Study of Oxygen Concentration in TMAH Solution for Improvement of Sigma-Shaped Wet Etching Process

2016 ◽  
Vol 255 ◽  
pp. 18-21
Author(s):  
Yong Gen He ◽  
Huan Xin Liu ◽  
Jia Lei Liu ◽  
Jin Gang Wu ◽  
Christian Haigermoser ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Wet Etching ◽  
Tetramethylammonium Hydroxide ◽  
Etching Process ◽  
Shape Formation ◽  
Ic Manufacturing ◽  
The Impact ◽  
Tmah Solution

Tetramethylammonium hydroxide (TMAH) is a common etchant for Sigma shape formation in IC manufacturing. The impact of oxygen dissolved in TMAH solution on process was studied in this paper. A novel O2 gas injector was developed to improve the process stabilization by control of the oxygen concentration in TMAH solution

Wet Etching Behavior of Poly-Si in TMAH Solution

2012 ◽  
Vol 195 ◽  
pp. 42-45 ◽  
Author(s):  
Hiroaki Takahashi ◽  
Masayuki Otsuji ◽  
Jim Snow ◽  
Farid Sebaai ◽  
Kenichiro Arai ◽  
...  
Keyword(s):  
Wet Etching ◽  
Tetramethylammonium Hydroxide ◽  
Process Performance ◽  
Etching Behavior ◽  
Dummy Gate ◽  
Tmah Solution

Since Tetramethylammonium Hydroxide (TMAH) became widely used as a silicon etchant, e.g. the dummy gate removal for gate-last approach (RMG) [1, or Si fin formation on FinFET [, some careful preparations and optimizations have required implementation. These adaptations have involved not only chemical-related issues, but also hardware-related in order to satisfy the necessary process performance.

scholarly journals Control of Oxygen Impurities in a Continuous-Feeding Czochralski-Silicon Crystal Growth by the Double-Crucible Method

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 264
Author(s):  
Wenhan Zhao ◽  
Jiancheng Li ◽  
Lijun Liu
Keyword(s):  
Oxygen Concentration ◽  
Silicon Crystal ◽  
Cost Effective ◽  
Czochralski Method ◽  
Crucible Wall ◽  
Oxygen Impurity ◽  
Continuous Feeding ◽  
The Impact ◽  
Oxygen Impurities ◽  
Crystal Interface

The continuous-feeding Czochralski method is a cost-effective method to grow single silicon crystals. An inner crucible is used to prevent the un-melted silicon feedstock from transferring to the melt-crystal interface in this method. A series of global simulations were carried out to investigate the impact of the inner crucible on the oxygen impurity distributions at the melt-crystal interface. The results indicate that, the inner crucible plays a more important role in affecting the O concentration at the melt-crystal interface than the outer crucible. It can prevent the oxygen impurities from being transported from the outer crucible wall effectively. Meanwhile, it also introduces as a new source of oxygen impurity in the melt, likely resulting in a high oxygen concentration zone under the melt-crystal interface. We proposed to enlarge the inner crucible diameter so that the oxygen concentration at the melt-crystal interface can be controlled at low levels.

Photosensitive terpolymer for all-wet-etching process: Material characterization and device fabrication

2010 ◽  
Vol 518 (8) ◽  
pp. 2147-2151
Author(s):  
Abderrafia Moujoud ◽  
Sungho Kang ◽  
Hyun Jae Kim ◽  
Mark Andrews
Keyword(s):  
Material Characterization ◽  
Device Fabrication ◽  
Wet Etching ◽  
Etching Process ◽  
Process Material

Towards a High-Pressure Microchannel Reactor for Fuel Characterization

2021 ◽  
Author(s):  
David Akinpelu ◽  
Ingmar Schoegl
Keyword(s):  
High Pressure ◽  
Oxygen Concentration ◽  
Combustion Characteristics ◽  
Test Time ◽  
Potential Candidate ◽  
Microchannel Reactor ◽  
Transportation Fuels ◽  
Intermediate Pressure ◽  
Fuel Blends ◽  
The Impact

Abstract Within the area of combustion, externally heated microtubes have been introduced to study the combustion characteristics of fuels and fuel blends. Microreactors have advantages over other conventional fuel testing methods because of their potential to test small volumes (< 20 μl) at high throughput. In this work, a high-pressure microreactor is designed and implemented to test fuels up to a pressure of 20 bar where automated testing reduces test time substantially. The novelty of this device is its capability to operate at pressure exceeding the current state of the art of 12 bar. The combustion behavior of fuels is tested in an externally heated quartz tube, with a diameter less than the conventional quenching diameter of the fuel. The ultimate objective of the experiment is to investigate the impact of fuel on flame characteristics. The ability to reach engine relevant pressure conditions and its inherent small volume requirements make this device a potential candidate for measurements of laboratory transportation fuels and fuel blends. For initial validation, tests from an earlier intermediate pressure experiment with ethane/air and nitrogen mixtures are repeated. Chemiluminescence images are taken to evaluate the combustion characteristics in terms of the three classical flame regimes: weak flames, Flames with Repetitive Extinction, and Ignition (FREI) and normal flames. Previous results at intermediate pressure showed that as the pressure increases, the weak flame and FREI regimes shift towards lower velocities. Also, as dilution level increase (i.e. reducing oxygen concentration), the transition from the weak flame to FREI becomes less abrupt and is completely lost for marginal oxygen concentration. The objective of this study is to document flame dynamics at higher pressures.

