Performance evaluation of poly-sige alloy growth with gold induced lateral crystallization for infrared photo-sensor applications

The hydrogenated poly-silicon germanium (poly-SiGe:H) epitaxial film has been investigated by gold induced lateral crystallization (Au-ILC) technology on a-SiGe:H layer at 10-hr 350degC annealing temperature and 60-sccm hydrogen (H₂) content. By this optimal condition, the growth rate by Au induced can be as large as 15.9 mum/hr. Due to low annealing temperature treatment (les 400degC) and large growth rate, this novel technology will be a noticeable poly-SiGe:H pin IR-sensing fabrication on a conventional pre-coated indium tin oxide (ITO)-glass substrate. Under 1-muW IR-LED incident (with peak wavelength at 710 nm) and at 5-V biased voltage, the poly-SiGe:H pin IR sensor developed by the Au-ILC technology, i.e., an Al (anode)/n poly-SiGe:H/i poly-SiGe:H/p poly-SiGe:H/ITO (cathode)/glass-substrate structure posses a maximum optical gain and response speed, almost 600% and 130%, respectively, better than that of a traditional pin type. Meanwhile, the FWHM of a poly-SiGe:H pin sensor with Au-ILC technology corresponding to a traditional pin sensor can be reduced from 280 to 150 nm, thus ascertaining its good IR-sensing selectivity. These better IR-sensing performances are demonstrated again that the proposed Au-ILC technology is a candidate to the low cost IC on opto-electronic applications.