Amorphization and Solid-Phase Epitaxial Growth of C-Cluster Ion-Implanted Si

Abstract

Amorphization and solid-phase epitaxial growth were studied in C-cluster ion-implanted Si. C 7 H 7 ions were implanted at a C-equivalent energy of 10 keV to C doses of 0.1 9 10 15 cm À2 to 8.0 9 10 15 cm À2 into (001) Si wafers. Transmission electron microscopy revealed a C amorphizing dose of $5.0 9 10 14 cm À2 . Annealing of amorphized specimens to effect solid-phase epitaxial growth resulted in defect-free growth for C doses of 0.5 9 10 15 cm À2 to 1.0 9 10 15 cm À2 . At higher doses, growth was defective and eventually polycrystalline due to induced in-plane tensile stress from substitutional C incorporation.

Effect of dose and size on defect engineering in carbon cluster implanted silicon wafers

“…Furthermore, in previous studies, amorphization occurred from the silicon wafer surface. 30) However, in this study, the C 3 H 5 -cluster ions formed an amorphous region inside the silicon wafer. Amorphization occurred from the C 3 H 5 -cluster-implanted region.…”

“…Several studies on carbon-cluster-ion implantation have been reported. [27][28][29][30] However, there have been few studies reporting the effects of the carbon cluster size and carbon dose on defect formation or giving a comparison with monomer implantation. Furthermore, it is not clear what kinds of defects are formed after epitaxial growth.…”

Defective Solid-Phase Epitaxial Growth of Si

“…Thus, once growth interface motion stops, further annealing allows crystallization to occur via RNG, which is a much slower process than SPEG for crystallizing an α-Si layer. Thus, with further annealing, the remaining α-Si layer will be polycrystalline in nature, rather than single crystal as was previously reported (Rudawski et al, 2009c;Strane et al, 1996).…”

“…Previous work established that when the starting growth interface is closer to the wafer surface, mask-edge defects are more difficult to form during SPEG (Rudawski et al, 2009b); the closer the initial growth interface is to the wafer surface, the portion of the growth interface with [001] normal effectively crystallizes the entire α-Si layer before the portion of the interface with [110] normal can impinge. Templating of the growth interface was also lessened when the initial growth interface was closer to the wafer surface, but the origin of this, similar to the origin of templating in general, is unclear.…”

“…However, it is important to consider the role that applied stress may have on the SPEG process in patterned material, since the presence of stresses of substantial magnitude is ubiquitous in current Si-based device fabrication (Hu, 1991). Interestingly, extensive prior work showed that the application of different forms of mechanical stress during SPEG could alter the morphology of the evolving growth interface thus favoring or impeding mask-edge defect formation (Olson et al, 2006;Rudawski et al, 2006Rudawski et al, , 2008aRudawski et al, , 2009bShin et al, 2001a,b,c). Specifically, when uniaxial tension was applied along the in-plane [110] direction during SPEG, the impingement of the two portions of the growth interface was retarded, which resulted in defect-free growth (Olson et al, 2006;Rudawski et al, 2006Rudawski et al, , 2008aRudawski et al, , 2009b.…”