Adaptation of the NDIR technology to13CO2breath tests under increased inspiratory O2concentrations

2009 ◽  
Vol 107 (1) ◽  
pp. 302-307 ◽  
Author(s):  
Josef A. Vogt ◽  
Ulrich Wachter ◽  
Jürgen Mehring ◽  
Peter Radermacher ◽  
Michael Georgieff ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Clinical Situation ◽  
Breath Tests ◽  
Accuracy And Precision ◽  
Synthetic Gas ◽  
Small Footprint ◽  
Expired Gas ◽  
High Bias ◽  
Respiratory Gases ◽  
The Impact

Nondispersive infrared spectroscopy (NDIR) allows the continuous analysis of respiratory gases. Due to its high selectivity, simple and robust setup, and small footprint, it is also used to support13CO2breath tests to assess bacterial growth in the stomach, gut, or liver function. CO2NDIR signals, however, are biased by oxygen in the gas matrix. This complicates NDIR-based breath tests, if the inspired oxygen concentration has to be adjusted to the subject's requirements, or hyperoxia-induced effects were studied. To avoid the oxygen-induced bias, a “dilution” approach was developed: expired gas is mixed with N2to lower the oxygen content down to the usual range of 15–20%. Accuracy and precision were tested using synthetic gas mixtures with increasing13CO2-to-12CO2ratios (13CO2/12CO2), either based on synthetic air with ∼20% volume O2or on pure O2. For samples with δ13C values smaller than 300 (or13CO2/12CO2smaller than 0.003), the dilution does not significantly increase the bias in the13CO2/12CO2determination, and the within-run imprecision is smaller than 1 δ13C. The practical use of this approach was validated in a pig study using a sepsis model reflecting a clinical situation that requires an increased oxygen concentration for respiration. The N2dilution eliminated the high bias in NDIR measurement, thus allowing the determination of the impact of oxygenation on glucose oxidation in patients ventilated with increased oxygen.

LiTaO3 Recording Media Prepared by Polarization Controlled Wet Etching Process

2004 ◽  
Vol 68 (1) ◽  
pp. 221-228
Author(s):  
YOSHIOMI HIRANAGA ◽  
YASUO WAGATSUMA ◽  
YASUO CHO
Keyword(s):  
Wet Etching ◽  
Etching Process ◽  
Recording Media

Impact of Oxygen Enriched Air on High Intensity Combustion and Emission

2015 ◽  
Author(s):  
Ahmed O. Said ◽  
Ahmed E. E. Khalil ◽  
Daniel Dalgo ◽  
Ashwani K. Gupta
Keyword(s):  
Oxygen Concentration ◽  
Reaction Zone ◽  
Combustion Efficiency ◽  
Oxygen Enrichment ◽  
Chemiluminescence Intensity ◽  
Exhaust Temperature ◽  
Lean Combustion ◽  
Unstable Combustion ◽  
The Impact ◽  
Co Emission

The influence of oxygen enriched air-methane flame under non-premixed and premixed fuel-lean combustion conditions is examined with focus on the emission of NO and CO, combustor exit temperature (Texit), and distribution of OH* chemiluminescence intensity. A cylindrical combustor was used at combustion intensity of 36MW/m3.atm and heat load of 6.25 kW. Results are also reported with normal air (21% oxygen). Oxygen enrichment provided stable combustion operation at lower equivalence ratios than normal air and also reduced CO emission. Increase in oxygen concentration from 21% to 25% and 30% increased the NO and decreased CO emissions at all equivalence ratios examined. Using 30% O2 enriched air in premixed case showed NO emissions of 11.4 ppm and 4.6 ppm at equivalence ratios of 0.5 and 0.4, respectively. Oxygen enrichment also reduced CO emission to 38 ppm at equivalence ratio of 0.5. Operating the combustor with normal air at these equivalence ratios resulted in unstable combustion. OH* Chemiluminescence revealed increased chemiluminescence intensity with the reaction zone to shift upstream at increased oxygen concentration. The exhaust temperature of the combustor increased with oxygen enrichment leading to lower CO concentration and increased combustion efficiency. The oxidizer injected at higher velocities mitigated the impact of reaction zone to move upstream that helped to reduce significantly both the NO and CO emission specifically under non-premixed combustion.

Reaction Kinetics of Poly-Si Etching in TMAH Solution

2021 ◽  
Vol 314 ◽  
pp. 60-65
Author(s):  
Taegun Park ◽  
Sangwoo Lim
Keyword(s):  
Reaction Kinetics ◽  
Alkaline Solution ◽  
Etching Rate ◽  
Tetramethylammonium Hydroxide ◽  
Dissolved Gas ◽  
Metal Free ◽  
Effect Of Water ◽  
Detailed Kinetics ◽  
Kinetics Of ◽  
Tmah Solution

Tetramethylammonium hydroxide (TMAH) is a metal-free strong alkaline solution which can etch poly-Si. The concentration of dissolved gas as well as the concentration of TMAH affects etching rate of poly-Si. The detailed kinetics of poly-Si etching in TMAH solution is investigated in this study. The effect of water and TMAH concentration on the etching kinetics of poly-Si was investigated by using various concentrations of TMAH solution. It is found that H2O in TMAH solution plays an important role in etching poly-Si. Presence of dissolved CO2 and O2 in TMAH solution tends to inhibit etching of poly-Si. The concentration of dissolved CO2 and O2 in TMAH were reduced by Ar bubbling, thereby the poly-Si etching rate increased.

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