Semiconducting and structural properties of CrSi2 A-type epitaxial films on Si(111)

Chromium disilicide (CrSi2) films 1 000 Angstrom thick have been prepared by molecular beam epitaxy on CrSi2 templates grown on Si(lll) substrate. The effect of the substrate temperature on the structural, electrical and optical properties of CrSi2 films has been studied by transmission and scanning electron microscopies, optical microscopy, electrical resistivity and Hall effect measurements and infrared optical spectrometry. The optimal temperature for the formation of the epitaxial A-type CrSi2 film have been found to be about 750 degrees C. The electrical measurement have shown that the epitaxial A-type CrSi2 film is p-type semiconductor having a hole concentration of 1 x 10(17) cm(-3) and Hall mobility of 2 980 cm(2) V-1 s(-1) at room temperature. Optical absorption coefficient data have indicated a minimum, direct energy gap of 0.34 eV. The temperature dependence of the Hall mobility (mu) in the temperature range of T=180-500 K can be expressed as mu=7.8 x 10(10)T(-3) cm(2)V(-1)s(-1).