Wet Etching Technique to Reduce Pyramidal Hillocks for Anisotropic Silicon Etching in NaOH/IPA Solution

2015 ◽  
Vol 659 ◽  
pp. 681-685
Author(s):  
Chu Pong Pakpum
Keyword(s):  
Etch Rate ◽  
Wet Etching ◽  
High Yield ◽  
Solution Temperature ◽  
Silicon Etching ◽  
Etching Technique ◽  
Ultrasonic Agitation ◽  
The Difference ◽  
Etched Surface ◽  
Anisotropic Silicon Etching

The various methods of silicon wet etching techniques, which utilize ultrasonic agitation to reduce pyramidal hillocks in etched patterns, were evaluated in NaOH+IPA solution. The comparison of the etching methods composed of; 1.) no agitation + sample horizontally orientated, 2.) ultrasonic agitation + sample horizontally orientated, 3.) ultrasonic agitation + sample vertically orientated, and 4.) ultrasonic with rotation agitation + sample vertically orientated. It was found that the percentages of the etched patterns presenting hillocks after etching were 100%, 79.77%, 32.67% and 2.62%, respectively. Ultrasonic coupled with rotation agitation along with the sample vertically orientated is the most powerful etching technique, offering a high yield of smooth etched surface. The difference in etch rate between without agitation and applying ultrasonic agitation was not observed in this experiment, as it was operated in a solution temperature 60-65°C and a 275nm/min etch rate was achieved. The theories that relate to each evaluated method are also discussed.

Feasibility to Fabricate the 45° Slant with Anisotropic Silicon Etching in NaOH Solution

2012 ◽  
Vol 503-504 ◽  
pp. 615-619 ◽  
Author(s):  
Alonggot Limcharoen ◽  
Chupong Pakpum ◽  
Pichet Limsuwan
Keyword(s):  
Data Storage ◽  
Etch Rate ◽  
Silicon Etching ◽  
Naoh Solution ◽  
Conventional Photolithography ◽  
Sio2 Mask ◽  
P Type ◽  
Anisotropic Silicon Etching ◽  
Wet Etch ◽  
Laser Light Source

The experiments to study the feasibility to fabricate the 45 slant on p-type (100)-oriented silicon wafer were done. The various mask shapes, rectangular, cross, circle and boomerang, were patterned on the SiO2 mask by utilizing the conventional photolithography and dry etching process for investigating the anisotropic wet etch characteristic. The edge of masks were align in two crystal direction, 110 and 100 that is allowable to get a better understanding about the crystal orientation and the angle between planes in a crystal system. The very low etch rate,  50 nm/min, process regime was selected to fabricate the 45 slant with the concept is the lowest of an overall etch rate in the system to reach the level that is possible to detect the (110) plane. The etch recipe can be used for the next development work to built a housing of the laser light source for applying in a data storage technology.

Fabrication of 90° Wall of {100} Plane on (100) Si by NaOH Solution via Design of Experiments

2014 ◽  
Vol 909 ◽  
pp. 27-31
Author(s):  
Chu Pong Pakpum ◽  
Nirut Pussadee
Keyword(s):  
Surface Roughness ◽  
Design Of Experiments ◽  
Etch Rate ◽  
Wet Etching ◽  
Experimental Results ◽  
Solution Temperature ◽  
Wall Angle ◽  
Etching Condition ◽  
Naoh Solution ◽  
Experimental Trials

The experimental trials were conducted by design of experiments (DOE) technique to find an anisotropic wet etching condition that achieves 90° wall angle on silicon (100) orientation wafer. Three considered factors assigned to the DOE were NaOH concentration, solution temperature, and stirring speed. The response aimed for this study was not only targeting at 90° wall but also providing highest etch rate. The experimental results showed that in order to fabricate the 90° wall angle, the best etching condition using was 30% wt NaOH concentration, 80°C solution temperature, and 300 rpm stirring speed. This condition gave an etch rate of 1245 nm/min with surface roughness (Ra) of 701.48 nm.

scholarly journals Optimization of deep silicon etching process for microstructures fabrication

2021 ◽  
Vol 2086 (1) ◽  
pp. 012190
Author(s):  
V Kuzmenko ◽  
A Miakonkikh ◽  
K Rudenko
Keyword(s):  
Bias Voltage ◽  
Etch Rate ◽  
Etching Process ◽  
Cyclic Process ◽  
Wall Roughness ◽  
Silicon Etching ◽  
Etching Depth ◽  
Deep Etching ◽  
Anisotropic Silicon Etching

