Chemical Vapor Deposition of Ga dopants for fabricating ultrashallow p-n junctions at 400°C

Chemical Vapor Deposition (CVD) of Ga on Si is performed in a commercial Si/SiGe epitaxial reactor at temperatures from 400 - 650 °C and conditions for which the Ga deposits selectivity on Si and the reactivity of the Ga with Si is so low that a thin-film deposition is achieved. Contact windows to c-Si are covered with a thin layer of Ga and contacted by sputtering Al/Si(1%). On the basis of an extensive electrical I-V characterization, it is concluded that the Ga gives a substantial doping of the Si at a temperature of 400°C and the resulting p-n junctions are near-ideal.