Evolution of implanted carbon in silicon upon pulsed excimer laser annealing

Abstract

Formation of epitaxial Si1−yCy substitutional alloy layers on monocrystalline silicon surfaces with y≊1 at. % is reported. The preparation method was carbon ion implantation, followed by KrF excimer laser annealing. Results of Rutherford backscattering (RBS), secondary ion mass spectrometry (SIMS) and infrared absorption analyses are compared. The authors concluded that, up to ∼1 at. % carbon content, the dominant process is nonequilibrium trapping of carbon in substitutional lattice sites upon fast resolidification. Above this concentration the complex carbon redistribution processes are influenced by silicon carbide precipitation in the melt and segregation effects in the near-surface region.

Pulsed Laser Annealing of Silicon-Carbon Source/Drain in MuGFETs for Enhanced Dopant Activation and High Substitutional Carbon Concentration

“…Hence, it is evident that the application of PLA on Si 1−x C x S/D not only improves dopant activation, but also increases C sub in S/D and enhances the strain in the transistor channel. Following laser anneal, the crystal-liquid interface in the melted S/D moves at a fast velocity (∼ 10 2 cm/s) during resolidification, and C atoms are trapped in substitutional sites at a concentration that is ∼3 orders of magnitude higher than in thermal equilibrium [11], [12]. Laser annealing therefore enables nonequilibrium trapping of C atoms in substitutional sites.…”

Carbon-Related Defects in Si:C/Silicon Heterostructures Assessed by Deep-Level Transient Spectroscopy

“…A similar conclusion was reached before in the study of pulsed excimer laser-annealed silicon implanted with carbon, demonstrating the formation of silicon carbide precipitates in the near surface region. 35,36 The band of hole traps could then correspond with states at the Si:C/silicon interface.…”

Pulsed KrF laser annealing of Ni/Si0.76Ge0.24 films

“…24 . For the Ni/Si 0.76 Ge 0.24 films annealed at an energy density of 0.1-0.3 J/cm 2 nickel germanosilicide associated with the amorphous overlayer was formed, while at energy densities above 0.4 J/cm 2 cellular structures of Ge-deficient Si 1Ϫx Ge x islands surrounded by Ni(Si 1Ϫx Ge x ) 2 due to the constitutional supercooling occurred.…”

“…17 Rapid thermal annealing could shorten the annealing time, resulting in a reduction of the Ge segregation. 9,10 Pulsed laser annealing has been extensively used in growing thin films of silicides, [18][19][20][21][22] Si 1Ϫx Ge x , 23 Si 1Ϫx C x , 24 and Si 1ϪxϪy Ge x C y . 25 In comparison with furnace annealing, pulsed laser annealing offers several advantages such as much shorter operational time, confinement of the heated area without causing changes in the pre-existing structure, reduction of contaminants, etc.…”