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Interference thin film based on metamerism is the latest means in the field of optical anti-counterfeiting. In this paper, we propose a pair of metal-dielectric metameric interference thin films that could create a hidden image for optical security devices. To improve color match tolerance of the metameric pair, the angle insensitive metal-dielectric Fabry-Perot structure was designed as the metameric pair background film B; The logo film A adopts the five-layer angle sensitive structure to enhance the contrast. The film B is designed to have a weak color-shift effect as the observation angle is increased. When the observation angle increases from 0° to 15°, the reflectance spectrum of film B changes smoothly, and the color difference indexes between film A (0°) and film B (0°, 5°, 10°, 15°) are 0.968, 0.988, 1.798 and 3.778, respectively. This design is less sensitive to manufacturing errors and has a good color match effect. Color target optimization optimac method is utilized in the design process and remote plasma sputtering is used in the deposition process. The color difference index of the experiment is 2.753, which shows good hidden image effect for the optical security devices.

Because of high color saturation and fewer layers, metal-dielectric thin film has been used for years in the field of special effect coatings such as security and decorative applications. In the application of red color, purple red and orange red metal-dielectric thin films have already been realized, however, pure red thin film has not been achieved. In this paper, color target optimization method is adopted to eliminate the blue second order reflect peak (460 nm–470 nm) and compress the red first order reflect peak (675 nm), consequently, a seven-layer metal-dielectric pure red thin film is designed and fabricated. The chromaticity coordinate is (x,y) = (0.635,0.32) at normal incidence, which is located in pure red region, and the gold color target coordinate is (x,y) = (0.52,0.45) at 45°. The final base structure is Air/1.5Cr/230SiO2/6.3Cr/225SiO2/8.9Cr/213SiO2/100Al/Glass, where the numbers refer to layer thicknesses in nanometers. As the observation angle is increased from 0° to 45°, the thin film varies from pure red to gold. Remote plasma sputtering technique is used to fabricate the multilayer thin film. Finally, pure red thin films are demonstrated for the automobile coatings and optically variable ink applications, and the practical color effects are presented.

Porous low- k films, deposited using a plasma-enhanced chemical vapor deposition (PECVD) porogen-based process, were treated by H 2 /He plasma at varied temperatures ranging from 25 °C to 350 °C in this study. Two different plasma treatment reactors: capacitive coupling plasma (CCP) and remote plasma (RP) systems, were used to compare the impacts of H 2 /He plasma treatment on the porous low- k film. Experimental results indicate that H 2 /He plasma treatment in CCP system caused a larger degradation in low- k film's properties due to the physical-chemical reaction by H ions, radicals, and VUV photons as compared to that in RP system with only presence of H radicals. Additionally, the operation temperature of H 2 /He plasma treatment operated in the CCP and RP systems resulted in an adverse effect. H 2 /He plasma-treated low- k films operated in CCP system at elevated temperatures exhibited a large scission of Si–CH 3 groups, a large increase in k -value and leakage current, and a large degradation in breakdown field and TTF. However, the damage induced by H 2 /He plasma in RP system was alleviated by increasing the operation temperature. Additionally, as the operation temperature is raised to 350 °C, the positive effects with the reduction of k -value and the improvement of reliability were detected in H 2 /He plasma-treated low- k films. These enhanced properties are attributed to the removal of carbon-based porogen residues by He/H 2 plasma in RP system at high temperatures. Consequently, remote He/H 2 plasma treatment operated at high temperatures is a damage-free process for porous low- k films as it is used to strip resist during the fabrication of interconnects.

