Growth Of Gan Films On Gaas (100) Substrate By Rf-Sputtering And E-Beam Evaporation Techniques

• Main Author: Md Taib, Muhamad Ikram
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: QC1 Physics (General)
• Online Access: http://eprints.usm.my/31850/1/MUHAMAD_IKRAM_BIN_MD_TAIB_24%28NN%29.pdf; http://eprints.usm.my/31850/

Kajian ini menunjukkan penumbuhan lapisan gallium nitrida (GaN) ke atas substrat gallium arsenida (GaAs) berliang melalui kaedah percikan frekuensi radio dan penyejat alur elektron. Sebagai perbandingan, penumbuhan secara terus ke atas substrat GaAs dan lapisan penampan nitrida seperti aluminum nitrida (AlN) dan titanium nitrida (TiN). Pada peringkat pertama kajian ini, parameter yang sesuai untuk menghasilkan GaAs berliang yang berkualiti dengan ketumpatan dan taburan yang seragam telah diperolehi. Didapati bahawa keseragaman dan ketumpatan liang yang tinggi boleh dicapai dengan campuran larutan dimetilformamida (DMF) dan asid sulfurik (H2SO4) dengan kepekatan DMF 75% selama 10 minit, pada ketumpatan arus 250 mA/cm2. Pada peringkat seterusnya, lapisan GaN ditumbuhkan secara berasingan ke atas permukaan yang berbeza melalui percikan frekuensi radio dan penyejat alur elektron. Bukti pengikatan Ga-N di dalam lapisan GaN diperhatikan melalui pengukuran spektroskopi fotoelektron sinar-x (XPS). This work studies the structure, morphology and optical properties of GaN layer grown on porous GaAs/GaAs substrate by radio frequency (RF) sputtering and electron beam (e-beam) evaporation. For comparison, the GaN layer was also grown directly on GaAs substrate and nitride based buffer layers, i.e. aluminum nitride (AlN) and titanium nitride (TiN). In the first part of this work, the best parameters used to obtain good quality porous GaAs on GaAs substrate with uniform distribution and density were determined. It was found that uniform distribution and high density of pores can be fabricated with a mixed solution of dimethylformamide (DMF) and sulphuric acid (H2SO4) with 75% DMF concentration for 10 minutes, at a current density of 250 mA/cm2. In the next stage, the GaN layer was grown separately on different surfaces using RF-sputtering and e-beam evaporation. The evidence of Ga-N bondings inside the GaN layer was observed by XPS measurement.