One time programmable EPROM for advanced CMOS technology
AssigneeTexas Instruments Incorporated
InventorsJozef Czeslaw Mitros, David Tatman
Life of this patent
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Abstract
A one time programmable (OTP) electrically programmable read only memory (EPROM) transistor (100) having an increased breakdown voltage (BVdss) is disclosed. The increased breakdown voltage reduces the probability that the OTP EPROM (100) will breakdown during a programming operation by maintaining a breakdown voltage above a programming voltage. The breakdown voltage is, at least partially, increased by forming a p-doped region (140) within a semiconductor substrate (102), and forming a drain region (166) of the OTP EPROM (100) within the p-doped region (140).
Claims16
A method of forming a one time programmable (OTP) electrically programmable read only memory (EPROM) transistor, comprising:
- forming an n buried layer (NBL) within a semiconductor substrate;
- forming an epitaxial layer over the substrate and the NBL;
- forming left and right NWELL regions within the epitaxial layer;
- forming a p doped region within the epitaxial layer between the left and right NWELL regions;
- forming a gate structure over the semiconductor substrate;
- and
- forming a source region and a drain region in the semiconductor substrate adjacent to a left side of the gate structure and a right side of the gate structure, respectively, such that the source region is at least partially formed within the left NWELL region and the drain region is at least partially formed within the p doped region.
Dependencies are inferred from the claim text.