Defect complexes of Cu and H in Si were studied in detail by deep-level transient spectroscopy. Floating-zone Si, both n and p types, which had been Cu-doped during growth, was hydrogenated by chemical etching. The electrical parameters of substitutional Cu and various Cu-related deep levels were determined. The concentration profiles after etching were measured and numerically fitted assuming a successive trapping of H atoms to substitutional Cu. On the basis of the data, the Cu-related deep levels were attributed to various charge states of Cu-H complexes which contained one or two H atoms. For the CuH1 defect deep levels were measured at EC – 0.36eV and EV + 0.54eV. The two levels at EC – 0.25eV and EV + 0.27eV were attributed to a CuH2 complex. Evidence was also found for a neutral complex which contained 3 or more H atoms. In p-type Si, the capture radii for H by the substitutional Cu were determined to be 0.3nm for the first and second H atoms and 1.0nm for a third H atom. In n-type material, these values were found to be higher: 0.7, 0.9 and 1.8nm, respectively.

Copper-Hydrogen Complexes in Silicon. S.Knack, J.Weber, H.Lemke, H.Riemann: Physical Review B, 2002, 65[16], 165203 (8pp)