Multiple-Time Programming Memory Cells and Methods for Forming the Same

A device comprising:

• a first active region and a second active region;
• a transistor, wherein portions of the first active region form a source region and a drain region of the transistor, and wherein a first floating gate acts as a gate electrode of the transistor;
• and
• a coupling capacitor comprising:
• a second floating gate as an upper capacitor plate, wherein the second floating gate is electrically coupled to the first floating gate, and wherein the second floating gate comprises:
• a first portion over a top surface of the second active region;
• and
• a second portion lower than the top surface of the second active region;
• a capacitor insulator between the second floating gate and the second active region;
• and
• a lower capacitor plate comprising a top surface layer and a side surface layer of the second active region, wherein the top surface layer and the side surface layer of the second active region are doped to have a same conductivity type, wherein the transistor and the coupling capacitor are portions of a Multiple-Time Programming (MTP) memory cell.

A method comprising:

• 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 to form a recess, wherein the portion of the STI regions contacts a sidewall of the second active region;
• implanting a top surface layer and a side surface layer of the second active region to form an implantation region, wherein the side surface layer of the second active region extends from the sidewall of the second active region into the second active region;
• oxidizing an upper portion of the top surface layer and an upper portion of the side surface layer to form a capacitor insulator;
• and
• forming a floating gate extending over the first active region and the second active region, wherein the floating gate comprises a portion extending into the recess.