Low-temperature Vapor Deposition Research Articles

Preparation and surface modification of magnesium-based sound absorbing materials via a low-temperature vapor deposition

The poor durability of lightweight cement due to hydrophilic property and porous microstructure limits its extensive application. In this study, a superhydrophobic magnesium-based sound absorbing materials (Mg-SAM) have been prepared using basic magnesium sulfate cement as the matrix material and then modified by a low-temperature vapor deposition (LTVD). The results reveal that an ultrathin film of perfluorodecyltriethoxysilane (PFDTS) can be gently deposited on the surface of Mg-SAM with a water contact angle higher than 150° via a low temperature (65 °C) heating process. The modification mechanism of LTVD can be described as the formation of a self-assembled fluorine-containing film through the condensation reaction between silanols and the hydroxyl groups on the surface of Mg-SAM. The noise reduction coefficient and mechanical strength of Mg-SAM with a density of 280 kg·m−3 reach 0.7 and 1.8 MPa respectively without any change after LTVD treatment. This facile, low-cost LTVD technique is a promising approach for large-scale modification of porous materials.

Structural characterization and magnetic response of poly(p-xylylene)\u2013MnSb and MnSb films deposited at cryogenic temperature

In this study, we employed several experimental techniques to investigate structure and magnetic properties of poly(p-xylylene)–MnSb composites synthesized by low-temperature vapor deposition polymerization technique and MnSb films deposited at various temperatures. The presence of MnSb nanocrystallites in the studied films was verified by the results of X-ray diffraction, electron microscopy and Raman spectroscopy studies. The obtained data revealed the formation of Sb-rich sublayer with well-oriented Sb grains near the susbtrate, which seems to act as a buffer for the consequent poly(p-xylylene)–MnSb or MnSb layer growth. Increasing the polymer content results in qualitative change of surface morphology of studied films. At high polymer content the hybrid nanocomposite with MnSb nanoparticles embedded into poly(p-xylylene) matrix is formed. All investigated samples demonstrated detectable ferromagnetic response at room temperature, while the parameters of this response revealed a complex correlation with nominal composition, presented crystal phases and surface morphology of studied films. Estimated values of the Curie temperature of the samples are close to that of bulk MnSb.

Effect of ZnO cap layer deposition environment on thermal stability of the electrical properties of Al-doped ZnO films

Al-doped ZnO (AZO) is a promising candidate as a transparent conducting electrode. However, the electrical properties of AZO deteriorate greatly after exposing it to excessive heat. This limits the applications of AZO in devices that experience a demanding operation environment. It has been shown that a ZnO cap layer with proper morphology is capable to dramatically improve the thermal stability of AZO. However, the detailed mechanism is not yet clear. A comparison study of the electrical properties of AZO with a ZnO cap layer prepared by magnetron sputtering (MS) at low substrate temperature (70 °C) and chemical vapor deposition (CVD) at high substrate temperature (600 °C) indicates that MS-prepared ZnO is much less effective in protecting AZO from an oxidizing environment under elevated temperature than the CVD-prepared ZnO. The morphology and crystal structures of two types of ZnO/AZO, investigated by a scanning electron microscope and x-ray diffraction, are relatively similar, whereas the atomic structures (e.g., defects) revealed by Raman spectroscopy are rather different. The results suggest that it is difficult to improve the thermal stability of electrical properties of AZO without a proper restructuring process and a ZnO cap layer that could sacrifice its own structural order. The discoveries offer a novel approach to improve the performance of other transparent conducting oxides.

Parylene-based polymeric dielectric top-gate organic field-effect transistors exposed to a UV/ozone environment

Abstract Organic field-effect transistors (OFETs) structured with a top-gate configuration have several advantages, such as better charge-carrier injection, easy gate line designing, and encapsulation or protection of devices, over those configured with a bottom-gate architecture. In particular, Poly (para-xylylene) (Parylene) -based polymer and its derivatives are considered suitable insulating materials for these transistors, due to thin film formation through a low-temperature vapor deposition process, superior barrier properties, and excellent dielectric characteristics. In this study, we analyzed two types of Parylene dielectrics (Parylene-C and Parylene -AF) considering their thin film formation process, surface, insulating, and OFET operation characteristics. Furthermore, we investigated the durability of the top-gate based OFETs composed of two polymer dielectrics while it was exposed to a UV/ozone environment. Also, we could fabricate UV/ozone durable top-gate OFETs composed by a bilayer with both Parylene dielectrics. We expect, therefore, that these results will help the selection and use of versatile dielectric layers for top-gate based OFETs.