Remote plasma processing (RPP) provides pathways to the formation of photovoltaic (PV) and thin-film-transistor (TFT) devices that include buried interfaces. This is made possible by separate and independent control of (i) plasma excited O- and N-atom deposition precursors in a up-stream plasma chamber, combined with (ii) down-stream injection of Si- and Ge-atoms with control gas flow rates providing control of buried interface bonding at monolayer levels. Devices with intrinsic, B p-type and P n-type “a-Si(H)” & “a-Si,Ge(H)” layers require 10% bonded H in monolayer (Si H arrangements) and deposition and/or annealing at temperatures between 240 and 275 °C. Deposition from SiH4 with either PH3 or B2H6 dopant gasses provides spectrally reflecting films which can be annealed yielding fine-grain films for gate, or source and drain regions for TFTs or FETs.

International audience; In this work silicon oxide has been deposited from silane on fluidized polyethylene powders placed in far cold remote nitrogen/oxygen plasma. The process temperature remained below 100°C. The influence on the powder wettability of several key parameters such as the amount of oxygen injected in the plasma, the SiH4 flow rate and the treatment duration has been studied. From hydrophobic, the polyethylene powder wettability can be drastically improved depending on process conditions. Based on surface analyses of treated powders under various processing conditions, a deposition mechanism has been proposed combining homogeneous and heterogeneous nucleation and growth phenomena. The observed wettability variations appear to be linked to the surface coverage of the powder by the deposit.

High density plasma assisted sputtering source (HiPASS) has been introduced to develop a remote plasma sputtering. In HiPASS the remote plasma source (RPS) was an electron beam excited plasma using a direct current discharge supplying Ar plasma (10 10–11 cm − 3 ). Ar plasma was transported from the RPS to a sputtering cathode by external magnetic fields. The transported Ar ions generated a physical sputtering at the negatively biased sputtering cathode. HiPASS has an advantage that sputtering current and voltage were controllable independently. The sputtering current was dominantly controllable by the discharge power of the RPS. And sputtering voltage was applied to the sputtering cathode freely with the fixed sputtering current modulated by the discharge power of the RPS. As the discharge power of the RPS is increased from 2.4 to 8.4 kW, the sputtering current of sputtering cathode (78.5 cm 2 ) was varied from 1.2 ± 0.1 to 3.6 ± 0.2 A. This was an improved sputtering current comparing with practical sputtering current (1 A at 78.5 cm 2 ) of radio frequency excited remote plasma sputtering. The remote plasma sputtering with the improved sputtering current could be applied to low voltage high current sputtering for damage-free transparent conductive oxide and barrier film depositions as well as high voltage high current sputtering for hard coating applications.

International audience; Polysiloxane films were deposited on an AISI316L stainless steel by remote plasma assisted chemical vapour deposition from 1.1.3.3-tetramethyldisiloxane. Thicknesses up to 5 μm were developed at a max growth rate of 400 nm min-1. The organosilicon films were then treated by remote plasma assisted oxidation and thermal treatment under air. The remote plasma assisted oxidation modified the surface composition of the coatings but let the bulk properties unchanged. The thermal treatment allowed a full mineralization of the coatings. Below 450°C the mineralization was partial and oxygen could not reach the coating core. This oxygen diffusion limitation was removed only for temperature of circa 600°C. The final surface composition appeared to be SiO1.8 which might represent a structure close to amorphous silica. After the most severe thermal treatment (600°C), neither desquamation nor cracking of the deposit occurred. The final composite is a steel substrate covered by a coherent layer of silica glass material. The steel underneath remained non-oxidized which testified of a strong diffusion barrier role vs. O2.

