A new LDD transistor with inverse-T gate structure
Abstract
A new submicrometer inverse-T lightly doped drain (ITLDD) transistor structure for alleviating hot-electron effects is demonstrated. A thin extension of the polysilicon gate under the oxide sidewall spacer is formed, giving the gate cross section the appearance of an inverted T. Due to the unique self-aligned n(+)-to-gate feature facilitated by the conducting polysilicon extension, the 'spacer-induced degradation' existing in a conventional LDD transistor is eliminated in ITLDD devices. This allows the use of low n(-) LDD doses for optimum channel electric field reduction and minimum post-implant drive-in for future VLSI compatibility. Submicrometer ITLDD transistors with good transconductance and hot-electron reliability have been achieved. The new ITLDD transistor offers a promising device structure for future VLSI applications.
- Publication:
-
IEEE Electron Device Letters
- Pub Date:
- April 1987
- Bibcode:
- 1987IEDL....8..151H
- Keywords:
-
- Electric Fields;
- Field Effect Transistors;
- Hot Electrons;
- Transconductance;
- Very Large Scale Integration;
- Volt-Ampere Characteristics;
- N-Type Semiconductors;
- P-Type Semiconductors;
- Electronics and Electrical Engineering