Structure of dielectric grid for a semiconductor device

A method comprising:

• providing a substrate, the substrate having sensor elements in a pixel region and having no sensor elements in a non-pixel region;
• depositing an anti-reflection coating (ARC) layer over the substrate;
• depositing a buffer layer over the ARC layer;
• forming metal pillars and a metal shield layer over the buffer layer, wherein spaces between adjacent metal pillars are directly above respective sensor elements, and wherein the metal shield layer is formed over the non-pixel region;
• depositing a dielectric layer over the metal pillars and the metal shield layer;
• and
• etching the dielectric layer, thereby forming first trenches over the pixel region, and forming second trenches over the non-pixel region, wherein each of the first trenches aligns to a respective sensor element and is surrounded by the dielectric layer at its bottom and sidewall surfaces, and wherein each of the second trenches exposes the metal shield layer.

A method comprising:

• providing a substrate, the substrate having sensor elements in a pixel region and having no sensor elements in a non-pixel region;
• forming metal pillars and a metal shield layer over the substrate, wherein spaces between adjacent metal pillars allow radiations to reach the respective sensor elements, and wherein the metal shield layer is formed over the non-pixel region;
• depositing a dielectric layer over the metal pillars and the metal shield layer;
• and
• etching the dielectric layer, thereby forming first trenches over the pixel region, and forming second trenches over the non-pixel region, wherein each of the first trenches aligns to a respective sensor element and is surrounded by the dielectric layer at its bottom and sidewall surfaces.