感应耦合等离子体选择性刻蚀GaN/AlGaN

采用Cl₂/Ar作为刻蚀气体，研究了在感应耦合等离子体干法刻蚀GaN、Al_0.27Ga_0.73N材料中工艺参数对刻蚀速率及选择比的影响．GaN与Al_0.27Ga_0.73N之间的刻蚀选择比随自偏压的增大而减小，随感应耦合等离子体功率的增大变化不大．在Cl₂/Ar为3:1的刻蚀气体中加入10％的O₂对GaN刻蚀速率影响不大，却使Al_0.27Ga_0.73N刻蚀速率明显下降，从而提高了GaN与Al_0.27Ga_0.73N之间的刻蚀选择比．对比了采用不同自偏压刻蚀的Al_0.27Ga_0.73N材料肖特基的特性，发现反向漏电流随自偏压的增大而增大．

Selective etching of GaN/ AlGaN by Inductively coupled plasma

A systematic study of etch rates and selectivities of GaN and Al_(0.27)Ga_(0.73)N at different processing terms is performed using Cl_2/Ar inductively coupled plasma.Selectivity between GaN and Al_(0.27)Ga_(0.73)N decreases with the increasing DC bias and changes a little with ICP power.Adding O_2(10%) to Cl_2/Ar(3:1) gas mixture has little effect on etch rates of GaN,but leads to a great reduction in etch rates of Al_(0.27)Ga_(0.73)N,thus improving selectivity between GaN and Al_(0.27)Ga_(0.73)N.Schottky characteristics at different etching DC biases are contrasted,with the result that the leakage current increases with the enhanced DC bias.