CALCULATION OF SURFACE AREAS FOR POROUS SILICON

1999 ◽  
Vol 13 (28) ◽  
pp. 1005-1009
Author(s):  
Q. R. HOU ◽  
N. CHI
Keyword(s):  
Atomic Force Microscopy ◽  
Simple Model ◽  
Porous Silicon ◽  
Surface Area ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Photoluminescence Intensity ◽  
Force Microscopy ◽  
Surface Areas ◽  
Atomic Force

Based on atomic force microscopy (AFM) images of porous silicon, a simple model has been proposed to calculate the surface areas of porous silicon. In this model, the porous silicon layer is assumed to be made of numerous identical cones with radius r and height h. The surface area changes due to the formation of porous silicon are found to be dependent on (h/r)2 and correlate with the growth of photoluminescence (PL) intensities. The rise and fall in photoluminescence intensity coincide with those of surface area changes qualitatively. This coincidence supports the hypothesis that the luminescence results from the presence of surface-localized or confined molecular emitters.

I-V and Surface Topography Study of Nanostructure Porous Silicon Layer Prepared by Electrochemical Etching

2012 ◽  
Vol 576 ◽  
pp. 519-522 ◽  
Author(s):  
Fadzilah Suhaimi Husairi ◽  
Maslihan Ain Zubaidah ◽  
Shamsul Faez M. Yusop ◽  
Rusop Mahmood Mohamad ◽  
Saifolah Abdullah
Keyword(s):  
Electrical Properties ◽  
Porous Silicon ◽  
Surface Topography ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Voltage ◽  
P Type

This article reports on the electrical properties of porous silicon nanostructures (PSiNs) in term of its surface topography. In this study, the PsiNs samples were prepared by using different current density during the electrochemical etching of p-type silicon wafer. PSiNs has been investigated its electrical properties and resistances for different surface topography of PSiNs via current-voltage (I-V) measurement system (Keithley 2400) while its physical structural properties was investigated by using atomic force microscopy (AFM-XE100).

scholarly journals The Effect of Etching Time On Structural Properties of Porous Quaternary AlInGaN Thin Films

2021 ◽  
Vol 19 (50) ◽  
pp. 77-83
Author(s):  
Ghasaq Ali Tomaa ◽  
Alaa Jabbar Ghazai
Keyword(s):  
Porous Silicon ◽  
Crystal Size ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
Etching Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Homogeneous Pattern

Using photo electrochemical etching technique (PEC), porous silicon (PS) layers were produced on n-type silicon (Si) wafers to generate porous silicon for n-type with an orientation of (111) The results of etching time were investigated at: (5,10,15 min). X-ray diffraction experiments revealed differences between the surface of the sample sheet and the synthesized porous silicon. The largest crystal size is (30 nm) and the lowest crystal size is (28.6 nm) The analysis of Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM) were used to research the morphology of porous silicon layer. As etching time increased, AFM findings showed that root mean square (RMS) of roughness and porous silicon grain size decreased and FESEM showed a homogeneous pattern and verified the formation of uniform porous silicon.

STUDY OF POROUS SILICON SURFACE PROPERTIES

1996 ◽  
Vol 03 (02) ◽  
pp. 1235-1239
Author(s):  
K. W. CHEAH ◽  
T. Y. LEUNG ◽  
M. H. CHAN ◽  
S. K. SO
Keyword(s):  
Porous Silicon ◽  
Surface States ◽  
Silicon Layer ◽  
Structural Difference ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
Free Standing ◽  
Force Microscopy ◽  
Photothermal Deflection Spectroscopy ◽  
Atomic Force

Porous silicon is a material with a coral-like structure which has a fractal surface. To study these aspects of porous silicon and its relationship with the luminescence property, we have used atomic force microscopy (AFM). Samples were prepared using either pure HF or HF diluted with ethanol. From the results of AFM, distinct structural difference was observed from samples prepared by these two etchants. If we relate the structures to their respective photoluminescence spectra, it appears that finer structure produced shorter wavelength peak photoluminescence. However, the columns of the samples were too large for one to attribute the luminescence to quantum confinement only. Hence, an alternative model may be required to explain the luminescence mechanism. We have also observed that the composition of the etchant can also affect the evolution of the fractal dimension with respect to etching time. Probing of the surfcace electron states was performed using photothermal deflection spectroscopy (PDS). In order to ensure that only porous silicon layer was probed, free-standing films of various porosity were produced for the PDS measurement. The probe energy range was from 0.56 eV to 2.5 eV so that both the bulk states and the surface states were probed. The results showed that there is a clear blueshift of the energy band gap with respect to porosity, and the absorption coefficient decreases with porosity increase at a fixed photon energy. Overtones of hydrides and fluorides of silicon were also observed.

scholarly journals Effect of SnS Thin Film on the Performance of Porous Silicon Photodiode

