Low dielectric constant fluoro-hydrocarbon polymer films were deposited using an electron cyclotron resonance (ECR) plasma source with pentafluorostyrene as a precursor. The pentafluorostyrene is a cyclic liquid monomer with relative high vapor pressure. The chemical structure of the deposited films were characterized by X-ray photoelectron spectroscopy, infrared spectroscopy and Rutherford backscattering spectroscopy. The structure of deposited films studies gave an insight of the fluorohydrocarbon polymer formation regarding to deposition conditions. The dielectric constant of the film was found in the range of 2.2 to 2.4. The influence of deposition conditions on chemical, physical and electrical properties of the resulting films were evaluated.

Nanocomposite films consisting of gold nanoclusters embedded in a fluorocarbon matrix were prepared by simultaneous plasma polymerization of a fluorocarbon gas and magnetron sputtering of a gold target. The optical constants of the films were determined using variable angle spectroscopic ellipsometry (VASE). The Maxwell-Garnett (M-G) effective medium theory (EMT) was used to extract the microstructural characteristics (gold volume fraction, cluster size). The predictions of the M-G EMT were compared with the results from x-ray photoelectron spectroscopy. Angle-resolved measurements suggest the presence of a carbonaceous layer at the cluster surface. The presence of such a layer is discussed in the context of its influence on the validity of the optical model

Fluorocarbon/silicon oxide composite thin films were prepared, expecting higher thermal stability, by mixing hexamethyldisiloxane (HMDSO, (CH 3) 3-Si-O-Si-(CH 3)3) with tetrafluoroethylene (TFE, CF2=CF2) using an RF( 13.56 MHz) PE-CVD method for the purpose of application to low-k IMDs. Structure of the deposited films was investigated by XPS and FT-IR. Film composition can be changed gradually from fluorinated carbon to organic siloxane by changing the HMDSO mixing ratio. The films possessed dielectric constants less than 2.5 for HMDSO mixing ratios less than 10%. Thermal treatment of the films revealed that C-Fn, Si-O-Si, Si-(CH3)n and Si-(CH2)n-Si bonds were stable to 400°C, but C-Hn bonds were not. In situ gas-phase FT-IR spectroscopy was performed on the TFE/HMDSO plasma to help determine reaction mechanisms.

It is very important to select superior interlayer Pre Metal Dielectric (PMD) materials which can act as a penetration barrier to various impurities created by the Chemical Mechanical Polishing (CMP) processes. In this paper, hot carrier degradation and device characteristics were investigated with material variation of PMD-1 layers, which were split by LP-TEOS, SR-oxide, PE-oxynitride, PE-nitride and PE-TEOS films. It was observed that the PE-oxynitride and PEnitride using plasma was greatly deteriorated in hot carrier effect in comparison with silicon oxide. Consequently, it is clearly shown that silicon oxide turned out to be a better PMD-1 material than both PE-oxynitride and PE-nitride. From the results, it is suggested that LP-TEOS film is the best PMD-1 material among the silicon oxide samples.

An organosilicon compound, hexamethyldisilane (HMDS) was incorporated for SiC thin film preparation by remote plasma enhanced CVD method. We investigated how plasma excited radicals react with source monomers using two kinds of gas mixtures. It was found that film component and formation mechanism depends on stronger on plasma gases. Using a mixture of nitrogen and hydrogen gases as plasma gas source, deposited films contained large amounts of nitrogen. When uing an argon and hydrogen mixture, deposited film was a SiC with large hydrogen contents. In this research, we found that hydrogen radicals are very active for decomposition of monomer source gas and this can be related to precursors for film deposition. When using a mixture of argon and hydrogen as plasma gas, the film deposition speed was influenced by substrate temperature. The estimated activation energy was larger than the case of using nitrogen and hydrogen gases. Different reaction mechanisms were observed for different plasma gas source

