Abstract: A new technique for the controlled incorporation of doping impurities into homoepitaxial silicon films by gas bombardment with arsine and diborane has been investigated. Hall effect and conductivity measurements have been used to show that P and N-type silicon thin films, having mobility values close to those of bulk material may be evaporated at 700.degree.C onto silicon <111> substrates. The substrates are precleaned by evaporating 50A of silicon at 775.degree.C. Step etch measurements have shown that the gas doped films possess uniform impurity concentrations. Diode structures formed by evaporating P and N-type layers onto substrates of the opposite doping type have been investigated. These diodes show good rectification properties. Capacitance-voltage measurements confirm the abrupt nature of the evaporated junctions. Minority carrier lifetimes of 2 to 3.mu. sec. have been measured in the evaporated structures.