Comparative analysis of low-temperature PVD-based TiN nano-thin-film-coated and -uncoated TNMG inserts in dry machining

ABSTRACTTitanium nitride (TiN) is a hard-ceramic material having excellent wear and corrosion resistance properties. In this study, TiN coating has been deposited on carbide cutting inserts by a low-temperature cathodic arc phsical vapor deposition (PVD) system. Comparative analysis of machining performance, based on tool life and work piece surface roughness, has been done between the TiN-coated carbide cutting inserts and uncoated carbide cutting inserts in dry machining of medium carbon AISI 1045 steel. Design of experiments (DOE) technique along with response surface regression has been used for the optimization of machining parameters. The most significant factor affecting the surface roughness of the work piece in dry machining was found to be the feed rate. TiN-coated carbide cutting inserts showed 15% improvement in the surface roughness of work piece and 60% improvement in tool life as compared to uncoated carbide cutting inserts.

Влияние наполнителя на ИК-спектры полимерных нанокомпозитов поли-n-ксилилен-сульфиды

Проведены исследования ИК-спектров в области 500—4000 см-1 пленок полимерных нанокомпозитов на основе поли-п-ксилилена (ППК) и сульфидов (ППК—PbS, ППК—CdS, ППК—S) в зависимости от содержания наполнителя (С ~ 0—100 об. %). Пленки толщиной d ~ 0.5 мкм получены методом твердофазного криохимического синтеза на подложках из кремния. Выявлены общие изменения в ИК-спектрах нанокомпозитов по сравнению с пленкой чистого ППК и индивидуальные особенности для каждого наполнителя. С ростом концентрации наполнителя наблюдались низкочастотный сдвиг полосы внеплоскостных деформационных колебаний С-Н-связей ароматического кольца и изменения интенсивностей характеристических полос матрицы ППК. Для нанокомпозитов ППК—PbS и ППК—CdS обнаружены дополнительные полосы в области 1000—1800 см-1, а для пленок ППК—CdS — еще дополнительная полоса в области 3100— 3600 см-1. В пленках ППК—S зарегистрировано только сильное ослабление полос поглощения валентных колебаний С—С- и С—Н-связей ароматического кольца, а также деформационных С—Н-колебаний в СН2-группе. Появление дополнительных полос в ИК-спектрах пленок ППК— PbS обусловлено образованием как сульфооксидных фаз с участием наночастиц PbS, так и групп С—О, С=О из-за окисления полимерных цепей матрицы ППК, а в пленках ППК—CdS — наличием сложных соединений, содержащих сульфо- (SO4, гидроксильные (OH) и карбоксилатные (СОО-) группы. Кроме того, в ИК-спектрах пленок ППК—PbS и ППК—CdS обнаружены полосы, связанные с изменениями структуры замещенного бензольного кольца из-за потери им симметрии.

High temperature synthesis and characterization of ultrathin tellurium nanostructures

Thin tellurium (Te) has been predicted as a potential two dimensional system exhibiting superior thermoelectric and electrical properties. Here, we report the synthesis of high quality ultrathin Te nanostructures and the study of their electrical properties at room temperature. High quality ultrathin Te nanostructures are obtained by high temperature vapor phase deposition on c-plane sapphire substrates. The obtained nanostructures are as thin as 3 nm and exhibit α-Te phase with trigonal crystal structure. Room temperature electrical measurements show significantly higher electrical conductivity compared to prior reports of Te in bulk form or in nanostructure form synthesized by low temperature vapor deposition or wet chemical methods. Additionally, these nanostructures exhibit high field effect hole mobility comparable to black-phosphorous measured previously under similar conditions.

