X-ray Reflectivity Study of Porous Silicon Formation

1998 ◽  
Vol 536 ◽  
Author(s):  
V. Chamard ◽  
G. Dolino ◽  
J. Eymery
Keyword(s):  
Porous Silicon ◽  
Surface Porosity ◽  
X Ray ◽  
X Ray Scattering ◽  
Specular Reflectivity ◽  
Nanoporous Layer ◽  
Ray Scattering

AbstractX-ray reflectometry is used to study the first stages of formation of thin n-type porous silicon layers. Results on classical n−-type porous silicon prepared under illumination are first reported. Then, the effect of the illumination during the formation is observed by comparing n+/− - type samples prepared in darkness or under illumination. X-ray specular reflectivity measurements allow to observe an increase of the surface porosity even for the short formation times and a macroporous layer under the nanoporous layer is also identified for illuminated samples. The presence of a crater at the top of the layer is observed by profilometer measurements, especially in the case of illuminated samples. Specular and diffuse x-ray scattering results show important effects of light during the porous silicon formation.

X-ray scattering profiles: revealing the porosity gradient in porous silicon

2021 ◽  
Vol 54 (3) ◽  
Author(s):  
Cosmin Romanitan ◽  
Pericle Varasteanu ◽  
Daniela C. Culita ◽  
Alexandru Bujor ◽  
Oana Tutunaru
Keyword(s):  
Porous Silicon ◽  
Strong Dependence ◽  
Total External Reflection ◽  
Surface Porosity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Porous Layers ◽  
X Ray Scattering ◽  
The Mean ◽  
Ray Scattering

Porous silicon layers with different porosities were prepared by adjusting the anodization current density of the electrochemical etching process, starting from highly doped p-type crystalline silicon wafers. The microstructural parameters of the porous layers were assessed by high-resolution X-ray diffraction, total external reflection, scanning electron microscopy and nitrogen adsorption–desorption analysis. Furthermore, both the surface porosity and the mean porosity for the entire volume of the samples were estimated by employing total external reflection measurements and X-ray reciprocal-space mapping, respectively. The results clearly indicate that the surface porosity is different from the mean porosity, and the presence of a depth porosity gradient is suggested. To evaluate the porosity gradient in a nondestructive way, a new laboratory method using the grazing-incidence X-ray diffraction technique is reported. It is based on the analysis of the X-ray scattering profiles of the porous layers to obtain the static Debye–Waller factors. In this way, a description of the porosity gradient in a quantitative framework becomes possible, and, as a result, it was shown that the porosity increases exponentially with the X-ray penetration depth. Moreover, a strong dependence between the porosity gradient and the anodization current was demonstrated. Thus, in the case of the lowest anodization current (e.g. 50 mA cm−2) a variation of only 15% of the porosity from the surface to the interface is found, but when applying a high anodization current of 110 mA cm−2 the porosity close to the bulk interface is almost three times higher than at the surface.

Influence of the doping level on the microstructure of P-type porous silicon studied by small-angle X-ray scattering

1991 ◽  
Vol 24 (5) ◽  
pp. 581-587 ◽  
Author(s):  
V. Vezin ◽  
Ph. Goudeau ◽  
A. Naudon ◽  
A. Herino ◽  
G. Bomchil
Keyword(s):  
Porous Silicon ◽  
Small Angle ◽  
Doping Level ◽  
X Ray ◽  
X Ray Scattering ◽  
P Type ◽  
Ray Scattering

Diffuse x‐ray scattering fromp+porous silicon by triple axis diffractometry

1994 ◽  
Vol 65 (12) ◽  
pp. 1504-1506 ◽  
Author(s):  
E. Koppensteiner ◽  
A. Schuh ◽  
G. Bauer ◽  
V. Holy ◽  
D. Bellet ◽  
...  
Keyword(s):  
Porous Silicon ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Studies of coherent and diffuse x‐ray scattering by porous silicon

1992 ◽  
Vol 71 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Daniel Bellet ◽  
Gérard Dolino ◽  
Mireille Ligeon ◽  
Pierre Blanc ◽  
Michäel Krisch
Keyword(s):  
Porous Silicon ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Structure and correlations in porous silicon studied by X-ray scattering methods

1996 ◽  
Vol 100 (1) ◽  
pp. 13-16 ◽  
Author(s):  
M. Binder ◽  
T. Edelmann ◽  
T.H. Metzger ◽  
J. Peisl
Keyword(s):  
Porous Silicon ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Small-angle X-ray scattering study of the microstructure of highly porous silicon

1993 ◽  
Vol 03 (C8) ◽  
pp. C8-349-C8-352
Author(s):  
A. NAUDON ◽  
Ph. GOUDEAU ◽  
A. HALIMAOUI ◽  
G. BOMCHIL
Keyword(s):  
Porous Silicon ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Highly Porous ◽  
Ray Scattering

X-ray scattering by porous silicon modulated structures

2012 ◽  
Vol 57 (2) ◽  
pp. 185-192 ◽  
Author(s):  
A. A. Lomov ◽  
V. I. Punegov ◽  
V. A. Karavanskii ◽  
A. L. Vasil’ev
Keyword(s):  
Porous Silicon ◽  
X Ray ◽  
X Ray Scattering ◽  
Modulated Structures ◽  
Ray Scattering

Small-Angle X-Ray Scattering from Light Emitting Porous Silicon and Siloxene

1992 ◽  
Vol 283 ◽  
Author(s):  
H. Franz ◽  
V. Petrova-Koch ◽  
T. Muschik ◽  
V. Lehmann ◽  
J. Peisl
Keyword(s):  
Porous Silicon ◽  
Shape Analysis ◽  
Small Angle ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

ABSTRACTWe studied the microstructure of two types of light emitting porous silicon (PS), as-etched and rapid thermal oxidized and of material prepared according to the siloxene recipe by Small-Angle X-Ray Scattering (SAXS). In all three types of samples we found particles with nanometer dimensions. The average particle size in as-etched PS is ingood agreement with results achieved by TEM and X-ray diffraction. Shape analysis shows, that the PS skeleton consists of cylindrical shaped particles with an average heigth of 20Å and a diameter of 40 Å.

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