Photocatalytic materials, and especially titanium dioxide, have gained wide popularity in recent years in reason of their interesting properties which can be useful in various fields of application, in particular as self-cleaning materials. When submitted to an illumination (in most cases UV-light), the surface of a photocatalytic material becomes chemically active and simultaneously displays a photo-generated hydrophilic activity (PSH effect). Classically, photocatalytic properties are displayed by crystalline titanium dioxide. In this paper we detail the chemical vapor deposition of TiO 2 carried out in two experimental set-ups: one is plasma enhanced reactor and the other is remote plasma enhanced reactor. Both experiments were carried out with titanium(IV) isopropoxide (TTIP). Titanium(IV) tetrachloride (TiCl 4 ) and titanium(IV) ethoxide (TEOT) were also used in the first setup. In RF-diode plasma reactor, titanium dioxide films were deposited in amorphous form and crystallization of amorphous films was obtained with the help of thermal post-treatments, since seeding and under-layers appeared unable to trigger the crystallization of films. In the remote plasma CVD reactor, allowing high plasma density and ion energy, deposition of crystalline anatase titanium dioxide was achieved at a deposition temperature of 400 °C. Conclusions are presented and suggest control mechanisms for the stoichiometry of titanium dioxide films.

Silicon oxide (SiO x ) layers were deposited on silicon and plastic substrates at a low substrate temperature of 100 °C by remote plasma-enhanced chemical deposition (RPE-CVD) using a combination of SiH 4 /N 2 gases in N 2 O/Ar remote plasma. The deposition rate of the SiO x layers initially increased with increasing N 2 O/SiH 4 flow ratio of 10 and then decreased with further increases. Under the current experimental conditions, gas-phase reactions leading to powder formation were minimized by increasing the N 2 O/SiH 4 flow ratio at the reduced SiH 4 flow rate of 10 sccm. The silicon oxide thin films became Si-rich with increasing N 2 O/SiH 4 flow ratio. The leakage current of the SiO x layer was higher at the lower N 2 O/SiH 4 flow ratio, which was attributed to the increased rate of gas-phase reactions leading to a film with a less dense structure.

Plasma oxynitridation of Si(001) was carried out by NH 3 /N 2 O/Ar remote plasma generated from a toroidal-type remote plasma source in a commercial 8-in. plasma-enhanced chemical vapor deposition (PECVD) system. Oxynitridation experiments of Si were performed by varying the NH 3 /N 2 O/Ar gas flow ratio and plasma exposure time at the substrate temperature of 500 °C. Time evolution of the layer thickness, chemical composition, and bonding characteristics of the silicon oxynitride layers were investigated by various analytical methods including X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry and high-resolution transmission electron microscopy (HR-TEM). The results showed a formation of the silicon oxynitride layers with the film thickness of 1.5–2.0 nm and different compositions depending on the experimental conditions. N content incorporated in the silicon oxynitride increases but the growth rate of silicon oxynitride layer decreases with increasing NH 3 /N 2 O gas flow ratio.

In this paper first results will be presented concerning our investigations on direct and remote plasma polymerization of SiOx films using a microwave induced PACVD process. The plasma source working at a frequency of 2.45 GHz was a slot antenna type CYRANNUS®-I source which was able to maintain a homogeneous plasma at atmospheric pressure. The carrier and the monomer gases used for the silica deposition were an argon–oxygen mixture or air and hexamethyldisiloxane, respectively. There will be given a description of the deposition conditions in the remote and the direct mode. Depending on the deposition parameters thin and smooth SiOx films on silicon or stainless steel substrates were prepared. The films were characterized by IR spectroscopy, ellipsometry and various microscopic methods like optical microscopy, SEM and HRTEM.

Hydrogenated and nitrogenated carbon films were obtained by PECVD with carbon species supplied by acetylene gas injected into an argon or argon/nitrogen remote plasma generated by an expanding radiofrequency discharge. The properties of carbon material like the nature of bonds, morphology, surface topography, crystallinity are presented. The reaction pathways linking the precursors with the depositing species, as revealed by emission spectroscopy, are discussed.

