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Surfactants in Nanotechnology

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Nano/micro Surface Treatments

Nano/micro Surface Treatments

Researchers work on proprietary particle coating and surface treatment technology to tailor the surface properties of the nanoparticles. By discreetly encapsulating individual particles with various chemical and physical processes, they are able to meet a customer’s performance requirements by controlling the particle size distribution, ensuring compatibility with the customer’s formulation, and including beneficial additives to control pH or rheology, to name a few.  In most instances, it is beneficial to mediate the interface between the nanoparticle surface and the application matrix in which the nanoparticles are to be utilized.  For example, for a naturally hydrophilic nanoparticle to be used effectively in non-polar media such as cosmetic oils, the surface of the particle may need to be rendered hydrophobic for uniform dispersion, compatibility, and performance.  The proprietary chemistry and process technology used to prepare these dispersions ensures that the customers receive ready-to-use products in which the nanoparticles are stabilized at their primary particle size, with no secondary structure or agglomeration.  The purpose to develop an optimized process is to impart a wide range of functionality to the particles, which not only ensures the success in the application but also provides the required flexibility in formulation with their nanoparticles.  The effectiveness of these surface treatment and coating processes can be examined, verified and optimized with our precision instruments such as OCA, DCAT, ODG and T-100 on the produced particle samples in either dry powder or pre-dispersed format.

Our devices which can help you: OCA15, OCA25, OCA50, DCAT11, DCAT21, ODG, T100

Surface Structures Fabrication and Verification

Surface Structures Fabrication and Verification

A fine (micro- or nano-patterned) Si-based mold is fabricated by a conventional VLSI process and the mold is directly pressed to a thin glass plate using a hot-press machine.  Fabrication of fine grating on a glass surface can be achieved by imprint lithography using a Si3N4/SiO2/Si mold and a low Tg glass. The imprint conditions are designed based on the glass surface property measured under a temperature, humidity or pressure controlled condition.  Recently micro-fluidics research will rely on the similar imprint and etching processes to create the desired patterns or channel designs as another example in other modern applications.

FDS/Dataphysics can help in the steps  of  your VLSI processes 

Lithography is used to transfer a pattern from a photomask to the surface of the wafer. The photoresistant coverage and wetting nature on the wafer surface will determine the effectiveness of the partner trafer when exposed to (often ultraviolet) light or another source of illumination (e.g. X-ray).  Therefore, the surface preparation of the wafer and selection of photoresistant needs to be checked with a contact angle meter OCA and tensiometer such as DCAT, t15, t100, etc.

Etching is used to remove material selectively in order to create patterns.   The selectivity and completeness of the etching are always desired by the process engineers and they can be verified with a contact angle device, OCA.

Deposition- A multitude of layers of different materials have to be deposited during the IC fabrication process. The two most important deposition methods are the physical vapor deposition (PVD) and the chemical vapor deposition (CVD). During PVD accelerated gas ions sputter particles from a sputter target in a low pressure plasma chamber. The principle of CVD is a chemical reaction of a gas mixture on the substrate surface at high temperatures. The need of high temperatures is the most restricting factor for applying CVD. This problem can be avoided with plasma enhanced chemical vapor deposition (PECVD), where the chemical reaction is enhanced with radio frequencies instead of high temperatures. An important aspect for this technique is the uniformity of the deposited material, especially the layer thickness.  You can use an OCA device to check on the uniformity of the deposited material.

Chemical Mechanical Planarization– Processes like etching, deposition, or oxidation, which modify the topography of the wafer surface lead to a non-planar surface. Chemical mechanical planarization (CMP) is used to plane the wafer surface with the help of a chemical slurry. First, a planar surface is necessary for lithography due to a correct pattern transfer.  The CMP slurry formulations can be optimized with a DCAT tensiometer or a MutiScan and the planarity of the wafer after CMP can be examined with a fully automated OCA50 contact angle scanning and mapping features.

