Options
1995
Journal Article
Titel
High-dose Ge+ implantation into silicon at elevated substrate temperature
Abstract
Germanium ions with a dose of 6x10(16) square centimetre and at an energy of 160 keV were implanted into (100) Si wafers at roomtemperature (FIT) and elevated substrate temperatures up to 500 degree. Post-implant annealing was performed at 950 degree for 1 h in N2, Experimental results from XTEM micrographs show that the substrate temperature has a considerable effect not only on the as-implanted, but also on the annealed behavior of Ge'-implanted Si. Higher substrate temperatures would be beneficial to improve the crystallinity of SiGe layer by the elimination of the surface defects. The influence of different substrate temperatures could be divided into two types. From implantation from RT to 100 degree, an amorphous layer still exists in as-implanted silicon, extended dislocations and high density of surface defects remain in the recrystallized SiGe layer after annealing. For implantation above 200 degree up to 5O0 degree, where the amophous layer could not be generated due to dynam ic annealing, a layer of about 150 nm thickness at the surface is nearly defect-free. Only extended dislocations, however large size and low in density, exist at the depth of 350 nm from surface. No EOR defects were observed in any of the samples.