Nano-structure fabrication of GaAs using AFM tip-induced local oxidation method: different doping types and plane orientations

Abstract

In this study, we have fabricated nano-scaled oxide structures on GaAs substrates that are doped in different conductivity types of p- and n-types and plane orientations of GaAs(100) and GaAs(711), respectively, using an atomic force microscopy (AFM) tip-induced local oxidation method. The AFM-induced GaAs oxide patterns were obtained by varying applied bias from approximately 5 V to approximately 15 V and the tip loading forces from 60 to 180 nN. During the local oxidation, the humidity and the tip scan speed are fixed to approximately 45% and approximately 6.3 μm/s, respectively. The local oxidation rate is further improved in p-type GaAs compared to n-type GaAs substrates whereas the rate is enhanced in GaAs(100) compared to and GaAs(711), respectively, under the identical conditions. In addition, the oxide formation mechanisms in different doping types and plane orientations were investigated and compared with two-dimensional simulation results.

A simple, effective NADH sensor constructed with phenothiazine via AFM tip-induced oxidative polymerization

“…Fig. 3 shows that increasing humidity and voltage could promote the formation of poly(TH), similar to the those observed for toluidine blue [5], silicon [2] and gallium arsenide [3]. The humidity effect indicates that water is essential to the polymerization.…”

“…For silicon and gallium arsenide, the oxides caused by ALO increased in height linearly with V tip with no clear thresholds. Reactive oxygen species, such as oxyanions, are likely the oxygenation sources [3], because these species generated in the water bridge beneath the AFM tip increase with the applied voltage in number. In fact, hot electrons can also be generated and participate in ALO.…”

“…Since its success in patterning non-conducting metal oxides on metal surfaces [1], atomic force microscope (AFM) tip (field)-induced local oxidation (ALO) has been recognized as a promising approach for the development of nanoelectronic devices [2][3][4]. With multi-functional molecules as the ink [5], the application potential of ALO has been more diversified than expected [6,7].…”

Formation of double ring patterns on Co2MnSi Heusler alloy thin film by anodic oxidation under scanning probe microscope

“…The electric field intensity (E) at the edge of the AFM tip for a bias of −12 volts is of the order ≈10 7 V/cm. 32 The corresponding current density (J) can be estimated by field emission phenomena based on Fowler-Nordhiem theory (F-N theory). is less than that of the Region 2 and 3 which are taken from the corona and bare CMS respectively, proving that it is mostly oxide.…”

Nondestructive tribochemistry-assisted nanofabrication on GaAs surface

“…However, since the required Hertzian contact pressure is quite high, plenty of defects may form in the substrate and it is difficult to grow high-quality quantum dots on these defective positions 9 10 11 12 . Recently, anodic oxidation nanolithography based on atomic force microscopy (AFM) has been successfully utilized for nanofabrication on GaAs surface 13 14 . This method depends strongly on the conductivity of sample and the endurance of Pt coating on the tip 15 16 , so that it is not fit for fabrication on semi-insulating GaAs samples, such as undoped GaAs.…”