电感耦合等离子体刻蚀对InGaP/GaAs台面形貌的影响  

Influences of Inductively-Coupled Plasma Etching on Morphology of InGaP/GaAs Mesa

作　　者：李碧媛 张永宏 魏育才 徐智文 蔡松智 周必顺 Li Biyuan;Chang Yunghung;Wei Yucai;Hsu Chihwen;Tsai Sungchih;Zhou Bishun(Unicompound Semiconductor Corporation,Putian 351115,China)

机构地区：[1]福建省福联集成电路有限公司,福建莆田351115

出　　处：《半导体技术》2020年第3期219-223,243,共6页Semiconductor Technology

摘　　要：制作InGaP/GaAs台面时,若使用湿法刻蚀需分多步进行,且易发生钻蚀问题,使得台面上的金属覆盖层易断裂。为改善InGaP/GaAs的台面形貌,以N2/Cl2混合气体为刻蚀剂,采用电感耦合等离子体(ICP)刻蚀,探讨了Cl2的体积分数、腔体压力、源功率和偏压功率等刻蚀条件对台面形貌的影响,并进一步研究刻蚀后台面形貌对金属台阶覆盖的影响。实验结果表明,Cl2的体积分数变化对刻蚀台面形貌影响最大,刻蚀后台面侧壁角的可控范围为64.1°~92.0°;而腔体压力、源功率和偏压功率对台面形貌的影响有限。当刻蚀台面侧壁角约为65°时,金属台阶覆盖良好;当刻蚀台面侧壁角约为75°时,金属台阶覆盖会出现裂纹;当刻蚀台面侧壁角约为90°时,金属台阶覆盖会断裂。When etching InGaP/GaAs mesa,wet etching needs to be carried out in multiple steps,and the problem of undercutting will occur,causing the metal cover layer on the mesa to be cracked.In order to improve the morphology of InGaP/GaAs mesa,N2/Cl2 were selected as the reaction gases,inductively coupled plasma(ICP)etching was used to investigate the effects of etching conditions such as Cl2 volume fraction,chamber pressure,source power and bias power on the mesa morphology.The inf-luence of the morphology of InGaP/GaAs mesa on the metal step coverage after etching was further investigated.The experimental results show that the volume fraction of Cl2 has the most significant influence on the mesa morphology and the sidewall angle can be controlled from 64.1°to 92.0°,while the influences of chamber pressure,source power and bias power are limited.Metal step coverage is better when the mesa sidewall angle is about 65°,while the metal crack exists as the angle is about 75°.Furthermore,the metal disconnection is occurred when the sidewall angle is about 90°.

关 键 词：ICP刻蚀 台面形貌 Cl2/N2 INGAP/GAAS 台阶覆盖 

分 类 号：TN405.98[电子电信—微电子学与固体电子学]