TERNARY SIGEC ALLOYS - GROWTH AND PROPERTIES OF A NEW SEMICONDUCTING MATERIAL

The growth and properties of Si1-yCy and Si1-x-yGexCy alloys pseudomor phically strained on Si(001) will be critically reviewed. Although the bulk solubility of carbon in silicon is small, epitaxial layers with more than 1 at.% C can be fabricated by molecular beam epitaxy and dif ferent chemical vapour deposition techniques. One of the most crucial questions is the relation between substitutional and interstitial carb on incorporation, which has a large impact on the electrical and optic al properties of these layers. We will show that the interstitial to s ubstitutional carbon ratio is strongly influenced by the chosen growth conditions, like growth temperature and Si growth rate. In addition, angle-resolved X-ray photoelectron spectroscopy measurements indicate a surface segregation of interstitial carbon-containing complexes (mor e significant for higher growth temperature). Substitutionally incorpo rated C atoms allow strain manipulation, including the growth of an in versely strained Si1-x-yGexCy. layer. Local ordering effects due to at omic size differences and the growth on reconstructed surfaces, the me chanical and structural properties, and the influence of C atoms on ba nd structure of Si and SiGe layers will be discussed.