FORMATION OF TERNARY CO1-XPDXSI2 ON SI(100) BY PD ION-IMPLANTATION INCOSI2 SI(100) HETEROSTRUCTURES/

Single crystalline metal/silicon heterostructures, such as CoSi2 on Si (100), an promising materials for microelectronic and optoelectronic applications. The crystalline perfection of epitaxial CoSi2/Si (100) h eterostructures is limited by the lattice mismatch of - 1.2% between C oSi2 and Si, leading to the formation of misfit and threading dislocat ions as a result of elastic strain in the layer, In the present work, a first attempt was made to reduce the lattice mismatch by substitutin g a few percent of the Co atoms by Pd, which has a larger covalent rad ius than Co, Single crystalline CoSi2/Si (100) heterostructures with a silicide thickness of about 130 nm were implanted at 450 degrees C wi th 260 keV Pd+ ions. The doses were varied between 4.6 x 10(15) and 2. 8 x 10(16)/cm(2). Rapid thermal annealing was employed to homogenize t he Pd distribution within the silicide layer. The samples were charact erized using Rutherford backscattering spectrometry, transmission elec tron microscopy, electrical resistivity measurements and X-ray diffrac tion. The results show that up to 2% of the Co atoms can be replaced b y substitutional Pd atoms, The ternary silicide layers exhibit channel ing minimum yields of 3-5%, Larger Pd concentrations lead to the preci pitation of PdSi as a second phase.