by a first tapered sidewall of a first dielectric layer of the one or more dielectric layers and a second tapered sidewall of the first dielectric layer;
• the first tapered sidewall of the first dielectric layer has a first slope;
• the second tapered sidewall of the first dielectric layer has a second slope;
• and
• the second slope is opposite in polarity relative to the first slope;
• and
• forming a plurality of layers, of a radiation channeling structure, in the trench, wherein the plurality of layers comprises:
• a first oxide layer;
• a second oxide layer;
• and
• a nitride layer between the first oxide layer and the second oxide layer.