Incorporation of Sn into epitaxial GaAs grown from the liquid phase |
| |
Authors: | E Kuphal A Schlachetzki and A P?cker |
| |
Institution: | (1) Forschungsinstitut der Deutschen Bundespost beim FTZ, D-6100 Darmstadt, Fed. Rep. Germany;(2) Present address: Institut für Hochfrequenztechnik, Tech. Universit?t, D-3300 Braunschweig, Fed. Rep. Germany |
| |
Abstract: | The incorporation of Sn into LPE GaAs was studied as a function of the atomic fractionx
Sn
l
of Sn in the liquid (1.6×10−4≤x
Sn
l
≤0.54), the growth temperatureT
K
and the cooling rate α. The diffusion coefficient of As in Ga for moderate Sn-doping was deduced from the growth velocities
to beD
As (760° C)=(3.3±1.0)×10−5 cm2/s. The epitaxial layers were analyzed after van der Pauw with special emphasis on the sources of experimental error. With
the aid of current mobility theories the concentrations of the ionized donors and acceptors were derived. From their dependence
onx
Sn
l
, on α and onT
K
combined with the Schottky-barrier model of Sn incorporation it can be concluded that the melt and the growing crystal surface
were in thermal equilibrium. The diffusion coefficient of Sn in GaAs is about 8×10−14 cm2/s at 760° C. The distribution coefficient for Sn increases from 4.4×10−5 to 12.3×10−5 in the temperature range from 690 to 800° C. The total Sn incorporationx
Sn
s
was measured using the atomic absorption spectroscopy for the first time down tox
Sn
s
=1017/cm3. From these data it can be concluded that up tox
Sn
l
=0.54 the dopant Sn is incorporated as donor and as acceptor only and that within the experimental scatter there is no indication
of incorporation as a neutral species. |
| |
Keywords: | 68 55 +b 72 80 Ey 72 20 Fr |
本文献已被 SpringerLink 等数据库收录! |