Improvement of infrared detection using Ge quantum dots multilayer structure

Abstract

Monocrystalline SiGe/Si multiquantum dot and well structures have been manufactured/compared as thermistor materials for infrared detection. The performance of the devices (both the thermal and electrical) has been very sensitive to the quality of the epitaxial layers which is evaluated by the interfacial roughness and strain amount. This study demonstrates that the devices containing quantum dots have higher thermal coefficient resistance 3.4%/K with a noise constant (K1/f) value of 2× 10-9

High performance infra-red detectors based on Si/SiGe multilayers quantum structure

“…These arguments make the single-crystalline thermistor material an excellent alternative for high performance thermal detectors. Moreover, the previous studies predicted as high TCR values as ≈8%/K for single crystalline Si 1−x Ge x /Si multilayer structure [2].…”

“…Higher signal-to-noise (SNR) ratio and temperature coefficient of resistance (TCR) than existing thermistor materials have converted it to a challenging candidate for this application. During the last decade, single crystalline (Sc) SiGe has been recognized and employed as a new low cost thermistor material for infrared (IR) detection [1][2][3]. Other thermistor materials available in the market include vanadium oxide (VOx), poly-or amorphous semiconductors which acquire relatively good SNRs and TCRs [4][5][6][7][8][9].…”

Group IV Materials for Low Cost and High Performance Bolometers

“…This material system is therefore very promising for future mass-market applications. The structures demonstrate low noise when high quality of epi-layers, interfacial roughness (or unevenness) and the contact resistances are obtained (Kolahdouz, Afshar Farniya, Di Benedetto, et al, 2010;Kolahdouz, Afshar Farniya, Östling, & H. Radamson, 2010).…”

“…Kolahdouz et al (Kolahdouz, Afshar Farniya, Di Benedetto, et al, 2010) presented the effect of Ge content (barrier height) on the performance of the SiGe/Si multi quantum wells (MQWs) and dots (MQDs) as thermistor material. In this study three Ge contents (23, 28 and 32%) in SiGe wells were applied and for higher Ge content (~47 %), Ge-dots/Si systems were grown.…”

“…Since 1/f noise relates to defects and imperfections in the active part of the bolometer, it is believed that using single-crystalline (sc) materials will demonstrate low noise constant in comparison to polycrystalline or amorphous ones. Thus, a solution for increasing the D* of a bolometer is to use mono-crystalline temperature sensing bolometer materials with a low 1/f noise constant (Kolahdouz, Afshar Farniya, Di Benedetto, & H. Radamson, 2010).…”