Infrared-sensitive SiGe-Si heterojunction internal photoemission detectors produced by rapid thermal chemical vapour deposition

We report the growth of Si1-XGeX on Si by rapid thermal chemical vapour deposition (RTCVD) for heterojunction internal photoemission (HIP) photodiodes. The emitter is a heavily in situ boron-doped SiGe layer with a Ge content of up to 46%. Photodiodes are characterized by Richardson plot analysis and Fourier transform infrared spectroscopy. A strained layer containing 30% Ge results in a device working at temperatures of up to 80K, with a cut-off wavelength of 8.5 mu m. First results with a polycrystalline SiGe emitter layer are also presented, opening the possibility of fabricating stacked optoelectronic devices.