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1

Three-Dimensional Simulations of the Anisotropic Etching Profile Evolution for Producing Nanoscale Devices

100%

Radjenović B., Radmilović-Radjenović M.

Acta Physica Polonica A

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2011

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vol. 119

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issue 3

447-450

EN

Refined control of etched profiles is one of the most important tasks of micro (nano) electro mechanical systems manufacturing process. In spite of its wide use, the simulation of etching for micro (nano) electro mechanical systems applications has been so far a partial success only, although a great number of commercial and academic research tools dedicated to this problem are developed. In this paper we describe an application of the sparse field method for solving level set equations in 3D anisotropic wet etching of silicon with potassium hydroxide (KOH). Angular dependence of the silicon etching rate is determined on the basis of the silicon crystal symmetry properties. Some examples illustrating developed methodology are given.

2

Detection of Shallow Dislocations on 4H-SiC Substrate by Etching Method

51%

Ishikawa Y., Yao Y., Sato K., Sugawara Y., Danno K., Suzuki H., Bessho T., Kawai Y., Shibata N.

Acta Physica Polonica A

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2011

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vol. 120

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issue 6A

A-25-A-27

EN

Correlation between dislocation types in epitaxial 4H-SiC and etch pit types on the 4H-SiC wafer surface were investigated by etch pit method and transmission electron microscope. Shallow dislocation on the wafer was found to form round pit without core. The shallow dislocation was estimated half-loop type in wafer and this estimation explains that step-flow growth converts half-loop dislocation into complex dislocation composed by threading dislocation and basal plane dislocation.

3

Revealing Prior-Austenite Grain Boundaries and Martensitic Structure of As-Quenched AISI 4140 Steel Treated by Plasma Electrolysis

51%

Cenk Kumruoglu L., Özel A.

Acta Physica Polonica A

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2013

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vol. 123

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issue 2

404-406

EN

The determination of prior-austenite grain size has been the subject of metallurgical research efforts for many years. Metallurgical laboratories are often required to perform prior-austenite grain size determinations on martensitic steel components that have been heat treated. Although these methods may occasionally be mandated by material or procedural specifications, they are typically not preferred because they have a tendency of altering the as-received microstructure. These processes can also be labour-intensive and costly. The goal of this work is to chemically etch and identify the prior austenite grain size and martensitic structure of AISI 4140 steel treated by plasma electrolysis. Polished samples were immersed in 60% HCl, 30% HNO_3, 5% HF, 5% H_2O for 5 seconds then immersed in 5% picric acid, 5% HCl, 90% ethanol to reveal microstructures. Finally, the grain boundary and lath martensitic structure were revealed.

4

Origin of Imperfections in ⟨100⟩ SrLaAlO_{4} Crystals

51%

Doerschel J., Hähnert I., Uecker R.

Acta Physica Polonica A

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1997

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vol. 92

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issue 1

157-162

EN

In Czochralski-grown SrLaAlO_{4} crystals with ⟨100⟩ orientation, (001) planar faults extending through the entire crystal boule can frequently be observed. Chemical etching and transmission electron microscopy including energy dispersive X-ray spectroscopy were used to characterise their nucleation sites, these being located in the upper part of the crystal cone. Three serious sources were found: (1) lateral {001} facets, (2) grown-in defects in the seed, and (3) small particles of a second phase in the interior of the cone. These particles were identified as trigonal and cubic form of lanthanum oxide with a different Sr content.

5

Silicon Etching in XeF_2 Environment

51%

Knizikevičius R.

Acta Physica Polonica A

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2013

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vol. 124

|

issue 1

137-140

EN

Enhancement of silicon etching rate in XeF_2 environment is considered by a proposed model, which includes processes of adsorption, activation, chemical reactions, relaxation, desorption, and sputtering. The enhancement of silicon etching rate is explained by considering hydrocarbon molecules from background gas contamination in the vacuum chamber, and assuming that hydrocarbon radicals enhance the etching rate. The composition of the adsorbed layer during silicon etching in XeF_2 environment is calculated. It is found that hydrocarbon radicals intensify reaction of XeF_2 molecules with Si atoms on the surface and that this changes the kinetics of the etching rate. Using the obtained theoretical results the difference in kinetics of the etching rates of first and subsequent run is explained.

6

Desorption Activation Energy of SiBr_2 Molecules according to Steady-State Approximation

51%

Knizikevičius R.

Acta Physica Polonica A

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2014

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vol. 125

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issue 5

1240-1243

EN

The chemical etching of intrinsic and n-type polycrystalline silicon in Br_2 ambient is considered. The theoretically calculated dependences of silicon etching rates on pressure of Br_2 molecules at different temperatures are compared with experimentally measured ones. The reaction and desorption activation energies are evaluated. It is found that activation energy of Si + Br_2 → SiBr_2 reaction for intrinsic silicon is equal to (1.82 ± 0.24) eV, and decreases to (1.45 ± 0.24) eV when n-type silicon films are used. Desorption activation energy of SiBr_2 molecules for intrinsic silicon is equal to (1.94 ± 0.17) eV, and decreases to (1.51 ± 0.17) eV when n-type silicon films are used. Desorption of SiBr_2 molecules is an etching-rate limiting process at high pressure of Br_2 molecules.

