TEM AND RBS STUDIES OF EPITAXIAL COSI2 LAYERS FORMED BY HIGH-DOSE COBALT IMPLANTATION INTO SILICON

Buried layers of CoSi2 have been fabricated by implanting high doses of energetic Co atoms, into single crystal (100) silicon substrates maintained at approximately 550-degrees-C. For doses greater-than-or-equal-to 4 x 10(17) Co-59+ cm-2, at 350 keV, a continuous buried layer of CoSi2 grows epitaxially during implantation. For lower doses the 'as implanted' structure is discontinuous and consists of discrete precipitates of both A- and B- type CoSi2. After annealing at 1000-degrees-C for 30 minutes a continuous buried layer of stoichiometric CoSi2 is produced for doses greater-than-or-equal-to 2 x 10(17) Co-59+ cm-2, at 200 keV and greater-than-or-equal-to 4 x 10(17) Co-59+ cm-2, at 350 keV. For lower doses the synthesised layer is discontinuous and consists of discrete octahedral CoSi2 precipitates which are aligned with the matrix (A-type)

TEM AND RBS STUDIES OF EPITAXIAL COSI2 LAYERS FORMED BY HIGH-DOSE COBALT IMPLANTATION INTO SILICON

Buried layers of CoSi2 have been fabricated by implanting high doses of energetic Co atoms, into single crystal (100) silicon substrates maintained at approximately 550-degrees-C. For doses greater-than-or-equal-to 4 x 10(17) Co-59+ cm-2, at 350 keV, a continuous buried layer of CoSi2 grows epitaxially during implantation. For lower doses the 'as implanted' structure is discontinuous and consists of discrete precipitates of both A- and B- type CoSi2. After annealing at 1000-degrees-C for 30 minutes a continuous buried layer of stoichiometric CoSi2 is produced for doses greater-than-or-equal-to 2 x 10(17) Co-59+ cm-2, at 200 keV and greater-than-or-equal-to 4 x 10(17) Co-59+ cm-2, at 350 keV. For lower doses the synthesised layer is discontinuous and consists of discrete octahedral CoSi2 precipitates which are aligned with the matrix (A-type)