Toward controlling the carrier density of Si doped Ga2O3 films by pulsed laser deposition

Abstract

Precise control of dopant composition is critical for the production of semiconductor films with desired properties. Here, we present results on the electrical properties for Si doped Ga2O3 films grown by pulsed laser deposition technique (PLD). The Si composition in the films can be controlled by changing the target composition as observed from the secondary ion mass spectroscopy measurement. The carrier density of the films is varied from the order of 1015 to 1020 cm−3 while the conductivity from 10−4 to 1 S cm−1 as measured by Hall equipment. The carrier density of the films has been verified by Kelvin force microscopy, which shows an increased surface work function with the increase of carrier density. The results suggest that the carrier density of β-Ga2O3 films is controllable by Si doping by PLD, paving a way to develop the Ga2O3 film-based electronic devices.

Epitaxial growth of β-Ga2O3 thin films on Ga2O3 and Al2O3 substrates by using pulsed laser deposition

“…Figure 3(a) shows the XRD patterns of the gallium oxide films deposited at various temperatures. All the diffraction peaks represent the (À201) plane family of β-Ga 2 O 3 , matching well with those in the PDF card (No: 43-1012) and consisting with previous reports 22 too. However, the quality of film grown at 600 ○ C is obviously inferior, comparing with that grown at 700 ○ C and 750 ○ C, as indicated by the extra (400) peak and larger FWHM of (À201) peak.…”

“…Sapphire substrates were usually pre-treated either by high temperature annealing, 20 or wet chemical etching. 21,22 By combining and optimizing the two kinds of pre-treatment methods, we observed clearly terraced surface of Al 2 O 3 substrate. AFM image of the sapphire substrate for atomic terraced surface are shown in Fig.…”

High‐Quality Si‐Doped β‐Ga2O3 Films on Sapphire Fabricated by Pulsed Laser Deposition

“…Silicon, a common impurity in Ga 2 O 3 grown from melt, has been shown to be acting as a donor and contribute to the n‐type character of substrates, presumably residing on substitutional Ga sites. [ 12 ] While most previous PLD‐deposited Si‐doped Ga 2 O 3 has used a silicon‐doped target for the PLD process, [ 13 ] in this article the Si doping is controlled by shifting the target during deposition from a nominally undoped Ga 2 O 3 target to a pure Si target. By shifting the target to Si every 50th pulse (1 out of 50 pulses) during a run, a Si doping of about 1 at% is achieved.…”

Проводимость гетеропереходов Ga-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=--GaAs

“…Обработка полученных с АСМ микрофотографий осу-ществлялась с помощью программы " Nova". Измерение вольт-фарадных и вольт-сименсных харак-теристик на частоте 10 6 Гц проводили с помощью изме-рителя Е7-12, который при использовании специально разработанных программы и устройства позволял в автоматическом режиме в одном цикле измерять зависи-мости емкости и активной проводимости от напряжения на образце.…”

“…При удалении от границы раздела двух материа-лов концентрация электронов в оксидной пленке прак-тически не изменяется, оставаясь в среднем равной (1−2) · 10 18 см −3 , что соответствует данным, приводи-мым для монокристаллов и пленок оксида галлия в ряде работ [6][7][8][9][10]. Изменение плотности поверхностных состояний на границе Ga 2 O 3 −GaAs не оказывает суще-ственного влияния на большие значения n 0 в оксидной пленке.…”