N-type highly conductive hydrogenated microcrystalline cubic silicon carbide (μc-3C-SiC:H) films were successfully deposited by hot wire chemical vapor deposition (HWCVD) at a low substrate temperature (∼300 °C). We employed phosphine (PH3) and hexamethyldisilazane (HMDS) as phosphorous and nitrogen source materials, respectively. For the phosphorous doped films, we obtained dark conductivity (σd) of 3.2×10-2 S/cm and activation energy of the dark conductivity (Ea) of 86 meV. For the nitrogen doped films, the σd and Ea were found to be 5.32 S/cm and 25 meV, respectively. These results indicates that doping with HMDS is effective to obtain highly conductive μc3C-SiC:H films. We also fabricated n-type μc-3C-SiC:H(doped with HMDS)/p-type crystalline silicon heterojunction diodes in order to investigate junction properties. The diodes showed good rectifying characteristics. These results suggest that nitrogen doped μc-3C-SiC:H films are promising for the doped layer of silicon based solar cells.