Study of the conduction‐type conversion in Si‐doped (631)A GaAs layers grown by molecular beam epitaxy

Abstract

We report the Si‐doping of GaAs (631)A layers grown by molecular beam epitaxy under different As overpressure. From Hall effect measurements, we have found that the increase of the As pressure induces conduction conversion from p‐ to n‐type, which is presumably related to lattice site switching of Si occupying an As site (where Si is acceptor) to a Ga site (where Si acts as a donor). This conversion is also studied by photoluminescence (PL) spectroscopy. The sharp conductivity conversion, at a critical As pressure value of 1.4‐1.7 x 10‐5 mbar is reflected in the optical properties of the samples by a change of As vacancy defects into pairs of Ga vacancy and Ga antisite defects. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Electrical and optical properties of Si doped GaAs (631) layers studied as a function of the growth temperature

“…Mobility showed similar dependence with temperature. In the range from 450 1C to 480 1C mobility decreases very rapidly from 1300 to 300 cm 2 /V s. Then, the conductivity type conversion occurs, and at 500 1C the carrier's mobility is about 100 cm 2 /V s. Further increase in growth temperature slightly varies mobility in the range from 100 to 120 cm 2 /V s. We have previously reported the V/III pressure ratio dependence during the Si doping of GaAs (631) [15], where we found a conduction-type conversion associated with the site that Si occupies in the doped-GaAs layer. At low V/III ratios, Si is incorporated in As sites, where it works as an acceptor and, when the V/III ratio is increased, Si atoms occupy Ga sites, where they work as donors.…”

Si-легированные эпитаксиальые пленки на подложках GaAs(110): морфология поверхности, электрофизические характеристики, спектры фотолюминесценции

“…Концентрация электронов в них при возрастании γ также изменяется немонотонно. Отметим, что немонотонное изменение концентрации электронов при возрастании γ в плeнках GaAs : Si (100) наблюдали авторы [3,19]. В структурах на GaAs (110) для получения p-типа проводимости с гладкой поверхностью необходимо провести дополнительные работы по выбору оптимальных условий роста.…”

“…. ., вызванный продемонстрированной перспективностью таких структур для создания нового поколения полевых транзисторов, топологических изоляторов и устройств спинтроники [1][2][3][4]. Структуры на (111)Аи (110)-ориентированных подложках обладают встроенным пьезоэлектрическим полем, направленным вертикально или в плоскости роста [5][6][7].…”