Evaluation of Crystal Quality and Dopant Activation of Smart CutTM - Transferred 4H-SiC Thin Film

The Smart CutTM process offers an advantageous opportunity to provide a large number of performance-improved SiC substrates for power electronics. The crystalline quality and the electrical activation of the 4H-SiC transferred layer are then at stake when it comes to the power device reliability. In this study, we find that the H⁺ ion implantation used for the Smart CutTM process leads to electrical deactivation of dopants and partially disorders the material. The transferred layer fully recovers its initial crystalline quality after a 1300°C anneal, with no further evolution beyond this temperature. At this point however, the n-type dopants are still inactive. The dopant reactivation occurs in the same temperature range than that of implanted nitrogen: between 1400°C and 1700°C. After 1700°C, the initial doping level of bulk SiC is recovered.