High-Performance Poly-Ge Thin-Film Transistor with NiGe Schottky Source/Drain

Abstract

High-performance poly-Ge thin-film transistors (TFTs) were fabricated using NiGe Schottky contacts as source/drain (S/D). First, formation of NiGe layers by annealing of Ni/n-Ge structures was investigated as a function of annealing temperature, and NiGe/n-Ge Schottky contacts (Φ Bn =0.51 eV) with a low reverse leakage current (∼10 -2 A/cm 2 ) were realized at 200-300°C. On the basis of the results, NiGe Schottky S/D contacts were fabricated using poly-Ge/quartz substrates. The TFTs showed good operation characteristics with a hole mobility of ∼140cm 2 V 1 s 1 . This is a great advantage for the realization of high-performance TFTs for future system-in-displays.