The Effect of Filler Content on the IR Spectra of Poly(p-xylylene)–Sulfide Nanocomposites

The effect of the nature of a filler and its concentration (C ~ 0–100 vol %) on the IR spectra (500–4000 cm–1) of thin nanocomposite films based on poly(p-xylylene) and sulfides (PPX–PbS, PPX–CdS, and PPX–S) was studied. Films with a thickness d ~ 0.5 μm are produced via low-temperature vapor deposition polymerization on silicon substrates. The common and specific variations in the IR-spectra of nanocomposite films are identified. The low-frequency shifts of C–H out-of-plane deformation vibrations of aromatic rings and the changes in characteristic band intensities of PPX are observed with increasing filler concentration. Additional IR-bands arise at 1000–1800 cm–1 for PPX–PbS and PPX–CdS films and at 3100–3600 cm–1 for PPX–CdS ones. However, the bands attributed to C–C and C–H stretch vibrations of the ring and С–Н deformation vibrations of СН2-groups are found to lose much of their intensity in PPX–S films. The occurrence of complementary IR bands in nanocomposites is due to the formation of (1) complex sulfoxide phases with PbS nanoparticles, (2) C–O and C=O groups because of the oxidation of PPX polymer chains in the PPX–PbS films, and (3) complex compounds with sulfo (SO4), hydroxyl (OH), and carboxylate (СОО–) groups in the PPX–CdS films. Furthermore, some IR bands in PPX–PbS and PPX–CdS films are structural modifications of the substituted aromatic ring due to loss of symmetry.

Effect of Filler Concentration and Film Thickness on Structure and Optical Properties of Poly(p-Xylylene)−Cadmium Sulphide Nanocomposites

The effect of filler concentration (C ≈ 0–100 vol %) and film thickness (d ≈ 0.02, 0.2, 0.5, and 1.0 μm) on the optical absorption spectra and surface morphology of thin nanocomposite films based on poly(p-xylylene) and cadmium sulphide (PPX–CdS) has been studied. The PPX–CdS films are prepared by low-temperature vapor deposition polimerization on quartz and silicon substrates. A nonmonotonic dependence of the absorption spectrum red shift on the filler concentration is revealed. The red shift of the spectrum reaches a maximum at some critical concentration of the filler C0. It is observed that the value of the critical concentration C0 increases with the film thickness and equals C0 ≈ 11, 30, and 50 vol % for d ≈ 0.02, 0.5, and 1 μm, correspondingly. The average size of the nanoparticles is evaluated by an analysis of the absorption spectra (via estimating the exciton-peak wavelength). It is found that the shift in the absorption spectra is determined by a variation in the nanoparticle size. Atomic force microscopy reveals the effect of the filler content on the surface morphology of the polymer matrix in nanocomposite films and their surface roughness. The size distribution of the polymeric grains is evaluated. The most significant changes in the absorption spectra and surface morpology of the composites with a variation in the filler content are observed in the filler concentration range from 0 to C0. The absorption spectra of the composites with the filler concentration above C0 are similar, which can be attributed to the almost equal nanoparticle size in these nanocomposites. The correlation between changes in the matrix morphology and filler optical properties is established.

X-ray Diffraction Study on Simple Molecular Glasses Created by Low-Temperature Vapor Deposition

The structure of simple molecular glasses has been one of the central issues in the research of glasses. We tried to form the glasses of carbon dioxide (CO2), carbon monoxide (CO), and nitrogen (N2) molecules by slow vapor deposition at 3 K (deposition rate: ca. 10 nm/h). Glassy CO2 was successfully obtained and it crystallized on heating at 25 K, which is lower than the hypothetical glass transition temperature of CO2. The CO2 glass is the simplest molecular glass ever created. The X-ray diffraction patterns and derived pair distribution functions revealed that the glassy CO2 has a structure in which the intermolecular distance is shorter and the intermolecular correlation is much stronger than those of liquid CO2. Orientational glasses, which are positionally ordered and orientationally disordered, of CO and N2 were obtained and they were gradually ordered as the annealing temperature is increased.

低温蒸着法で作製した単純分子ガラスの構造

低温蒸着法で作製した単純分子ガラスの構造

Structure and optical properties of thin poly(p-xylylene) – Silver nanocomposite films prepared by low-temperature vapor deposition polymerization

In this study, variable-temperature grazing-incidence X-ray diffraction, transmission electron and scanning force microscopy were employed to address the semicrystalline structure and surface morphology of thin poly(p-xylylene) – silver nanocomposite films with Ag concentrations up to 12 vol.%. It was observed that the dominant crystalline modification of poly(p-xylylene) in the studied films is α-form, which is in contrast to thick poly(p-xylylene) films deposited at liquid nitrogen temperature where β-form prevails. The films exhibit planar texture that can be further enhanced on annealing. The optical properties of the films were studied by UV–vis and IR-spectroscopy. It was found that the samples display surface plasmon resonance, with the peak wavelength in the range of 435–445 nm. The peak positions undergo a redshift upon a long-term storage under ambient conditions. The IR-spectroscopy reveals the bands, which can be assigned to the vibrations of oxygen-containing groups, with intensity increasing with silver content.

