Growth of epitaxial (100)$CoSi_2$ layer on (100)Si substrate using cobalt metallorganic chemical vapor deposition

Abstract

Epitaxially grown layers of $CoSi_2$ on Si (100) substrate are of special interest because of their excellent thermal stability, low junction leakage, and ultra-shallow junction formation. For their possible applications in microelectronics, it deserves to research the epitaxial growth of $CoSi_2$ on (100) Si substrate. Despite the promising structural match of $CoSi_2$ and Si, the growth of an epitaxial $CoSi_2$ layer on (100) Si substrate has not been successfully realized due to the strong tendency of growth of misoriented grains. The special growth techniques such as interlayer mediated epitaxy, molecular beam epitaxy, molecular beam allotaxy, ion beam synthesis, and reactive deposition epitaxy. However, the techniques require complicated tools and multistep process not commonly used in silicon processing. A new method, cobalt metallorganic chemical vapor deposition was presented for the epitaxial growth of $CoSi_2$ layers on (100) substrate in this thesis. Chemical vapor deposition vapor deposition commonly used in the silicon process offers several advantages, such as a uniform conformal deposition over a large area and no substrate damage. It also can control the deposition rate in a relatively broad range. The epitaxial growth of $CoSi_2$ on (100) Si substrate using cobalt metallorganic chemical vapor deposition, the epitaxial growth behavior, and the epitaxial growth kinetic have been investigated. Furthermore, the characterization of epitaxial $CoSi_2$ layer, the application to polycide, and the growth of $CoSi_2$ layer at low temperature also have been studied. An epitaxial $CoSi_2$ layer was grown on (100) Si substrate by the diffusion of Co from a cobalt-carbon (Co-C) film without the use of an interlayer, which is usually required between the Si and cobalt layers for the formation of epitaxial $CoSi_2$ layers. Co-C and pure Co layers were deposited by metallorganic chemical vapor deposition (MOCVD) using the Co precursor cyclopentadienyl dicarbony...