Method of fabricating semiconductor components through implantation and diffusion in a semiconductor substrate

US7144796B2 · kind B2 · utility

Assignee

• ATMEL Germany GmbH · DE

Inventors

• Franz Dietz · Heilbronn, DE
• Volker Dudek · Ditzingen, DE
• Michael Graf · Leutenbach, DE

Key dates

• Filing date: Sep 20, 2004
• Grant date: Dec 5, 2006
• Expiry date: Jun 7, 2025

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/307
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A semiconductor element such as a DMOS-transistor is fabricated in a semiconductor substrate. Wells of opposite conductivity are formed by implanting and then thermally diffusing respective well dopants into preferably spaced-apart areas in the substrate. At least one trench and active regions are formed in the substrate. The trench may be a shallow drift zone trench of a DMOS-transistor, and/or a deep isolation trench. The thermal diffusion of the well dopants includes at least one first diffusion step during a first high temperature drive before forming the trench, and at least one second diffusion step during a second high temperature drive after forming the trench. Dividing the thermal diffusion steps before and after the trench formation achieves an advantageous balance between reducing or avoiding lateral overlapping diffusion of neighboring wells and reducing or avoiding thermally induced defects along the trench boundaries.