The Structural Design Of Mems Nuclear Battery Energy Conversion And Production Process

Nowadays, the electrical mobile products are developed rapidly. As a result, it is necessary to develop some novel kinds of micro power with high power density, low weight, small volume, and long lifetime. Recently a new RMB (Radioisotope Micro Battery) was used for solving the energy problems of MEMS devices. It is based on betavoltaic effect that is similar to photovoltaic effect. As a result, it has high power density, low weight, small volume, and long lifetime.Firstly, the construction (including semiconductor pn junction, electrodes section, electro plating section, isotope source etc.) and the working principle of RMB are introduced in this paper.Conventional direct conversion devices of Radioisotope Micro Battery (RMB) suffer from small surface area and unreliability. A method, which is verified with simulation results, is introduced for modeling the direct conversion devices. The fundamental structure of RMB is presented, and the equations of current are founded. The novel direct conversion device of vertical wall array is demonstrated. As a result, 171% increase of the surface area is acquired and the reliability is enhanced owing to the electro plating section. Optimization of the method has resulted in that the optimum doping concentrations are N_A=10¹⁷/cm³ & N_D=10¹⁷/cm³, and the optimum junction depth for the performance of RMB is 3μm.The quality and preparation of RMB are discussed. For the microfabrication flow of Radioisotope Micro Battery (RMB), lift-off technology is used to fabricate the electrode and metallic layer which can be introduced to plate the radioactive film. The positive resist BP212 is applied in the whole process, and obtained the optimal method of spinning process, photolithography and development. In the condition of these parameters, the process of altering the shape of photosensitive resist using chlorobenzene can be omitted. The result shows that 400nm metallic layer can be rapidly done.It was proved that the performance of semiconductor pn junction and the quantity of isotope source had great influence on the performance of RMB. It shows that there are better performance which are I_SC{short circuit electricity) -1.3×10^-6A,...