In-situ phosphorous-doped SiGe layer on Si substrate by reactive thermal chemical vapor deposition at low temperature

We have studied in-situ phosphorus-doping characteristics in Ge-rich Si1−xGex (0.95≤x≤1) epitaxially grown on Si substrate by Reactive Thermal Chemical Vapor Deposition system at 350 °C using GeF4 and Si2H6. The impact of PH3 in-situ doping on the growth kinetics, micro-structure and electric properties of Si1−xGex layers is investigated. The results indicate that the growth rate of Si1−xGex layers drops when the doping ratio (PH3/GeF4) is increased up to 750 ppm. Correspondingly, the surface morphology as well as the crystal quality of Si1−xGex layers starts to deteriorate. The electrical measurements show that an excellent doping efficiency is achieved in the case of an acceptable surface morphology and crystalline quality. These results provide the promise for future n+/p diode fabrication by Reactive Thermal Chemical Vapor Deposition at low temperature.