Effect of ionized impurities at heterointerface on concentration and mobility of two-dimensional electrons in selectively doped heterojunction structures
The concentration N S and the low-temperature mobility µ of two-dimensional electron gas in GaAs/AlGaAs selectively doped heterojunctions have been studied theoretically and experimentally for the case where ionized impurities are present at heterointerfaces. It is found that N S scarcely changes wh...
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Published in | Japanese Journal of Applied Physics Vol. 33; no. 9A; pp. 4859 - 4862 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Tokyo
Japanese journal of applied physics
1994
|
Subjects | |
Online Access | Get full text |
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Summary: | The concentration
N
S
and the low-temperature mobility µ of two-dimensional electron gas in GaAs/AlGaAs selectively doped heterojunctions have been studied theoretically and experimentally for the case where ionized impurities are present at heterointerfaces. It is found that
N
S
scarcely changes when the concentration
N
IF
of interfacial impurities is below 1×10
11
cm
-2
, but it rapidly disappears at higher values of
N
IF
if the impurities are of the acceptor type. In contrast, the mobility is found to decrease substantially even when
N
IF
is as low as 10
9
cm
-2
. Based on these results, a quantitative guideline is drawn on the acceptable level of contamination in ultrahigh-vacuum wafer processings including molecular beam epitaxial regrowth. |
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ISSN: | 0021-4922 1347-4065 |
DOI: | 10.1143/JJAP.33.4859 |