Mechanism of PVA Brush Loading with Ceria Particles during Post-CMP Cleaning Process

2021 ◽  
Vol 314 ◽  
pp. 259-263
Author(s):  
Samrina Sahir ◽  
Hwi Won Cho ◽  
Nagendra Prasad Yerriboina ◽  
Tae Gon Kim ◽  
Satomi Hamada ◽  
...  
Keyword(s):  
Electrostatic Attraction ◽  
Particle Removal ◽  
Cross Contamination ◽  
Cleaning Process ◽  
Particle Loading ◽  
Cleaning Efficiency ◽  
Solution Ph ◽  
Cleaning Solution ◽  
Oppositely Charged ◽  
Process Interaction

Brush scrubbing is a well-known post CMP cleaning process. Interaction between PVA brush and the particles removed during the process must be considered while designing a cleaning process. In this work, the effect of cleaning solution pH was investigated in terms of particle removal from the wafer and subsequent loading to the PVA brush nodule. Higher cleaning of particles from wafer was observed for pH 2 and 12 cleaning solutions and poor cleaning for pH 7 cleaning solution. In contrast, the brushes were loaded heavily for pH 7 compared to pH 2 and 12. Higher electrostatic attraction between oppositely charged PVA and ceria surfaces provided higher ceria particles loading to PVA brush in acidic and neutral cleaning solutions. This particle loading to PVA brush can further effect cleaning efficiency as well as cross-contamination.

Effect of Various Cleaning Solutions and Brush Scrubber Kinematics on the Frictional Attributes of Post Copper CMP Cleaning Process

2009 ◽  
Vol 145-146 ◽  
pp. 363-366 ◽  
Author(s):  
Yasa Sampurno ◽  
Yun Zhuang ◽  
Xun Gu ◽  
Sian Theng ◽  
Takenao Nemoto ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Direct Contact ◽  
Chemical Mechanical Planarization ◽  
Wafer Surface ◽  
Poly Vinyl Alcohol ◽  
Particle Removal ◽  
Cleaning Process ◽  
Cleaning Performance ◽  
Cleaning Solution ◽  
Copper Cmp

Brush scrubbing has been widely used in post chemical mechanical planarization (CMP) applications to remove contaminations, such as slurry residues and particles, from the wafer surface. During brush scrubbing, particle removal results from direct contact between a soft poly vinyl alcohol (PVA) brush and the wafer surface in which the brush asperities engulf the particles while the rotating motion of the brush, as well as the cleaning fluid at the surface, dislodge and carry the particles away from the wafer. The cleaning performance of brush scrubbing depends heavily on the choice of the cleaning solution and brush scrubber kinematics. In this work, the effect of various cleaning solutions and brush scrubber kinematics on the frictional attributes of post copper CMP cleaning process was investigated.

The Influence of the Angle of Incidence in Megasonic Cleaning

2012 ◽  
Vol 187 ◽  
pp. 163-166 ◽  
Author(s):  
Steven Brems ◽  
Marc Hauptmann ◽  
Elisabeth Camerotto ◽  
Xiu Mei Xu ◽  
Stefan De Gendt ◽  
...  
Keyword(s):  
Silicon Wafer ◽  
Acoustic Waves ◽  
Angle Of Incidence ◽  
Particle Removal ◽  
Cleaning Process ◽  
Acoustic Transmission ◽  
Cleaning Efficiency ◽  
Megasonic Cleaning ◽  
Schlichting Streaming ◽  
Si Wafer

The megasonic cleaning efficiency is evaluated as a function of the angle of incidence of acoustic waves on a Si wafer. Acoustic Schlichting streaming alone is not able to remove nanoparticles smaller than 400 nm. It is shown that oscillating or collapsing behavior of bubbles are responsible for removing nanoparticles smaller than 400 nm during a cleaning process with ultrasound. Optimal particle removal efficiency is obtained around the angle of acoustic transmission of the silicon wafer.

Exploratory Materials and Devices to Advance CMOS beyond the Classical Si Roadmap

2012 ◽  
Vol 187 ◽  
pp. 3-5 ◽  
Author(s):  
Marc M. Heyns
Keyword(s):  
Silicon Wafer ◽  
Acoustic Waves ◽  
Angle Of Incidence ◽  
Particle Removal ◽  
Cleaning Process ◽  
Acoustic Transmission ◽  
Cleaning Efficiency ◽  
Megasonic Cleaning ◽  
Schlichting Streaming ◽  
Si Wafer

The megasonic cleaning efficiency is evaluated as a function of the angle of incidence of acoustic waves on a Si wafer. Acoustic Schlichting streaming alone is not able to remove nanoparticles smaller than 400 nm. It is shown that oscillating or collapsing behavior of bubbles are responsible for removing nanoparticles smaller than 400 nm during a cleaning process with ultrasound. Optimal particle removal efficiency is obtained around the angle of acoustic transmission of the silicon wafer.

