Nano-pits on GaAs (1 0 0) surface: Preferential sputtering and diffusion

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• 作者：Tanuj Kumar^a ; ^{tanujkumar@cuh.ac.in" class="auth_mail" title="E-mail the corresponding author} ; ^{tkdeswal@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Vandana Panchal^b ; Ashish Kumar^c ; D. Kanjilal^c
• 关键词：Ion beam ; Sputtering ; AFM ; Pattern ; Pits
• 刊名：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
• 出版年：2016
• 出版时间：15 July 2016
• 年：2016
• 卷：379
• 期：Complete
• 页码：52-56
• 全文大小：1283 K

文摘

Self organized nano-structure array on the surfaces of semiconductors have potential applications in photonics, magnetic devices, photovoltaics, and surface-wetting tailoring etc. Therefore, the control over their dimensions is gaining scientific interest in last couple of decades. In this work, fabrication of pits of nano-dimensions is carried out on the GaAs (1 0 0) surface using 50 keV Ar⁺ at normal incidence. Variation in fluence from 3 × 10¹⁷ ions/cm² to 5 × 10¹⁸ ions/cm² does not make a remarkable variation in the dimension of pits such as size and depth, which is confirmed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). However the simultaneous dots formation is observed along with the pits at higher fluences. Average size of pits is found to be of 22 nm with depth of 1–5 nm for the used fluences. The importance of preferential sputtering of ‘As’ as compared to ‘Ga’ is estimated using energy dispersive X-ray analysis (EDX). The observed alteration in near surface composition shows the Ga enrichment of surface, which is not being much affected by variation in fluence. The growth evolution of pits and dots for the used experimental conditions is explained on the basis of ion beam induced preferential sputtering and surface diffusion.