Self-aligned trench MOSFETs and methods for making the same

US7078296B2 · kind B2 · utility

Assignee

• FAIRCHILD SEMICONDUCTOR CORPORATION · US

Inventors

• Duc Chau · San Jose, US
• Becky Losee · Cedar Hills, US
• Bruce D. Marchant · Murray, US
• Dean E. Probst · West Jordan, US
• Robert Herrick · Lompoc, US
• James J. Murphy · South Jordan, US

Key dates

• Filing date: Jan 16, 2002
• Grant date: Jul 18, 2006
• Expiry date: Jan 16, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/038

Abstract

Self-aligned trench MOSFETs and methods for manufacturing the same are disclosed. By having a self-aligned structure, the number of MOSFETS per unit area—the cell density—is increased, making the MOSFETs cheaper to produce. The self-aligned structure for the MOSFET is provided by making the sidewall of the overlying isolation dielectric layer substantially aligned with the sidewall of the gate conductor. Such an alignment can be made through any number of methods such as using a dual dielectric process, using a selective dielectric oxidation process, using a selective dielectric deposition process, or a spin-on-glass dielectric process.