Microlens structure for image sensors
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsMing-Chang Kao, Chih-Kung Chang, Fu-Tien Weng, Bii-Junq Chang
Life of this patent
Estimating the term…
Abstract
A microlens structure and a method of fabrication thereof are provided. The method comprises forming a layer of microlens material over a substrate, which has photo-sensitive elements formed therein. The microlens material, which comprises a photo-resist material, is exposed in accordance with a desired pattern a plurality of times. The energy used with each exposure process is less than the energy required if a single exposure is used. Furthermore, the masks used for each exposure may differ. In an embodiment, the masks are varied so as to create a notch in the upper corner of the microlens.
Claims22
A method of forming a microlens, the method comprising:
- providing a substrate, the substrate having one or more photo-sensitive elements;
- forming a photo-sensitive layer over the substrate;
- performing a first exposure in accordance with a mask;
- performing a second exposure in accordance with the mask;
- removing a portion of the photo-sensitive layer such that remaining portions of the photo-sensitive layer form one or more microlenses;
- and
- reflowing the microlenses.
A method of forming a microlens, the method comprising:
- providing a substrate, the substrate having one or more photo-sensitive elements;
- forming a photo-sensitive layer over the substrate;
- performing a plurality of exposures in accordance with a mask, the exposures exposing at least a portion of the photo-sensitive layer;
- removing at least a portion of the photo-sensitive layer such that remaining portions of the photo-sensitive layer form a plurality of microlenses;
- and
- reflowing the microlenses.
A method of forming an image sensing semiconductor device, the method comprising:
- providing a substrate, the substrate having an image sensing portion and a logic portion, the image sensing portion having a plurality of photo-sensitive devices formed thereon and the logic portion having one or more interconnection layers;
- and
- forming a photo-sensitive layer over the image sensing portion;
- performing a plurality of exposures in accordance with a mask, the exposures exposing at least a portion of the photo-sensitive layer;
- removing at least a portion of the photo-sensitive layer exposed during the exposures, remaining portions of the photo-sensitive layer forming one or more microlenses;
- and
- reflowing the microlenses.
Dependencies are inferred from the claim text.