Pt, Ni and Ti Schottky barrier contacts to \{beta}-(Al0.19Ga0.81)2O3 grown by Molecular Beam Epitaxy on Sn doped \{beta}-Ga2O3 substrate

TL;DR

This study characterizes the electrical properties of Pt, Ni, and Ti Schottky contacts on -(Al0.19Ga0.81)2O3 grown by MBE, revealing how different metals influence barrier heights and device behavior across temperatures.

Contribution

It provides a detailed analysis of Schottky barrier heights and electrical parameters for three metals on -(Al0.19Ga0.81)2O3, highlighting the dependence on work function and temperature.

Findings

SBHs vary with metal work function, with Pt highest and Ti lowest.

The -(Al0.19Ga0.81)2O3 layer is fully depleted at room temperature.

Barrier heights increase with metal work function.

Abstract

A comprehensive current-voltage (I-V) characterization is performed for three different Schottky contacts; Pt, Ni and Ti, to unintentionally doped (UID) \{beta}-(Al0.19Ga0.81)2O3 grown by molecular beam epitaxy (MBE) on \{beta}-Ga2O3 for temperatures ranging between 25C -300C. Reciprocal space mapping shows the (Al0.19Ga0.81)2O3 films are strained and lattice matched to the substrate. Schottky Barrier Height (SBH), ideality factor (n), and series resistance (Rs) are extracted from the I-V characteristics for the three types of metals and temperatures. Room temperature capacitance-voltage (C-V) measurements revealed fully depleted \{beta}-(Al0.19Ga0.81)2O3 layer. Extracted room temperature SBHs after zero field correction for Pt, Ni and Ti were 2.39 eV, 2.21 eV, and 1.22 eV respectively. Variation of SBHs with metal clearly indicates the dependence on work function.