Sains Malaysiana 42(2)(2013): 247–250

Characterization of AlInN Layer Grown on GaN/Sapphire Substrate by MOCVD

(Pencirian Lapisan AlInN yang Ditumbuh di Atas Substrat GaN/Nilam Menggunakan MOCVD)

Wei-Ching Huang, Edward-Yi Chang^,*, Yuen-Yee Wong, Kung-Liang Lin,

Yu-Lin Hsiao, Chang Fu Dee & Burhanuddin Yeop Majlis

Wei-Ching Huang, Edward-Yi Chang^*, Yuen-Yee Wong, Kung-Liang Lin, Yu-Lin Hsiao

Department of Material Science and Engineering, National Chiao Tung University

Ta Hsueh Road, 30050 Hsinchu 1001, Taiwan

Chang Fu Dee & Burhanuddin Yeop Majlis

Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia

43600 Bangi, Selangor Darul Ehsan, Malaysia

Received: 7 January 2012/Accepted: 21 May 2012

ABSTRACT

The AlInN layers have been grown with different growth parameters on GaN/sapphire substrates by metal-organic chemical vapor deposition (MOCVD). The effects of growth parameters such as pressure and temperature on the Al incorporation during AlInN material growth have been investigated. The result showed that lower pressure provides a tendency for higher Al incorporating in the AlInN layer. Besides, as the temperature was increased from 700°C to 780°C, an estimation of 4% reduction on the indium composition has been observed for each 20°C increment. XRD analysis showed that the best crystal quality of AlInN occured at 80% Al composition because of the higher lattice matching with GaN. Based on the above criteria, an Al_0.8In_0.2N/GaN HEMT device with 2 μm gate length has also been fabricated. The DC characteristics showed a saturated current, Idss of 280 mA/mm and transconductance of 140 mS/mm.

Keywords: AlInN layer; GaN; MOCVD

ABSTRAK

Lapisan AlInN telah ditumbuh dengan menggunakan pelbagai parameter di atas substrat GaN/nilam dengan menggunakan pemendapan wap kimia organik logam (MOCVD). Kesan bagi parameter-parameter seperti tekanan dan suhu terhadap percampuran Al di dalam lapisan AlInN telah dikaji. Kajian menunjukkan bahawa tekanan yang lebih rendah memberi kecenderungan untuk percampuran Al yang lebih tinggi di dalam lapisan AlInN. Selain daripada itu, untuk suhu yang meningkat daripada 700°C ke 780°C, pengurangan komposisi indium sebanyak 4% telah diperhatikan bagi setiap pertambahan suhu sebanyak 20°C. Melalui analisis XRD, kualiti AlInN yang paling baik diperhatikan apabila lapisan mempunyai 80% komposisi Al kerana pemadanan kekisi yang paling baik dengan GaN pada komposisi ini. Berdasarkan kepada kriteria di atas, satu peranti HEMT Al_0.8In_0.2N/GaN dengan panjang get 2 μm telah difabrikasi. Ciri-ciri DC menunjukkan arus tepu, Idss pada 280 mA/mm dan bacaan transkonduksi sebanyak 140 mS/mm.

Kata kunci: GaN; lapisan AlInN; MOCVD

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*Corresponding author; email: edc@mail.nctu.edu.tw