Size effect on Field Emission properties of Si nanowires arrays and electronic properties of Ni-Silicide/Si heterostructure nanowires

• Main Authors: Jiun-Yu Wang, 王俊喻
• Other Authors: Hsun-Feng Hsu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/44674757409904380085

碩士 === 國立中興大學 === 材料科學與工程學系所 === 100 === Nanoscale Schottky contact used for diodes, Schottky barrier field effect transistors and solar cells have been extensively studied. The Schottky metal silicide/Si heterojunctions in nanostructures have been widely investigated due to their applicability to Si-based devices. The free-standing Si NW arrays have been fabricated by the combining nanosphere lithography with metal-assisted catalytic etching. Further, chemical etching using a KOH solution was performed for adjusting the diameter of nanowires. Then, nickel silicide/Si heterostructure nanowires were formed by reactive deposition epitaxy and a glancing angle deposition technique. The results show that with reducing the diameter of Si nanowires, the turn-on field decreased and field emission enhancement factor increased. This phenomenon indicated that increasing the aspect ratio of nanowires can improve their field emission properties. Ni-silicides were formed at the apex of Si nanowires after depositing Ni at 400°C by the glancing angle deposition technique. The phase of silicide at the silicide/Si interface was NiSi2. When the diameter of nanowires reduced to 70 nm the front end of silicide was Ni2Si. The NiSi2/silicon heterojunction was Schottky contact. The Schottky barrier height was in the range of 0.39 to 0.45 eV, and the ideal factor was in the range of 3.1 to 3.5.