A thermopile detector array with scaled TE elements for use in an integrated IR microspectrometer

Abstract

The design and fabrication of a thermopile detector array for use in a fully integrated infrared optical spectrometer are described. IC-compatible MEMS technologies are used for fabrication of the spectrometer components, such as the slit, planar imaging diffraction grating and detector array. The IR micro-spectrometer was designed for operation in the 1.5–3 µm wavelength range with the size of the largest dimension about 8 mm. The imaging properties of the diffraction grating result in non-uniform dispersion, which imposes special requirements on the dimensions of each single detector in the array. The result is an array of unequally sized elements. The design considers technological constraints, sensitivity and cross-talk between elements. Simulation results, final design, fabrication technique and fabricated devices are presented.