SU-8 BASED UV-LIGA FABRICATION PROCESS FOR REALIZATION OF NICKEL BASED MEMS INERTIAL SENSOR

This paper reports the complete fabrication process flow based on UV-LIGA technology for realization of metal based MEMS inertial sensor. In this process, nickel is used as the structural layer and copper as the sacrificial layer. The economical three mask process has been optimized and the detailed step by step procedure for carrying out the fabrication is presented. The opti- mized process parameters to achieve void free copper and nickel electroplated layers with extremely low roughness have been reported. Footing problem asso- ciated with lithography process has been analysed and its solution discussed. The fabrication results after each process step have been presented and dis- cussed. Scanning electron micrograph images of the released prototype inertial sensor devices have been presented to demonstrate the successful fabrication of the prototypes using the economical UV-LIGA process.