Measurements of thermal characteristics in silicon germanium un‐cooled micro‐bolometers

Abstract

We present a study of the thermal characteristics of an infrared detector (un‐cooled micro‐bolometer), based on an amorphous silicon germanium film (a‐SixGey:H), deposited by plasma at low temperature (∼ 300 °C) and compatible with the standard CMOS technology. These films have been studied due to their high performance characteristics as high activation energy (Ea≈ 0.37 eV), high temperature coefficient of resistance (TCR≈ ‐0.047 K‐1) and moderate room temperature conductivity (σRT≈ 2x10‐5Ω cm), which provides a moderate pixel resistance (Rcell≈3.5x108Ω). We have used two simple methods to calculate the thermal characteristics of the micro‐bolometer. The thermal conductance (Gth) has been obtained from the electrical I(U) characteristics in the range where self heating due to bias is not presented. The temperature dependence of the electrical resistance and as well the temperature dependence of the thermal resistance have been obtained by measuring the I(U) characteristics in the device at different temperature values. Finally the results of both methods have been compared. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Un-Cooled Microbolometers with Amorphous Germanium-Silicon (a-GexSiy:H) Thermo-Sensing Films

“…Kosarev, 2006;M. Moreno, 2007M. Moreno, , 2010, amorphous germanium-silicon, a-Ge x Si y :H, deposited by PECVD has been studied as thermo-sensing films in un-cooled microbolometer, obtaining high activation energy, E a = 0.34 eV, consequently a high value of TCR = 0.043 K -1 and improved but still high resistivity.…”

“…Kosarev, 2006;M. Moreno, 2007M. Moreno, , 2010, due its high activation energy and consequently high TCR, and its relatively high room temperature conductivity, RT, in comparison with a-Si:H films.…”

Ge/SiGe Quantum Well p-i-n Structures for Uncooled Infrared Bolometers

“…Polycrystalline SiGe (poly-SiGe, T CR = 2%/K) [6], α-SiGe (T CR = 4.7%/K) [7], and SiGe multi-quantum-well (MQW) (T CR < 3.5%/K) [8]- [12] structures have gathered much attention due to their high TCR values. Among these, single crystal structures of SiGe MQWs exhibit the best 1/f noise performance due to high level of order and material quality.…”

Ringworm in calves: Risk factors, improved molecular diagnosis, and efficacy of Aloe vera gel extract for treatment

“…Although the antidermatophytic potentials of natural products promising, are plagued by a lack of in-vivo studies to affirm the antifungal activity of bioactive compounds announced in-vitro [9]. Aloe vera is a plant of Liliaceae family has multiple applications including antifungal, antibacterial, antioxidant, antiseptic and in cosmetics industries [10]. Investigations for in-vitro and in-vivo antidermatophytic potential of Aloe Vera and determination of its bioactive compounds are still meager.…”