O181 Projected benefits of a home-based approach to chronic heart failure management: Long-term data from the multicentre Which Intervention is most cost-effective and Consumer friendly in reducing Hospital stay Trial

Hard coatings based on ternary Ti–Al–N and Cr–Al–N are commercial products currently employed in many industrial applications due to their outstanding chemical and physical properties, including high hardness and toughness and thermal as well as chemical stability. In this chapter the current understanding of mechanisms relevant for the thermal and chemical stability of these coating systems will be summarized based on state-of-the-art experimental and computational data.Synthesized by low-temperature (substrate temperatures below 500 °C) plasma-assisted vapor deposition (PVD) techniques, ternary Ti1−xAlxN, Cr1−xAlxN, and related coatings form metastable solid solutions. Depending on the chemical composition (and the deposition parameters used, like substrate temperature, gas pressure, and ion bombardment), the coatings crystallize in a face centered cubic (fcc) NaCl-type (c) or a hexagonal close packed (hcp) wurtzite-type (w) phase. For the main engineering applications, the cubic modification is preferred due to the superior mechanical, tribological, and oxidation properties. For example, the hardness of as-deposited c-Ti1−xAlxN and c-Cr1−xAlxN coatings, with AlN content (x) close to its metastable cubic solubility limit of x ∼ 0.7, can be as high as 37 and 30 GPa, respectively. During thermal treatments above the deposition temperature (e.g., during cutting application), the coatings undergo various processes to reach equilibrium. While for single-phase cubic Ti1−xAlxN the decomposition into the stable phases c-TiN and w-AlN occurs across the formation of cubic Al-rich and Ti-rich domains, the decomposition of Cr1−xAlxN is driven by nucleation and growth of w-AlN as well as by the release of N2 starting at temperatures around 1000 °C. The combination of experimental (e.g., x-ray diffractometry, calorimetry, nanoindentation, scanning and transmission electron microscopy, and atom probe tomography) with computational (e.g., density functional theory and continuum mechanics) studies allows for identifying, describing, and understanding the mechanisms and processes that govern the thermally induced decomposition. Thermal stability is discussed for Ti1−xAlxN-based coating systems, while chemical stability is analyzed for Cr1−xAlxN-based coating systems. Furthermore, the influence of alloying elements such as Y, Nb, Ta, Zr, and Hf on the phase formation, structure, mechanical, and thermal properties of these ternary Ti1−xAlxN and Cr1−xAlxN coatings is discussed.

Electrical properties, structure, and surface morphology of poly(p-xylylene)–silver nanocomposites synthesized by low-temperature vapor deposition polymerization

The crystalline structure, surface morphology, electrical, and optical properties of thin films of nanocomposites consisting of silver nanoparticles embedded in poly(p-xylylene) matrix prepared by low-temperature vapor deposition polymerization were studied. Depending on the filler content, the average size of silver nanoparticles varied from 2 to 5 nm for nanocomposites with 2 and 12 vol.% of silver, correspondingly. The optical adsorption in the visible region due to surface plasmon resonance also exhibited a clear correlation from silver content, revealing a red shift of the adsorption peak with the increase of the metal concentration. The temperature dependences of the dc resistance of pure p-xylylene condensate and p-xylylene–silver cocondensates during polymerization as well as temperature dependences of the formed poly(p-xylylene)–silver nanocomposites were examined. The observed variation of the temperature dependences of electrical resistance as a function of silver concentration are attributed to different conduction mechanisms and correlated with the structure of the composites. The wide-angle X-ray scattering and AFM measurements consistently show a strong effect of silver content on the nanocomposite structure. The evolution of the size of silver nanoparticles by thermal annealing was demonstrated.

