Record Breakdown Voltage (2200 V) of GaN DHFETs on Si With 2- \mu\hbox Buffer Thickness by Local Substrate Removal

• Published in: IEEE electron device letters Vol. 32; no. 1; pp. 30 - 32
• Main Authors: Srivastava, Puneet, Das, Jo, Visalli, Domenica, Van Hove, Marleen, Malinowski, Pawel E, Marcon, Denis, Lenci, Silvia, Geens, Karen, Kai Cheng, Leys, Maarten, Decoutere, Stefaan, Mertens, Robert P, Borghs, Gustaaf
• Format: Journal Article
• Language: English
• Published: IEEE 01-01-2011
• Subjects: AlGaN/GaN/AlGaN; Aluminum gallium nitride; breakdown voltage; double-heterostructure FETs (DHFETs); Gallium nitride; Hall measurement; HEMTs; local Si substrate removal; Logic gates; MOCVD; MODFETs; Silicon; Substrates
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2010.2089493

In this letter, we present a local substrate removal technology (under the source-to-drain region), reminiscent of through-silicon vias and report on the highest ever achieved breakdown voltage (V BD ) of AlGaN/GaN/AlGaN double heterostructure FETs on a Si (111) substrate with only 2-μm-thick AlGaN buffer. Before local Si removal, V BD saturates at ~700 V at a gate-drain distance (L GD ) ≥ 8 μm. However, after etching away the substrate locally, we measure a record V BD of 2200 V for the devices with L GD = 20 μm. Moreover, from Hall measurements, we conclude that the local substrate removal integration approach has no impact on the 2-D electron gas channel properties.