High Velocity Aerosol Cleaning with Organic Solvents: Particle Removal and Substrate Damage

2009 ◽  
Vol 145-146 ◽  
pp. 39-42 ◽  
Author(s):  
Michael T. Andreas ◽  
Kurt Wostyn ◽  
Masayuki Wada ◽  
Tom Janssens ◽  
Karine Kenis ◽  
...  
Keyword(s):  
High Velocity ◽  
Particle Removal ◽  
Spray Nozzle ◽  
Cleaning Process ◽  
Ultrapure Water ◽  
Cleaning Efficiency ◽  
Impact Forces ◽  
Cleaning System ◽  
Aerosol Spray ◽  
Dilute Aqueous Solutions

High velocity aerosol cleaning using ultrapure water or dilute aqueous solutions (e.g. dilute ammonia) is common in semiconductor IC fabrication [1]. This process combines droplet impact forces with continuous liquid flow for improved cleaning efficiency of sub-100nm particles. As with any physically enhanced cleaning process, improved particle removal can be accompanied by increased substrate damage, especially to smaller (<80nm) features [2]. Solvents such as N-methylpyrrolidone (NMP) and tetrahydrofurfuryl alcohol (THFA) are used for resist strip applications [3]. It is possible, and sometimes useful, to deliver these solvents through the same spray nozzle normally used for aqueous spray cleaning. In this presentation we explore the particle removal and substrate damage performance of 2-ethoxyethanol (EGEE), NMP and THFA as used in a conventional aerosol spray cleaning system

scholarly journals Intrinsically disordered caldesmon binds calmodulin via the “buttons on a string” mechanism

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1265 ◽  
Author(s):  
Sergei E. Permyakov ◽  
Eugene A. Permyakov ◽  
Vladimir N. Uversky
Keyword(s):  
Local Structure ◽  
Intrinsically Disordered Proteins ◽  
String Model ◽  
Electrostatic Attraction ◽  
Disordered Proteins ◽  
Wild Type ◽  
Intrinsically Disordered ◽  
Tryptophan Residues ◽  
Specific Packing ◽  
Oppositely Charged

We show here that chicken gizzard caldesmon (CaD) and its C-terminal domain (residues 636–771, CaD136) are intrinsically disordered proteins. The computational and experimental analyses of the wild type CaD136and series of its single tryptophan mutants (W674A, W707A, and W737A) and a double tryptophan mutant (W674A/W707A) suggested that although the interaction of CaD136with calmodulin (CaM) can be driven by the non-specific electrostatic attraction between these oppositely charged molecules, the specificity of CaD136-CaM binding is likely to be determined by the specific packing of important CaD136tryptophan residues at the CaD136-CaM interface. It is suggested that this interaction can be described as the “buttons on a charged string” model, where the electrostatic attraction between the intrinsically disordered CaD136and the CaM is solidified in a “snapping buttons” manner by specific packing of the CaD136“pliable buttons” (which are the short segments of fluctuating local structure condensed around the tryptophan residues) at the CaD136-CaM interface. Our data also show that all three “buttons” are important for binding, since mutation of any of the tryptophans affects CaD136-CaM binding and since CaD136remains CaM-buttoned even when two of the three tryptophans are mutated to alanines.

scholarly journals Use of ultrasound for cleaning of components of historical vehicles in Technical Museum in Brno

2020 ◽  
Vol 64 (3) ◽  
pp. 79-86
Author(s):  
K. Rapouch ◽  
M. Mrázek
Keyword(s):  
Water Drop ◽  
Bath Temperature ◽  
Cleaning Process ◽  
Fuel System ◽  
Dissolved Metals ◽  
Cleaning Efficiency ◽  
Ultrasound Frequency ◽  
Aas Method ◽  
Ultrasound Effect

Abstract In the collections of Technical Museum in Brno, large number of historical vehicles is placed. During the operation, parts of their motors are being fouled. Frequently, they become even immobile (e. g. due to a fouled fuel system). In this case, the method using ultrasound with a suitable concentrate appears as the most suitable. In fact, ultrasound works also in inaccessible places with large efficiency. Not only the chosen solution influences the cleaning efficiency, but also parameters as time, bath temperature and ultrasound frequency. The cleaning process was evaluated according to the volume of removed dirt and by observing wettability change using the measuring of contact angle of a water drop. The ultrasound shock waves influence the surface to a certain extent also mechanically. That is why, the ultrasound effect on defects in the structure was observed. The aggressivity of cleaning concentrates was evaluated on the ground of determination of dissolved metals in the baths by ET AAS method.

Roles of Surfactant Molecules in Post-CMP Cleaning

2005 ◽  
Author(s):  
Dedy Ng ◽  
Milind Kulkarni ◽  
Hong Liang
Keyword(s):  
Surfactant Concentration ◽  
Substrate Surface ◽  
Wafer Surface ◽  
Particle Removal ◽  
Abrasive Particles ◽  
Effective Particle ◽  
Cleaning Solution ◽  
Before And After ◽  
First Time ◽  
Hydrophilic Particles

One major concern in post-CMP cleaning is particles contamination on the substrate surface after the CMP process. These particles can be abrasive particles from the slurry, debris from pad material, and particles of film being polished. The cleaning method used in this study is direct contact of the substrate surface and brush sweeping. To enhance the cleaning process, an anionic surfactant is added in the cleaning solution. In order to understand effects of surfactant molecules on post-CMP cleaning, for the first time, we use a tribological approach over a range of surfactant concentration and temperature. In this regard, we observe how the surfactant behavior before and after it reaches the critical micelles concentration (cmc). Experimental results show that increase in surfactant concentration can promote bilayer interaction of micelles on the hydrophilic particles. Based on our study, we propose an interactive explanation of surface molecules with the wafer surface and nanoparticles through friction. This understanding will serve as a guide on how much surfactant should be added in order to achieve effective particle removal.

Tough and responsive oppositely charged nanocomposite hydrogels for use as bilayer actuators assembled through interfacial electrostatic attraction

2016 ◽  
Vol 4 (19) ◽  
pp. 3239-3246 ◽  
Author(s):  
Shuhui Liu ◽  
Guorong Gao ◽  
Ying Xiao ◽  
Jun Fu
Keyword(s):  
Electrostatic Attraction ◽  
Nanocomposite Hydrogels ◽  
Oppositely Charged

Tough nanocomposite hydrogels carrying opposite charges were assembled through interfacial electrostatic attraction into Janus bilayer actuators.

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