To achieve an ultra-shallow junction formation with low resistivity, Cluster Carbon (CC) co-implantation for NMOS source drain and source drain extension condition are investigated. It is found that using CC co-implantation, Phosphorus (P) TED was suppressed and the lower junction depth Xj is achieved. The sheet resistivity Rs is increased with the increment of the Carbon dose, but the Rs×Xj product has a minimum condition is confirmed. From the experimental data, it is shown that the Cluster Carbon ion implantation (CCII) condition is important to suppress P TED effectively.