Development of SiNx LPCVD processes for microtechnological applications

Abstract
Various silicon rich silicon nitride SiN_x films have been deposited by low-pressure chemical vapour deposition (LPCVD) from dichlorosilane SiH₂Cl₂, and ammonia NH₃. Deposition rate, refractive index, residual stress and SiN_x stoichiometry are studied as a function of deposition parameters, evidencing the main influence of the NH₃/SiH₂Cl₂ gas ratio. However, as such SiN_x layers have special applications for micro-opto-electromechanical systems (MOEMS), the influences of the deposition conditions are more precisely studied for improving the uniformity properties along the load. In order to achieve this goal, different load configurations are tested and the use of non-isothermal furnace profiles is proposed in order to develop the LPCVD deposition technique of SiN_x films for industrial microtechnological processes.