Deep-level transient spectroscopic analyses of Cu-doped p-type float-zone wafers were performed. Five deep energy level states were observed (Ev + 0.1, Ev + 0.15, Ev + 0.22, Ev + 0.26 and Ev + 0.43eV), with concentrations of 1011 to 1012/cm3. It was noted that the amplitude of only one peak (deep level at Ev + 0.26eV) decreased markedly with time during storage at room temperature. It stabilized at a concentration of about 1012/cm3 after 48h. The other deep-level concentrations did not change during 2 months storage at room temperature. It was concluded that room-temperature annealing resulted in a decrease in the deep level at Ev + 0.26eV, due to the formation of Cu precipitate-related defects.

Room Temperature Annealing Behavior of Copper-Related Deep Levels in p-Type Floating Zone Silicon Wafers. K.Kurita, T.Shingyouji: Japanese Journal of Applied Physics - 1, 2001, 40[3A], 1167-71