Plasma Impulse Chemical Vapour Deposition Research Articles

Recent trends and future of pharmaceutical packaging technology

The pharmaceutical packaging market is constantly advancing and has experienced annual growth of at least five percent per annum in the past few years. The market is now reckoned to be worth over $20 billion a year. As with most other packaged goods, pharmaceuticals need reliable and speedy packaging solutions that deliver a combination of product protection, quality, tamper evidence, patient comfort and security needs. Constant innovations in the pharmaceuticals themselves such as, blow fill seal (BFS) vials, anti-counterfeit measures, plasma impulse chemical vapor deposition (PICVD) coating technology, snap off ampoules, unit dose vials, two-in-one prefilled vial design, prefilled syringes and child-resistant packs have a direct impact on the packaging. The review details several of the recent pharmaceutical packaging trends that are impacting packaging industry, and offers some predictions for the future.

Coatings on plastics with the PICVD technology

Plasma impulse chemical vapor deposition (PICVD) was developed by Schott more than 10 years ago. It was the first CVD – based coating technology for the mass production of optical coatings on glass components (cold light mirrors, infrared reflective coatings and others). During the last few years, a modified PICVD-process for the deposition of three different functional coatings on plastics has been developed. These functions—anti-reflective, anti-scratch and easy-to-clean layers—are provided by only one technology—PICVD. This is a major progress compared for instance to the standard production line of polymer based eyeglass lenses, which uses a PVD process for anti-reflective coating, dip coating for anti-scratch and plasma polymerization for easy-to-clean coatings. Moreover, the development was extended to different kinds of plastics including optical polymers like polymethylmethacrylate (PMMA) and polycarbonate (PC). Until now, plasma CVD coating technologies were not capable of depositing durable functional coatings on PMMA with a sustained adhesion to the substrate. A completely new layer system on PMMA with an adapted adhesive layer has been developed for these coatings. Durability has been proven by passing different types of functionality tests like tape test, grid test, climate tests or temperature shock tests. In the near future, Schott will start the first mass-production of coatings on plastics with the PICVD technology, e.g. in the telecommunications and automotive business.

Correlation between the density of TiO 2 films and their properties

Stress, density and refractive index of approximate 100 nm thick titania films are determined for layers deposited on fused silica substrates by reactive evaporation (RE), reactive ion plating (IP), plasma impulse chemical vapour deposition (PICVD) and spin coating (SC). Relative densities ( ϱ film ϱ ana ) vary between 0.7 and 1.0 with respect to the crystal phase of anatase ( ϱ ana = 3.84 g cm −3). The refractive index depends linearly on density. Film stress is tensile at low densities and compressive for layers with densities of the order of anatase. A strong correlation between stress and density is found to be independent from the deposition conditions and the crystal structure of the as-deposited films. The phase transition from amorphous to anatase caused by annealing induces an increase in stress. The film density is correlated to the crystallization temperature, the size of stress increase during crystallization and the grain size.

Multilayer barrier coating system produced by plasma-impulse chemical vapor deposition (PICVD)

We demonstrate a new coating system for diffusion-barrier applications on polymer substrates like PET and PC. The barrier system is designed as a multilayer coating, which is composed of oxide-like barrier layers embedded in “soft” polymer-like material. This system acts as a highly stable unit, which shows excellent adhesion to the substrate and has been shown to be stable up to 121 °C for 30 min without microcracks. It is deposited by plasma-impulse chemical vapor deposition (PICVD) technology, which employs a pulsed microwave plasma working at very low substrate temperatures and high coating rates. This technology uses the advantages of the CVD process, to coat three-dimensional substrate geometries with high-quality and nearly pinhole-free films. On 1 mm polycarbonate, the permeation of oxygen has been reduced by a factor of 360 to only 0.375 cm 3 m −2 bar −1 per day and the water permeability was measured to be as low as 0.23 g m −2 per day. This allows its use in extremely sensitive packaging products, such as medical applications.

Microscratch Analysis of The Adhesion Failure on Oxide Thin Films With Different Thickness

AbstractAdhesion failures of Ti2and Ta2O5thin films deposited by reactive evaporation (RE), reactive ion plating (IP) and plasma impulse chemical vapour deposition (PICVD) on fused silica, AF 45, TEMPAX and soda-lime glass substrates are investigated by means of a micro-scratch tester. The oxide films possess thickness between 60 and 500 nm and show different mass densities depending on the deposition conditions. Scratch testing exhibits well pronounced detachment for thicker films on hard substrates. The clearance of the scratch signal is reduced with decreasing layer thickness or for softer substrate materials. The test results are also influenced by the various substrates and different chemical and mechanical properties of the films due to the alternate deposition techniques.

Highly sensitive interfacial mass detection using ultracompact waveguiding films

We demonstrate quantitative detection of interfacial mass changes with submonolayer sensitivity during the sorption of a small molecule at a planar surface. The optical transducer consists of a 140-nm-thick ultracompact waveguiding film of amorphous TiO2 prepared by low-temperature microwave plasma-impulse chemical vapor deposition.

