Heavily P-Doped (>10²¹ cm⁻³) Silicon Films Grown by Photochemical Vapor Deposition at a Very Low Temperature of 250°C

Heavily phosphorus-doped epitaxial silicon films have been successfully grown by a novel photochemical vapor deposition process at a very low temperature of 250°C. The epitaxial layers were deposited from SiH 4 -SiH 2 F 2 -PH 3 gases diluted with H 2 on single-crystal silicon substrates. The highest electron concentration of 2.3×10 21 cm -3 was obtained at a doping quantity (PH 3 /SiH 4 ) of 4.2%. From the dependence of resistivity on the sample temperatures, it was found that the obtained samples were “metallic”.