Rf-Mbe Growth Of Iii-Nitrides Heterostructures For Light Detecting Applications

• Main Author: Mohd Yusoff, Mohd Zaki
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: QC1 Physics (General)
• Online Access: http://eprints.usm.my/31760/1/MOHD_ZAKI_BIN_MOHD_YUSOFF_24%28NN%29.pdf; http://eprints.usm.my/31760/

Dalam penyelidikan ini, GaN p-n struktur homo, AlN/GaN struktur hetero, dan AlxGa1-xN/GaN struktur hetero telah berjaya ditumbuhkan di atas substrat silikon (Si) (111) menerusi epitaksi alur molekul plasma terbantu (MBE) untuk aplikasi pengesan foto. Galium (7N) dan aluminium (6N5) dengan ketulenan yang tinggi telah digunakan dalam sel Knudsen dan nitrogen (7N) berketulenan tinggi telah dibekalkan kepada frekuensi radio (RF) 13.56 MHz untuk menjana sumber spesis nitrogen reaktif. Nilai tekanan nitrogen dan kuasa pelepasan masing-masing ditetapkan malar pada 1.5x10-5 Torr dan 300 W sepanjang projek ini. Morfologi permukaan, sifat-sifat struktur dan optik daripada semua sampel telah disiasat dengan menggunakan pantulan belauan elektron bertenaga tinggi (RHEED), mikroskop imbasan elektron (SEM), mikroskop imbasan electron pancaran medan (FESEM), mikroskop electron transmisi (TEM), mikroskop daya atom (AFM), belauan sinar-X beresolusi tinggi (XRD-HR), fotoluminesen (PL), dan spektroskopi Raman, masing-masing. In this research work, GaN p-n homostructures, AlN/GaN heterostructures, and AlxGa1-xN/Ga heterostructures were successfully grown on silicon (Si) (111) substrates by plasma-assisted molecular beam epitaxy (MBE) for photodetector applications. High purity gallium (7N) and aluminum (6N5) were used in the Knudsen cells and high purity nitrogen (7N) was supplied to 13.56 MHz radio frequency (RF) source to generate reactive nitrogen species. The nitrogen pressure and discharge power values were kept constant at 1.5x10-5 Torr and 300 W during this project, respectively. The surface morphology, structural and optical properties of all the samples were investigated by using reflection high energy electron diffraction (RHEED), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), transmission electron microscopy, atomic force microscopy (AFM), high-resolution X-ray diffraction (HR-XRD), photoluminescence (PL), and Raman spectroscopy, respectively.