A novel oxidation-based wet etching method for AlGaN/GaN heterostructures  

作　　者：蔡金宝 王金延 刘洋 徐哲 王茂俊 于民 解冰 吴文刚 

机构地区：[1]Wide Bandgap Semiconductor Laboratory,Institute of Microelectronics,Peking University

出　　处：《Journal of Semiconductors》2013年第8期201-204,共4页半导体学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.60406004,60890193,60736033);the National Key Micrometer/Nanometer Processing Laboratory,China

摘　　要：A novel wet etching method for AlGaN/GaN heterojunction structures is proposed using thermal oxidation f ollowed by wet etching in KOH solution.It is found that an AlGaN/GaN heterostructure after high temperature oxidation above 700℃could be etched off in a homothermal（70℃） KOH solution while the KOH solution had no etching effects on the region of the AlGaN/GaN heterostructure protected by a SiO_2 layer during the oxidation process.A groove structure with 150 nm step depth on an AlGaN/GaN heterostructure was formed after 8 h thermal oxidation at 900℃followed by 30 min treatment in 70℃KOH solution.As the oxidation time increases,the etching depth approaches saturation and the roughness of the etched surface becomes much better.The physical mechanism of this phenomenon is also discussed.A novel wet etching method for AlGaN/GaN heterojunction structures is proposed using thermal oxidation f ollowed by wet etching in KOH solution.It is found that an AlGaN/GaN heterostructure after high temperature oxidation above 700℃could be etched off in a homothermal（70℃） KOH solution while the KOH solution had no etching effects on the region of the AlGaN/GaN heterostructure protected by a SiO_2 layer during the oxidation process.A groove structure with 150 nm step depth on an AlGaN/GaN heterostructure was formed after 8 h thermal oxidation at 900℃followed by 30 min treatment in 70℃KOH solution.As the oxidation time increases,the etching depth approaches saturation and the roughness of the etched surface becomes much better.The physical mechanism of this phenomenon is also discussed.

关 键 词：AlGaN/GaN wet etching thermal oxidation KOH solution 

分 类 号：TN304[电子电信—物理电子学]