Scanning Probe Microscopy Imaging before and after Atomic Layer Oxide Deposition on a Compound Semiconductor Surface

2012 ◽  
Vol 187 ◽  
pp. 9-10
Author(s):  
W. Melitz ◽  
J.B. Clemens ◽  
J. Shen ◽  
E.A. Chagarov ◽  
S. Lee ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Atomic Layer ◽  
Semiconductor Surface ◽  
Angle Of Incidence ◽  
Particle Removal ◽  
Cleaning Efficiency ◽  
Microscopy Imaging ◽  
Megasonic Cleaning ◽  
Before And After ◽  
Oxide Deposition

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.

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.

Evaluation of Megasonic Cleaning for Sub-90nm Technologies

2005 ◽  
Vol 103-104 ◽  
pp. 141-146 ◽  
Author(s):  
Guy Vereecke ◽  
Frank Holsteyns ◽  
Sophia Arnauts ◽  
S. Beckx ◽  
P. Jaenen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Mass Balance ◽  
Semiconductor Manufacturing ◽  
Particle Removal ◽  
Dissolved Gas ◽  
Cleaning Efficiency ◽  
Megasonic Cleaning ◽  
High Particle ◽  
The Cost

Cleaning of nanoparticles (< 50nm ) is becoming a major challenge in semiconductor manufacturing and the future use of traditional methods, such as megasonic cleaning, is questioned. In this paper the capability of megasonic cleaning to remove nanoparticles without inflicting damage to fragile structures is investigated. The role of dissolved gas in cleaning efficiency indicates that cavitation is the main cleaning mechanism. Consequently gas mass-balance analyses are needed to optimize the performance of cleaning tools. When gas is dissolved in the cleaning present tools can remove nanoparticles down to about 30 nm using dilute chemistries at low temperature. Ultimate performance is limited by cleaning uniformity, which depends on tool design and operation. However no tool reached the target of high particle removal efficiency andlow damage. Significantly lower damage could only be obtained by decreasing the power, at the cost of a lower cleaning efficiency for nanoparticles. The development of damage-free megasonic is discussed.

Acoustic Field Analysis of a T Type Waveguide in Single Wafer Megasonic Cleaning and its Effect on Particle Removal

2007 ◽  
Vol 134 ◽  
pp. 229-232 ◽  
Author(s):  
Yang Lae Lee ◽  
Eui Su Lim ◽  
Kook Jin Kang ◽  
Hyun Se Kim ◽  
Tae Gon Kim ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Acoustic Pressure ◽  
Field Analysis ◽  
Particle Removal ◽  
Pressure Measurements ◽  
Cleaning Efficiency ◽  
Transverse Waves ◽  
Megasonic Cleaning ◽  
Longitudinal Waves ◽  
Wafer Cleaning

T type megasonic waveguide was analyzed by finite element method (FEM), acoustic pressure measurements and particle removal efficiency for the single wafer cleaning application. Compared to conventional longitudinal waves, a transverse waves were generated in a T type waveguide. Not like longitudinal waves, transverse waves showed changes of direction and phase which increased the cleaning efficiency.

Post-CMP Megasonic Cleaning Using Dilute SCI Solution

1999 ◽  
Vol 566 ◽  
Author(s):  
A. A. Busnaina ◽  
N. Moumen ◽  
J. Piboontum ◽  
M. Guarrera
Keyword(s):  
High Frequency ◽  
Semiconductor Manufacturing ◽  
Acoustic Streaming ◽  
Wafer Surface ◽  
Particle Removal ◽  
Optimum Conditions ◽  
Small Particles ◽  
Cleaning Efficiency ◽  
Megasonic Cleaning ◽  
Thermal Oxide

Non contact cleaning or wet-cleaning processes, were the megasonic play a key role in the separation of the particles from the wafer is a commonly used technique in semiconductor manufacturing. CMP process can be very damaging to the production yield if not followed by an effective post clean process. McQueen identified the effect of the acoustic boundary layer and its role in the removal of small particles at high frequency. Busnaina et alt studied ultrasonic and megasonic particle removal and the effect of acoustic streaming. They showed that the cleaning efficiency increased with power until a certain range and then decrease slightly. Busnaina et al result indicted that SCI removes more particles than DI water particularly at lower megasonic powers specially in the case were the slurry particles are deposited onto the wafer surface by dipping experiments. But they also demonstrated that it was possible to achieve 100 % removal in DI water when using the optimum conditions. This paper presents the latest results of the post-CMP megasonic cleaning process, this study is focused on the cleaning of thermal oxide silicone wafer polished using silica based slurry and cleaned using diluted SC1 (H20/H202/NH4OH: 40/2/1).

