The Research of Low Ohmic Contact Resistance to p-GaN

利用低压MOCVD系统,获得了p-GaN和p-InGaN/GaN超晶格结构2种材料,用圆形传输线模型(CTLM)测量了它们的比接触电阻率,并对表面处理、金属沉积和合金化处理的工艺条件进行了优化,得到了550℃、O2氛围下合金30min的最佳条件,获得最低的比接触电阻率为1.99×10-4Ω.cm2。P-GaN bulk material and p-InGaN/GaN superlattice used as p-contact layer are grown by low pressure metal organic chemical vapor deposition(LP-MOCVD),and their specific contact resistivity(SCR)is measured by circular transmission line model(CTLM).Meanwhile,surface pretreatment,metal deposion and annealing processes of ohmic contact on p-InGaN/GaN superlattice are optimized,and the best result with the SCR of 1.99×10-4 Ω·cm2 is achieved after annealing at 550 ℃ for 30 min in oxygen.国家自然科学基金资助项目(60276029);; 国家“863”计划资助项目(2004AA311020);; 福建省科技项目(2005HZ1018