The Growth Of ZnO Thin Film On GaAs Substrate By MOCVD

ZnO,a wide direct-gap semiconductor,attracts as much attention as GaN inoptoelectronics research field.Its optoelectronic characteristics were littleaffected by vacancies.And it has great uses in this information age.It can beused to fabricate display devices,high frequency filters,emitting diode,lasersand high speed optical switch.Therefore,it has great uses in both civil andmilitary fields.In order to fabricate the above-mentioned devices and realize itsuses,what we Should do firstly is to get high quality ZnO film.A lot ofmethods have Been used to deposit ZnO films such as Molecure BeamEpitaxy(MBE),Metal-organic Chemical Vapor Deposition(MOCVD),PulsedLarge Deposition(PLD),Sputter and Thermal Evaporation.Among them,highquality ZnO films can be Obtained by MBE, MOCVD and PLD.And MOCVDprovides high growth rate and growth efficiency,large area uniformity anddifferent doping processes.Therefore, MOCVD offers the advantage ofindustrial production.in this thesis,we grow high quality ZnO film by newMOCVD system on GaAs and study its characteristics.First of all, we have studied influence of ZnO thin film crystal structureand the characteristic of giving out light about different temperature ofgrowing. X ray diffraction spectrum analyses that shows: To 610-660 degreesCentigrade of temperature of growing, film is all many kinds of orientationsfilm, though film was strongly (002) growth, at the same time we found theZnO on (100) and (101) piece,the reason is that As and Ga doped ZnO film.Improve temperature contributes to improvement of crystallization quality, andreaching 640 degrees Centigrade the crystallization quality is best ,it can makecrystallization quality of fllm become poor when we continue to improvetemperature.Because Too high growth temperature will make much Ga and Asto be doped into ZnO film, this will inevitablely influence becoming cores andgrowing of ZnO film, and these two kinds of elements doped will make ZnObrilliant afterbirth twist too ,them can make the crystallization quality of thefilm drop finally . While ZnO films were grown on GaAs by MOVCD,wefound that thermal annealing was performed on ZnO film.The experimentalresults showed that ZnO films became more crystalline after thermal annealingin O2 and N2.This is because ZnO film grow for rich Zn,and O is scarce, it canmake ZnO increase content of O thermal annealing in O2,and high temperaturecan optimize Zn , O proportion,thus can improve the quality of ZnO film.intensity of UV emission was stronger than those without thermal annealing,itindicates there are close relations in characteristic of giving out light and Zn ,O proportion.after thermal annealing ,the intensity of UV emission was211and 206 stronger than that of deep level transition about two differentsubstrate. Through to ZnO XPS measurement ,we found As and Ga element exceptZn,O.Eroding have remarkable influence on O1s, this is because ZnO film hasvery strong absorbing, a large amount of absorb the vapor of the air make thebinding energy of O1s electron obviously greater than ZnO film eroded.Andhigh temperature can reduce the binding energy of O1s , ZnLMM , As3d, itindicates high temperature contribute to change three element state ofcombination in film. Hall effect to ZnO film combine XPS result,we found the binding energyof As were greater than the film after thermal annealing in 600,630,660℃.the binding energy of Zn-As,As2O3,As-As are 41.3eV,44.0eV, 42eV.As of...