Thermoelectric bolometers based on ultra-thin heavily doped single-crystal silicon membranes

Andrey V. Timofeev; Aapo Varpula; Andrey Shchepetov; Kestutis Grigoras; Juha Hassel; Jouni Ahopelto; Markku Ylilammi; Mika Prunnila

doi:10.1063/1.4989683

arXiv · 1704.02511

Thermoelectric bolometers based on ultra-thin heavily doped single-crystal silicon membranes

Andrey V. Timofeev·Aapo Varpula·Andrey Shchepetov·Kestutis Grigoras·Juha Hassel·Jouni Ahopelto·Markku Ylilammi·Mika Prunnila

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Abstract

We present ultra-thin silicon membrane thermocouple bolometers suitable for fast and sensitive detection of low levels of thermal power and infrared radiation at room temperature. The devices are based on 40 nm-thick strain tuned single crystalline silicon membranes shaped into heater/absorber area and narrow n- and p-doped beams, which operate as the thermocouple. The electro-thermal characterization of the devices reveal noise equivalent power of 13 pW/rtHz and thermal time constant of 2.5 ms. The high sensitivity of the devices is due to the high Seebeck coefficient of 0.39 mV/K and reduction of thermal conductivity of the Si beams from the bulk value. The bolometers operate in the Johnson-Nyquist noise limit of the thermocouple, and the performance improvement towards the operation close to the temperature fluctuation limit is discussed.

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Andrey V. Timofeev, Aapo Varpula, Andrey Shchepetov, Kestutis Grigoras, Juha Hassel, Jouni Ahopelto, Markku Ylilammi, Mika Prunnila. 2017-04-08. Thermoelectric bolometers based on ultra-thin heavily doped single-crystal silicon membranes. https://doi.org/10.1063/1.4989683

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