Study on the failure temperature of Ti/Pt/Au and Pt_5Si_2–Ti/Pt/Au metallization systems  

作　　者：Jie Zhang Jianqiang Han Yijun Yin Lizhen Dong Wenju Niu 

机构地区：[1]The College of Mechanical&Electrical Engineering,China Jiliang University,Hangzhou 310018,China

出　　处：《Journal of Semiconductors》2017年第9期99-102,共4页半导体学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.61376114)

摘　　要：The Ti/Pt/Au metallization system has an advantage of resisting KOH or TMAH solution etching. To form a good ohmic contact, the Ti/Pt/Au metallization system must be alloyed at 400℃. However, the process temperatures of typical MEMS packaging technologies, such as anodic bonding, glass solder bonding and eutectic bonding, generally exceed 400℃. It is puzzling if the Ti/Pt/Au system is destroyed during the subsequent packaging process. In the present work, the resistance of doped polysilicon resistors contacted by the Ti/Pt/Au metallization system that have undergone different temperatures and time are measured. The experimental results show that the ohmic contacts will be destroyed if heated to 500℃. But if a 20 nm Pt film is sputtered on heavily doped polysilicon and alloyed at 700℃ before sputtering Ti/Pt/Au films, the Pt5 Si2-Ti/Pt/Au metallization system has a higher service temperature of 500℃, which exceeds process temperatures of most typical MEMS packaging technologies.The Ti/Pt/Au metallization system has an advantage of resisting KOH or TMAH solution etching. To form a good ohmic contact, the Ti/Pt/Au metallization system must be alloyed at 400℃. However, the process temperatures of typical MEMS packaging technologies, such as anodic bonding, glass solder bonding and eutectic bonding, generally exceed 400℃. It is puzzling if the Ti/Pt/Au system is destroyed during the subsequent packaging process. In the present work, the resistance of doped polysilicon resistors contacted by the Ti/Pt/Au metallization system that have undergone different temperatures and time are measured. The experimental results show that the ohmic contacts will be destroyed if heated to 500℃. But if a 20 nm Pt film is sputtered on heavily doped polysilicon and alloyed at 700℃ before sputtering Ti/Pt/Au films, the Pt5 Si2-Ti/Pt/Au metallization system has a higher service temperature of 500℃, which exceeds process temperatures of most typical MEMS packaging technologies.

关 键 词：Ti/Pt/Au metallization system PACKAGING ohmic contacts MEMS 

分 类 号：TN305[电子电信—物理电子学]