Ga-implantation in Ge: Electrical activation and clustering

Journal Article · Wed Jul 01 04:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3159031· OSTI ID:21359285

Impellizzeri, G; Mirabella, S; Irrera, A; Grimaldi, M G ^[1]; Napolitani, E ^[2]

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1. MATIS CNR-INFM and Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, 95123 Catania (Italy)
2. MATIS CNR-INFM and Dipartimento di Fisica, Universita di Padova, Via Marzolo 8, 35131 Padova (Italy)

The electrical activation and clustering of Ga implanted in crystalline Ge was investigated in the (0.3-1.2)x10{sup 21} Ga/cm{sup 3} concentration range. To this aim, Ge samples implanted with 50 keV gallium, and annealed at several temperatures up to 650 deg. C, have been subjected to a detailed structural and electrical characterization. The substrate was maintained at 77 K during implantation to avoid the formation of the honeycomb structure that occurs during implantation at room temperature of heavy ions at high fluence. Secondary ion mass spectrometry analyses indicated a negligible Ga diffusion and dopant loss during the thermal annealing. The carrier concentration in the recrystallized samples measured by Hall effect showed a maximum concentration of active Ga of approx6.6x10{sup 20} Ga/cm{sup 3}. A remarkable Ga deactivation occurred with increasing the annealing temperature from 450 to 650 deg. C although the sheet resistance did not change considerably in this temperature range. It turned out that the carrier concentration reduction is balanced by the enhancement of the hole mobility that exhibits a steep variation with the concentration of the ionized scattering centers in this range. A simple model is proposed to explain the experimental results taking into account the thermally activated Ga clustering. These studies, besides clarifying the mechanism of Ga deactivation in Ge, can be helpful for the realization of future generation devices based on Ge.

• OSTI ID: 21359285
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 1 Vol. 106; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CARRIER DENSITY
CHARGED PARTICLES
DEACTIVATION
ELEMENTS
ENERGY RANGE
GALLIUM
GERMANIUM
HALL EFFECT
HEAT TREATMENTS
HEAVY IONS
HOLE MOBILITY
HONEYCOMB STRUCTURES
ION IMPLANTATION
IONS
KEV RANGE
KEV RANGE 10-100
MASS SPECTRA
MASS SPECTROSCOPY
MATERIALS
MECHANICAL STRUCTURES
METALS
MOBILITY
SCATTERING
SEMICONDUCTOR MATERIALS
SPECTRA
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K