Influence of Aging Processes on Adhesion Properties of Metallic and Oxidic Thin Films

AbstractAdhesion of oxidic and metallic films with thicknesses between 40 nm and 350 nm has been investigated by means of a scratch-test method based on a vibrating diamond micro-indenter. SiO2 and TiO2 films are precipitated on fused silica substrates by sol-gel techniques (SG), reactive evaporation (RE), reactive low-voltage ion plating (IP), and plasma impulse chemical vapour deposition (PICVD), and Cr-layers are produced by rf magnetron sputtering (SP). The influence of aging effects on film adhesion is investigated in respect of several conditions, like storage under ambient surroundings with differences in relative humidity or temperature treatment. A method is presented allowing control of the long-term stability of the scratch-test conditions. Temperature treatment up to 600 °C is found to have the most significant impact on adhesion properties. Adhesion increases for some SiO2 films, whereas for TiO2 layers an opposite behavior is observed. Here, the adhesion of the originally amorphous titania films is reduced due to the phase transition to polycrystalline anatase, which correlates with a significant increase in film stress.

Stress and Density of Thin TiO2 Films Produced by Different Methods

AbstractStress, density and refractive behavior are analyzed for TiO2 layers deposited by reactive evaporation (RE), ion plating (IP), plasma impulse chemical vapour deposition (PICVD) and spin coating (SP) from bending of the substrate and by means of Rutherford Backscattering Spectroscopy (RBS), respectively. Densities between 2.7 gem-3 and 3.8 gem-3 are obtained depending on coating techniques and coating conditions. Refractive index depends linear on density. A correlation between film stress and density is observed which is independent from coating process, production parameters and crystal structure of the as-deposited films. Stress is tensile at low densities and compressive for films with densities of the order of the crystal phase of anatase (3.84 gem-3). The phase transition from amorphous to anatase due to annealing induces an increase in stress. Film density determines the transition temperature, and the magnitude of stress increase.

Ultramicrotomy: an alternative cross section preparation for oxidic thin films on glass

Ultra-thin cross sections of various oxidic thin films (TiO 2, Ta 2O 5, SiO 2, ZrO 2, ITO) deposited on glass by reactive evaporation (RE), ion plating (IP), sputtering (SP) and plasma impulse chemical vapour deposition (PICVD) are prepared by ultramicrotomy (UM) and are investigated by transmission electron microscopy (TEM). The principles of UM and the relevant steps of pretreatment before cutting are reported, and the capability of UM is demonstrated on single layers and multilayer systems. Suitability and limitations of UM are outlined and common problems and artifacts are discussed. The results of the TEM investigations on technical oxidic thin films and the related interfaces are correlated with data obtained by other methods.

Adhesion Properties of Metallic and Oxide Thin Films Produced by Several Methods

ABSTRACTAdhesion of Cr, SiO2, TiO2 and Ta2O5 films with thicknesses between 40 nm and 380 nm has been investigated using a new scratch-test method based on a vibrating diamond micro-indenter. The oxide films are produced on different substrates by sol-gel technique (SG), reactive evaporation (RE), reactive ion plating (IP) and plasma impulse chemical vapor deposition (PICVD); Cr-layers are deposited by sputtering (SP) on quartz. Large variations in adhesion are found for different coating techniques and deposition conditions, especially the substrate temperature. The adhesion can be correlated with microscopic properties in the film-substrate interface where differences are analyzed in term of hydrogen content, film growth and density. The adhesion is also connected with other macroscopic film quantities.

Stress of Tio2 Thin Films Produced by Different Deposition Techniques

ABSTRACTStress in thin films has been measured very precisely (< 10 MPa) by analysing the curvature of quartz glass substrates before and after film deposition by means of a ZYGO Mark IV interferometer system. TiO2 films of approximately 100 nm thickness were prepared by reactive evaporation (RE), reactive ion plating (IP), plasma impulse chemical vapor deposition (PICVD) and spin coating (SC). Large variations in stress are found for different coating techniques and deposition conditions. This can be correlated to differences in optical properties, film density and crystalline structure. Relaxation effects and the influence of thermal treatment are also studied. The crystallization of amorphous TiO2 during heat treatment is accompanied by significant changes in film stress. The crystal size and morphology of TiO2 films after heat treatment strongly depend on the deposition technique and process conditions.

Plasma impulse chemical vapour deposition—a novel technique for the production of high power laser mirrors

Chemical vapour deposition (CVD) methods are known to be most advantageous for the production of very high quality optical materials ( i.e. performs for low loss fibres or high damage threshold, and reflection coatings on thin fibres). It is also well known that plasma-enhanced CVD methods show improved deposition efficiencies. Pulsed microwave plasmas (2.45 GHz) are used to realize interference filters with very high laser damage threshold as well as high reflection. The impact of the coating temperature on the layer quality is discussed. The high deposition rate together with the almost monolayer-by-monolayer growth control in the pulsed plasma mode is suitable for producing extreme small-band, high reflection coatings, which have no harmonics. By almost individual shaping of the refractive index distribution within one λ/4 layer a new degree of freedom in the design of these coatings has been accomplished. The theoretical background as well as experimental results are discussed.