IEEE Transactions on Electron Devices · 1991 · 43 citations · 10 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsDetector TechnologyInfrared DetectorsIntegrated PhotonicsOptical DetectorsSemiconductor DetectorsSilicon MaterialsBand Offset EngineeringConcentrationHeterojunction DevicesMolecular Beam EpitaxySilicon Infrared DetectorsSilicon Semiconductor DetectorsValence BandValence Band Structure
A new SiGe/Si heterojunction internal photoemission (HIP) long-wavelength infrared (LWIR) detector has been fabricated by molecular beam epitaxy (MBE). The detection mechanism of the SiGe/Si HIP detector is infrared absorption in the degenerately doped p/sup +/-SiGe layer followed by internal photoemission of photoexcited holes over a heterojunction barrier. By adjusting the Ge concentration in the SiGe layer, and, consequently, the valence band offset between SiGe and Si, the cutoff wavelength of SiGe HIP detectors can be extended into the LWIR (8-17- mu m) regime. Detectors were fabricated by growing p/sup +/-SiGe layers using MBE on patterned p-type Si substrates. The SiGe layers were boron-doped, with concentrations ranging from 10/sup 19/ cm/sup -3/ to 4*10/sup 20/ cm/sup -3/. Infrared absorption of 5-25% in a 30-nm-thick p/sup +/-SiGe layer was measured in the 3-20- mu m range using a Fourier transform infrared spectrometer. Quantum efficiencies of 3-5% have been obtained from test devices in the 8-12- mu m range.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
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Modulation doping in Ge<i>x</i>Si1−<i>x</i>/Si strained layer heterostructures
R. People, J. C. Bean, D. V. Lang et al. · Applied Physics Letters · 1984 · 302 citations