Method for forming structure for reducing noise in CMOS image sensors
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsTien-Chi Wu, Tsung-Yi Lin
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Abstract
A method and device is disclosed for reducing noise in CMOS image sensors. An improved CMOS image sensor includes a light sensing structure surrounded by a support feature section. An active section of the light sensing structure is covered by no more than optically transparent materials. A light blocking portion includes a black light filter layer and an opaque layer covering the support feature section. The light blocking portion may also cover a peripheral portion of the light sensing structure. The method for forming the CMOS image sensors includes using film patterning and etching processes to selectively form the opaque layer where the light blocking portion is desired but not over the active section.
Claims12
A method for forming a CMOS image sensor, the method comprising:
- providing a light sensing structure at least partially surrounded by a support feature section, the light sensing structure including an active section;
- covering the active section with optically transparent materials;
- forming a light blocking portion that does not extend over the active section by forming an opaque layer covering the support feature section and a covered section of the light sensing structure that is contiguous with and completely surrounds the active section of the light sensing structure, forming a transparent dielectric layer on and directly contacting the opaque layer, and forming a black light filter layer on and directly contacting the transparent dielectric layer,
- the light sensing structure being a uniform and unitary structure formed over a uniform substrate substructure.
A method for forming a CMOS image sensor, the method comprising:
- providing a light sensing structure at least partially surrounded by a support feature section, the light sensing structure including an active section;
- covering the active section with optically transparent materials;
- and
- forming a light blocking portion that does not extend over the active section, by forming an opaque metal layer covering the support feature section and a covered section of the light sensing structure that is contiguous with and completely surrounds the active section of the light sensing structure;
- forming a transparent dielectric layer on and directly contacting the metal opaque layer;
- forming a further metal opaque layer on and directly contacting the transparent dielectric layer and forming a black light filter layer on and directly contacting the further metal opaque layer,
- the light sensing structure being a uniform and unitary structure formed over a uniform substrate substructure.
Dependencies are inferred from the claim text.