The n-type Si-rich SiNx film is deposited on a p-type crystalline Si (c-Si) substrate by facing target sputtering technique, and the Si-rich SiNx/c-Si heterojunction device is finally formed. The heterojunction device shows a high rectification ratio (1.3 103 at 2 V) at room temperature. Three distinct regions of temperature-dependence J-V characteristic curve can be identified, where different current density variations are indicated. In the low voltage range the current follows Ohmic behavior. In the intermediate range of voltage the current is governed by tunneling and recombination process, while space-charge-limited current (SCLC), with an exponential distribution of trapping states, dominates the conduction mechanism in the relatively high voltage range.