Electrical properties of N atomic layer doped Si epitaxial films grown by ultraclean low-pressure chemical vapor deposition

Sheet carrier concentration and Hall mobility of the N atomic layer doped Si epitaxial films on Si(1 0 0) were obtained by Hall effect measurement. It is found that the N atoms act as a donor. Donor activation ratio tends to decrease with increasing N amount, and the typical ratio is about 0.4% at the N amount of 5×10¹³ cm^-2/layer. Sheet carrier concentration in the temperature region higher than 160 K drastically increases with increase of the measurement temperature. The ionization energy of the donor level is estimated about 150-180 meV and almost independent of the N amount. Measured Hall mobility is as high as that of the uniformly P-doped Si with the P concentration of 10¹⁶-10¹⁷ cm^-3 in the measurement temperature range of 160-300 K.