In this study, remote plasma cleaning process was investigated in a silicon nitride plasma enhanced chemical vapor deposition chamber using C 4 F 8 /O 2 /Ar and C 4 F 8 /O 2 /Ar+additive gas. The remote plasma source used in the present experiments showed the capability of nearly complete destruction, destruction removal efficiency ≅100%, of C 4 F 8 gas with or without the additive N 2 , N 2 O and NO gases. The cleaning rate of the silicon nitride layers is increased 32–40% by adding N 2 , N 2 O and NO gases to the optimized C 4 F 8 /O 2 cleaning chemistry. This is presumably due to the effective reaction of NO radicals formed in the remote plasma with N on the silicon nitride surface, followed by the effective fluorination of Si atoms. As a result, the million metric tons of carbon equivalent values could be effectively reduced due to the decreased emission of CF 4 as well as the increased cleaning rate of the silicon nitride layers, comparable to those of NF 3 /Ar remote plasma cleaning. For the effective reduction of global warming effects, the experimental results indicate a possibility of using the alternative gas such as C 4 F 8 with the N-containing additive gases for the environmentally benign remote plasma cleaning process.

Hydrogen radicals are crucial for: remote plasma enhanced chemical vapor deposition; metal–organic chemical vapor deposition; or plasma cleaning. A new type of 13.56 MHz hollow cathode jet shows high efficiency of radical generation. For better understanding of plasma heating mechanisms, the source is characterized by optical emission spectroscopy from hydrogen plasma in the wavelength range from 200 to 800 nm. The examined parameter range was: pressure from 0.1 to 4 torr; gas flow up to 100 sccm; and rf power from 20 to 180 W. The emission intensity in the jet zone is 2 orders of magnitude higher than in the anode or cathode zone. The axial emission intensity distributions in the remote zone indicate the propagation and absorption of rf power along the remote plasma column. The emission intensities of lines related to C1Πu–XA1Σg+ transition, are compared with the intensities of Hα, Hβ and Hγ atomic lines. The molecular-to-atomic emission intensity ratio increases with increasing pressure and with increasing distance from the plasma source, due to the increase of vibrational excitation.

Fundamental studies on post-discharges deal with the understanding and the modelling of transport of active species and their interactions with surfaces. Coupling kinetic models of volume and surface processes is a major step in the numerical modelling of surface treatments. Restricted chemical reaction pathways, occurring in post-discharge, are a main advantage in understanding basic phenomena. Efforts to both model and control post-discharge processes have helped to optimise applications of current interest in industry. Nitriding, enhancement of polymer printability, adhesion and wettability properties or remote plasma enhanced chemical vapour deposition of thin films are used for material processing applications. New developments are devoted to surface cleaning and low temperature sterilisation. Versatility of late post-discharge processes may be used for duplex treatments.

Diamond-like carbon films (DLC) were deposited in a novel 13.56 MHz RF–RF system (Plasma Consult GmbH PlasCon HCD-System) at a substrate temperature of 60°C. Typically, a radiofrequency (RF) power of 400 W was used for plasma generation by a hollow cathode discharge plasma source (HCD). The substrate holder was also RF powered and had a negative DC self bias voltage in the range of 200–600 V. Both HCD and the RF-substrate holder are run with synchronized RF-power generators and automated impedance matching units. The carrier gas He was introduced into the primary hollow cathode discharge at a flow rate of typical 400 sccm. Methane and acetylene were used as a carbon source at flow rates between 15 and 100 sccm. An ion concentration of up to 2×10 11 cm −3 was measured in the plasma with a HCD and RF bias on. Without the HCD an ion concentration of approximately 5×10 10 cm −3 was achieved. Higher ion concentration had a positive influence on the deposition process and allowed to achieve a higher deposition rate. In the stationary mode deposition rates of 70–80 nm min −1 with methane as a precursor gas and 180–260 nm min −1 with acetylene as a precursor gas were measured. The films were investigated by micro-Raman spectroscopy, FTIR, ellipsometry and microhardness measurements. It was found that even in the stationary mode deposition the film thickness variations across a 5″ Si-wafer were lower than ±3.5%. The acetylene based DLC films have a refractive index of 2.1–2.15 at wavelength of 632 nm. The refractive index of DLC films, deposited with methane as a precursor, was between 2.2 and 2.3. Vickers microhardness of these films of up to 30 GPa were achieved.

