Preparation Of AIN Film By Medium Frequency Sputtering And Investigation Of Ions Implanted AIN Film

This thesis presents investigations on the structure and properties of A1N films and nc-AlN/a-Si3N4 prepared by medium frequency magnetron sputtering. The cathodoluminescence and magnetic properties of Mn+ implanted A1N films are also studied.Recently researchs indicate that nitride based semiconductor has the potential applications as materials of photoeletric devices (include emittion device and inductor) and high power and high temperature devices. The direct 6.28eV band gap of A1N results in the transparent window at ultraviolet region. The A1N based emittion devices at ultraviolet region will be realized if A1N could be doped siutably. Useful mechanic and electronic properties of A1N such as high hardness and high themal conductance and high temperature resistance and corrosion resistant and siutably temperature adaptation with Si and GaAs make A1N as good electronic encapsulation materials. While A1N is not influenced by electromagnetism radiation and the ions and electrons bombardment. It is interesting that AlGaN/GaN based electronic and optical devices, which are made by alloy of A1N and GaN, are valid from green to ultraviolet region.Among early preparation methods of A1N films, such as magnetron sputtering and plasma discharge and sublimation and chemical vapour deposition (CVD) and etc, CVD is widely used. The CVD feature is that A1N films are prepeared by reaction between compound including Al and ammonia at high temperature. Pulsed laser deposition is one of familiar methods. Wang Honghai used XeCl quasimolecule laser to ablate Al target to deposite AIN by reaction between sputtered Al and ionic N2+.The magnetron sputter technology is the most familiar method for Al films preparation. Although polycrystal and amouphous films are prepeared by this method, it is simply and cheap. Many research groups invastigate th deposition condition of Al films by RF and DC magnetron sputter. Long Wu etc prepeared c-axis preferential AIN films by RF magnetron sputter.Since AIN is insulator, if DC is used for sputter Al target directly, the target surface and components in vacuum chamber will be covered with insulated AIN films although metal Altarget is used. It causes target poison and anode disppearance. To solve these problems, medium frequency (MF) power supply is used in our work. Rectangular wave exported by medium frequency power supply is matched load by a export network. By prevent arc discharge, which affect deposition stability and films quality, due to positive charge accumulation, 15kHz pulsed discharge supply is used.Since it is very interralated between application and quality of AIN films, we study influence of reaction gas for microstructure and properties of AIN films and influence of substrates for microstrucutre at preparation of AIN films by MF magnetron sputter to optimal AIN films deposition conditions.The investigations of the structure and optical properties of AIN films prepared with various N2 gas flux show that N2 gas flux is one most important factor when AIN is prepared by medium frequency magnetron sputtering. At low N2 gas flux, the small gains and poor orientation cause low hardness and poor optical properties. At high N2 gas flux, large gains and perfect orientation cause high hardness 20.4GPa and high refrective index. But excessive N2 gas flux casue the deposition rate dropping, and the propeties become bad. The influence of various substates is invastigated. The result of comparing the microstructure of AIN films on Si(111) substrate and glass substrate indicate that the modes and the microstructure and morphology of AIN films growing on two substrates have many difference.Degree of freedom of electronic spin has been ingored for long term because energy of electronic two spins status is almost degenerate. With semiconductor technology development, it becomes possible to control degree of freedom of semiconductor spin gradually. By using defree of freedom of spin the functions of existing devices and circuits can be enhanced to process information while information i...