Electrical Performance Determination and Stress Reliability Estimation of ALD- Derived Er2O3/InP Heterointerface

High-quality gate dielectric layers and high-grade interfaces between high-
${k}$
films and substrates are essential to achieve favorable performance and electrical stability of metal–oxide–semiconductor field effect transistors (MOSFETs). The carrier trapping behavior of the oxide layer and interface defects under different external stresses has raised concerns about the instability of the performance of II I–V compound semiconductor devices. Herein, we explore the atomic-layer-deposition (ALD) growth method of erbium oxide (Er2O3) and the fabrication of InP-based MOS capacitors. Moreover, the trapping effects of oxide layer traps and interface traps were separated using the mid-band voltage method, and the stability evolution of the ALD-derived Er2O3/InP MOS capacitors under irradiation, voltage stress, and temperature was investigated comparatively. In this work, favorable interface chemical states and optimized interface roughness in the Er2O3/InP structure achieved a low-leakage current density of
$2.0\times 10^{-{5}}\text{A}$
/cm2 and an interface density of states of
$3.97\times 10^{{12}}$
eV
$^{-{1}} \cdot $
cm−2. The stability tests results show that irradiation mainly applied at the interface leads to the generation of defects, the capture of electrons increases, and the device performance varies; under the voltage stress primarily the electrons capture by defects inside the oxide layer shifts the flat-band voltage; high-temperature damages both the gate oxide layer and interface, and the defects primarily capture positive charges, which affects the stability considerably.