Sains Malaysiana 40(1)(2011): 63–66

Effect of Plasma Power and Flow Rate of Silane Gas on Diameter of Silicon Nanowires Grown by Plasma Enhanced Chemical Vapor Deposition

(Kesan Kuasa Plasma dan Kadar Aliran Gas Silan Terhadap Diameter Dawai Nano Silikon yang Ditumbuhkan Melalui Deposisi Wap Kimia Berbantukan Plasma)

¹Habib Hamidinezhad*, ¹Yussof Wahab, ²Zulkafli Othaman & ¹Imam Sumpono

¹Ibnu Sina Institute for Fundamental, Science Studies (IIS)

Universiti Teknologi Malaysia, Skudai, 81310 Johor, Malaysia

²Physics Department, Faculty of Science

Universiti Teknologi Malaysia, Skudai, 81310 Johor, Malaysia

Received: 7 December 2009 / Accepted: 15 July 2010

ABSTRACT

Silicon nanowires (SiNWs) have been synthesized by plasma enhanced chemical vapor deposition (PECVD) at different power for generation of plasma and different flow rate of silane gas. Silane (10% SiH₄ in Ar) gas with flow rate ranging between 6-15 standard cubic centimeter per minute(sccm) were employed as the source and gold colloid as the catalyst. A p-type Si (100) wafer was used as substrate in this experiment and the substrate’s temperature was 370°C. The plasma power range was 12-17 watts. The grown silicon nanowires were analyzed using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). FESEM results show that some silicon nanowires are cone like and some of them are cylindrical. The EDX result revealed that the existence of silicon and oxygen elements in the nanowires. The silicon nanowires obtained have different diameters and lengths and the SiNWs consist of silicon core which are surrounded by oxide sheath. It has been found that the plasma power and flow rate of the silane gas influence the size of silicon nananowires growth by PECVD. The diameter of wires decreased from 140 nm to 80 nm averagely when plasma power was increased from 12 to 17 watts. The diameter also increased about 90 nm to 150 nm when the flow rate of silane gas is increased from 6 to 15 sccm.

Keywords: Gold catalyst; PECVD; silicon nanowire

ABSTRAK

Dawai nano silicon (SiNW) telah dihasilkan secara pemendapan wap kimia peneguh plasma (PECVD) dengan kuasa penjanaan plasma dan kadar aliran gas silan yang berbeza. Gas silan (10% SiH₄ dalam Ar) dengan kadar aliran daripada 6 -15 centimeter isipadu piawai seminit (sccm) digunakan sebagai sumber dan koloid emas sebagai pemangkin. Wafer Si (100) jenis-p digunakan sebagai substrat dalam uji kaji ini dengan suhu substrat 370°C. Kuasa plasma adalah dalam julat 12-17 watt. Dawai nano silikon yang ditumbukan dianalisis dengan menggunakan Mikroskop Pengimbas Elektron Emisi Medan (FESEM) dan spektroskopi sinar-X penyebar tenaga (EDX). Hasil FESEM menunjukkan sebahagian dawai nano silikon berbentuk kon dan sebahagian berbentuk silinder. Hasil EDX pula menunjukkan kewujudan unsur silikon dan oksigen di dalam dawai. Dawai nano silikon yang dihasilkan mempunyai diameter dan panjang yang berlainan dan SiNW terdiri dari teras silikon yang dikelilingi oleh lapisan oksida. Didapati saiz SiNWs dipengaruhi oleh kuasa plasma dan kadar aliram gas silan. Diameter purata dawai berkurang daripadsa 140 nm ke 80 nm apabila kuasa plasma bertambah daripada 12 ke 17 watt. Diameter dawai juga bertambah daripada 90 nm ke 150 nm apabila kadar aliran gas silan bertambah daripada 6 ke 15 sccm.

Kata kunci; Dawai nano silicon; emas pemangkin; PECVD

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*Corresponding author; email: habib_hamidinezhad@yahoo.com