Defect production in strained p-type Si{sub 1-x}Ge{sub x} by Er implantation

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3531539· OSTI ID:21538025

Mamor, M ^[1]; Pipeleers, B; Vantomme, A ^[1]; Auret, F D ^[2]

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1. Instituut voor Kern-en Stralingsfysica and INPAC, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)
2. Department of Physics, University of Pretoria, Pretoria 0002 (South Africa)

Strained p-Si{sub 1-x}Ge{sub x} (x=5.3%, 10.2%, and 15.4%) was irradiated at room temperature with 160 keV {sup 166}Er{sup 2+} ions to a fluence of 1x10{sup 10} or 3x10{sup 13} Er/cm{sup 2}. The defects induced by ion implantation were investigated experimentally using high-resolution x-ray diffraction, Rutherford backscattering and channeling spectroscopy, and deep level transient spectroscopy. X-ray diffraction indicates that the damage induced by Er implantation produces a slight perpendicular expansion of the SiGe lattice. For all compositions, channeling measurements reveal that Er implantation in p-Si{sub 1-x}Ge{sub x} to a fluence of 3x10{sup 13} Er/cm{sup 2} induces an amorphous region below the Si{sub 1-x}Ge{sub x} surface. Annealing at 850 deg. C for 30 s, results in a reduction in damage density, a relaxation of the implantation-induced perpendicular expansion of the SiGe lattice in the implanted region, while a more pronounced relaxation of the compressive strain SiGe is observed for higher Ge content (x=0.10 and 0.15). On the other hand, for the annealed SiGe samples that were implanted with Er at the fluence of 10{sup 10} Er/cm{sup 2}, the compressive strain in the SiGe layer is nearly completely retained. Deep level transient spectroscopy studies indicate that two prominent defects with discrete energy levels above the valence band are introduced during Er implantation. Their activation energy was found to decrease with increasing Ge content. However, the relatively large local strain induced by high fluence Er implantation reduces the activation energy by 40 meV with respect to the low fluence Er implanted p-Si{sub 1-x}Ge{sub x}. This shift (40 meV) in the activation energy remains constant regardless of the Ge content, suggesting that the Si{sub 1-x}Ge{sub x} layers remained fully strained after Er implantation. The observed defects are further compared to those introduced by alpha particle irradiation and electron beam metal deposition. The results indicate that defects introduced by Er implantation have similar electronic properties as those of defects detected after electron beam deposition and alpha particle irradiation. Therefore, it is concluded that these defects are due to the Er implantation-induced damage and not to the Er species specifically.

• OSTI ID: 21538025
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 1; Other Information: DOI: 10.1063/1.3531539; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ACTIVATION ENERGY
ANNEALING
CRYSTAL DEFECTS
DEEP LEVEL TRANSIENT SPECTROSCOPY
DENSITY
ELECTRON BEAMS
ENERGY LEVELS
GERMANIUM ALLOYS
GERMANIUM SILICIDES
ION IMPLANTATION
IONS
IRRADIATION
KEV RANGE 100-1000
LAYERS
RELAXATION
RUTHERFORD BACKSCATTERING SPECTROSCOPY
SILICON ALLOYS
SURFACES
TEMPERATURE RANGE 0273-0400 K
X-RAY DIFFRACTION
ALLOYS
BEAMS
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ENERGY
ENERGY RANGE
GERMANIUM COMPOUNDS
HEAT TREATMENTS
KEV RANGE
LEPTON BEAMS
PARTICLE BEAMS
PHYSICAL PROPERTIES
SCATTERING
SILICIDES
SILICON COMPOUNDS
SPECTROSCOPY
TEMPERATURE RANGE