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

Area of Science:

• Materials Science
• Solid State Physics
• Semiconductor Device Physics

Background:

• Metal-insulator-semiconductor (MIS) heterostructures are fundamental components in modern electronics.
• Aluminum nitride (AlN) is a promising material for interlayers due to its unique properties.
• Understanding the electrical and dielectric behavior of AlN/Si interfaces is critical for device optimization.

Purpose of the Study:

• To conduct a comprehensive spectroscopic and impedance-based analysis of a Au/Ti/AlN/n-Si MIS heterostructure.
• To investigate the frequency- and temperature-dependent electrical and dielectric characteristics of the AlN interlayer.
• To elucidate the role of interfacial trap states and dipolar relaxation in device performance.

Main Methods:

• Hydride vapor-phase epitaxy (HVPE) for AlN interlayer synthesis.
• Admittance spectroscopy across a wide temperature range (100-350 K) and frequencies (100 Hz, 500 Hz, 1 MHz).
• Capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements.

Main Results:

• Observed strong dispersion effects at low frequencies and temperatures, attributed to interfacial trap states and dipolar relaxation.
• Detected negative capacitance behavior under reverse bias at low frequencies.
• Demonstrated thermally activated and frequency-sensitive dielectric parameters, indicating interplay between dipolar alignment, trap reconfiguration, and energy dissipation.

Conclusions:

• The study provides critical insights into the interfacial physics of AlN/Si systems.
• The findings establish a framework for optimizing AlN-based MIS devices for high-frequency, high-temperature applications.
• The research contributes to the advancement of microelectronic and optoelectronic technologies.