Room Temperature Annealing Behavior of Copper-Related Deep Levels in P-Type Floating Zone Silicon Wafers

Abstract

Deep level transient spectroscopy analysis of copper-doped p-type floating-zone silicon (FZ-Si) wafer was performed. Five deep energy level states observed in copper-doped silicon (Ev+0.1 eV, Ev+0.15 eV, Ev+0.22 eV, Ev+0.26 eV and Ev+0.43 eV) with concentrations of 1×1011 to 1×1012 cm-3 were detected. We observed that the amplitude of only one peak (deep level at Ev+0.26 eV) dramatically decreased with time during storage at room temperature, but stabilized at a concentration of about 1×1012 cm-3 after 2 days. The other deep level concentrations did not change after two months storage at room temperature. Therefore, it was concluded that room-temperature annealing resulted in a decrease in the deep level at Ev+0.26 eV due to the formation of copper-precipitate related defects and out-diffusion to the silicon surface.