CHARACTERIZATION OF HYDROGEN IN EPITAXIAL SILICON FILMS GROWN AT VERY-LOW TEMPERATURES

Experimental and theoretical analyses of hydrogen atoms incorporated i n epitaxial silicon films grown at very low temperatures were investig ated using a high resolution X-ray diffractometer (HRXRD) and an ab-in itio total energy calculation. We found that the lattice constant of t he epitaxial films was expanded by the H atoms and this lattice expans ion occurred only in a direction normal to the surface, We proposed th e Si-H-Si configuration as a model to explain the lattice expansion ph enomenon. The results of the calculation supported this model and also suggested that the microscopic stress was introduced by the H atom in the configuration. In B-doped epitaxial Si films, the B atoms were 10 0% neutralized by the H atoms ana activated by thermal annealing, We i ncreased the growth temperature to overcome these H related problems a nd succeeded in controlling the H incorporation. The B-doped Si film w ith a hole concentration of 1.7 x 10(19) cm(-3) was obtained at a grow th temperature of 240 degrees C.