CO2 laser-assisted particle removal from silicon surfaces

1996 ◽  
Vol 74 (S1) ◽  
pp. 95-99
Author(s):  
J. B. Héroux ◽  
S. Boughaba ◽  
E. Sacher ◽  
M. Meunier
Keyword(s):  
Co2 Laser ◽  
Laser Fluence ◽  
Final Concentration ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
Particle Removal ◽  
Particle Counter ◽  
Raster Scan ◽  
Alumina Particles ◽  
Removal System

A CO2 laser particle removal system was built that enables the removal of 0.1 μm alumina particles from silicon substrates. This system has raster scan capabilities to clean large surfaces, which were analysed using a particle counter. After deposition and removal of 0.1 μm alumina particles, the final concentration is less than 25 particles cm−2 for particle clusters between 0.1 and 10 μm. The efficiency of particle removal is nearly independent of the laser fluence between 0.65 and 2.9 J cm−2 and drops suddenly below 0.65 J cm−2.

Particulate Removal from Silicon Substrates in Megasonic-Assisted Dilute SC1 Chemistry

1997 ◽  
Vol 477 ◽  
Author(s):  
Ismail Kashkoush ◽  
Eric Brause ◽  
Robert Grant ◽  
Rich Novak
Keyword(s):  
Real World ◽  
Lower Cost ◽  
Bath Temperature ◽  
Silicon Wafers ◽  
Silicon Substrates ◽  
Particle Removal ◽  
Dilute Solutions ◽  
Cost Of Ownership ◽  
Particulate Removal ◽  
Removal System

ABSTRACTThis paper demonstrates the use of megasonic energy to enhance particulate removal in dilute SC1 solutions. Ideal, as well as “real world”, particles were deposited on silicon wafers to challenge the SCl/megasonic particle removal system. Different dilute SCI concentrations were used, e.g., 1:4:20, 1:10:120, and 1:1:100. Bath temperature was varied between 50 and 70°C with megasonic energy kept constant at 800 W. Results showed that the megasonic energy enhanced the particle removal even in dilute solutions. The chemical concentrations were shown to be a significant factor and must be monitored or controlled in dilute SC1 solutions for particle removal to take place. A lower cost of ownership can be obtained from these techniques as a result of using dilute chemicals and extending current bath lives.

2. Adhesion of the plasma-polymerized fluorocarbon films to silicon substrates The adhesion properties of the plasma-polymerized FC coatings were determined by using a test, already employed by Yasuda and Sharma [13] (see Fig. 1 and Table 1) in which the silicon substrates coated with plasma FC-films were boiled in a0.9% sodium chloride solution. The FC thin films produced in the processes 1 and 2 were lifted after a very short time (15 minutes). Coatings generated in process 3 were lifted after the second cycle of boiling. The films produced in processes 4 and 5 withstood the complete test procedure. The results are shown in Fig. 3. The poor adhesion of the polymerized films in the first two processes is due to the fact that these processes do not involve a plasma pre-treatment process. The difference between processes 1 and 3 is only in the plasma pre-treatment (process 1 does not contain the pre-treatment step of the silicon surface). The fluorocarbon films deposited by processes 4 and 5 have shown the best adhesion. These test results indicate that the plasma pre-treatment is very important and necessary for a good adhesion of the FC coatings to the silicon surfaces. 2.3. Patterning of FC films 2.3.1. Patterning through resist mask. The patterning of the FC films through a photoresist mask (conventional All resist AR-P351) was examined after deposition for process No. 5. Different coating parameters were investigated to improve the adhesion of the resist to the FC surface. The best adhesion results were obtained using the process parameters, shown in Table 3. Differences in the thickness uniformity of so-deposited resists were in a range below 5%. The samples were etched in a pure oxygen plasma in an RIE-system after the lithography steps (pre-bake, exposure, development, post-bake). A resolution of 2 /xm was obtained. A significant increase in the surface energy was not observed after resist stripping. The sessile contact angle of water was 103°. 2.3.2. Lift-off process for patterning thin plasma polymerized FC films. A lift-off process was also examined to pattern the thin FC films. The lithography steps were used before the plasma polymerization process was carried out (Fig. 2). A standard resist AR-P351 was coated directly onto the Si substrates. After all lithography