Abstract The paper presents the study of cyclic process of deep anisotropic silicon etching, called Oxi-Etch, in which the steps of etching and oxidation alternate, allowing deep etching of silicon with an anisotropic profile. This process forms typical for cyclic etching process sidewall profile called scalloping. Opportunities for modification and optimization of the process for specific application were investigated. The effects of optimization of the bias voltage and the duration of the etching step on the parameters of the resulting structures, such as the etching depth, wall roughness, and the accuracy of transferring the lithographic size, are considered. Balance between etch rate and scalloping was established.

scholarly journals Highly selective photoenhanced wet etching of GaN for defect investigation and device fabrication

2000 ◽  
Vol 639 ◽  
Author(s):  
P. Visconti ◽  
M. A. Reshchikov ◽  
K. M. Jones ◽  
F. Yun ◽  
D. F. Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Dislocation Density ◽  
Etch Rate ◽  
Device Fabrication ◽  
Wet Etching ◽  
Cross Sectional ◽  
Band Bending ◽  
Plan View ◽  
Calculated Density ◽  
Etched Surface

ABSTRACTPhotoenhanced electro-chemical (PEC) wet etching has been shown to be suitable for dislocation-density estimation in n-GaN films as well as for GaN-based device fabrication. We report on PEC etching of n-GaN samples grown by MBE and HVPE methods in unstirred aqueous KOH solution under He-Cd laser illumination. Characterization of the etched samples was carried out using atomic force microscopy (AFM) in both cross-sectional and plan-view configurations and scanning electron microscopy (SEM). At moderate illumination densities, the SEM and AFM analyses reveal sub-100 nm scale threading vertical wires on the etched surfaces. The calculated density (∼1×10 9cm−2) is in agreement with dislocation density found by transmission electron microscopy. Using cross-sectional AFM, we find that these vertical wires are ∼1[.proportional]m high and are perpendicular to the sapphire surface. Applying a higher illumination density or an external voltage, we obtain a higher etch rate with a smooth free-feature etched surface. Some highly resistive samples that cannot be etched under normal conditions because the band bending is too small to confine the holes to the surface for them to participate in the PEC process, can be etched with the application of a voltage to the sample. In this case, the etch rate depends on both the polarity and the magnitude of the voltage applied. In an MBE-grown sample with an AlN/GaN superstructure inside, we report on high selectivity between AlN and GaN (AlN is an etch stop); the selectivity is due to the etching mechanism of the PEC process.

Wet Anisotropic Etching Characteristics of Si{100} in TMAH+Triton at near the Boiling Point

2015 ◽  
Vol 645-646 ◽  
pp. 58-63 ◽  
Author(s):  
Ming Qiu Yao ◽  
Bin Tang ◽  
Wei Su ◽  
Gang Tan
Keyword(s):  
Boiling Point ◽  
Etch Rate ◽  
Etching Rate ◽  
Ammonium Hydroxide ◽  
Optical Microscope ◽  
Atomic Force ◽  
Tetramethyl Ammonium Hydroxide ◽  
Wet Anisotropic Etching ◽  
Etched Surface ◽  
Anisotropic Silicon Etching

The anisotropic silicon etching characteristics of TMAH(tetramethyl ammonium hydroxide)+Triton at near the boiling point were investigated. The etch rate of Si {100}, the convex corners, and the roughness of the etched surface contact with the fabrication of bulk microstructures and thus micromechanical devices in silicon. This study presents that the etch rate of Si {100} in 25 wt.% TMAH with 0.1% Triton at near boiling point (112°C) is 1.37μm/min, it is three times higher than it at 80°C. The surface roughness and convex corners of Si {100} after etching at different temperature were investigated by optical microscope, scanning electron microscope (SEM) and atomic force microscope (AFM). The etching rate and smoothness of an etched surface can be improved simultaneously at near boiling point, meanwhile, the undercutting on convex corner should be accepted.

