AVS 50th International Symposium
    Electronic Materials and Devices Monday Sessions
       Session EM+SC-MoA

Paper EM+SC-MoA8
Surface Defects After the Growth of Highly P and Sb Doped Si

Monday, November 3, 2003, 4:20 pm, Room 321/322

Session: Defects and Interfaces in Electronic Materials and Devices
Presenter: G.G. Jernigan, US Naval Research Laboratory
Authors: G.G. Jernigan, US Naval Research Laboratory
P.E. Thompson, US Naval Research Laboratory
Correspondent: Click to Email
Doping in semiconductors is crucial to the formation of electronic devices, but our knowledge of the physical characteristics of electrical interfaces, as they are formed during device fabrication, is limited. We will present a unique study of Si doping with P and Sb during MBE growth on Si (100) wafers using an in vacuuo STM. The process of doping affects the surface morphology, as compared to an undoped film, leading to surface defects. Under dopant flux conditions of ~10@super 12@ atoms/cm@super 2@/s and Si growth rates ~0.10 nm/s, we will report the changes to the Si surface morphology and the production of defects at growth temperatures of 500 °C. The segregation of the n-type dopants, P and Sb, is observed to affect Si adatom attachment at step-edges resulting in an increase in island formation. For thin films of P less than 50 nm, where less than 0.1 monolayers (ML) of P has segregated, the surface roughness is not increased significantly but line defects parallel to dimer rows can be observed. At high P surface coverages observed on films greater than 50 nm, there are blockages at step-edge sites to form pothole-like defects with a density of 2x10@super 10@ /cm@super 2@. For all Sb films grown, there is an increase in surface roughness with increasing film thickness (>2.0 nm) and Sb surface coverage (>0.01 ML). At high Sb surface coverages (0.8 ML), Si islands form into pyramid-like defects with a density of 8x10@super 10@ /cm@super 2@, and this casts concern for the use of Sb in surfactant assisted growth. The evolution of the surface morphology and defect appearance with film growth and dopant segregation will be discussed.