A novel hybrid plasma apparatus optimized for diamond-like carbon (DLC) film deposition is presented. A plasma was generated by use of a jet matrix plasma source (JeMPS) operated at 13.56 MHz and up to 1 kW. The 48 plasma jets were arranged as a hexagonal matrix within a 15-cm diameter circle. In the center of an argon plasma at pressure of 1 mbar the ion concentration is 4.82×10 11 cm −3 . At a distance of 6 cm from the plasma source a water-cooled substrate holder biased with 13.56 MHz power was positioned. A plasma-enhanced chemical vapor deposition (PECVD) process was used. Helium was used as a carrier gas excited in the jet matrix plasma source. Methane, used as a source of carbon, was introduced in the zone between the plasma source and the substrate holder. A fractal carrier and process gas distribution system allowed high film homogeneity. Typical gas flows were 500 and 100 sccm, respectively; typical process pressure was 1 mbar. A Root’s blower with a pumping speed of 250 m 3 h −1 was used. A deposition rate of 78 nm min −1 at room temperature was achieved. The film thickness variation over a 5 inch wafer was less than 7%. As the dc bias of the substrate holder increased from 350 to 400 V the sp 2 /sp 3 ratio increased from 0.79 to 0.88. The refractive index of almost 2.4 and a Vickers hardness of 3000 were evidence of high quality DLC films.

A novel jet matrix plasma source (JEMPS) for large area film deposition is presented. A high density plasma is produced by use of low temperature plasma jets extracted from 13.56 MHz hollow cathode discharges. A prototype of JEMPS is realized as the matrix of 7 x 11 plasma jets. The influence of gas flow, radio frequency (RF) power and pressure on the ion concentration is investigated. The typical working conditions of JEMPS are discharge gas flow 500-1000 sccm, pressure 30-100 Pa and RF power up to 400W. The ion concentration measured under such conditions by use of a double Langmuir probe amounts up to 7 x 10 10 cm -3 for argon plasma jets. Local variation of the ion concentration in a plane parallel to the anode decreases from 35% to 5% if the distance from the anode increases from 10 to 45 mm. A remote plasma deposition process is carried out with an oxygen plasma and the silicon organic monomer hexamethyldisiloxane and has a pressure range of between 30 and 100 Pa. The actual maximum deposition rate is 366 nm min -1 . The local film thickness variation is

Thin films with hydrophobic character are required for many applications, e.g., as diffusion barrier or as corrosion protection. These properties can be realized by plasma polymerization of fluorocarbon monomers such as C 4 F 8 to produce homogeneous layers of PTFE-like structure. Plasma polymerization requires plasma sources with high deposition rates even when processing thermally unstable substrates or those that absorb RF power. Furthermore, excellent film homogeneity is often needed when coating large surface areas. Here we characterize a radio frequency (RF) remote process to deposit such films where discharge and processing zone are separated. As primary discharge we use a novel, linear, hollow-cathode RF plasma source. The feasibility for homogeneous large-area deposition has already been demonstrated for organosilicon compounds (HMDSO). In this paper the remote polymerization of C 4 F 8 is characterized. Geometric effects are discussed as well as the influence of excitation power and gas flows on the process. Deposition rates of 160 nm min −1 and a homogeneity of ±2% over a linear dimension of 250 mm are realized. Contact angles of up to 120 correspond to those on conventional poly(tetrafluoroethylene) (PTFE). The refractive index of the films was determined to 1.375 ±0.025. Fourier transform infra-red spectra proved the existence of PTFE-like structures.

