Reduction of phosphorus diffusion in germanium by fluorine implantation

Journal Article · Sat Dec 14 00:00:00 EST 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4847555· OSTI ID:22217777

El Mubarek, H. A. W. ^[1]

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1. School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom)

The control of phosphorus (P) diffusion in germanium (Ge) is essential for the realisation of ultrashallow n-type junctions in Ge. This work reports a detailed study of the effect of fluorine (F) co-implantation on P diffusion in Ge. P and F profiles were characterized by secondary ion mass spectroscopy. The ion implantation damage was investigated using cross sectional transmission electron microscopy. It is shown that F co-implantation reduces the implanted P profile width and reduces both intrinsic and extrinsic P diffusion in Ge. A defect mediated mechanism for the strong influence of F co-implantation on P diffusion in Ge is proposed and invokes the formation of F{sub n}V{sub m} clusters in the F-amorphized Ge layer. A fraction of these F{sub n}V{sub m} clusters decorate the interstitial type end-of-range defects in the re-grown Ge layer and the rest react during re-growth with interstitial germanium atoms diffusing back from the amorphous crystalline interface. The Ge vacancies are then annihilated and mobile interstitial F is released and out diffuses from the surface. This results in a re-grown Ge layer which has a low vacancy concentration and in which the P diffusion rate is reduced. These results open the way to the realization of enhanced Ge n-type devices.

• OSTI ID: 22217777
• Journal Information: Journal of Applied Physics, Vol. 114, Issue 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DIFFUSION
ELECTRIC CONTACTS
FLUORINE
GERMANIUM
INTERSTITIALS
ION IMPLANTATION
ION MICROPROBE ANALYSIS
MASS SPECTRA
MASS SPECTROSCOPY
PHOSPHORUS
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS
TRANSMISSION ELECTRON MICROSCOPY
VACANCIES