Gallium nitride-on-silicon interface using multiple aluminum compound buffer layers

US7598108B2 · kind B2 · utility

Assignee

• Sharp Laboratories of America, Inc. · US

Inventors

• Tingkai Li · Vancouver, US
• Douglas J. Tweet · Camas, US
• Jer-Shen Maa · Vancouver, US
• Sheng Teng Hsu · Camas, US

Key dates

• Filing date: Jul 6, 2007
• Grant date: Oct 6, 2009
• Expiry date: Jul 31, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/02647
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A thermal expansion interface between silicon (Si) and gallium nitride (GaN) films using multiple buffer layers of aluminum compounds has been provided, along with an associated fabrication method. The method provides a (111) Si substrate and deposits a first layer of AlN overlying the substrate by heating the substrate to a relatively high temperature of 1000 to 1200° C. A second layer of AlN is deposited overlying the first layer of AlN at a lower temperature of 500 to 800° C. A third layer of AlN is deposited overlying the second layer of AlN by heating the substrate to the higher temperature range. Then, a grading Al1-XGaXN layer is formed overlying the third layer of AlN, where 0<X<1, followed by a fixed composition Al1-XGaXN layer overlying the first grading Al1-XGaXN layer. An epitaxial GaN layer can then be grown overlying the fixed composition Al1-XGaXN layer.