scholarly journals Etching of Uncompensated Convex Corners with Sides along and in 25 wt% TMAH at 80 °C

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 253 ◽  
Author(s):  
Milče M. Smiljanić ◽  
Žarko Lazić ◽  
Vesna Jović ◽  
Branislav Radjenović ◽  
Marija Radmilović-Radjenović
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Water Solution ◽  
Wet Etching ◽  
Tetramethylammonium Hydroxide ◽  
Convex Corner ◽  
Crystallographic Planes ◽  
Good Agreement

This paper presents etching of convex corners with sides along <n10> and <100> crystallographic directions in a 25 wt% tetramethylammonium hydroxide (TMAH) water solution at 80 °C. We analyzed parallelograms as the mask patterns for anisotropic wet etching of Si (100). The sides of the parallelograms were designed along <n10> and <100> crystallographic directions (1 < n < 8). The acute corners of islands in the masking layer formed by <n10> and <100> crystallographic directions were smaller than 45°. All the crystallographic planes that appeared during etching in the experiment were determined. We found that the obtained types of 3D silicon shape sustain when n > 2. The convex corners were not distorted during etching. Therefore, no convex corner compensation is necessary. We fabricated three matrices of parallelograms with sides along crystallographic directions <310> and <100> as examples for possible applications. Additionally, the etching of matrices was simulated by the level set method. We obtained a good agreement between experiments and simulations.

scholarly journals Evolution of Si Crystallographic Planes-Etching of Square and Circle Patterns in 25 wt % TMAH

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 102 ◽  
Author(s):  
Milče Smiljanić ◽  
Žarko Lazić ◽  
Branislav Radjenović ◽  
Marija Radmilović-Radjenović ◽  
Vesna Jović
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Silicon Substrate ◽  
Water Solution ◽  
Three Dimensional ◽  
Silicon Etching ◽  
3D Simulations ◽  
Circle Patterns ◽  
Crystallographic Planes ◽  
Good Agreement

Squares and circles are basic patterns for most mask designs of silicon microdevices. Evolution of etched Si crystallographic planes defined by square and circle patterns in the masking layer is presented and analyzed in this paper. The sides of square patterns in the masking layer are designed along predetermined <n10> crystallographic directions. Etching of a (100) silicon substrate is performed in 25 wt % tetramethylammonium hydroxide (TMAH) water solution at the temperature of 80 °C. Additionally, this paper presents three-dimensional (3D) simulations of the profile evolution during silicon etching of designed patterns based on the level-set method. We analyzed etching of designed patterns in the shape of square and circle islands. The crystallographic planes that appear during etching of 3D structures in the experiment and simulated etching profiles are determined. A good agreement between dominant crystallographic planes through experiments and simulations is obtained. The etch rates of dominant exposed crystallographic planes are also analytically calculated.

scholarly journals Controllable arrangement of integrated obstacles in silicon microchannels etched in 25 wt.% TMAX

2021 ◽  
Vol 75 (1) ◽  
pp. 15-24
Author(s):  
Milce Smiljanic ◽  
Branislav Radjenovic ◽  
Zarko Lazic ◽  
Marija Radmilovic-Radjenovic ◽  
Milena Rasljic-Rafajilovic ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Level Set Method ◽  
Level Set ◽  
Cost Effective ◽  
Tetramethylammonium Hydroxide ◽  
Experimental Results ◽  
Etching Technique ◽  
Paper Fabrication ◽  
Analytical Relations ◽  
Good Agreement

In this paper, fabrication of silicon microchannels with integrated obstacles by using 25 wt.% tetramethylammonium hydroxide (TMAH) aqueous solution at the temperature of 80?C is presented and analysed. We studied basic island patterns, which present union of two symmetrical parallelograms with the sides along predetermined crystallographic directions <n10> (2<n<8) and <100>. Acute angles of the parallelograms were smaller than 45?. We have derived analytical relations for determining dimensions of the integrated obstacles. The developed etching technique provides reduction of the distance between the obstacles. Before the experiments, we performed simulations of pattern etching based on the level set method and presented evolution of the etched basic patterns for the predetermined crystallographic directions <n10>. Combination of basic patterns with sides along the <610> and <100> crystallographic directions is used to fabricate a matrix of two row of silicon obstacles in a microchannel. We obtained a good agreement between the experimental results and simulations. Our results enable simple and cost-effective fabrication of various complex microfluidic silicon platforms with integrated obstacles.

scholarly journals The Level-Set Method for Multi-Material Wet Etching and Non-Planar Selective Epitaxy

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 115406-115422
Author(s):  
Alexander Toifl ◽  
Michael Quell ◽  
Xaver Klemenschits ◽  
Paul Manstetten ◽  
Andreas Hossinger ◽  
...  
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Wet Etching ◽  
Selective Epitaxy

Computation of a Propagating Interface in Multiphase Flows Using an Adaptive Coupled Level Set Method

