Formation of heavily P-doped Si epitaxial film on Si(1 0 0) by multiple atomic-layer doping technique

Phosphorus (P) incorporation process during Si epitaxial growth by SiH ₄ reaction in ultraclean low-pressure chemical vapor deposition (CVD) and the electrical characteristics of the heavily P-doped epitaxial Si film on Si(1 0 0) have been investigated. Si layer growth on the P layer formed on Si(1 0 0) at 500°C at SiH ₄ partial pressure of 6 Pa is observed when the surface P amount becomes below 7 × 10 ¹⁴ cm ^-2 . It is also found that about 1.1 × 10 ¹⁴ cm ^-2 P atoms segregate onto the Si surface and the other desorbs. On the other hand, by lowering the Si growth temperature to 450°C and increase in the SiH ₄ partial pressure to 220 Pa, P incorporation occurs and about 1.5 × 10 ¹⁴ cm ^-2 P atoms are buried at the initial position without segregation. By using the multiple atomic-layer doping technique, very low-resistive heavily P-doped epitaxial Si film on Si(1 0 0) can be formed with effective suppression of the electrically inactive P formation.