Reduction of internal stress in SU-8 photoresist layer by ultrasonic treatment  

作　　者：DU LiQun WANG QiJia ZHANG XiaoLei 

机构地区：[1]Key Laboratory for Micro/Nano Technology and System of Liaoning Province,Dalian University of Technology,Dalian 116024,China [2]Key Laboratory for Precision&Non-traditional Machining Technology of Ministry of Education,Dalian University of Technology,Dalian 116024,China

出　　处：《Science China(Technological Sciences)》2010年第11期3006-3013,共8页中国科学(技术科学英文版)

基　　金：supported by the National Natural Science Foundation of China (Grant No50675025)

摘　　要：At present, high internal stress in SU-8 photoresist layer has become one of the most primary problems and restricted structure stability and higher aspect ratio of SU-8 photoresist. However, the existing studies all focused on optimizing the process pa-rameters or mask design, and could not be popularized. The purpose of this paper is to reduce the internal stress in cured SU-8 photoresist layer by ultrasonic stress relief technology. The ultrasonic stress relief mechanism in SU-8 photoresist layer was presented. Based on improved Stoney’s formula, the profile mothod calculation model for SU-8 internal stress was proposed. The effect of ultrasonic stress relief on SU-8 layers was studied by experiments. Some important factors, such as amplitude of vibration, power input and relief time, were discussed. The values of internal stress before and after the ultrasonic stress relief process were compared. The research results show that the internal stress in cured SU-8 layer can be reduced effectively if the proper experimental parameters are chosen, and ultrasonic stress relief technology in nonmetal field has some practical value.At present, high internal stress in SU-8 photoresist layer has become one of the most primary problems and restricted structure stability and higher aspect ratio of SU-8 photoresist. However, the existing studies all focused on optimizing the process pa-rameters or mask design, and could not be popularized. The purpose of this paper is to reduce the internal stress in cured SU-8 photoresist layer by ultrasonic stress relief technology. The ultrasonic stress relief mechanism in SU-8 photoresist layer was presented. Based on improved Stoney’s formula, the profile mothod calculation model for SU-8 internal stress was proposed. The effect of ultrasonic stress relief on SU-8 layers was studied by experiments. Some important factors, such as amplitude of vibration, power input and relief time, were discussed. The values of internal stress before and after the ultrasonic stress relief process were compared. The research results show that the internal stress in cured SU-8 layer can be reduced effectively if the proper experimental parameters are chosen, and ultrasonic stress relief technology in nonmetal field has some practical value.

关 键 词：ultrasonic stress relief SU-8 photoresist layer internal stress profile method 

分 类 号：R454.3[医药卫生—治疗学]