US 12,336,313 B2
Back side illumination image sensor and method of manufacturing the same
Chih-Ping Chung, Hsinchu (TW); Saysamone Pittikoun, Hsinchu County (TW); Chih-Hao Peng, Taoyuan (TW); and Ming-Yu Ho, Taichung (TW)
Assigned to Powerchip Semiconductor Manufacturing Corporation, Hsinchu (TW)
Filed by Powerchip Semiconductor Manufacturing Corporation, Hsinchu (TW)
Filed on Jan. 9, 2023, as Appl. No. 18/152,061.
Claims priority of application No. 111144669 (TW), filed on Nov. 22, 2022.
Prior Publication US 2024/0170526 A1, May 23, 2024
Int. Cl. H10F 39/12 (2025.01); H10F 39/00 (2025.01)
CPC H10F 39/199 (2025.01) [H10F 39/024 (2025.01); H10F 39/8053 (2025.01); H10F 39/8057 (2025.01); H10F 39/8063 (2025.01); H10F 39/811 (2025.01)] 15 Claims
OG exemplary drawing
 
1. A back side illumination image sensor comprising:
an epitaxial substrate having a first surface and a second surface opposite to each other;
a deep trench isolation structure extending from the second surface to the first surface of the epitaxial substrate to divide the epitaxial substrate into a plurality of regions;
a buried oxide (BOX) layer disposed on the first surface of the epitaxial substrate, wherein the buried oxide layer has a plurality of openings exposing the plurality of regions;
an epitaxial layer formed on the first surface of the epitaxial substrate and covering the buried oxide layer;
a well region formed in the epitaxial layer and extending into the first surface of the epitaxial substrate, wherein the plurality of regions other than the well region become a plurality of photosensitive element regions;
a floating diffusion (FD) region formed in the well region above the buried oxide layer between the plurality of photosensitive element regions, wherein a width of the buried oxide layer is greater than a width of the floating diffusion region;
a shallow trench isolation structure disposed in the epitaxial layer and in contact with the buried oxide layer, so that the shallow trench isolation structure, the deep trench isolation structure and the buried oxide layer form a continuous isolation structure; and
a plurality of vertical transfer gates (VTGs) disposed in the epitaxial layer and passing through the plurality of openings of the buried oxide layer.