Comprehensive Schottky Barrier Height Behavior and Reliability Instability with Ni/Au and Pt/Ti/Pt/Au on AlGaN/GaN High-Electron-Mobility Transistors

Abstract

The reliability instability of inhomogeneous Schottky contact behaviors of Ni/Au and Pt/Ti/Pt/Au gate contacts on AlGaN/GaN high-electron-mobility transistors (HEMTs) was investigated via off-state stress and temperature. Under the off-state stress condition, Pt/Ti/Pt/Au HEMT showed abruptly reduced reverse leakage current, which improved the Schottky barrier height (SBH) from 0.46 to 0.69 eV by suppression of the interfacial donor state. As the temperature increased, the reverse leakage current of the Pt/Ti/Pt/Au AlGaN/GaN HEMT at 308 K showed more reduction under the same off-state stress condition while that of the Ni/Au AlGaN/GaN HEMT increased. However, with temperatures exceeding 308 K under the same off-state stress conditions, the reverse leakage current of the Pt/Ti/Pt/Au AlGaN/GaN HEMT increases, which can be intensified using the inverse piezoelectric effect. Based on this phenomenon, the present work reveals the necessity for analyzing the concurrent SBH and reliability instability due to the interfacial trap states of the MS contacts.

Ti3C2Tx MXene van der Waals Gate Contact for GaN High Electron Mobility Transistors

“…[5] Despite several excellent attributes like highelectron mobility and excellent thermal stability, Schottky gate GaN HEMTs suffer from high gate leakage current (I G ) and low drain current ON/OFF ratio (I ON /I OFF ). [6][7][8][9][10][11] In particular, the high I G can limit the maximum breakdown voltage and gate-voltage swing, resulting in high power consumption and early device breakdown. [6,8,12] In addition, a high I G and low I ON /I OFF bring detrimental effects to the radio frequency device performance such as reduced gain, power efficiency, and increased flicker noise.…”

“…[6,8,15,16] To enhance the gate controllability of Schottky gate GaN HEMTs, high-quality interfaces between metal electrodes and GaN are required. Several 2D and 3D materials have been evaluated as Schottky gate electrodes in GaN HEMTs, such as Cu, [2,17] Pt, [7] Cr, [18] Pb, [17,19] Ir, [19] Mo, [20] ITO, [21,22] TaN, [23] TiN, [3] W, [24,25] WN or WC, [18] TiSi 2 , [11] Au [9] graphene, [10] MoS 2 , [26] and Ni. [27][28][29] However, the most extensively used gate electrode, Ni/Au bilayer film, is not CMOS-compatible.…”

Impact of Charge-Trapping Effects on Reliability Instability in AlxGa1−xN/GaN High-Electron-Mobility Transistors with Various Al Compositions

“…GaN-based HEMTs have recently attracted much attention because of their remarkable material properties and device performances, notably in high-power and RF applications up to the sub-terahertz regime [ 4 , 5 , 6 ]. These advantageous properties and performances are caused primarily by the excellent quality of the epitaxial layer consisting of the Al x Ga 1−x N barrier and the GaN channel layer, resulting from the fundamental electronic properties of two-dimensional electron gas (2DEG) on top of Si, Sapphire, and silicon carbide (SiC) substrates [ 7 , 8 , 9 ]. Because high-density 2DEG accumulates at the Al x Ga 1−x N/GaN interface, those electronic properties would reflect the quality of the interface via scattering procedures caused by dislocations [ 10 ].…”

Explicit Thermal Resistance Model of Self-Heating Effects of AlGaN/GaN HEMTs with Linear and Non-Linear Thermal Conductivity

“…Owing to their high frequency and power handling potentialities, AlGaN/GaN high-electron-mobility transistors (HEMTs) are expected to play substantial roles in future satellite and information technologies [ 1 , 2 , 3 , 4 ]. The majority of the power of such devices is dissipated over relatively small areas of about 0.5–1 μm around the gate contact, resulting in local Joule self-heating [ 5 , 6 , 7 , 8 , 9 , 10 ].…”