Zn_(1-x)Mg_xO薄膜的低压MOCVD生长与性质

利用低压金属有机物气相沉积 (L P- MOCVD)技术 ,采用两步生长法 ,在 (0 0 0 1 )蓝宝石衬底上获得了纤锌矿结构的 Zn1 - x Mgx O合金单晶薄膜 .实验发现随着 Mg原子的增多 ,Zn Mg O的晶格常数逐渐减小 .X射线衍射谱中未出现除 (0 0 0 2 )峰之外的其他峰位 ,表明该合金薄膜具有很强的择优取向和较好的晶体质量 .室温透射谱与光致发光谱显示 ,其吸收边或带边发光峰随 Mg原子浓度的增加首先出现红移然后出现蓝移 .该反常现象与 Zn Mg O薄膜中产生的杂质缺陷的行为有关 .研究表明在 MOCVD生长 Zn Mg O合金薄膜过程中 ,必须优化与控制反应条件 ,以抑制杂质缺

LP-MOCVD Growth and Properties of Zn1－xMgxO Thin Film

Zn 1-x Mg x O thin films are epitaxially grown on Al 2O 3(0001) substrates using metal organic chemical vapor deposition.It was found that a thin ZnO buffer layer is needed to achieve wurtzite type Zn 1-x Mg x O film on sapphire.By increasing the content of Mg in the film,the c axis constant of film decreases.Furthermore,no significant phase separation is observed by X ray diffraction measurements,which demonstrates good quality of the film.The abnormal shift of curve in the transmission spectroscopy for Zn 1-x Mg x O film at room temperature (first red shift,then blue shift) is due to the property of the defects in alloy films.The study indicates that,in the growing of ZnMgO alloy by MOCVD,growth condition should be optimized in order to avoid defects.