Method for bonding two silicon substrates, and a correspondeing system of two silicon substrates

US9123716B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Julian Gonska · Reutlingen, DE
• Heribert Weber · Leverkusen, DE
• Jens Frey · Echterdingen, DE
• Timo Schary · Grötzingen, DE
• Thomas Mayer · Reutlingen, DE

Key dates

• Filing date: Dec 19, 2012
• Grant date: Sep 1, 2015
• Expiry date: Dec 19, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2924/16251
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for bonding two silicon substrates and a corresponding system of two silicon substrates. The method includes: providing first and second silicon substrates; depositing a first bonding layer of pure aluminum or of aluminum-copper having a copper component between 0.1 and 5% on a first bonding surface of the first silicon substrate; depositing a second bonding layer of germanium above the first bonding surface or above a second bonding surface of the second silicon substrate; subsequently joining the first and second silicon substrates, so that the first and the second bonding surfaces lie opposite each other; and implementing a thermal treatment step to form an eutectic bonding layer of aluminum-germanium or containing aluminum-germanium as the main component, between the first silicon substrate and the second silicon substrate, spikes which contain aluminum as a minimum and extend into the first silicon substrate, forming at least on the first bonding surface.