Growth Rate Enhancement of Heavy n- and P-Type Doped Silicon Deposited by Atmospheric-Pressure Chemical Vapor Deposition at Low Temperatures

Abstract

n and p-Type doping of epitaxially grown Si over the temperature range from 850°C to as low as 550°C was investigated in an atmospheric pressure reactor. P, As, and B could be incorporated into single-crystal silicon at levels exceeding the solid solubility at growth temperatures to levels greater than 1 x 1020/cm3. Remarkably, each of the hydride dopant sources, PH3, AsH3) and B2H6, dramatically enhanced the growth rate of Si from dichlorosilane (DCS) at lower temperatures. Such results are unprecedented for the growth of Si from dichlorosilane (DCS) (which has been restricted to higher growth temperatures until recently) and for growth from SiH4 (which has been practiced over a wide range of temperatures). Growth was carried out primarily from DCS in H2 carrier gas, although some experiments utilizing SiH4 were performed, in order to explore the mechanisms responsible for growth rate enhancement of doped films. Instrumental in achieving these results has been the ultraclean, load–locked atmospheric pressure reactor, which permits high-quality epitaxial growth at temperatures not previously obtainable with DCS. Thus utilizing conventional Si and dopant sources in an unconventional regime, doping behavior suitable for advanced device structures was obtained. © 1993, by The Electrochemical Society, Inc. All rights reserved.