US 12,446,338 B2
Method for manufacturing image sensor including forming FinFET transfer gate having a plurality of channel fins above a p-type region
Feng-Chien Hsieh, Pingtung (TW); Yun-Wei Cheng, Taipei (TW); Wei-Li Hu, Tainan (TW); Kuo-Cheng Lee, Tainan (TW); and Cheng-Ming Wu, Tainan (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Mar. 26, 2021, as Appl. No. 17/214,329.
Prior Publication US 2022/0310687 A1, Sep. 29, 2022
Int. Cl. H01L 27/146 (2006.01); H10F 39/00 (2025.01)
CPC H10F 39/80377 (2025.01) [H10F 39/014 (2025.01); H10F 39/8033 (2025.01); H10F 39/802 (2025.01)] 20 Claims
OG exemplary drawing
 
1. A method of forming a pixel sensor, comprising:
forming, in a substrate, a cell p-well (CPW) region;
forming, in the substrate, a p-type region;
forming, in the substrate and above the p-type region, a plurality of channel fins for a transfer fin field effect transistor (finFET);
forming, in the substrate and within a perimeter of the CPW region, an n-type region of a photodiode;
forming, in the substrate and within the perimeter of the CPW region, a drain extension region of the transfer finFET,
wherein the plurality of channel fins couple the n-type region and the drain extension region;
forming a transfer gate above the p-type region and at least partially around the plurality of channel fins;
etching the CPW region to form an isolation structure that surrounds the n-type region, the p-type region, the drain extension region, and the transfer gate; and
connecting the transfer gate to an interconnect.
 
6. A method of forming a pixel sensor, comprising:
forming, in a substrate, a cell p-well (CPW) region;
forming, in the substrate, a p-type region;
forming, in the substrate and above the p-type region, a plurality of channel fins for a transfer fin field effect transistor (finFET);
forming, in the substrate and within a perimeter of the CPW region, an n-type region of a photodiode;
forming, in the substrate and within the perimeter of the CPW region, a drain extension region of the transfer finFET,
wherein the plurality of channel fins couple the n-type region and the drain extension region;
forming a transfer gate above the p-type region and at least partially around the plurality of channel fins,
wherein the transfer gate comprises a high-k dielectric layer over a bottom interface oxide layer; and
etching the CPW region to form an isolation structure that surrounds the n-type region, the p-type region, the drain extension region, and the transfer gate.
 
8. A method of forming a pixel sensor, comprising:
forming, in a substrate, a cell p-well (CPW) region;
forming, in the substrate, a p-type region;
forming, in the substrate and above the p-type region, a plurality of channel fins for a transfer fin field effect transistor (finFET);
forming, in the substrate and within a perimeter of the CPW region, a drain region;
forming, in the substrate and within the perimeter of the CPW region, an n-type region of a photodiode;
forming, in the substrate and within the perimeter of the CPW region, a drain extension region of the transfer finFET,
wherein the plurality of channel fins couple the n-type region and the drain extension region;
forming a transfer gate above the p-type region and at least partially around the plurality of channel fins;
etching the CPW region to form an isolation structure that surrounds the n-type region, the p-type region, the drain extension region, the drain region, and the transfer gate;
connecting the drain region to a first interconnect; and
connecting the transfer gate to a second interconnect.