G. Glass et al., EFFECTS OF HIGH B-DOPING AN SI(001) DANGLING BOND DENSITIES, H DESORPTION AND FILM GROWTH-KINETICS DURING GAS-SOURCE MOLECULAR-BEAM EPITAXY, Surface science, 392(1-3), 1997, pp. 63-68
Si(001) layers doped with B concentrations C-B ranging from 5 x 10(16)
to 2 x 10(21) cm(-3) were grown on Si(001)-(2 x 1) substrates by gas-
source molecular beam epitaxy using Si2H6 and B2H6. B was incorporated
into substitutional electrically active sites at concentrations up to
2.5 x 10(20) cm(-3). With increasing incident flux ratios J(B2H6)IJ(S
i2H6)greater than or equal to 0.01 (corresponding to C-B=2 x 10(19) cm
(-3)), film growth rates decreased at T-s greater than or equal to 600
degrees C, but increased al T-s less than or equal to 550 degrees C.
Deuterium temperature-programmed desorption measurements as a function
of increasing C-B show strong B surface segregation, decreased steady
-state H coverages theta(H), and lower dangling bond densities. The Si
:B growth kinetics are well described by a model showing that at low t
emperatures, where steady-state theta(H) values are high, increased H
desorption rates from B-backbonded Si adatoms dominate, leading to an
enhancement in R-Si, whereas at higher temperatures R-Si decreases due
to the decreased adsorption-site density. (C) 1997 Elsevier Science B
.V.