2002 ◽  
Author(s):  
Ruquan Liang ◽  
Satoru Komori
Keyword(s):  
Surface Tension ◽  
Level Set Method ◽  
Level Set ◽  
Multiphase Flows ◽  
Surface Tension Force ◽  
Numerical Results ◽  
Passive Transport ◽  
Effect Of Surface ◽  
Good Agreement ◽  
Numerical Strategy

We present a numerical strategy for a propagating interface in multiphase flows using a level set method combined with a local mesh adaptative technique. We use the level set method to move the propagating interface in multiphase flows. We also use the local mesh adaptative technique to increase the grid resolution at regions near the propagating interface and additionally at the regions near points of high curvature with a minimum of additional expense. For illustration, we apply the adaptive coupled level set method to a collection of bubbles moving under passive transport. Good agreement has been obtained in the comparision of the numerical results for the collection of bubbles using an adaptative grid with those using a single grid. We also apply the adaptive coupled level set method to a droplet falling on a step where it is important to accurately model the effect of surface tension force and the motion of the free-surface, and the numerical results agree very closely with available data.

scholarly journals A description of crevasse formation using continuum damage mechanics

2003 ◽  
Vol 37 ◽  
pp. 77-82 ◽  
Author(s):  
Antoine Pralong ◽  
Martin Funk ◽  
Martin P. Lüthi
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Interface Motion ◽  
Glacier Surface ◽  
Polycrystalline Ice ◽  
Isotropic Damage ◽  
Good Agreement

AbstractContinuum damage mechanics describes the progressive deterioration of material subjected to loading. Jointly used with a level-set method, it proves to be a promising approach to computing the interface motion of a damaged material. For polycrystalline ice, a local isotropic damage evolution law (generalized Kachanow’s law) applied to Glen’s flow law allows the description of tertiary creep and facilitates the modeling of crevasse opening using a failure criterion based on damage accumulation. The use of a level-set method permits the description, in a continuum approach, of the motion of a fractured glacier surface. Using these methods, a model is developed. The ability of this model to describe phenomena connected to crevasse opening is presented. The rupture of a large ice block from a hanging glacier is computed and analyzed. The regular acceleration of such an unstable ice block prior to its collapse is calculated and compared to the acceleration function obtained from observations. A good agreement between the two acceleration functions was found.

Numerical Simulation of Film Boiling Near Critical Pressures With a Level Set Method

1998 ◽  
Vol 120 (1) ◽  
pp. 183-192 ◽  
Author(s):  
G. Son ◽  
V. K. Dhir
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Level Set Method ◽  
Level Set ◽  
Vapor Phase ◽  
Film Boiling ◽  
Release Pattern ◽  
Wall Superheat ◽  
Change Effect ◽  
Good Agreement

Attempts have recently been made to numerically simulate film boiling on a horizontal surface. It has been observed from experiments and numerical simulations that during film boiling the bubbles are released alternatively at the nodes and antinodes of a Taylor wave. Near the critical state, however, hydrodynamic transition in bubble release pattern has been reported in the literature. The purpose of this work is to understand the mechanism of the transition in bubble release pattern through complete numerical simulation of the evolution of the vapor-liquid interface. The interface is captured by a level set method which is modified to include the liquid-vapor phase change effect. It is found from the numerical simulation that at low wall superheats the interface moves upwards, bubbles break off, and the interface drops down alternatively at the nodes and antinodes. However, with an increase in wall superheat, stable vapor jets are formed on both the nodes and antinodes and bubbles are released from the top of the vapor columns. The numerical results are compared with the experimental data, and visual observations reported in the literature are found to be in good agreement with the data.

scholarly journals Implementation and evaluation of the Level Set method: Towards efficient and accurate simulation of wet etching for microengineering applications

2013 ◽  
Vol 184 (10) ◽  
pp. 2299-2309 ◽  
Author(s):  
C. Montoliu ◽  
N. Ferrando ◽  
M.A. Gosálvez ◽  
J. Cerdá ◽  
R.J. Colom
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Wet Etching

scholarly journals Application of the level set method on the non-convex Hamiltonians

2009 ◽  
Vol 7 (1) ◽  
pp. 33-44
Author(s):  
B. Radjenovic ◽  
M. Radmilovic-Radjenovic ◽  
M. Mitric
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Etching Rate ◽  
Three Dimensional ◽  
Field Method ◽  
Rate Function ◽  
Wet Etching ◽  
Silicon Etching ◽  
Symmetry Properties ◽  
Interpolation Technique

Application of the level set method extended for the case of non-convex Hamiltonians is illustrated by the three dimensional (3D) simulation results of the profile evolution during anisotropic wet etching of silicon. Etching rate function is modeled on the basis of the silicon symmetry properties, by means of the interpolation technique using experimentally obtained values of the principal [100], [110], [111], and high index [311] directions in KOH solutions. The resulting level set equations are solved using an open source implementation of the sparse field method.

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