OXIDATION ENHANCED DIFFUSION OF BORON IN SILICON AT 650-750-DEGREES-CUSING STEAM IN THE RANGE 1-15 ATMOSPHERES

Buried boron layers were epitaxially grown on single crystal silicon s ubstrates and subjected to steam oxidation at 650-750 degrees C and pr essures of 1, 5, and 15 atm. The layers were approximately 200 nm thic k and capped by 400 nm of undoped silicon. The boron concentration var ied from 8x10(17) to 4X10(18) atoms/cm(3). The ensuing enhanced boron diffusion was modeled on the assumption that the oxidation maintained a supersaturation of interstitials at the surface which was proportion al to the square root of the oxidation rate. Fully coupled dopant-defe ct diffusion equations were necessary to accurately model the oxidatio n enhanced diffusion. (C) 1995 American Institute of Physics.