SOI-SIMNI (Silicon On Insulator-Separation by Implanted Nitrogen) films were formed by standard and multiplestep implantation methods. The Hal-l effects measurements (4-300K) show that the multiple-step implanted SIMNI films have a lower sheet resistance and higher carrier mobility than those in standard SIMNI films. The DLTS results indicated that there is a deep level defects E _t=0.152eV in the standard SIMNI films‚, and no deep level defects in the multiple-step implanted SIMNI films‚, which have good electrical properties.