Multiple-time programming memory cells and methods for forming the same

摘要

A method includes forming Shallow Trench Isolation (STI) regions to separate a first active region and a second active region of a semiconductor substrate from each other, etching a portion of the STI regions that contacts a sidewall of the second active region to form a recess, and implanting a top surface layer and a side surface layer of the second active region to form an implantation region. The side surface layer of the second active region extends from the sidewall of the second active region into the second active region. An upper portion of the top surface layer and an upper portion of the side surface layer are oxidized to form a capacitor insulator. A floating gate is formed to extend over the first active region and the second active region. The floating gate includes a portion extending into the recess.

主权项

1. A method comprising:
etching a portion of a Shallow Trench Isolation (STI) region to form a recess, with a sidewall of a first active region of a semiconductor substrate exposed to the recess, wherein the STI region further comprises a lower portion overlapped by the etched portion of the STI region; implanting a side surface layer of the first active region to form an implantation region, wherein the side surface layer is exposed to the recess; oxidizing an outer portion of the side surface layer to form a capacitor insulator of a capacitor; and forming a conductive feature comprising a first portion extending into the recess to form an upper capacitor plate of the capacitor.