Sains Malaysiana 43(6)(2014): 923–927

Structural Properties of Zinc Oxide Thin Films Deposited on Various Substrates

(Ciri Struktur Filem Nipis Zink Oksida yang Dimendapkan di atas Substrat Berlainan)

C.G. CHING*, P.K. OOI, S.S. NG, Z. HASSAN, H. ABU HASSAN & M.J. ABDULLAH

Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Penang, Malaysia

Received: 2 March 2013/Accepted: 26 January 2014

ABSTRACT

 In this work, the structural properties of radio frequency sputtering-grown zinc oxide (ZnO) thin films on sapphire (Al2O3), gallium arsenide (GaAs) and n-type silicon (Si) substrates were characterized. Scanning electron microscopy was employed to study the surface morphology of the samples. X-ray diffraction (XRD) measurements were also performed to obtain the structural information of the samples. The XRD results showed that the ZnO layers grown on different substrates have similar lattice constant (c) values, which were used to calculate the strain percentages of the ZnO thin films. The surface morphologies of the ZnO thin films indicated the formation of a granular surface when ZnO is deposited on n-type Si(100) and Si(111) substrates. Meanwhile, a leaf-like surface is obtained when ZnO is deposited on GaAs and Al2O3 substrates. The results showed that the ZnO thin film grown on n-type Si(100) has the best quality among all the samples.

Keywords: Gallium arsenide; sapphire; silicon; XRD; zinc oxide  

ABSTRAK

 Dalam kajian ini, pencirian struktur filem nipis zink oksida (ZnO) yang ditumbuhkan dengan teknik percikan frekuensi radio ke atas substrat nilam (Al2O3), galium arsenik (GaAs) dan silikon (Si) jenis-n telah dijalankan. Mikroskop elektron imbasan digunakan untuk memperoleh morfologi permukaan sampel manakala pembelauan sinar-X (XRD) pula digunakan untuk memperoleh maklumat struktur bagi sampel. Keputusan XRD menunjukkan ZnO yang ditumbuhkan di atas substrat berlainan mempunyai pemalar kekisi paksi-c yang hampir sama. Nilai pemalar kekisi paksi-c yang diperoleh digunakan untuk menghitung peratusan ketegangan filem nipis ZnO. Morfologi permukaan filem nipis ZnO menunjukkan pembentukan permukaan bercorak butiran apablia ZnO ditumbuhkan ke atas substrat Si(100) dan Si(111) jenis-n dan permukaan bercorak daun diperoleh apabila ZnO ditumbuhkan ke atas substrat GaAs dan Al2O3. Akhirnya, keputusan XRD menunjukkan bahawa filem nipis yang ditumbuhkan ke atas Si(100) jenis-n mempunyai kualiti kristal yang terbaik antara sampel.

Kata kunci: Galium arsenida; nilam; pembelauan sinar-X; silikon; zink oksida

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*Corresponding author; email: chingchinguan@gmail.com