CVD‐BN for Boron Diffusion in Si and Its Application to Si Devices

Abstract

Amorphous and polycrystalline boron nitride (BN) films were deposited on n‐type Si substrates using a system. During deposition of the BN film, boron diffuses into the Si; a BN film deposited at temperatures below about 1000°C acts as an infinite diffusion source of boron in Si. The maximum values of boron surface concentration give solid solubility of boron in Si at each temperature. A thin layer of BN (below 80Å) gives a surface concentration of boron in the range between 1016 and 1020 cm−3, by varying the heat‐treatment conditions. Amorphous BN decomposes easily when heated in a nitrogen atmosphere. This can be used for planar diode processes using only one photomask. An MIS‐memory diode with structure, shows an anomalous C‐V shift due to the formation of borosilicate glass between BN and .