AlGaN/GaN Superlattice‐Based p‐Type Field‐Effect Transistor with Tetramethylammonium Hydroxide Treatment

• Published in: Physica status solidi. A, Applications and materials science Vol. 217; no. 7
• Main Authors: Krishna, Athith, Raj, Aditya, Hatui, Nirupam, Koksaldi, Onur, Jang, Raina, Keller, Stacia, Mishra, Umesh K.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.04.2020
• Subjects: Aluminum gallium nitrides; Charge density; Contact resistance; Current modulation; gallium nitride; Gallium nitrides; Hall effect; Ions; Magnesium; Metalorganic chemical vapor deposition; nitride semiconductors; Organic chemicals; Organic chemistry; p-type doping; Room temperature; Semiconductor devices; Superlattices; Transistors; Transmission lines
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201900692

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. The first p‐type field‐effect transistor (pFET) based on an AlGaN/GaN superlattice (SL), grown using metal–organic chemical vapor deposition (MOCVD), is reported. Magnesium is used as the p‐type dopant. A sheet resistance of 11.6 kΩ □−1 and a contact resistance of 14.9 Ω mm are determined using transmission line measurements (TLMs) for Mg doping of 1.5 × 1019 cm−3. Mobilities in the range of 7–10 cm2 (V s)−1 and a total sheet charge density in the range of 1 × 1013–6 × 1013 cm−2 are measured using room temperature Hall effect measurements. Without tetramethylammonium hydroxide (TMAH) treatment, the fabricated pFETs have a maximum drain‐source current (IDS) of 3 mA mm−1 and an on‐resistance (RON) of 3.48 kΩ mm and do not turn off completely. With TMAH treatment during fabrication, a maximum IDS of 4.5 mA mm−1, RON of 2.2 kΩ mm, and five orders of current modulation are demonstrated. Herein, a p‐type field‐effect transistor (pFET) based on an AlGaN/GaN superlattice (SL) is demonstrated, for which the metal–organic chemical vapor deposition (MOCVD) growth technique is used. Magnesium is used as the p‐type dopant. With tetramethylammonium hydroxide (TMAH) treatment during fabrication, a maximum IDS of 4.5 mA mm−1, RON of 2.2 kΩ mm, and five orders of current modulation are demonstrated.