Sains Malaysiana 37(3): 217-221 (2008)

Fabrication of Silicon Oxide Nanodot Arrays by

Scanning Probe Lithography

(Fabrikasi Nanotitik Tersusun Silikon Oksida Menggunakan

Litografi Kuar Imbasan)

Sabar D. Hutagalung, Teguh Darsono

& Khatijah A. Yaacob

School of Materials and Mineral Resources Engineering

Universiti Sains Malaysia, 14300 Nibong Tebal

Penang, Malaysia

Received:  12 June 2007 / Accepted: 6 November 2007

Abstract

Atomic force microscopes (AFM) as one of the scanning probe microscopy (spm) modes have become useful tools, not only for observing surface morphology and nanostructure topography but also for fabrication of various nanostructures itself. In this work, silicon oxide (SiO_x) patterns were formed on Si(100) surface by means of AFM anodization, where a non-contact mode used to oxidize Si wafer at the nanoscale size. The oxide patterns could serve as masks for the chemical etching of Si surface in alkaline solution in order to create the Si nanodots. A special attention is paid to finding relations between the size of dots and operational parameters as tip bias voltage and tip writing speed Dot arrays with 10 nm high and less than 50 nm in diameter have been successfully fabricated. The ability to control oxidation and scanning speed can be utilized in fabrication of complex nanostructures and make scanning probe lithography (SPL) as a very promising lithographic technique in nanoelectronic devices, nanophotonics and other high-tech areas.

Keywords: Silicon oxide; nanodot; scanning probe lithograpy; atomic force microscope; tip voltage

Abstrak

Mikroskop daya atom (AFM) sebagai salah satu daripada mod mikroskop kuar imbasan (SPM) telah menjadi perkakasan yang sangat berguna bukan sahaja untuk pengamatan morfologi permukaan dan topografi nanostruktur tetapi juga untuk fabrikasi berbagai-bagai nanostruktur itu sendiri. Corak silikon oksida (SiO_x) telah dibentuk pada permukaan Si(100) dengan penganodan AFM, dengan mod AFM taksentuh telah diguna untuk mengoksidakan kepingan Si pada saiz berskala nano. Corak-corak oksida ini boleh digunapakai sebagai topeng untuk punaran kimia permukaan Si dalam larutan beralkali yang membolehkan pembentukan nanowayar atau nanotitik Si. Tumpuan telah diberikan kepada hubungkait antara saiz nanostruktur oksida dan parameter-parameter kendalian seperti voltan sampel-hujung dan laju penulisan hujung. Hasilnya, titik tersusun dengan ketinggian 10 nm dan garispusat kurang daripada 50 nm telah berjaya dihasilkan. Kebolehkawalan pengoksidaan dan laju imbasan dapat digunakan dalam fabrikasi nanostruktur kompleks sehingga litografi kuar imbasan (spl) merupakan suatu teknik litografi yang amat menggalakkan dalam peranti nanoelektronik, nanofotonik dan bidang-bidang berteknologi tinggi lainnya.

Kata kunci: Silikon oksida; nanotitik; litografi kuar imbasan; mikroskop daya atom; voltan hujung

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