Fabrication Process Of PN Junction Radioisotope Micro Battery

As the development of MEMS (Micro Electro Mechanical System), Micro power becomes a key problem in MEMS application gradually. Conventional micro power can not meet the energy requirement of MEMS because of restrict of volume, life-time, adaptation for environment, integration, and so on. Radioisotope Micro Battery based onβ-radio-voltaic effect has the characteristics of little volume, sample structure, high stability, long life-time, high density of energy, robust, and so on, more importantly, in the course of application, it does not need frequently to supply materials or energy for them, thus become the research direction of micro power. Energy convert structure is the core of Radioisotope Micro Battery, and its performance affects the efficiency of the Radioisotope Micro Battery seriously, thus it is important to improve the efficiency of the energy convert structure.In this thesis, optimization of the energy convert structure of Radioisotope Micro Battery based onβ-radio-voltaic effect is performed, mask of the metal contacts is designed, and the fabrication process is investigated at the same time. The main content is as follows:Firstly, the structure and work principle of Radioisotope Micro Battery are introduced, including the sort of Radioisotope Micro Battery, the generation, recombination and transmission of electron-hole pairs.Secondly, the energy convert structure is optimized; the surface area is increased to 173% via etching inverted pyramid and channel array. And the performance is expected to be improved by selective emitter structure. At the same time, mask design is performed use L-EDIT.Finally, fabrication process of Radioisotope Micro Battery, especially of the metal contacts is investigated. MIC is avoided through use Si mold. And a new process for the fabrication of the metal contacts of Radioisotope Micro Battery using lift-off process with SU8 photo resist is proposed, via using BP212 photo resist as a sacrificial layer, SU8 in the channels is removed effectively. Radioisotope Micro Battery with inverted pyramid and channel array is fabricated successfully. Satisfied output characteristic is obtained.