Sa. Stockman et al., CARBON INCORPORATION IN INP GROWN BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION AND APPLICATION TO INP INGAAS HETEROJUNCTION BIPOLAR-TRANSISTORS/, Journal of applied physics, 75(8), 1994, pp. 4233-4236
The incorporation of residual carbon has been studied for InP grown at
low temperatures using TMIn and PH3 by low-pressure metalorganic chem
ical vapor deposition. n-type conduction is observed with electron con
centrations as high as 1 X 10(18) cm-3, and the electrical activation
efficiency is 5%-15%. Carbon incorporation is found to be highly depen
dent on substrate temperature, suggesting that the rate-limiting step
is desorption of CH(y) (0 less-than-or-equal-to y less-than-or-equal-t
o 3) from the surface during growth. Hydrogen is also incorporated in
the layers during growth. The electron mobilities are lower for C-dope
d InP than for Si-doped InP. InP/InGaAs heterojunction bipolar transis
tors with C as the p-type base dopant and either Si or C as the n-type
emitter dopant have been fabricated and compared. Devices with a carb
on-doped base and emitter showed degraded performance, likely as a res
ult of deep levels incorporated during growth of the emitter.