摘要
采用O2等离子体及HF溶液对AlGaN/GaN异质结材料进行表面处理后,Ni/Au肖特基接触特性比未处理有了明显改善,反向泄漏电流减小3个数量级.对制备的肖特基接触进行200—600℃5min的N2气氛退火,发现退火冷却后肖特基反向泄漏电流随退火温度增大进一步减小.N2气中600℃退火后肖特基二极管C-V特性曲线在不同频率下一致性变好,这表明退火中Ni向材料表面扩散减小了表面陷阱密度;C-V特性曲线随退火温度增大向右移动,从二维电子气耗尽电压绝对值减小反映了肖特基势垒的提高.
After pre-metallization processing of AlGaN/GaN heterostructure with O2 plasma and HF solution, the Ni/Au Schottky contact characteristics were improved obviously and reverse leakage current reduced by three orders. In addition, annealing experiments were carried out at 200-600℃ for 5min in N2 atmosphere on many batches of Schottky diodes, the reverse leakage current decreased further with annealing temperature increasing. Especially after annealing at 600℃ for 5min in N2 atmosphere, the better uniformity of C-V characteristics at different frequencies indicated that surface trap density was reduced when Ni diffused to AlGaN/GaN surface during annealing. On the other hand, the C-V curves moved to the right and the reduction of absolute value of 2D electron gas depletion voltage proved that the Schottky barrier height was elevated when the annealing temperature increased.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第11期6085-6089,共5页
Acta Physica Sinica
基金
重大科技预研项目(批准号:41308060106)
国家重点基础研究发展计划(973计划)(批准号:2002CB3119)资助的课题.~~