Carbon dioxide adsorption performance of N-doped zeolite Y templated carbons

N-Doped microporous carbons are prepared using zeolite NaY as a hard template with furfuryl alcohol/acetonitrile as carbon precursors. CO2 adsorption performances of these carbons are investigated intensively. Structure analysis shows that the replication of zeolite regularity, pore texture and the type of nitrogen functionalities strongly depends on the carbonization temperature. Basic nitrogen functionalities can be efficiently introduced into the carbon framework, which significantly facilitate CO2 uptake via chemical adsorption. The CO2 adsorption isotherms correlated with the Dubinin–Astakhov models, and the isosteric heats of adsorption are calculated using the Clausius–Clapeyron equation. The maximum CO2 adsorption capacity of 10.4 wt% is obtained for the YTC7 carbon due to its high surface area and abundant nitrogen functionalities. CO2 chemical adsorption on the carbons decreases with carbonization temperature due to the decomposition of basic nitrogen functionalities at higher temperature. High CO2 adsorption capacities of up to 9.3 wt% at 25 °C and 4.1 wt% at 70 °C are obtained for the YTC6 carbon. The present study suggests that low temperature vapor deposition of acetonitrile is a promising alternative method of toxic ammonia treatment for CO2 adsorption.

Formation mechanisms of precursors of radiation-induced color centers during fabrication of silica optical fiber preform

Samples in the form of transverse slices of rods and optical fiber preforms made from the high-hydroxyl KU-1 and low-hydroxyl KS-4V silica by the plasma outside deposition (POD) method are γ-irradiated to a dose of ∼1 MGy (SiO2). Next, the radial dependences of the radiation-induced nonbridging oxygen hole center (NBOHC) and E′-center (three-coordinated silicon) in the samples are constructed by measuring the amplitudes of their 4.8 and 5.8 eV absorption bands, respectively. Based on the analysis of these radial dependences and considering the temperature and duration of the preirradiation heat treatment of the rods and preforms at the POD-installation, we determine the ratio of the oscillator strengths of the above bands and the microscopic thermoinduced processes occurring during preform fabrication and producing precursors of the radiation-induced NBOHC and E′-center. These processes are found to be associated with the escape of either H2 or H2O from neighboring hydroxyl groups, and, therefore, can occur in high-hydroxyl silica only. It is concluded that enhancement of the radiation resistance of high-hydroxyl silica optical fibers requires decreasing the temperature and duration of the preform fabrication process, in particular, changing from the POD-technology to the low-temperature plasmachemical vapor deposition (PCVD) or surface PCVD (SPCVD)-technology.

비정질 Ge1-xMnx박막의 자기수송특성에 미치는 열처리 효과

Amorphous _ semiconductor thin films grown by low temperature vapor deposition were annealed at various temperatures from 400 to for 3 minutes in high vaccum chamber. The electrical and magnetotransport properties of as-grown and annealed samples have been studied. X-ray diffraction patterns analysis revealed that the samples still maintain amorphous state after annealling at for 3 minutes and they were crystallized when annealing temperature increase to . Temperature dependence of resistivity measurement implied that as-grown and annealed _ films have semiconductor characteristics, the increase of resistivity with annealling temperature was obseved. The -annealed sample exhibited negative magnetoresistance (MR) at low temperatures and the MR ratio was 8.5% at 10 K. The asymmetry was present in all MR curves. The anomalous Hall Effect was also observed at 250 K.