Monolayer N-atom incorporation at Si-SiO 2 interfaces in device-quality SiO 2 gate oxides has been accomplished by a three-step low-thermal budget process: (i) 300 °C remote plasma-assisted oxidation in N 2 O to form the nitrided Si-SiO 2 interface, (ii) 300 °C remote plasma-assisted chemical vapor deposition from SiH 4 and O 2 or N 2 O to form the oxide layer, and (iii) a 30 s 900 °C post-deposition rapid thermal anneal for chemical and structural relaxation. This paper reports on an extension of low-temperature plasma processing to ultra-thin gate dielectrics (

This paper presents experimental studies in which N-atoms have been incorporated at Si−SiO 2 interfaces by forming the interface and oxide film by a 300 °C remote plasma-assisted nitridation/oxidation process using N 2 O. Process dynamics have been studied by interrupted plasma processing using on-line Auger electron spectroscopy (AES). Based on the on-line AES, and complementary ex situ secondary ion mass spectroscopy and optical second harmonic generation results, monolayer nitrogen atom interface coverage has been confirmed. The factors that contribute to preferential nitrogen atom attachment at the Si−SiO 2 interface have been identified.

A 3D model has been developed for a post-discharge microwave nitriding reactor. It enables prediction of the hydrodynamics of the gas, together with the distribution of atomic nitrogen mass fractions, representing the map of the active nitriding species, and the temperature distribution inside the reactor. The coupled transport equations are solved using the PHOENICS calculation code. The model has been used to simulate the phenomena occurring in the gas phase during the nitriding of three pure iron rods placed in the reactor. The optimum nitriding conditions were determined by optical emission spectroscopy and N atoms titration by NO. Under these conditions, numerical validation of the model was performed by comparison with experiments, using a second solid-state diffusion model to evaluate the interaction between the solid and gas phases.

A new method for large area polymer deposition, based on a r.f. multi-jet plasma source is presented. Plasma jets with conical shape are extracted from a common r.f. hollow cathode discharge (HCD). The performance of the plasma sources with a single row of 14 nozzles and with a two-row matrix of 27 nozzles was characterized. At low pressure ( 10 mbar) intense plasma jets are extracted from all nozzles. Their length is a function of r.f. power and pressure, and ranges between few millimeters and 10 cm. The ignition power increases from 125 to 245 W with pressure increasing from 10 to 45 mbar. Jets can be sustained down to 3 W for 10 mbar and down to 7 W for 45 mbar. This work shows the ability of the multi-jet plasma source for large area polymer film deposition on substrates such as metal and plastic foils, membranes, textile, paper or web. To improve the homogeneity of the film and to avoid the frequent removal of polymeric residue from the HCD walls, a remote process was developed. A carrier gas (argon) is introduced into the primary HCD. The monomer (C4F8) is distributed homogeneously outside the plasma source at a distance of 35 mm from the anode surface and 12 mm from the coated substrate. Typical deposition rate is 15 nm/min.

A 2.45 GHz slot antenna microwave plasma source with a quartz tube as plasma chamber (diameter 66 cm and length 42 cm) has been applied for the removal of organic lubricants from glass substrates in a remote plasma. Optionally, a remote cage separating the primary discharge directly at the quartz tube wall from the diffusion bulk plasma in the process chamber was used. The radial and axial distributions of the ion concentrations (double-Langmuir-probe) and the removal rates (gravimetric technique) for source versions with and without the remote cage were investigated. Typical process conditions are power of 4 kW, pressure of 2–5 Pa, oxygen flow of 100 sccm. Ion concentrations of 8 × 10 10 and 1.5 × 10 10 cm −3 were measured for direct and remote plasma, respectively. The removal rates are 800 and 150 nm min −1 , respectively. The remote cage allows the suppression of local heating of substrates by microwaves and a reduction of the removal rate variation along the source length (less than 20%).

