Semiconductor substrate with trenches of varying depth

US6932916B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Dirk Manger · Dresden, DE
• Hans-Peter Moll · Dresden, DE
• Till Schloesser · Dresden, DE

Key dates

• Filing date: Apr 29, 2003
• Grant date: Aug 23, 2005
• Expiry date: Jun 2, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D1/047
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for etching trenches having different depths on a semiconductor substrate includes providing a mask with first and second openings. The first and second openings are located where corresponding first and second trenches are to be etched. A slow-etch region, made of a slow-etch material, is provided above the substrate at a location corresponding to the second opening. When exposed to a selected etchant, the slow-etch material is etched at a rate less than the rate at which the semiconductor substrate is etched when exposed to the selected etchant.