P. Sellitto et al., HALL-EFFECT CHARACTERIZATION OF SILICON ACTIVATION AND SEGREGATION INPLANAR-DOPED GAAS-ALAS SUPERLATTICES, Applied physics letters, 67(7), 1995, pp. 989-991
We have analyzed Hall data in GaAs-AlAs superlattices grown by molecul
ar beam epitaxy. All samples had a very short period (3.7 nm) and were
planar doped with silicon at a sheet density of 3.3 X 10(10) cm(-2) p
er plane. Silicon was introduced selectively either in the GaAs layers
, in the AlAs layers, or at the interface. The silicon electrical acti
vation did not depend on the doping plane location. Conversely, the th
ermal activation energy of the Hall carrier concentration was found to
depend strongly on the doping plane location. From our experimental r
esults, we estimate the silicon segregation length to be lower than 1.
5 nm at a growth temperature of 550 degrees C. (C) 1995 American Insti
tute of Physics.