2014 ◽  
pp. 275-278
Keyword(s):  
Treatment Process ◽  
Test Procedure ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
Fluorocarbon Films ◽  
Si Substrates ◽  
Complete Test ◽  
The Difference ◽  
Pre Treatment ◽  
Lift Off

The Role of HO2− in SC-1 Cleaning Solutions

1997 ◽  
Vol 477 ◽  
Author(s):  
Steven Verhaverbeke ◽  
Jennifer W. Parker ◽  
Chris F. McConnell
Keyword(s):  
Hydrogen Peroxide ◽  
Silicon Oxide ◽  
Bubble Formation ◽  
Ammonium Hydroxide ◽  
Silicon Surfaces ◽  
Wafer Surface ◽  
Particle Removal ◽  
Oxide Interface ◽  
Protective Oxide ◽  
Industry Standard

The RCA Standard Clean, developed by W. Kern and D. Puotinen in 1965 and disclosed in 1970 [1] is extremely effective at removing contamination from silicon surfaces and is the defacto industry standard.[2]. The RCA clean consists of two sequential steps: the Standard Clean 1 (SC-1) followed by the Standard Clean 2 (SC-2). The SC-1 solution, consisting of a mixture of ammonium-hydroxide, hydrogen-peroxide, and water, is the most efficient particle removing agent found to date. This mixture is also referred to as the Ammonium- Hydroxide/Hydrogen-Peroxide Mixture (APM). In the past, SC-1 solutions had the tendency to deposit metals on the surface of the wafers, and consequently treatment with the SC-2 mixture was necessary to remove metals. Ultra-clean chemicals minimize the need for SC-2 processing. SC-I solutions facilitate particle removal by etching the wafer underneath the particles; thereby loosening the particles, so that mechanical forces can readily remove the particles from the wafer surface. The ammonium hydroxide in the solution steadily etches silicon dioxide at the boundary between the oxide and the aqueous solution (i.e., the wafer surface). The hydrogen peroxide in SC-I serves to protect the surface from attack by OH" by re-growing a protective oxide directly on the silicon surface (i.e., at the silicon/oxide interface). If sufficient hydrogen peroxide is not present in the solution, the silicon will be aniostropically etched and surface roughening will quickly occur. On the other hand, hydrogen peroxide readily dissociates and forms water and oxygen. If the concentration of the resulting oxygen is too high, bubbles will appear in the solution. The gas liquid interfaces that result from the bubble formation act as a “getter” for particles that can re-deposit on the wafer surface if a bubble comes in contact with the wafer.

Surface Morphology and Compositional Analysis of Undoped Amorphous Carbon Thin Films via Bias Assisted Pyrolysis-CVD

2013 ◽  
Vol 667 ◽  
pp. 468-476 ◽  
Author(s):  
A. Ishak ◽  
K. Dayana ◽  
Mohamad Rusop
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Amorphous Carbon ◽  
Palm Oil ◽  
Compositional Analysis ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
Negative Bias ◽  
Electron Microscopic ◽  
P Type

Amorphous carbon (a:C) were successfully deposited on the silicon surfaces via bias assisted pyrolysis-CVD in the range between 350oC to 500oC with constant of negative bias -50V in 1 hour deposition. The heated of palm oil at about 150oC was vaporized then used for deposited onto p-type silicon substrates. The deposited thin films were characterized by using field emission scanning electron microscopic (FESEM), energy dispersive analyser x-ray (EDAX). We have found carbon element at about 0.15 keV from EDAX with surface morphology formed a nano-ball like structure at 450oC of palm oil precursor. These results indicated deformation of physical and structural thin films caused by applied negative bias and the temperature.

Effect of Laser Fluence on the Properties of Sm1-XNd X NiO3 Thin Films Deposited by KrF Laser Ablation

2011 ◽  
Vol 227 ◽  
pp. 72-75
Author(s):  
Slimane Lafane ◽  
Tahar Kerdja ◽  
Samira Abdelli-Messaci ◽  
Smail Malek ◽  
Malik Maaza
Keyword(s):  
Thin Films ◽  
Laser Fluence ◽  
Room Temperature ◽  
Silicon Substrates ◽  
X Ray ◽  
Substrate Distance ◽  
Laser Fluences ◽  
Krf Excimer Laser ◽  
Rotating Target ◽  
Scanning Electron

