InGaN/GaN micro mirror with electrostatic comb drive actuation integrated on a patterned silicon-on-insulator wafer

Area of Science:

• Materials Science
• Optoelectronics
• MEMS Technology

Background:

• Micro-electro-mechanical systems (MEMS) are crucial for optical applications.
• Indium Gallium Nitride (InGaN) and Gallium Nitride (GaN) films offer unique optoelectronic properties.

Purpose of the Study:

• To develop a novel two-dimensional (2D) tunable micro-mirror using InGaN/GaN multilayer films on a silicon-on-insulator (SOI) substrate.
• To characterize the mechanical and optical performance of the fabricated device.

Main Methods:

• Fabrication of micro-actuators and micro-mirrors on SOI wafers using a double-sided mask process.
• Deposition of InGaN/GaN multilayer films via molecular beam epitaxy (MBE).
• Characterization of displacement response and photoluminescence (PL) properties.

Main Results:

• The micro-mirror demonstrated a two-dimensional (2D) tuning effect with a near-linear relationship between displacement and the square of applied voltage.
• Cross-axis coupling effects were evaluated.
• Temperature-dependent and laser intensity-dependent PL spectra revealed localized state and/or band-gap narrowing effects, causing S-shaped behavior with increasing temperature.

Conclusions:

• The developed InGaN/GaN micro-mirror device shows promising performance for 2D optical tuning.
• The observed optical phenomena are attributed to material properties and environmental factors, offering insights for future device optimization.