Even under demanding environments, like clean rooms, polymers are already used in different-ranges of applications. The wear and particle generation within a specific particle size even under-mechanical stress is a limiting factor. So it was the aim to develop an innovative material-concept, that enables to apply a thermoplastic polymer coated with a thin hard material (thickness-up to 2.5 gm), which also prevents for electrostatical discharges and is usable for complex-bodies. Therefore it was necessary to improve the wear resistance and the adherence between the-polymer and the coating. To take also economic aspects into consideration a two step production-process sequence was required, consisting of the injection moulding process and then the plasma-deposition process including a plasma pre-treatment. In this investigation, poly(butyleneterephthalate)-(PBT) and poly(amide) 6.6 (PA) and polycarbonate (PC) were chosen as substrate-material. The coating materials used, which were mainly deposited by Magnetron Sputter Ion-Plating (MSIP), were on titanium basis (Ti-N). To get detailed chemical information about the-coatings and the interfacial region they were analyzed by X-Ray Photoelectron Spectroscopy-(XPS), additionally Secondary Ion Mass Spectrometry (SIMS) experiments were carried out to-confirm the results. The process parameter's influence on the microstructure, which extend from-amorphous to columnar (crystalline), and the film thickness were analyzed by SEM. It will be-shown and discussed, that it is possible to improve the coating's adherence by plasmapretreatment-as well as to reduce the particle generation after a suitable etching and coating process.

The drift of PECVD TEOS etch rate has been observed during MERIE oxide etch for damascene process. Etch rate typically fluctuates between 5300 Å/min. and 6000 Å/min. depending on chamber condition. Studies using fluorocarbon based chemistry show high TEOS etch rate when chamber wall is heavily coated with polymer deposition. Low etch rate appears when chamber has less deposition. Hysteresis behavior has been observed in TEOS etch rate and emission intensity trends ofF and CFx (x = 1 ∼ 3). From the correlation between etch rate and emission intensity, a model is proposed to explain the impact of chamber wall polymer deposition on TEOS etch rate. It clearly shows that F is directly responsible for the etch of TEOS. Comparing to F, CFx plasma chemistry has a closer link in chamber wall polymer formation, but less contribution in the etch of TEOS.

The materials with lower dielectric constant ( low k ) have been attracting attention recently because the low k material has the potential to be used in place of SiO2 in ULSI. In this work, we focused on evaluating organic low k material performance with plasma etch in the Applied Material's eMxP+ anisotropic etch chamber. The films studied were Dow Chemical BCB and Silk, Allied Signal Flare 2.0, and Du Pont FPI. The feature sizes of the wafer s were 0.25 to 1 micron trenches. Du Pont FPI resulted in the highest achieved etch rate of more than lum/min, followed by BCB, and Flare. The microloading study indicated that the etch rate microloading is less than 10% between lum and 0.25 urn feature sizes, which suggests that the chance of etch stop for a high aspect ratio features will be small. The profile could vary from bowing to vertical, to tapering by using different process conditions, mainly by temperature. The FP1 profile was more tapered than those of BCB and Flare when the same process was used to etch the same type of patterned wafer having these three different low k films. The detailed study showed that the trend of etch rate and profile for BCB and Flare film etch were similar, but that the absolute value for profile, as well as the trend of etch rate uniformity and profile were somewhat different. In conclusion, low k materials can be etched in AMAT traditional dielectric chamber (eMxP+) with a good etch rate and profile control.

Chemical vapor deposition (CVD) continues to generate immutable interest as a method of producing thin fluorocarbon films. This impetus stems from both the process advantages of CVD and the extensive market potential for the resultant films. Fluorocarbon films find extremely diverse applications because of their unique electrical, chemical and surface properties. They are currently being evaluated, among other applications, as dielectric interconnects in microelectronic circuits1–3 and as passivation coatings in clinical devices.

The flux of vacuum ultraviolet (VUV) and ultraviolet (UV) photons from a hydrogen plasma was detected by fluorescence measurements of sodium salicylate sheets with and without a MgF2 window. In order to expose the samples to the same photon flux in all experiments, the power input to the microwave plasma source was adjusted. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) were treated with VUV radiation or with a remote hydrogen plasma. The mass loss and the CH-absorption loss were recorded by in situ quartz crystal micro balance and by in situ IR reflection absorption spectroscopy, respectively. The VUV irradiation and plasma treatment caused similar effects in the case of PE, PP showed an increased polymer ablation in plasma treatments, and for PS a negligible loss in mass and CH absorption was detected in plasma and VUV treatments.

