Nitrogen-plasma surface treatment in a direct bonding method

US8318586B2 · kind B2 · utility

Assignee

• COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES · FR

Inventors

• Laure Libralesso · Le Pont-de-Claix, FR
• Hubert Moriceau · Saint-Égrève, FR
• Christophe Morales · Le Pont-de-Claix, FR
• Francois Rieutord · St-Estève, FR
• Caroline Ventosa · Fontaine, FR
• Thierry Chevolleau · Grenoble, FR

Key dates

• Filing date: Apr 28, 2009
• Grant date: Nov 27, 2012
• Expiry date: Apr 28, 2029

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/2007
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Two plates, each comprising a thin layer of silicon or silicon oxide at a surface thereof, are bonded by subjecting the thin layer of at least one of the plates to a surface treatment step forming a silicon oxynitride superficial thin film with a thickness of less than 5nm. The thin film is performed with a nitrogen-based plasma generated by an inductively coupled plasma source. Furthermore, a potential difference applied between the plasma and a substrate holder supporting said plate during the surface treatment step is less than 50 V, advantageously less than 15 V and preferably zero. This enables a defect-free bonding interface to be obtained irrespective of a temperature of any heat treatment carried out after a contacting step between the respective thin layers of the two plates.