Effect Of Ambient Humidity And Etching Temperature On The Friction-Induced Nanofabrication On Gallium Arsenide

Gallium arsenide (GaAs) has become a widely used compound semiconductor material because of its direct bandgap and high electron mobility. GaAs serves as a good substrate for fabricating quantum luminescent devices, such as photoelectric detector and lasers. In recent years, lots of fabrication technologies have been invented to produce nanostructures on GaAs, which mainly involve optical lithography, nanoimprint, focused ion, electron beam, and so on. However, each of them has its limitation, and one nanofabricaton method is difficult to satisfy a variety of nanofabrication requirements. Therefore, it is of significance to develop new nanofabrication method on GaAs surface. The friction-induced nanofabrication can provide a new fabrication method on GaAs surface.This paper not only studied the effect of GaAs friction-induced nanofabrication in different humidity and sliding velocity, but also investigated the effect of temperature on friction-induced selective etching of GaAs surface. The fabrication mechanism was discussed on the basis of the detection of X-ray photoelectron spectrum and transmission electron microscope on the GaAs surfaces. The main experimental results and conclusions are summarized as below.(1) The effects of sliding velocity and relative humidity (RH) on the stereochemistry removal on GaAs surface were investigated. In ambient air, the micro material removal depth of gallium arsenide surface became shallow with the sliding velocity increasing. With the increase of RH, the micro material removal on GaAs surface increased gradually, and the material removal depth reached its maximum in water.(2) The mechanism for tribochemical removal on GaAs surface was discussed in this paper. An X-ray photoelectron spectroscopy (XPS) detection showed that the main compositions of the debris were Ga and As oxides. The cross-section microstructures of the grooves were observed by a transmission electron microscope (TEM). No deformation, such as dislocation and crystal slipping, was detected in the bulk matrix of cross-section surface of GaAs grooves. Further analysis showed that tribochemical removal by the reactive tip (SiO2 tip) scratching included three steps, i.e., the formation of interfacial bonds, oxidation and the removal of debris. The low scratch speed can promote the form of chemical bonds between interfaces and facilitate the material removal on GaAs surface. The water-solubility of arsenic oxides can lead to the softening of the debris and promote greatly the removal of debris during tip sliding.(3) The effects of temperature on friction-induced selective etching of GaAs surface were studied. The variation of the nanostructure height and surface roughness on GaAs surface created by the post-etching was contrastively studied under different etching temperatures in H2SO4-H2O2 solution. The mechanism for the temperature-dependent etching was interpreted. As a result, taking the surface roughness and nanostructure height into account, the optimized etching condition was addressed.The tribochemical removal provides a new method for defect-free nanofabrication on GaAs surface. Meanwhile, the study on friction-induced selective etching of GaAs surface under different temperature provides a guidance for the fabrication of the large aspect ratio structures on GaAs surface. This study can not only enrich the knowledge on nanotribology, but also promote the application of friction-induced nanofabrication.