摘要 |
A method for fabricating corner implants in the shallow trench isolation regions of an image sensor includes the steps of forming a photoresist layer on a first hard mask layer overlying an etch-stop layer on a semiconductor substrate. The photoresist mask is patterned to create an opening and the portion of the first hard mask layer exposed in the opening is etched down to the etch-stop layer. A first dopant is implanted into the semiconductor substrate through the exposed etch-stop layer. The photoresist mask is removed and a second hard mask layer is formed on the remaining structure and etched to create sidewall spacers along the side edges of the first hard mask layer. The etch stop layer and the semiconductor substrate positioned between the sidewall spacers are etched to create a trench and a second dopant implanted into the side and bottom walls of the trench. |