# Spectroscopic Evaluation of AlN/n-Si MIS Structures through Frequency-Driven Dielectric Characterization

## TL;DR

This paper studies the electrical and dielectric properties of a Au/Ti/AlN/n-Si structure under varying frequencies and temperatures.

## Contribution

The study introduces a detailed frequency-driven dielectric characterization framework for AlN/n-Si MIS structures.

## Key findings

- Strong dispersion effects were observed at low frequencies and temperatures due to interfacial trap states and dipolar relaxation.
- Negative capacitance behavior was detected under reverse bias at low frequencies.
- Dielectric parameters showed thermally activated and frequency-sensitive behavior.

## Abstract

This study presents a comprehensive spectroscopic and
impedance-based
analysis of a Au/Ti/AlN/n-Si metal–insulator–semiconductor
(MIS) heterostructure, focusing on its frequency- and temperature-dependent
electrical and dielectric behavior. The AlN interlayer, synthesized
via hydride vapor-phase epitaxy (HVPE), was electrically characterized
through admittance spectroscopy across a wide temperature range (100–350
K) and multiple frequencies (100, 500, and 1 MHz). Capacitance–voltage
(C–V) and conductance–voltage (G/ω–V) measurements revealed
strong dispersion effects, particularly at low frequencies and temperatures,
where interfacial trap states and dipolar relaxation dominate the
response. A negative capacitance behavior was observed under a reverse
bias at low frequencies. Series resistance (R
s) analysis confirmed a transition from trap-limited to bulk-controlled
conduction with increasing frequency. Dielectric parameters, including
real and imaginary permittivity, loss tangent, AC conductivity, and
electric modulus components, exhibited a thermally activated and frequency-sensitive
behavior, highlighting the interplay between dipolar alignment, trap
reconfiguration, and energy dissipation. These findings provide critical
insight into the interfacial physics of AlN/Si systems and establish
a robust framework for optimizing AlN-based MIS devices for high-frequency,
high-temperature microelectronic and optoelectronic applications.