金刚石表面损伤层及其对外延金刚石性能的影响研究OA

Hydrogen-terminated diamond-induced two-dimensional hole gas is an important pathway for achieving semiconductor behavior in diamond.Mechanical polishing,as a key process in the preparation of diamond substrates,inevi-tably introduces a subsurface damage layer,leading to surface lattice distortion and increased defect density.During selec-tive etching in hydrogen plasma treatment,it causes deterioration of surface morphology and an increase in roughness,sig-nificantly suppressing the transport properties of the two-dimensional hole gas and limiting the electrical performance and device applications of hydrogen-terminated diamond.This study focuses on(001)-oriented chemical vapor deposition single-crystal diamond substrates.By controlling the inductively coupled plasma(ICP)etching time,the subsurface damage layer can be removed,and the effects of ICP etching time on diamond surface morphology,damage layer structure,and hydrogen-terminated electrical properties were systematically investigated.The results show that with increased ICP etching time,the etching pits and scratches on the hydrogen-treated sample surfaces gradually disappear,and surface deterioration is effective-ly suppressed.Transmission electron microscopy reveals that polished diamond has a subsurface damage layer of about 80 nm,which can be almost completely removed after 15 minutes of ICP etching,leaving only a surface reconstruction layer of approximately 1.5 nm.Moreover,as the damage layer is gradually removed,the carrier concentration of hydrogen-terminated diamond decreases from 1.16×1013/cm2 to 5.3×1012/cm2,while mobility increases from 66.3 cm2/(V·s)to 98.3 cm2/(V·s).Further homoepitaxial growth on the damage layer-removed samples produced a low-defect,high-purity diamond epitaxial layer,with mobility further increased to 122 cm2/(V·s).This study clarifies the regulation of hydrogen-terminated diamond electrical performance through ICP etching removal of the subsurface damage layer and provides theoretical and experimen-tal references for optimizing the surface quality and electrical characteristics of hydrogen-terminated diamond.