Design of Experiments for (100) Si Vertical Wall Wet Etching Using Sonicated NaOH Solution

2015 ◽  
Vol 804 ◽  
pp. 12-15 ◽  
Author(s):  
Chupong Pakpum ◽  
Nirut Pussadee
Keyword(s):  
Design Of Experiments ◽  
Etch Rate ◽  
Vertical Wall ◽  
Clean Energy ◽  
Wet Etching ◽  
Solution Temperature ◽  
Thermoelectric Device ◽  
Si Substrates ◽  
Etching Condition ◽  
Naoh Solution

Silicon-based thermoelectric device fabricated using standard semiconductor manufacturing technique is a promising technology that could lead to a mass production of clean energy. The vertical wall fabrication on Si substrates is typically achieved by high cost plasma etching and involved hazardous gases. The proper wet etching condition offers an economically alternative method in obtaining vertical wall on the Si substrate. Experimental trials were conducted by design of experiments (DOE) technique to find an anisotropic wet etching condition that achieves vertical etched wall on (100) Si wafer. Three considered factors assigned to the DOE were NaOH concentration, solution temperature, and IPA addition. The response aimed for this study was not only targeting at 90° wall but also providing highest etch rate. The experimental results showed that in order to get the 90° wall, the best etching condition achieved was using 45% wt of NaOH concentration, 40°C solution temperature, and without IPA added. This condition gave an etch rate of 97.11 nm/min with surface roughness (Ra) of 10.58 nm.

ИССЛЕДОВАНИЕ ПРОЦЕССА ГЛУБОКОГО ТРАВЛЕНИЯ КРЕМНИЯ С МИНИМАЛЬНОЙ ШЕРОХОВАТОСТЬЮ СТЕНОК И ДНА СТРУКТУР

2020 ◽  
Vol 96 (3s) ◽  
pp. 668-675
Author(s):  
Я.А. Мирошкин
Keyword(s):  
Analytical Model ◽  
Phenomenological Description ◽  
Silicon Etching ◽  
Anisotropic Silicon Etching

Данная работа посвящена исследованию процессов глубокого анизотропного травления кремния. В качестве предложенных методов были проанализированы два подхода - Bosch и Cryo. Представлено феноменологическое описание вышеупомянутых методов, проведен анализ эксперимента по криогенному травлению кремния, полученный на базе ФТИАН, также предложена аналитическая модель Cryo-процесса. This work is devoted to the study of the processes of deep anisotropic silicon etching. Two approaches (Bosch and Cryo) have been analyzed as proposed methods. The phenomenological description of the above mentioned methods has been presented, the analysis of the experiment on cryogenic etching of silicon obtained on the basis of FTIAN has been carried out, as well as an analytical model of Cryo process has been proposed.

Study on the Manufacture of Microfluidic Chip with Coated Glass

2012 ◽  
Vol 548 ◽  
pp. 254-257 ◽  
Author(s):  
Yan He ◽  
Bai Ling Huang ◽  
Yong Lai Zhang ◽  
Li Gang Niu
Keyword(s):  
Microfluidic Chip ◽  
Low Cost ◽  
Microfluidic Channel ◽  
Critical Factor ◽  
Wet Etching ◽  
Microfluidic Chips ◽  
Etching Technique ◽  
Chip Quality ◽  
Wet Chemical ◽  
Wet Chemical Etching

In this paper, a simple and facile technique for manufacturing glass-based microfluidic chips was developed. Instead of using expensive dry etching technology, the standard UV lithography and wet chemical etching technique was used to fabricate microchannels on a K9 glass substrate. The fabrication process of microfluidic chip including vacuum evaporation, annealing, lithography, and BHF (HF-NH4F-H2O) wet etching were investigated. Through series experiments, we found that anneal was the critical factor for chip quality. As a representative example, a microfluidic channel with 20 m of depth, and 80 m of width was successfully prepared, and the channel surfaces are quite smooth. These results present a simple, low cost, flexible and easy way to fabricate glass-based microfluidic chips.

High-Rate Anisotropic Silicon Etching with the Expanding Thermal Plasma Technique

2019 ◽  
Vol 3 (10) ◽  
pp. 291-298 ◽  
Author(s):  
Michiel A. Blauw ◽  
Peter Van Lankvelt ◽  
F. Roozeboom ◽  
Erwin Kessels ◽  
Richard van de Sanden
Keyword(s):  
Thermal Plasma ◽  
High Rate ◽  
Silicon Etching ◽  
Plasma Technique ◽  
Anisotropic Silicon Etching
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