Abstract: Cubic crystalline p-SiCN films are deposited on n-Si substrates to form SiCN/Si heterojunction diodes (HJDs) with a rapid thermal chemical vapor deposition (RTCVD) technique. The developed SiCN/Si HJDs exhibit good rectifying properties up to 200/spl deg/C. At room temperature, the reverse breakdown voltage is more than 29 V at the leakage current density of 1.2/spl times/10/sup -4/ A/cm/sup 2/. Even at 200/spl deg/C, the typical breakdown voltage of SiCN/Si HJDs is still preserved about 5 V at the leakage current density of 1.47/spl times/10/sup -4/ A/cm/sup 2/. These properties are better than the /spl beta/-SiC on Si HJDs for high temperature applications.