AlGaAs/InGaAs thermopiles for infrared imaging using surface bulk micromachining technology

In this work, modulation-doped AIGaAs/InGaAs micromachined thermopile-based infrared (IR) sensor is reported. The key features of the IR sensors are the incorporation of high mobility - modulation-doped AlGaAs/InGaAs heterostructure and a multi-layer Cr
₂
O
₃
absorber combined with the surface bulk micromachined device structure to achieve high sensing performance. A responsivity of ~3000 V/W and a relative detectivity of 1.4 × 10
⁸
cm·Hz
^1/2
/W at λ > 5 μm have been achieved.