Polysilicon-Al Based Ohmic Contact on p-Type 3C-SiC Film Grown on Silicon Substrate

In this paper, a method that combines radio frequency (RF) plasma with hot filament (HF) chemical vapor deposition (CVD) together has been used to prepare 3C-SiC film. The samples obtained through the above method have been systematically demonstrated by atom force microscopy (AFM), X-ray diffraction (XRD). Its concentration is measured to be p=1.33times10¹⁷cm^-3 using Hall effect. The samples have been divided into two parts: one ohmic contact is made with deposition of aluminum directly on its surface. Alternately, the other´s metal contact is deposited following a polysilicon pre-deposition. Both of them are annealed at 450, 600 and 710 degC, separately. The specific contact resistance of sample without polysilicon annealed at 710degC is rho _c = 0.014 Omega cm² and that of sample with polysilicon annealed at the same condition exhibits an improved property. Its specific contact resistance can be lowered to be rho _c = 3.5 times 10^-4 Omega cm². The mechanism for this experimental result has been explained in this paper, too. And attempt to add nanometer grain on polysilicon to lower barrier