7

Micropatterning of Silicon Surface by Direct Laser Interference Lithography

51%

Lorens M., Zabila Y., Krupiński M., Perzanowski M., Suchanek K., Marszałek K., Marszałek M.

Acta Physica Polonica A

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2012

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vol. 121

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issue 2

543-545

EN

Direct laser interference lithography is a new and low cost technique which can generate the line- or dot-like periodic patterns over large areas. In the present work, we report on direct fabrication of micrometer structures on Si surface. In the experiments the pulsed high power Nd:YAG laser operating at 1064 nm wavelength was used. Two-beam configuration with an angle of incidence of 40° was employed and different laser fluences up to 2.11 J/cm^2 were tested. Areas about 1 cm in diameter have been processed with a single pulse of 10 ns. The laser treated samples were analyzed by atomic force microscopy to investigate the surface topography and to measure the size and depth of the achieved structures. We observed periodic line-like arrays with grating period of the order of 1 μm.

8

Formation of Excess Silicon on 6H-SiC(0001) during Hydrogen Etching

45%

Grodzicki M., Wasielewski R., Surma S., Ciszewski A.

Acta Physica Polonica A

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2009

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vol. 116

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issue S

S-82-S-85

EN

The surface of 6H-SiC(0001) samples was subjected to etching under H_{2}/Ar gas mixture in a cold-wall tubular furnace. Its topography and properties were characterized by atomic force microscopy and X-ray photoelectron spectroscopy before and after hydrogen etching. The conditions have been found, under which surface polishing-related damages could be removed. Si droplets were observed under certain etching conditions. The effect of the samples' cooling rate on the obtained surface morphology and chemistry was investigated to unveil the mechanism of Si recrystallization onto the crystal surface upon etching.

9

Nanoscale Pattern Definition by Edge Oxidation of Silicon under the Si_{3}N_{4} mask - PaDEOx

45%

Zaborowski M., Grabiec P., Dobrowolski R., Panas A., Skwara K., Szmigiel D., Wzorek M.

Acta Physica Polonica A

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2009

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vol. 116

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issue S

S-139-S-141

EN

Well-controlled method of Si nanopattern definition - pattern definition by edge oxidation have been presented. The technique is suitable for fabrication of narrow paths of width ranged from several tens of nm to several μm by means of photolithography equipment working with μm-scale design rules. Process details influencing a shape of the Si pattern have been discussed. SEM examinations have been presented.

10

Atomic Force Microscopy and Quartz Crystal Microbalance Study of the Lectin-Carbohydrate Interaction Kinetics

38%

Lebed K., Kulik A., Forró L., Lekka M.

Acta Physica Polonica A

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2007

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vol. 111

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issue 2

273-286

EN

Two analytical methods, atomic force microscopy and quartz crystal microbalance, were applied to the study of the reaction kinetics occurring between concanavalin A and carboxypeptidase Y, presenting the specific lectin-carbohydrate recognition. The dissociation rate constants for concanavalin A-carboxypeptidase Y complex obtained using both atomic force microscopy and quartz crystal microbalance were of the same order of magnitude: k_{diss}=0.170± 0.060 s^{-1} and k_{diss}=0.095±0.002 s^{-1}, respectively. In addition, each method alone aided in determining other parameters characterizing the studied interaction. Quartz crystal microbalance permitted us to estimate the association rate (k_{ass}=(5.6 ±0.1)×10^4 M^{-1} s^{-1}) and the equilibrium (K_a=(0.59×0.01)×10^6 M^{-1}) constants for the binding process occurring between concanavalin A and mannose residues of carboxypeptidase Y under given experimental conditions. Atomic force microscopy in force spectroscopy mode enabled the determination of the energy barrier position of r=2.29±0.04 Å characterizing the dissociation of concanavalin A- carboxypeptidase Y molecular complex. The presented results show that both atomic force microscopy and quartz crystal microbalance can be used to determine quantitative parameters characterizing the specific molecular interaction. Both methods can be easily combined for complementary and/or alternative studies of a chosen molecular interaction. By preparing the samples in the same manner the direct comparison between the data obtained via atomic force microscopy and quartz crystal microbalance can be made.

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Three-Dimensional Simulations of the Anisotropic Etching Profile Evolution for Producing Nanoscale Devices

Detection of Shallow Dislocations on 4H-SiC Substrate by Etching Method

Revealing Prior-Austenite Grain Boundaries and Martensitic Structure of As-Quenched AISI 4140 Steel Treated by Plasma Electrolysis

Origin of Imperfections in ⟨100⟩ SrLaAlO_{4} Crystals

Silicon Etching in XeF_2 Environment

Desorption Activation Energy of SiBr_2 Molecules according to Steady-State Approximation

Micropatterning of Silicon Surface by Direct Laser Interference Lithography

Formation of Excess Silicon on 6H-SiC(0001) during Hydrogen Etching

Nanoscale Pattern Definition by Edge Oxidation of Silicon under the Si_{3}N_{4} mask - PaDEOx

Atomic Force Microscopy and Quartz Crystal Microbalance Study of the Lectin-Carbohydrate Interaction Kinetics