비정질 Ge1-xMnx박막의 전기적, 자기적 특성에 미치는 열처리 효과

저온 증착법으로 성장시킨 비정질 <TEX>$Ge_{1-x}Mn_x$</TEX> 박막을 열처리하여 전기적, 자기적 특성을 연구하였다. 비정질 박막의 두께는 <TEX>$1,000{\sim}5,000\;{\AA}$</TEX>이고 비정질 <TEX>$Ge_{1-x}Mn_x$</TEX> 박막을 고 진공 분위기 하에서 각각 <TEX>$300^{\circ}C$</TEX>, <TEX>$400^{\circ}C$</TEX>, <TEX>$500^{\circ}C$</TEX>, <TEX>$600^{\circ}C$</TEX>, <TEX>$700^{\circ}C$</TEX> 온도에서 3분 동안 열처리 하였다. 원 시료의 <TEX>$Ge_{1-x}Mn_x$</TEX> 박막을 X-선 회절로 분석해보면 비정질 구조를 보였지만 열처리를 함으로써 결정화되었다. 비정질 <TEX>$Ge_{1-x}Mn_x$</TEX> 박막에서 결정화가 이루어진 온도는 Mn 농도에 따라 변화하였다. 비정질 <TEX>$Ge_{1-x}Mn_x$</TEX> 박막은 p형 캐리어를 가지고 있고 열처리 동안에도 캐리어 형태는 변하지 않았다. 하지만, 전기 비저항은 열처리 온도가 증가함에 따라 증가하였다. 자기적 특성에서 원 시료의 비정질 <TEX>$Ge_{1-x}Mn_x$</TEX> 박막은 강자성특성을 보이면서 큐리온도는 약 130 K 정도이다. 열처리한 <TEX>$Ge_{1-x}Mn_x$</TEX> 박막의 큐리온도와 포화 자화값은 열처리 온도에 따라 증가한다. 자화거동과 X-선 분석을 통해 열처리한 <TEX>$Ge_{1-x}Mn_x$</TEX> 박막에 전기적, 자기적 특성의 변화는 강자성 <TEX>$Ge_3Mn_5$</TEX> 상이 형성되었음을 나타낸다. Amorphous <TEX>$Ge_{1-x}Mn_x$</TEX> semiconductor thin films grown by low temperature vapor deposition were annealed, and their electrical and magnetic properties have been studied. The amorphous thin films were <TEX>$1,000{\sim}5,000\;{\AA}$</TEX> thick. Amorphous <TEX>$Ge_{1-x}Mn_x$</TEX> thin films were annealed at <TEX>$300^{\circ}C$</TEX>, <TEX>$400^{\circ}C$</TEX>, <TEX>$500^{\circ}C$</TEX>, <TEX>$600^{\circ}C$</TEX> and <TEX>$700^{\circ}C$</TEX> for 3 minutes in high vacuum chamber. X-ray diffraction analysis reveals that as-grown <TEX>$Ge_{1-x}Mn_x$</TEX> semiconductor thin films are amorphous and are crystallized by annealing. Crystallization temperature of amorphous <TEX>$Ge_{1-x}Mn_x$</TEX> semiconductor thin films varies with Mn concentration. Amorphous <TEX>$Ge_{1-x}Mn_x$</TEX> thin films have p-type carriers and the carrier type is not changed during annealing, but the electrical resistivity increases with annealing temperature. Magnetization characteristics show that the as-grown amorphous <TEX>$Ge_{1-x}Mn_x$</TEX> thin films are ferromagnetic and the Curie temperatures are around 130 K. Curie temperature and saturation magnetization of annealed <TEX>$Ge_{1-x}Mn_x$</TEX> thin films increase with annealing temperature. Magnetization behavior and X-ray analysis implies that formation of ferromagnetic <TEX>$Ge_3Mn_5$</TEX> phase causes the change of magnetic and electrical properties of annealed <TEX>$Ge_{1-x}Mn_x$</TEX> thin films.

Atomistic examinations of the solid-phase epitaxial growth of silicon

The low-temperature vapor deposition of silicon thin films and the ion implantation of silicon can result in the formation of amorphous silicon layers on a crystalline silicon substrate. These amorphous layers can be crystallized by a thermally activated solid-phase epitaxial (SPE) growth process. The transformations are rapid and initiate at the buried amorphous to crystalline interface within the film. The initial stages of the transformation are investigated here using a molecular dynamics simulation approach based upon a recently proposed bond order potential for silicon. The method is used first to predict an amorphous structure for a rapidly cooled silicon melt. The radial distribution function of this structure is shown to be similar to that observed experimentally. Molecular dynamics simulations of its subsequent crystallization indicate that the early stage, rate limiting mechanism appears to be removal of tetrahedrally coordinated interstitial defects in the nominally crystalline region just behind the advancing amorphous to crystalline transition front. The activation barriers for this interstitials migration within the bulk crystal lattice are calculated and are found to be comparable to the activation energy of the overall solid-phase epitaxial growth process simulated here.

Pattern formation during vapor deposition of organic films on inorganic substrates-continuum modeling vs experiments

The early stages during low temperature vapor deposition of organic materials onto inorganic substrates are frequently characterized by surface pattern formation on a characteristic length scale, accompanied by dramatic roughening, while these structures level at higher film thicknesses. Unexplainable by traditional liquid-state dewetting scenarios, we employ a combined experimental/modeling study to track down the underlying physics using poly(bisphenol A carbonate) (PC) on GaAs (100) as a model system. We present a minimum continuum model, which incorporates only material deposition and chemical potential driven surface diffusion as material processes, whose numerical solution is capable of reproducing key experimental features.