Ion beam crystallography of surfaces and interfaces

Silicon molecular beam epitaxy

Single‐crystal CoSi2 films have been grown under ultrahigh vacuum conditions on Si (111) by both standard deposition and molecular beam epitaxy techniques. Films were analyzed by Rutherford backscattering spectroscopy and channeling, transmission electron microscopy, and low energy electron diffraction. The films are free of grain boundaries but are rotated 180° about the normal to the Si surface. The crystalline perfection, as measured by channeling, is the best yet reported for an epitaxial silicide system. The expected hexagonal misfit dislocation arrays, along with a coarser triangular defect structure, are confined to the plane of the interface.

Growth of single‐crystal CoSi2 on Si(111)

Growth and characterization of epitaxial Ni and Co silicides

Epitaxial NiSi2 and CoSi2 layers have been grown on crystalline silicon by molecular beam epitaxy (MBE) Stoichiometric, highly crystalline films can be grown by either silicon‐metal codeposition or by pure metal deposition on substrates heated to 550–800 °C Crystalline quality is relatively insensitive to deposition conditions Film smoothness is maximized by codeposition at temperatures near 600 °C Both silicides have been epitaxially overgrown with silicon producing a fully crystalline silicon/metal silicide/silicon heterostructure

Silicon/metal silicide heterostructures grown by molecular beam epitaxy

High‐quality epitaxial NiSi2 films have been fabricated on 〈111〉 Si substrates and examined by grazing‐angle Rutherford backscattering and channeling techniques. The channeled backscattering yields are close to single‐crystal values and permit examination of the silicide‐silicon interface. The yields indicate that the number of disordered Ni atoms at the interface must be less than 1.5×1015 Ni/cm2.

K. C. R. Chiu

Papers

Interfacial order in epitaxial NiSi2