AlGaN /GaN superlattice based p-channel field effect transistor (pFET) with TMAH treatment

• Published in: arXiv.org
• Main Authors: Athith Krishna, Raj, Aditya, Hatui, Nirupam, Koksaldi, Onur, Jang, Raina, Keller, Stacia, Mishra, Umesh
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 25.08.2019
• Subjects: Aluminum gallium nitrides; Charge density; Field effect transistors; Gallium nitrides; Magnesium; Physics - Applied Physics; Semiconductor devices; Superlattices; Transistors
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1902.02022

To realize the full spectrum of advantages that the III-nitride materials system offers, the demonstration of p-channel III-nitride based devices is valuable. Authors report the first p-type field effect transistor (pFET) based on an AlGaN/GaN superlattice (SL), grown using MOCVD. Magnesium was used as the p-type dopant. A sheet resistance of 11.6 k{\Omega}/sq, and a contact resistance of 14.9{\Omega}.mm was determined using transmission line measurements (TLM) for a Mg doping of 1.5e19cm^-3 of Mg. Mobilities in the range of 7-10 cm\^2/Vs and a total sheet charge density in the range of 1e13-6e13 cm-2 were measured using room temperature Hall effect measurements. Without Tetramethylammonium hydroxide (TMAH) treatment, the fabricated pFETs had a maximum drain-source current (IDS) of 3mA/mm and an On-Resistance (RON) of 3.48 k{\Omega}.mm, and did not turn-off completely. With TMAH treatment during fabrication, a maximum IDS of 4.5mA/mm, RON of 2.2k{\Omega}.mm, and five orders of current modulation was demonstrated, which is the highest achieved for a p-type transistor based on (Al,Ga)N.