Electrical and Thermal Stability of ALD-Deposited TiN Transition Metal Nitride Schottky Gates for AlGaN/GaN HEMTs

Abstract

TiN, a transition metal nitride, has been evaluated as an electrically and thermally stable Schottky gate material for AlGaN/GaN high electron mobility transistors. HEMTs with 75 nm TiN gates deposited via atomic layer deposition at 350°C exhibited improved static and dynamic on-state characteristics compared to Ni/Au-gated HEMTs. Reverse bias gate stressing indicated a higher critical voltage and higher breakdown voltage for the TiN-gated HEMTs. The TiN gated devices exhibited stable DC operation after annealing at temperatures as high as 800°C, while the Ni/Au gates exhibited significant degradation after annealing above 500°C and failed catastrophically at 800°C.

Thermionic Emission Analysis of TiN and Pt Schottky Contacts to β-Ga2O3

“…8,9 On the other hand, transition metal nitrides such as TiN and NbN have a lower work function (∼3 eV) but are attractive for their mechanical hardness, thermal stability, and ability to conformally coat confined channels on a wafer scale by techniques such as atomic layer deposition (ALD). [10][11][12] We thus compare the rectifying characteristics of a high work function metal (Pt, M ∼5.6 eV) and a transition metal nitride (TiN, TiN ∼3 eV) deposited on β-Ga 2 O 3 . 13,14 Experimental Two samples of non-intentionally n-type doped (-201) β-Ga 2 O 3 (∼3 × 10 17 cm −3 ) were diced from a commercial 2-inch substrate (Tamura Corp.) and cleaned in UV/ozone for 10 min.…”

Electrical Characterization of Postmetal Annealed Ultrathin TiN Gate Electrodes in Si MOS Capacitors

“…The TiN/TaN double-layer stack is also incorporated to tune the work function for the MOSCAP structure [5,6]. The added advantage of TiN is its midgap work function and alongside compatibility with the standard CMOS processing techniques making it a viable choice to investigate it further [7][8][9][10][11][12][13].…”

ALD TiN Schottky Gates for Improved Electrical and Thermal Stability in III-N Devices

“…Previous experiments suggest that these films are electrically stable up to 800 °C and even show a slight improvement in performance at lower anneals (17). To understand this better, the TiN films grown on AlGaN/GaN planar structures were subjected to similar device anneals from 400 to 800 °C.…”