Direct Observation of Single Bubble Cavitation Damage for MHz Cleaning

2009 ◽  
Vol 145-146 ◽  
pp. 3-6 ◽  
Author(s):  
Hiroshi Tomita ◽  
Minako Inukai ◽  
Kaori Umezawa ◽  
Li Nan Ji
Keyword(s):  
Bubble Formation ◽  
High Energy ◽  
Aluminum Film ◽  
Wafer Surface ◽  
Particle Removal ◽  
Physical Force ◽  
Cavitation Damage ◽  
Bubble Cavitation ◽  
Gate Structure ◽  
Complex Phenomena

It is well known that the physical force cleaning such as megasonic (MS) and ultrasonic (US) cleaning are used in FEOL (front-end-of-line) and BEOL (back-end-of-line). Recently, with scaling down below 43 nm, the influence of pattern damage by physical force methods such as MS and US irradiation has been reported. Hence, for the 2x and 3x nm node devices, it will be very difficult to apply MS cleaning for particle removal process without understanding the cavitation force. Cavitation is a complex phenomena based on bubble formation and explosion in the liquid. To control “MS cleaning” and “cavitation” induced pattern damage, many studies using “Sonoluminescence” have been reported. This method is able to demonstrate the existence of high energy fields such as cavitation throughout the megasonic field. The damage clustering distribution was investigated for the damage size and damage length in batch MS conditions using gate structure patterned [1]. In this method, it is difficult to discuss the cavitation force, quantitatively. And this method can not obtain the quantitative physical force on the wafer surface, directly. To understand “cavitation force” induced pattern damage, the observation of “cavitation force” is highlighted with “imaging films” such as blanket aluminum film and resist film, directly.

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.

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

An Electrical Characterization of Sol Films Using Devices Formed by Oxygen Implant and Rapid Thermal Processing

1987 ◽  
Vol 92 ◽  
Author(s):  
Jim D. Whitfield ◽  
Marie E. Burnham ◽  
Charles J. Varker ◽  
Syd.R. Wilson
Keyword(s):  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
High Energy ◽  
Thermally Grown Oxide ◽  
Silicon On Insulator ◽  
Wafer Surface ◽  
High Dose ◽  
Active Device ◽  
Insulating Layer ◽  
Oxygen Implantation

The advantages of Silicon-on-Insulator (SO) devices over bulk Silicon devices are well known (speed, radiation hardened, packing density, latch up free CMOS,). In recent years, much effort has been made to form a thin, buried insulating layer just below the active device region. Several approaches are being developed to fabricate such a buried insulating layer. One viable approach is by high dose, high energy oxygen implantation directly into the silicon wafer surface (1-3). With proper implant and annealing conditions, a thin stoichiometric buried oxide with a good crystalline quality silicon overlayer can be formed on which an epitaxial layer can be grown and functional devices and circuits built. As SO1 circuits become market viable, mass production tools and techniques are being developed and evaluated. Of particular interest here is the evaluation of high current oxygen implantation with rapid thermal processing on the electrical characteristics of the oxide-silicon interfaces, the silicon overlayer and the thermally grown oxide on the top surface using measurements on gated diodes and guarded capacitors.

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.

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.

Physical Cleaning Enhancement Using Advanced Spray with Uniform Droplet Control

2012 ◽  
Vol 195 ◽  
pp. 195-197 ◽  
Author(s):  
Ying Hsueh Chang Chien ◽  
Matt Yeh ◽  
Scott Ku ◽  
C.M. Yang ◽  
C.C. Chen ◽  
...  
Keyword(s):  
Semiconductor Device ◽  
Droplet Diameter ◽  
Particle Removal ◽  
Physical Force ◽  
Cleaning Efficiency ◽  
Lift Off ◽  
The Moment ◽  
The Relationship ◽  
Uniform Droplet ◽  
Droplet Control

In semiconductor device manufacturing, single wafer processors are widely used in not only BEOL process but also in FEOL process for 2X devices to improve the cleaning efficiency and get the higher productivity. Because the scaled down devices require the minimum substrate loss in the cleaning steps, the physical force by a dual fluid spray is still the main position to improve the cleaning efficiency at the moment comparing with chemical effects as the dissolution of contaminants and/or the lift off of particles. Sato, et al., reported that the relationship between particle removal and droplet characteristics linked to the droplet energy densityEdas following equation [. The kinetic energyEkof droplet is calculated from droplet diameterdand velocityv, as shown in Equation 1.

Reduction of Cavitation Damage in a High-Energy Water Injection Pump

2011 ◽  
Author(s):  
Paul Cooper ◽  
Ron Ungewitter ◽  
Rehan Farooqi ◽  
James McKenzie ◽  
Bruno Schiavello ◽  
...  
Keyword(s):  
Erosion Rate ◽  
Cavitation Erosion ◽  
Acoustic Analysis ◽  
Water Injection ◽  
High Energy ◽  
Cavitation Number ◽  
Two Phase ◽  
Cavitation Damage ◽  
Injection Pump ◽  
Unsteady Rans

The conventionally-designed first-stage impeller of a high-energy, two-stage 19MW seawater injection pump, running at 4950 rpm and generating 1500m of head at a flow rate of 1.05 m3/s was seriously damaged by cavitation erosion in the first two months of operation. The impeller was redesigned by reshaping the blades in the region near the leading edges so as to reduce the inception cavitation number. This impeller has been running for more than a year, and the cavitation erosion rate is predicted to be low enough for it to last 40,000 hours. However, a prominent tone at blade passing frequency appeared with the new impeller, which interacts more effectively with the distorted inflow from the side-suction approach passage. Acoustic analysis of both single- and two-phase unsteady RANS CFD solutions corroborate the presence of this tone, which had not been observed when the pump operated with the original, conventional impeller.

Pulsed X-Ray Annealing of Arsenic-Implanted Silicon

1981 ◽  
Vol 4 ◽  
Author(s):  
T. W. Sigmon ◽  
D. E. Osias ◽  
R. L. Schneider ◽  
C. Gilman ◽  
G. Dahlbacka
Keyword(s):  
Energy Density ◽  
Structural Properties ◽  
Energy Flux ◽  
High Energy ◽  
Wafer Surface ◽  
X Rays ◽  
Density Range ◽  
X Ray ◽  
Large Numbers ◽  
Unique Capability

ABSTRACTIn this paper we report experiments on annealing of arsenic-implanted silicon using a pulsed imploding-plasma X-ray source. Silicon wafers of <100> orientation were implanted with arsenic ions at 50 keV to a dose of 3.5 ∼ 1015 cm−2 and exposed to a single 50 ns pulse of X-rays in the energy density range of 0.15 to 0.55 J/cm2 The characteristic X-ray absorptiog coeificient in silicon for these experiments was 1.6 ∼ 10 cm−1, resulting in most of the energy being absorbed in the first 100 nm of the wafer surface.For wafers annealed in the energy density range of 0.3 to 0.4 J/cm2 backscattering and channeling measurements show recovery of the crystallinity of the damaged layer with incorporation of about 86% of the implanted arsenic onto substitutional lattice positions. Evidence of redistribution and flattening of the arsenic profile in the annealed wafer was observed in the backscattering data and confirmed by SIMS profiling. Detailed results on the electrical and structural properties of these annealed layers will be presented. High energy pulsed X-ray sources offer the unique capability of simultaneously exposing large numbers of wafers to an extremely uniform energy flux at much higher efficiencies than conventional lasers.

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