Particle removal from semiconductor wafers by megasonic cleaning

1996 ◽  
Vol 27 ◽  
pp. S427-S428 ◽  
Author(s):  
T.H. Kuehn ◽  
D.B. Kittelson ◽  
Y. Wu ◽  
R. Gouk
Keyword(s):  
Particle Removal ◽  
Megasonic Cleaning

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.

scholarly journals Atmospheric radiation boundary conditions for the Helmholtz equation

2018 ◽  
Vol 52 (3) ◽  
pp. 945-964 ◽  
Author(s):  
Hélène Barucq ◽  
Juliette Chabassier ◽  
Marc Duruflé ◽  
Laurent Gizon ◽  
Michael Leguèbe
Keyword(s):  
Boundary Conditions ◽  
Helmholtz Equation ◽  
Acoustic Waves ◽  
Numerical Study ◽  
Outgoing Wave ◽  
Atmospheric Radiation ◽  
Angle Of Incidence ◽  
Radiation Boundary Conditions ◽  
Radiation Boundary ◽  
Dirichlet To Neumann Map

This work offers some contributions to the numerical study of acoustic waves propagating in the Sun and its atmosphere. The main goal is to provide boundary conditions for outgoing waves in the solar atmosphere where it is assumed that the sound speed is constant and the density decays exponentially with radius. Outgoing waves are governed by a Dirichlet-to-Neumann map which is obtained from the factorization of the Helmholtz equation expressed in spherical coordinates. For the purpose of extending the outgoing wave equation to axisymmetric or 3D cases, different approximations are implemented by using the frequency and/or the angle of incidence as parameters of interest. This results in boundary conditions called atmospheric radiation boundary conditions (ARBC) which are tested in ideal and realistic configurations. These ARBCs deliver accurate results and reduce the computational burden by a factor of two in helioseismology applications.

scholarly journals Regional synapse gain and loss accompany memory formation in larval zebrafish

2022 ◽  
Vol 119 (3) ◽  
pp. e2107661119
Author(s):  
William P. Dempsey ◽  
Zhuowei Du ◽  
Anna Nadtochiy ◽  
Colton D. Smith ◽  
Karl Czajkowski ◽  
...  
Keyword(s):  
Classical Conditioning ◽  
Structural Changes ◽  
Memory Formation ◽  
Excitatory Synapses ◽  
Microscopy Imaging ◽  
Functional Changes ◽  
Larval Zebrafish ◽  
Before And After ◽  
Synaptic Changes ◽  
With Memory

Defining the structural and functional changes in the nervous system underlying learning and memory represents a major challenge for modern neuroscience. Although changes in neuronal activity following memory formation have been studied [B. F. Grewe et al., Nature 543, 670–675 (2017); M. T. Rogan, U. V. Stäubli, J. E. LeDoux, Nature 390, 604–607 (1997)], the underlying structural changes at the synapse level remain poorly understood. Here, we capture synaptic changes in the midlarval zebrafish brain that occur during associative memory formation by imaging excitatory synapses labeled with recombinant probes using selective plane illumination microscopy. Imaging the same subjects before and after classical conditioning at single-synapse resolution provides an unbiased mapping of synaptic changes accompanying memory formation. In control animals and animals that failed to learn the task, there were no significant changes in the spatial patterns of synapses in the pallium, which contains the equivalent of the mammalian amygdala and is essential for associative learning in teleost fish [M. Portavella, J. P. Vargas, B. Torres, C. Salas, Brain Res. Bull. 57, 397–399 (2002)]. In zebrafish that formed memories, we saw a dramatic increase in the number of synapses in the ventrolateral pallium, which contains neurons active during memory formation and retrieval. Concurrently, synapse loss predominated in the dorsomedial pallium. Surprisingly, we did not observe significant changes in the intensity of synaptic labeling, a proxy for synaptic strength, with memory formation in any region of the pallium. Our results suggest that memory formation due to classical conditioning is associated with reciprocal changes in synapse numbers in the pallium.

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