In this contribution we study the effect of the laser fluence on the stoichiometry, morphology and density of Sm1-xNdxNiO3 thin films. The latter were grown by a KrF excimer laser (λ = 248 nm, τ = 25 ns) ablation of a rotating target onto unheated (100) silicon substrates for 9000 pulses at different laser fluences into vacuum. The target used was a mixture of samarium, neodymium and nickel oxides. The relative ratio of neodymium (x = 0.45) is set to have a transition temperature close to room temperature (TMI = 310 K). The target-substrate distance was maintained at 4 cm. The composition and the morphology of the deposited layers were analysed by energy dispersion X-ray spectroscopy (EDX) and scanning electron microscope (SEM) respectively. It was found that films properties depend strongly on the laser fluence. The EDX measurements revealed that the laser fluence must be higher than 1 Jcm-2 for a congruent evaporation. However, even at this condition, the films were deficiency in oxygen. The morphology study showed that the films surface was widely contaminated by droplets for fluences superior to 2 Jcm-2. Also, it was found that by increasing laser fluence the films density increases and reach a plateau at 1.3 Jcm-2. According to all those elements, the laser fluence was set to be in the range of 1.3 – 2 Jcm-2.

Study on the Design of Particle Removal System for Autonomous Robotic Vehicle

2013 ◽  
Vol 694-697 ◽  
pp. 1646-1651
Author(s):  
Bagus Bhirawa Putra ◽  
He Xu ◽  
Liu Zhao Jie
Keyword(s):  
Embedded System ◽  
Design Methodology ◽  
Wide Spectrum ◽  
Autonomous Vehicle ◽  
Particle Removal ◽  
Future Developments ◽  
Jet Nozzle ◽  
The Embedded System ◽  
Robotic Vehicle ◽  
Removal System

The robustness of an autonomous robotic vehicle (ARV) and the embedded supporting architecture permit the investigation of a wide spectrum of research options for particle removal and cleaning apparatus. Applications for particle removal are aimed at supporting the autonomous vehicle in performing its mission, especially in areas considered hazardous, hence emphasize the importance of the embedded system in which the development of air and water jet nozzle is being introduced. By understanding the present basic theory and design methodology, this would capture the outline for future developments of the novelty in particle removal methods especially in an autonomous robotic vehicle (ARV). Accordingly, it can be ascertained that at the same time the main line of the research on particle removal methods remains clear, still in a correspondence research context it is relatively easy to identify alternative subjects which are worthwhile to investigate further.

Large-area silica films deposited on silicon substrates by a CO2 laser

1990 ◽  
Author(s):  
Tamas Szoerenyi ◽  
P. Gonzalez ◽  
M. D. Fernandez ◽  
Juan Pou ◽  
Betty M. Leon-Fong ◽  
...  
Keyword(s):  
Co2 Laser ◽  
Silicon Substrates ◽  
Large Area ◽  
Silica Films

Copper Contamination Mechanism of Silicon Substrates from HF Solutions

1997 ◽  
Vol 52 (6-7) ◽  
pp. 465-476 ◽  
Author(s):  
Valérie Bertagna ◽  
François Rouelle ◽  
Marius Chemla
Keyword(s):  
Copper Ions ◽  
Open Circuit ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
In Situ Characterization ◽  
Quantitative Measurements ◽  
Corrosion Pits ◽  
Voltammetric Measurements

The contamination of silicon wafers from dilute HF solutions containing ultratrace levels of metallic ion impurities is a subject of constant interest. The mechanism of copper electroless deposition from HF onto monocrystalline silicon was investigated using a new electrochemical cell, which proved to be a very sensitive detector for in situ characterization of silicon surfaces. Upon addition of copper trace amounts, the open-circuit potential was observed to shift rapidly towards more positive values at a rate nearly proportional to the copper concentration. All potential/ time curves tend to reach a limiting value of the potential, while quantitative measurements of radioactive tracers revealed that during a few tens of minutes, copper ions were continuously reduced on the silicon surface. Electrochemical potentials and voltammetric measurements were interpreted in terms of the mixed potential theory and led to the conclusion that copper nuclei act as a catalyst which enhances the cathodic activity for protons reduction. The model was supported by AFM observations which demonstrated the initiation of corrosion pits around the nuclei.

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