Oxidation is a process which converts silicon on the wafer into silicon dioxide. The chemical reaction of silicon and oxygen already starts at room temperature but stops after a very thin native oxide film. For an effective oxidation rate the wafer must be settled to a furnace with oxygen or water vapor at elevated temperatures. Silicon dioxide layers are used as high-quality insulators or masks for ion implantation. The quality of the formed silicon dioxide can be examined with an OCA25 equipped with a temperature, humidity or pressure chamber.

Ion implantation is the dominant technique to introduce dopant impurities into crystalline silicon. This is performed with an electric field which accelerates the ionized atoms or molecules so that these particles penetrate into the target material until they come to rest because of interactions with the silicon atoms. Ion implantation is able to control exactly the distribution and dose of the dopants in silicon, because the penetration depth depends on the kinetic energy of the ions which is proportional to the electric field.  With an OCA25 and one of environmental chamber for either electrical field, pressure, temperature or humidity, you can research for an optimized ion implantation process.

Cleaning Processes Optimization and Validation

Cleaning Processes Optimization and Validation

There is a tremendous amount of types of industrial parts and surfaces required for cleaning before they become a finished product for users.  All the relevant processes or procedures to respond to the required cleanliness, whether they are chemical or physical methods will be interested in the effectiveness of their cleaning processes and cleaning formulations. The industry which is involved in cleaning process is widespread.

  • Cleaning equipment systems and cleaning reagents for
    1. wet cleaning processes
    2. thermal processes
    3. blasting processes
    4. special processes
    5. mechanical processes
  • Systems for drying processes will need to check on water stains or chemical leftover
  • Processes and systems for corrosion protection and preservation
  • Reagents for corrosion protection and preservation
  • Processes and systems for quality assurance
  • Clean room systems
  • Surface treatment systems
  • Processes and techniques in recycling and disposal
  • Components for cleaning systems
  • On-line automation cleaning systems
  • Cleaning products

SITA CleanoSpector, SITA ConSpector, SITA Cleanline ST, SITA Cleanline CL for direct cleanliness validation and the Dataphysics OCA devices for contact angle measuring are all available for both batch and on-line cleanliness checking to help you maintain and optimize your cleaning requirements.

Surfactants in Nanotechnology

Surfactants in Nanotechnology

Interest in nano-emulsions has been developing for about 20 years now, mainly for nano-particle preparation.  Not until recent years did direct applications of nano-emulsions in consumer products develops, mainly in pharmaceutical/drug, personal care, health care, agrochemical, film coating, cosmetic, consumable, carbon nano-tubes, and oil industries. Surfactants play major roles to ease the formation of nano-emulsions by lowering the interfacial tension; the Laplace pressure is reduced and hence the stress needed to break up a drop is reduced.  In addition, their self-assembling amphiphilic nature also make surfactants very useful for applications used in many new technology areas.

Nano-emulsions are attractive in various application fields due to the following advantages:

– The very small droplet size causes a large reduction in gravitational force, so Brownian motion may be sufficient to overcome gravity. This means that no creaming or sedimentation occurs on storage.

– The small droplet size also prevents their coalescence, since these droplets are non-deformable and hence surface fluctuations are prevented.

– The significant surfactant film thickness (relative to droplet radius) prevents any disruption of the liquid film between the droplets.

– The large surface area of the emulsion system allows rapid penetration of actives.  Due to their small size, nano-emulsions can penetrate through the rough skin surface and this enhances penetration of actives.

– The fluidity of the transparent nature of the system, as well as the absence of any thickeners may give them a pleasant aesthetic character and skin feel.

– The small size of the droplets allows them to deposit uniformly on substrates; wetting, spreading and penetration may be also enhanced because of the low surface tension of the whole system and the low interfacial tension of the O/W droplets.

– Nano-emulsions can be applied for delivery of fragrant or active ingredients, which may be incorporated in many personal care, food, and medical products. For example, this could be applied in perfumes, lubricants, cutting oils and corrosion inhibitors.

– Nano-emulsions may be applied as a substitute for liposomes and vesicles and it is possible in some cases to build lamellar liquid crystalline phases around the nano- emulsion droplets.

Our devices which can help you in this field are: OCA, DCAT, CMC tool, MS, SVT, DCAT-LBE, SITA R2000, T100, T15+, Dynotester, etc.