Only one weak point of all aromatic group polyimide surface was changed to water repellency. Polyimide surface was photo-chemically modified to be fluorinate with ArF excimer laser and Xe2 · excimer lamp irradiation. To promote the photo- chemical reaction, Xe2· excimer lamp was employed to produce CFn. radical from CF4 gas. Simultaneously, ArF excimer laser was irradiated on the polyimide surface to dissociate C-H bond. Dangling bond of C was reacted with CF, radical and produced C-CF, on the polyimide surface. By this modification, polyimide surface was changed to water repellency. As a result, polyimide surface was photo-chemically modified to fluorinate with CF4 gas pressure of 100Torr, the Xe2 excimer lamp of 7mW/cm2, and the ArF excimer laser of 30mJ/cm2, 10Hz and 3000shots, the contact angle with water was 134 degrees. And chemical composition of the photo-modified polyimide surface was inspected by ATR-FTIR spectra measurement.

The energy and the flux of impinging ions are important factors which determine the properties of deposited films and of exposed surfaces (microstructure, density, hardness, roughness, stress, chemical structure, adhesion etc.). In the present work, we use a multigrid retarding field analyzer to study ion bombardment characteristics in two different systems: a pulsed microwave plasma reactor, and a cold cathode ion source. We have found that the ion energy distribution functions (IEDF) possess specific features for each mode of operation: we evaluate the shape and the maximum and the mean ion energies of the IEDF for different gases such as Ar and N2. These ion characteristics are correlated with surface restructuring of differently treated polymers (polycarbonate and polyethylene terephthalate), analyzed by XPS.

By means of microwave-assisted plasma polymerization it is possible to deposit polymer coatings on different surfaces such as plastics or metals. The surface tension can be influenced in a wide range. However, many applications require a high thermal stability of such low surface tension layers. Therefore, the influence of variations of the process parameters on temperature stability of such layers is examined. The produced layers were studied regarding their chemical and physical characteristics under temperature influence by means of contact angle measurements, xray photoelectron spectroscopy (XPS), thermo gravimetric analysis (TGA) combined with Fouriertransformed infrared spectroscopy (FTIR). Fluorine containing monomers offer good perspectives. Up to temperatures of approx. 200°C the antiadhesivity of these coatings is adjustable to values close to those of poly(tetrafluoroethylene) (PTFE).

Transparent ceramic barrier films are the object of increasing interest in packaging, pharmaceutical, optical, and electronics industries, since they can reduce the permeation rate of oxygen (OTR) and/or water vapor (WVTR) by several orders of magnitude. We prepare silicon dioxide (Si02) or nitride (“SiN”) barrier layers by plasma-enhanced chemical vapor deposition (PECVD). We have shown that OTR (and WVTR) decrease with increasing coating thickness, d, to a certain asymptotic minimum value, when d ≥ 50 nm; the residual permeation is attributed to the presence of microscopic defects in the coating. Since the coatings are transparent and very thin, the detection of defects and the analysis of their origin are very difficult.

We have recently developed techniques based on reactive ion etching (RIE) in oxygen plasma to render visible micrometer- or sub-micrometer-sized defects in transparent barrier coatings on transparent polymers. These techniques can be used to better understand the origins of defects in these coatings on a microscopic scale, as well as for mapping and counting defect density on a macroscopic scale (tens of cm2 or more).

In this article we present a correlation between measured 02 transmission rate (OTR) values and the number density and size distribution of defects in SiO2 barrier coatings. Excellent agreement between measured and calculated OTR values allows us to confirm that residual OTR is indeed controlled by pinhole defects; our results also compare well with published data for aluminized PET.

Plasma enhanced chemical vapor deposition (PECVD) is increasingly being applied for the fabrication of functional coatings on polymeric substrates. This presentation briefly reviews the energetics of plasma-surface interactions leading to the deposition of films for different applications such as optical coatings, barriers against gas and vapor permeation, and protective coatings for space. Particular emphasis is placed on the formation and characterization of a relatively wide (tens of nm) interfacial region (“interphase”) between the coating and the polymer, its role in adhesion, and in optical, mechanical and other functional porperties of thin film systems on plastic substrates.

