Characterization of deep levels in oxygen-implanted silicon wafers by capacitance deep level transient spectroscopy

Deep levels in oxygen-implanted silicon-on-insulator (SOI) films have been characterized by applying the capacitance deep level transient spectroscopy (DLTS) method to a conductivity-type inverted vertical SOI capacitor with Schottky gate. The interface charge coupling problems inherent in conventional vertical-type SOI capacitors are removed by biasing the interfaces into accumulation region during measurements. The effect of high series resistance of SOI films on the DLTS measurements is shown to be significantly reduced by using a conductivity-type inverted Vertical capacitor structure. Two distinct deep electron traps have been detected with medium oxygen dose SOI films at the levels of 0.33 and 0.40 eV below the conduction band edge. The corresponding concentrations of the two deep level traps have been exactly estimated to be 1.6x10(16)/cm(3) and 1.2x10(16)/cm(3), respectively. These donor levels are believed to be originated from oxygen implantation and high temperature annealing.