Physical and electrical characterization of in situ boron-doped single-crystal silicon films grown at 450°C using remote plasma-enhanced chemical vapor deposition

Abstract

The ability to deposit boron-doped homoepitaxial silicon films at very low temperatures (450°C) using remote plasma-enhanced chemical vapor deposition (RPCVD) has been investigated. The boron incorporation efficiency is found to be between 0.2 and 0.4. 100% electrical activation is obtained for an epitaxial silicon film with boron doping of 1 x 10 19 cm −3 deposited at 450°C. The current-voltage characteristics for mesa diodes fabricated on these in situ boron-doped films where the maximum temperature during the entire fabrication process was kept below 450°C indicate an ideality factor of 1.2 and reverse bias leakage current of 320 nA cm −2. Addition of diborane is found to result in the genaration of defects which require increased deposition temperatures compared with undoped films to maintain excellent crystalline quality.