Performance improvement and better scalability of wet-recessed and wet-oxidized AlGaN/GaN high electron mobility transistors. (May 2017)

• Record Type: Journal Article
• Authors: Takhar, Kuldeep; Meer, Mudassar; Upadhyay, Bhanu B.; Ganguly, Swaroop; Saha, Dipankar
• Is Part Of: Solid-state electronics. Volume 131(2017)
• Page Start: 39
• Page End: 44
• Publication Date: 2017-05
• Subjects: GaN HEMT -- Oxide -- Radio frequency -- Scalability; Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2017.02.002
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: Wet-recessed and wet-oxidized AlGaN/GaN HEMTs for better scalability. Oxide HEMTs show superior performance in comparison to conventional HEMTs. Effective velocity in the channel increases for oxide HEMTs. Oxide HEMTs show a very large unity-current gain frequency and gate length product. Abstract: We have demonstrated that a thin layer of Al2 O3 grown by wet-oxidation of wet-recessed AlGaN barrier layer in an AlGaN/GaN heterostructure can significantly improve the performance of GaN based high electron mobility transistors (HEMTs). The wet-etching leads to a damage free recession of the gate region and compensates for the decreased gate capacitance and increased gate leakage. The performance improvement is manifested as an increase in the saturation drain current, transconductance, and unity current gain frequency (fT ). This is further augmented with a large decrease in the subthreshold current. The performance improvement is primarily ascribed to an increase in the effective velocity in two-dimensional electron gas without sacrificing gate capacitance, which make the wet-recessed gate oxide-HEMTs much more scalable in comparison to their conventional counterpart. The improved scalability leads to an increase in the product of unity current gain frequency and gate length (fT × Lg ).