Surface Segregation and Electrical Studies of Heavily Arsenic and Phosphorus in situ Doped Epi and Poly Silicon

ABSTRACTWe have studied the deposition of GexSi1−x layers on (100) Si substrates by gas source molecular beam epitaxy (GSMBE) using disilane and germane.The investigation of RHEED intensity oscillations during growth reveals the well known rate enhancement obtained when adding a small amount of germane to the disilane flux. However, when exposing a previously deposited Ge layer to a pure disilane flux the growth rate during the first few monolayers remains at an enhanced value but returns to its homoepitaxial value after about 10 to 15 monolayers. This behaviour was observed under a variety of growth conditions. It is in marked contrast to the experience obtained in conventional Si/Ge MBE and suggests a catalytic effect of the particular surface present during GSMBE growth. We propose that this effect is caused by the surface segregation of Ge species and leads to a smear-out of the Ge profile in the layer.

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Monitoring Arsenic In-Situ Doping with Advanced Models for Poly-Silicon CVD

Simulation of Semiconductor Processes and Devices 2001 ◽

10.1007/978-3-7091-6244-6_27 ◽

2001 ◽

pp. 124-127 ◽

Cited By ~ 2

Author(s):

W. Pyka ◽

C. Heitzinger ◽

N. Tamaoki ◽

T. Takase ◽

T. Ohmine ◽

...

Keyword(s):

Poly Silicon

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Study Of Al Surface Segregation In Icosahedral A162Cu25.5Fe12.5

MRS Proceedings ◽

10.1557/proc-553-75 ◽

1998 ◽

Vol 553 ◽

Cited By ~ 8

Author(s):

M. GIL-GAVATZ ◽

D. Rouxel ◽

P. Pigeat ◽

B. Weber ◽

J.-M. Dubois

Keyword(s):

Surface Segregation ◽

Vacuum Chamber ◽

High Vacuum ◽

Ultra High Vacuum ◽

Electron Spectrometer ◽

Temperature Dependent ◽

Self Diffusion ◽

Different Temperatures ◽

High Vacuum Chamber

AbstractSurface segregation of aluminium was observed during oxidation experiments of icosahedral A162Cu25.5 Fel12.5, performed in-situ and at different temperatures in the ultra-high vacuum chamber of a scanning Auger electron spectrometer. Two regimes, below and above 770K, were observed in relation with severe segregation of Al atoms at the surface for T > 770K. We postulate that this temperature dependent segregation rate is representative of the aluminium transport towards the surface of the quasicrystal. By analogy with classical diffusion experiments, we can thus determine reasonable estimates of the activation energy for Al self-diffusion in this quasicrystal. The results are consistent with the existence of phason flips below 770K and thermal vacancies above this temperature.

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