Demonstration of AlGaN/GaN MISHEMT on Si with Low-Temperature Epitaxy Grown AlN Dielectric Gate

Abstract

AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MISHEMT) with a low-temperature epitaxy (LTE)-grown single crystalline AlN gate dielectric were demonstrated for the first time and the post-gate annealing effects at 400 °C were studied. The as-deposited LTE-AlN MISHEMT showed a maximum drain current (IDmax) of 708 mA/mm at a gate bias of 4 V and a maximum extrinsic transconductance (gmmax) of 129 mS/mm. The 400 °C annealed MISHEMT exhibited an increase of 15% in gmmax, an order of magnitude reduction in reverse gate leakage and about a 3% suppression of drain current (ID) collapse. The increase of gmmax by post-gate annealing is consistent with the increase of 2DEG mobility. The suppression of ID collapse and the reduction of gate leakage current is attributed to the reduction of interface state density (5.0 × 1011 cm−2eV−1) between the AlN/GaN interface after post-gate annealing at 400 °C. This study demonstrates that LTE grown AlN is a promising alternate material as gate dielectric for GaN-based MISHEMT application.

DC performance improvement of nanochannel AlGaN/AlN/GaN HEMTs with reduced OFF-state leakage current by post-gate annealing modulation

“…The diffusion of Au and Ni into the active layer could have increased the gate leakage current significantly, which would subsequently have deteriorated the device performance [40]. Furthermore, there was a minimal change in the Hall parameters after PGA at 400 • C as previously reported [41]. Moreover, in our previous study, it was found that the I G was not significantly reduced with PGA at 300 • C. Based on the above analyses, the annealing temperature and time were optimized at 400 • C for 10 min.…”

Trapping Dynamics in GaN HEMTs for Millimeter-Wave Applications: Measurement-Based Characterization and Technology Comparison

“…At the same time, they must become economically viable for low-cost communications applications. In this sense, while Silicon Carbide (SiC) substrates provide state-of-the-art Monolithic Microwave Integrated Circuit (MMIC) design performance [4], a whole new generation of GaN-on-Si RF devices is being developed with the aim of reducing the cost of the substrate and of exploiting the established Si-based RF and digital process technology [5][6][7][8][9][10].…”

Research Progress and Development Prospects of Enhanced GaN HEMTs

“…At the same time, they must be economically viable in low-cost communications applications. In this sense, while silicon carbide (SiC) substrates offer the most advanced monolithic microwave integrated circuit (MMIC) design performance, a new generation of GaN-on-Si RF devices is being developed that can reduce substrate costs and utilize existing silicon-based RF and digital processing technologies [70][71][72]. Because the Si substrate's heat dissipation performance is worse than SiC, the long-term reliability of GaN-on-Si HEMTs in practical applications needs to be fully investigated.…”