External Gettering Comparison and Structural Characterization of Single and Polycrystalline Silicon

1995 ◽  
Vol 378 ◽  
Author(s):  
Henry Hieslmair ◽  
Scott McHugo ◽  
Eicke Weber

AbstractVarious silicon samples, both single and polycrystalline, were intentionally contaminated and externally gettered using phosphorus, aluminum and co- phosphorus/aluminum gettering. Gettering efficiencies were quantified via diffusion length improvements. Structural characterization was used to correlate defects with low gettering efficiencies. External gettering was found to be particularly effective at recovering diffusion length in large grain polycrystalline silicon and solar grade single crystal silicon despite Fe contamination and high defect densities. One of two explanations is possible, 1) the structural defects are initially undecorated and are completely gettered after Fe contamination, or 2) metal decoration on as-grown structural defects are structurally and/or chemically different from intentional Fe decoration.

Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.


1981 ◽  
Vol 4 ◽  
Author(s):  
Rajiv R. Shah ◽  
Robert Mays ◽  
D. Lloyd Crosthwait

ABSTRACTWe report an investigation of the effects of laser processing on the thermal oxides of polysilicon. LPCVD polysilicon, 500 nm thick, deposited on 500 nm thermal oxide of single crystal silicon was laser processed at various stages in the process sequence for device fabrication. Effects of CW Ar+ and pulsed 1.06 and 0.53 μm laser processing were investigated. Laser annealed polysilicon was oxidized in a steam ambient. Using a second level of polysilicon, guard ring diode and capacitors were fabricated. Electrical characterization revealed an improvement in breakdown field strengths of these oxides without deleterious effects on any of the associated interfaces.


2021 ◽  
Author(s):  
Lianmin Yin ◽  
Yifan Dai ◽  
Hao Hu

Abstract In order to obtain ultra-smooth surfaces of single-crystal silicon in ultra-precision machining, an accurate study of the deformation mechanism, mechanical properties, and the effect of oxide film under load is required. The mechanical properties of single-crystal silicon and the phase transition after nanoindentation experiments are investigated by nanoindentation and Raman spectroscopy, respectively. It is found that pop-in events appear in the theoretical elastic domain of single-crystal silicon due to the presence of oxide films, which directly leads the single crystal silicon from the elastic deformation zone into the plastic deformation zone. In addition, the mechanical properties of single-crystal silicon are more accurately measured after it has entered the full plastic deformation.


2004 ◽  
Vol 443-444 ◽  
pp. 83-86
Author(s):  
Giovanni Berti ◽  
U. Bartoli ◽  
G. Basile ◽  
P. Becker ◽  
Andrew N. Fitch

Three blocks of silicon have been crashed in this experiment in order to verify the crashing effects on specimens having distinct original micro-structural arrangements. One of them comes from a rod bar of mono-crystal silicon, two others were from polycrystalline silicon manufactured by two distinct manufacturers with distinct growing process. Several specimens of powders, differing in type and grain size, were obtained by treating these source samples. This paper reports on data collected from synchrotron and conventional radiation and the results show that powders obtained from mono-crystalline silicon provide diffraction profiles, where the structural contribution is smaller than for polycrystalline silicon specimens. The peaks from the 'mono-crystal powder' resulted even narrower than peaks from SRM Silicon 640b by NIST.


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