The Influence of MIM Metamaterial Absorbers on the Thermal and Electro-Optical Characteristics of Uncooled CMOS-SOI-MEMS Infrared Sensors

Uncooled infrared (IR) sensors Including bolometers, thermopiles, and pyroelectrics have traditionally dominated the market. Nevertheless, a new innovative technology, dubbed TMOS sensor, has emerged. It is based on CMOS-SOI-MEMS (complementary-metal-oxide-semiconductor silicon-on-insulator micro-electromechanical systems) fabrication. This pioneering technology utilizes a suspended, micro-machined floating transistor to directly convert absorbed infrared radiation into an electrical signal.

The miniaturization of IR sensors, including the TMOS, is crucial for seamless integration into wearable and mobile technologies. However, this presents a significant challenge: balancing size reduction with sensor sensitivity. Smaller sensor footprints can often lead to decreased signal capture and consequently, diminished performance.

Metamaterial advancements offer a promising solution to this challenge. These engineered materials exhibit unique electromagnetic properties that can potentially boost sensor sensitivity while enabling miniaturization. Strategic integration of metamaterials into sensor design offers a pathway towards compact, high-sensitivity IR systems with diverse applications.

This study explores the impact of electro-optical metal-insulator-metal (MIM) metamaterial absorbers on the thermal and electro-optical Characteristics of CMOS-SOI-MEMS sensors in the mid-IR region. We target key thermal properties critical to IR sensor performance: thermal conductance (G_th), thermal capacitance (C_th), and thermal time constant (τ_th). The study shows how material selection, layer thickness, and metamaterial geometry fill-factor affect the sensor's thermal performance. An analytical thermal model is employed alongside 3D finite element software for precise numerical simulations.