2016 ◽  
Vol 63 ◽  
pp. 67-76 ◽  
Author(s):  
Ahmed N. Abd ◽  
Wasna'a M. Abdulridha ◽  
Mohammed Odda Dawood
Keyword(s):  
Thin Film ◽  
Porous Silicon ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
X Ray Diffraction ◽  
Silicon Photodiode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Evaporation Technique

In this study, Al/SnS/PS/n-Si/Al photodiode was fabricated and investigated. SnS thin film were prepared by thermal evaporation technique on porous silicon layer which prepared by anodization technique at 32mA/cm2 etching current density and etching time 15min.The characteristics of porous silicon and SnS were investigated by using x-ray diffraction XRD, atomic force microscopy AFM, Fourier transformation infrared spectroscopy FT-IR.Dark and illuminated current-voltage I-V characteristics, spectral responsivity, specific detectivity of photodiode were investigated after depositing. Significant improvement in photosensitivity and detectivity of porous silicon photodiode after SnS deposition on porous silicon was noticed.

Scaling Analysis of a- and poly-Si Surface Roughness by Atomic Force Microscopy

1994 ◽  
Vol 367 ◽  
Author(s):  
T. Yoshinobu ◽  
A. Iwamoto ◽  
K. Sudoh ◽  
H. Iwasaki
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Surface Area ◽  
Scaling Behavior ◽  
Linear Size ◽  
Scaling Analysis ◽  
Macroscopic Scale ◽  
Force Microscopy ◽  
Atomic Force ◽  
Roughness Exponent

AbstractThe scaling behavior of the surface roughness of a-and poly-Si deposited on Si was investigated by atomic force microscopy (AFM). The interface width W(L), defined as the rms roughness as a function of the linear size of the surface area, was calculated from various sizes of AFM images. W(L) increased as a power of L with the roughness exponent ∝ on shorter length scales, and saturated at a constant value of on a macroscopic scale. The value of roughness exponent a was 0.48 and 0.90 for a-and poly-Si, respectively, and σ was 1.5 and 13.6nm for 350nm-thick a-Si and 500nm-thick poly-Si, respectively. The AFM images were compared with the surfaces generated by simulation.

scholarly journals Particle Adhesion Measurements on Insect Wing Membranes Using Atomic Force Microscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Gregory S. Watson ◽  
Bronwen W. Cribb ◽  
Jolanta A. Watson
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Area ◽  
Wing Surface ◽  
Silica Spheres ◽  
Wing Membrane ◽  
Insect Wing ◽  
Force Microscopy ◽  
Plant Matter ◽  
Atomic Force ◽  
Eurema Hecabe

Many insects have evolved refined self-cleaning membrane structuring to contend with an environment that presents a range of potential contaminates. Contamination has the potential to reduce or interfere with the primary functioning of the wing membrane or affect other wing cuticle properties, (for example, antireflection). Insects will typically encounter a variety of air-borne contaminants which include plant matter and soil fragments. Insects with relatively long or large wings may be especially susceptible to fouling due to the high-wing surface area and reduced ability to clean their extremities. In this study we have investigated the adhesion of particles (pollens and hydrophilic silica spheres) to wing membranes of the super/hydrophobic cicada (Thopha sessiliba), butterfly (Eurema hecabe), and the hydrophilic wing of flower wasp (Scolia soror). The adhesional forces with both hydrophobic insects was significantly lower for all particle types than the hydrophilic insect species studied.

Non Destructive Determination of the Threading Dislocation Density of Smooth Simox Substrates using Atomic Force Microscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 1088-1089
Author(s):  
A. Domenicucci ◽  
R. Murphy ◽  
D. Sadanna ◽  
S. Klepeis
Keyword(s):  
Atomic Force Microscopy ◽  
High Temperature ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
High Dose ◽  
Threading Dislocation ◽  
Crystal Silicon ◽  
Force Microscopy ◽  
Atomic Force ◽  
High Temperature Anneal

Atomic force microscopy (AFM) has been used extensively in recent years to study the topographic nature of surfaces in the nanometer range. Its high resolution and ability to be automated have made it an indispensable tool in semiconductor fabrication. Traditionally, AFM has been used to monitor the surface roughness of substrates fabricated by separation by implanted oxygen (SIMOX) processes. It was during such monitoring that a novel use of AFM was uncovered.A SIMOX process requires two basic steps - a high dose oxygen ion implantation (1017 to 1018 cm-3) followed by a high temperature anneal (>1200°C). The result of these processes is to form a buried oxide layer which isolates a top single crystal silicon layer from the underlying substrate. Pairs of threading dislocations can form in the top silicon layer during the high temperature anneal as a result of damage caused during the high dose oxygen implant.

Sign in / Sign up

Export Citation Format

Share Document