Remote plasma polymerization is the method of choice for achieving high deposition rates with low thermal substrate load and damage. Since the radical density roughly scales-up with the plasma excitation frequency, microwave plasmas are often used to yield optimum results. However, scale-up often causes problems in terms of plasma homogeneity over extended areas. It has been found also that a high degree of molecular gas fragmentation may be detrimental to high deposition rates, and in extreme cases leads to etching instead of deposition. In these cases r.f.-excited plasmas offer an attractive technological alternative with respect to performance and source complexity. We report on results with a linear 13.56 MHz hollow cathode multijet discharge (HCMD) operated in the remote processing mode. This type of source features an array of equidistantly arranged holes placed alongside the source tube axis. The incremental length of such a tube is chosen as 30 cm. Several of those tubes can be connected in series yielding total source lengths as multiples of 30 cm. Scratch resistant as well as anticorrosive thin films based on hexamethyldisiloxane (HMDSO) and hydrophobic layers based on fluorocarbon monomers have been deposited successfully. Typical growth rates were 60 nm min −1 for fluorocarbons and 1400 nm min −1 for HMDSO. The films exhibit an excellent thickness homogeneity along the linear tube axis better than 3.5%. Similar thickness variations could be achieved by moving planar substrates such as foils or membranes across the remote plasma zone.

A 13.56 MHz remote plasma reactor has been characterized by Langmuir double-probe and retarding field energy analyser measurements and optical emission spectroscopy. Under thoroughly controlled conditions the plasma density in the vicinity of the substrate holder and the ion flux reaching the substrate are very low (5 × 10 7 cm −3 and 20 nA cm −2 respectively). Above a certain power level P rf t the plasma reaches into the reaction zone and the conditions of a remote plasma are no longer fulfilled. P rf t depends on parameters such as pressure, process gas and geometrical arrangement.

Direct plasma polymerization (DPP) and remote plasma polymerization (RPP) for deposition of scratch-resistant films on polycarbonate substrates are compared. A slot antenna microwave plasma source (SLAN I) was applied for plasma generation. Argon and oxygen as carrier gases and hexamethyldisiloxane (HMDSO) as a monomer were used. Variation of the oxygen-to-HMDSO ratio for RPP allows a smooth transition between polymeric and quartz-like layers of the film. Deposition rates of 2.5 μm min −1 for DPP and 0.5 μm min −1 for RPP are typical. The substrate thermal load limits the microwave power for the DPP to below 1.2 kW. No such limitation was found for the RPP. Good films are achieved for distances from the edge of the slot antenna of less than 20 mm for DPP and up to 25 cm for RPP. RPP allows organic deposits on the plasma chamber walls to be avoided. Typical pressure, oxygen flow and HMDSO flow are 0.8 mbar, 200 sccm and 25 sccm respectively.

The ion energy distribution of a capacitively coupled r.f. (13.56 MHz) plasma and ion beam source has been measured. The extraction optics consists of two stainless steel grids. The source has been operated in two different configurations, either with or without extraction optics. In the latter case the discharge serves only as a plasma source to be used directly or as remote plasma. For measurements of ion energy in the plasma mode a four-grid retarding field analyser (RFA) was used. For analysis of ion energy in the ion beam mode a slightly different RFA was used, because the retarding voltage here is higher, corresponding to extraction voltages of several hundred volts. In the plasma mode, all distributions exhibit a single-peak structure with a low-energy tail. With increasing pressure from 4 × 10 −2 to 4 Pa the distribution width shows an increase from 1.5 to 4.5 eV, whereas the average ion energy decreases from 48 to 17.4 eV. In the ion beam mode, the ion energy distribution is studied as a function of the r.f. power and pressure.

The principles and advantages of the remote plasma-enhanced chemical vapour deposition (RPECVD) technique are discussed. Separation of plasma and substrate leads to reduce bombardment of the substrate and growing film with energetic particles. Separation of plasma and reaction zone results in an improved control of reaction mechanisms, thereby yielding films of higher purity. By using metal organic source compounds tailored for a specific process the degree of control can be enhanced. Finally, we discuss the suitability of RPECVD (using metal organic source compounds) for industrial applications and stress the need for further research in order to take full advantage of the possibilities of RPECVD.