METAL ASSISTED CHEMICAL ETCHING OF SEMICONDUCTORS FOR ELECTRONICS APPLICATION

Abstract

In this dissertation, he metal-assisted chemical etching (MacEtch) of silicon (Si) and indium gallium arsenide (InGaAs) compound semiconductor are presented. Firstly, the systematic study of the mass and charge transport processes in Si MacEtch demonstrates the MacEtch process is governed by the redox reaction mechanism. The new understanding allows us to achieve lift-off free etching of Si nanowires using self-assembled nickel nanoparticles template. Subsequently, the instability of isolated catalysts motion during MacEtch is investigated. It is found that a reduction in the van der Waals force between the catalyst and Si could be achieved by proper manipulation of Si porosity. This results in a lower bending torque that can prevent the straying of the isolate catalyst from its directional etching. Finally, the fabrication of regular ordered, uniform, array-based InGaAs pillars with minimum diameter of 200 nm using MacEtch and digital etching is demonstrated. Comparison of the interface state density and flat-band capacitance hysteresis of both the unprocessed planar and MacEtch pillar InGaAs metal-oxide-semiconductor capacitors (MOSCAPs) confirm the surface of the resultant pillars are perfectly smooth and free of damages.