Study On Properties Of Ga-doped ZnO Thin Films By RF Magnetron Sputtering And The Effect Of Annealing Treatment

Zn O-TCO thin film is a new type of direct wide and band gap(3.37 e V)semiconductor materials.Because of its abundant raw materials,cheap,environmentally friendly and stable performance,Zn O is expected to replace ITO and FTO used in solar cells,flat Panel display,field gas sensors and other optical devices which has a wide application prospect.The conductive performance of intrinsic Zn O is poor and we can adopt doping the Zn O to obtain for the better conduction and more stable performance.In recent years,researchers at home and abroad have made gratifying achievements in this regard.P –Zn O are commonly used N,P,Li and n-Zn O doped use Al,Ga,In so.At present,the Al doped Zn O thin films(AZO)mature study and its photoelectric performance is the best.In contrast,the Ga doped Zn O thin films(GZO)study reported less.Compared with AZO films,Ga ionic radius is larger and closer to Zn,which can be reduced the lattice distortion by doping;meanwhile,the oxidation resistance of GZO thin films is strong,and the performance is more stable.In this Paper,GZO films were deposited on quartz substrates by RF magnetron sputtering and study the effect of the sputtering Parameters(the distance between the target,sputtering power and sputtering pressure)and later rapid thermal annealing e on the properties of the GZO.Samples tested by X-ray diffractometry(XRD)and dispersive X-ray energy spectrum analyzer(EDX),scanning electron microscopy(SEM),four probe resistance meter and UV-VI spectrophotometer and study of microstructure,chemical composition and optical properties of GZO thin films.The mainly found the following conclusions:(1)Through the design three factors and three level orthogonal experiment with target to substrate distance,sputtering power and sputtering pressure.We found that the photoelectric performance of primary and secondary order of GZO thin films by RF magnetron sputtering is: the distance between target > sputtering power> sputtering pressure.At the same time,we find the increase of GZO thin film photoelectric integrated performance continues to decline with the distance between the target and substrate;with the sputtering power increasing,the photoelectric properties increased first and then decreased;sputtering pressure and sputtering power has the same rules.The optimal process Parameters: distance between target and substrate is 50 mm,sputtering pressure is 1Pa,sputtering power is 200 W.(2)Through specific experiments to study effects of sputtering power to GZO films,we found that sputtering power change did not affect the GZO along the(002)preferred orientation of crystal growth.With the increase of the sputtering power,the grain size of the films continue to change;Zn/O atomic number ratio becomes larger and larger,conductive rate rise,transmittance decreased first and then increased slightly and the films exist larger tensile stress.(3)Through the latter Part of GZO rapid thermal annealing treatment we found: the extension of annealing temperature and annealing time did not affect the GZO(0002)crystal growth of preferred orientation along.But(002)angle of diffraction peaks occur obvious offset,crystal plane distance variable small,transition of the films in the tensile stress to compressive force.Conductive of GZO by low temperature annealing performance greatly improved.Annealing temperature and annealing time prolonged,transmittance have generally declined.But the Q-Factor of photoelectric properties by annealing are greatly increased.The GZO thin films by 2 minute annealing and annealing temperature of 300 ? to 400? is better whose photoelectric comprehensive performance.