A new process has been developed for the high rate vacuum deposition of solid films from high molecular weight/low vapor pressure liquid, or even liquid/solid suspension, monomer precursors. The gas resulting from the flash evaporation of a liquid monomer mixture, or from a suspension of insoluble solid particles in liquid monomer, is used as the support medium for a glow discharge in a Plasma Enhanced Chemical Vapor Deposition-like (PECVD) process. Due to the high molecular weight/low vapor pressure nature of the precursors, the plasma of the flash evaporated gas cryocondenses at extremely high rate on substrates at ambient, and higher, temperatures. Upon condensation the liquified plasma immediately begins to polymerize to form a solid film due to the high concentration of radicals and ions contained in the liquid film. The process has been successfully implemented in a vacuum roll coating system in a roll-to-roll deposition process. Polymer films, Molecularly Doped Polymer (MDP) composite films of polymer containing light emitting organic molecules, and MDP composite films of polymer containing organic dye molecules have been deposited at thicknesses ranging from 0.1 microns to 24 microns at webs speeds as high as 96 linear meters per minute. This new deposition process will be discussed along with some properties of the films fabricated with this new process.

PET and Kapton thin films have been plasma processed in order to increase sputtered aluminum adhesion. The effect of different plasma feedings, such as NH3, O2, and He, has been evaluated on polymer/metal adhesion and on chemical modifications of polymer surface at different plasma power and treatment time. The chemistry at polymer/metal interface has been studied in order to find the suitable experimental conditions for transferring the plasma process to industrial scale.

The role of acid-base reactions in promoting Polymer/Aluminum adhesion has been investigated. Surface composition has been investigated by X-ray Photoelectron Spectroscopy; adhesion measurements have been accomplished by 180° Peel Test.

Adhesion of plasma-deposited optical and protective coatings, such as amorphous hydrogenated silicon nitride, SiN1.3, on polymethyl-methacrylate (PMMA) substrates has been found to be limited by a cohesive failure inside the PMMA bulk. Using direct exposure to a low pressure plasma in helium or to vacuum ultraviolet radiation generated from H2 plasma for an extended period of time, we succeeded to obtain excellent adhesion even under a humidity test at elevated temperature. We found, using a multitechnique approach, that such improved adhesion is achieved by forming a crosslinked, mechanically stabilized layer in the interfacial region, which possesses a physical thickness of 50 to 100 nm.

For the improvement of the adhesion to ethylene vinylacetate copolymer (EVA), poly (ethylene terephthalate) (PET) films were treated with low pressure plasmas in a laboratory batch reactor and in a pilot scale semi-continuous treatment system. The effects of the treatments were investigated by mechanical testing of the PET-EVA laminates, by XPS, by chemical derivatization for XPS, and by contact angle measurements including a data processing for the determination of Lewis acid/ base properties of the surfaces. It was found that the adhesion between the polymer surfaces seems to be based on rather specific interactions which ask for certain conditions for the surface treatment. The differences between the batch treatments and the semi-continuous treatments are discussed.

Surface effects produced by plasma processing Ultra High Molecular Weight polyethylene (UHMW) were examined. The goal was to enhance adhesion of UHMW to a variety of polar polymers. This research focussed on enhancing adhesion to polyurethane. UHMW samples were immersed in a DC discharge and subjected to various processing conditions. The background gases experimented with were oxygen, nitrogen, and argon, and the pressure was varied between 6-67 Pa. The processing time, discharge current and discharge potential were also varied. A polar polymer (polyurethane) was subsequently applied to the processed UHMW samples and the tensile strength of the bonds was measured. Standard dogbone specimens were fabricated, and the polymer interfaces placed in the middle of the gage section and oriented normal to the tensile axis. The specimens were tested to failure in displacement control at an approximate strain rate of 0.2% per sec. In general, significant enhancement in yield strength was observed over unprocessed samples, where essentially no bonding occurred. Samples subjected to plasma processing in oxygen showed the strongest adhesion, while those in argon were almost as good, followed by nitrogen.

The contact angle of water on the processed UHMW samples ranged from about 45° to less than 2°, while unprocessed samples had a contact angle of about 70°. These data correlated with the yield tests. XPS was used to examine the composition of the UHMW surfaces before and after plasma processing with oxygen. It is believed that the plasma etched off surface layers, creating unsaturated carbon bonds that can chemically react with polar polymer groups. Precast, processed UItMW surfaces were found to be reactive for periods of up to one week. Optimum conditions of plasma processing were identified, and will be discussed in light of the chemistry occurring at the interface.