Method for manufacturing a mis structure on silicon carbide (SiC)

摘要

A method for producing a MIS structure on silicon carbide is provided. Given application of a known CVD method for occupying the surface of a SiC substrate provided with a gate oxide with the silicon serving as gate material, stationary positive charges arise in the region of the oxide/SiC boundary surface whose extremely high effective density (Qtot>1012 cm-2) disadvantageously influences the electrical properties of the finished component. The present method modifies the deposition conditions for the silicon serving as a gate material. Thus, the silicon is deposited from the vapor phase at a temperature of T<580 DEG C. and is thus amorphously applied. During the subsequent doping (drive-in of phosphorous at T>800 DEG C.), the amorphous silicon converts into the polycrystalline condition. Since the crystalline regions in the silicon layer can grow comparatively unimpeded and free of mechanical stresses, the effective density of the negative boundary surface charges arising in the gate oxide lies at values Qtot<1011 cm-2. The method is particularly applied in the manufacture of MOSFETs, MOS capacitors and the like.