Power device manufacture on the recessed side of a thinned wafer

US8716067B2 · kind B2 · utility

Assignee

• IXYS, LLC · US

Inventors

• Elmar Wisotzki · Darmstadt, DE
• Peter Ingram · Hemsbach, DE

Key dates

• Filing date: Feb 20, 2012
• Grant date: May 6, 2014
• Expiry date: Jul 13, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2224/94
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A recess is formed into a first side of a wafer such that a thinned center portion of the wafer is formed, and such that the central portion is surrounded by a thicker peripheral edge support portion. The second side of the wafer remains substantially entirely planar. After formation of the thinned wafer, vertical power devices are formed into the first side of the central portion of the wafer. Formation of the devices involves forming a plurality of diffusion regions into the first side of the thinned central portion. Metal electrodes are formed on the first and second sides, the peripheral portion is cut from the wafer, and the thin central portion is diced to form separate power devices. In one example, a first commercial entity manufactures the thinned wafers, and a second commercial entity obtains the thinned wafers and performs subsequent processing to form the vertical power devices.