We report the formation and directed self-assembly of sub-10 nm half-pitch line patterns from lamellar microdomains of a block copolymer hybrid. The hybrid, which is a mixture of poly(styrene-b-ethylene oxide) (PS-b-PEO) and a low molecular weight organosilicate (OS), shows strong segregation between two phases (i.e. PS and PEO+OS) and forms lamellar microdomains of down to approximately 7 nm in half-pitch. Patterns applicable to multifinger device layouts are created by self-assembling the hybrid on topographic pre-patterns with a chemically non-selective surface. With careful design of the guiding topographic pattern geometry, well-controlled lateral placement including bent structures of lamellar microdomains can be obtained by this approach.

The directed self-assembly of a lamellar-forming hybrid block copolymer system comprising of a poly(styrene-b-ethylene oxide) and organosilicates (OSs) has been investigated. The addition of OS to the block copolymer is found to provide additional control over the persistence length of lamellae as well as the behavior of directed self assembly. Two OSs with different molecular weights and reactivities have been compared in this experiment. Both OSs yield the same local structure of lamellar domains but different degrees of mid- and long-range order. Longer correlation length and better alignment of lamellar domains were observed with the lower molecular weight, more reactive OS, which suggest a potential guidance for controlling over microdomains in block copolymer-containing hybrid systems.

Sol-gel hybrid glass films doped with benzildimethylketal (BDK) were prepared from [(methacryloxy)propyl]trimethoxysilane, methacrylic acid, and zirconium n-propoxide. Polymerization of methacryl groups and polycondensation of alkoxides by UV illumination and baking were observed using Fourier-transformed infrared spectroscopy. Polymerization kinetics and refractive index increase depend on UV illumination time. The refractive index increase is sensitive to BDK concentration and agrees well with photodecomposition of BDK. Thus, it is found that the refractive index increase is made by incorporation of the radicals produced by photodecomposition of BDK in the network as well as polymerization of methacryl groups.

Thin films that contain well-defined nanoscopic cylindrical pores oriented perpendicular to the surface are highly desirable for a variety of applications. Of great interest is the use of porous structures for templating well-defined nanostructures of various functional materials. [1][2][3][4][5] Numerous approaches have been reported to generate well-defined nanoscopic templates. One of them is to use the porous oxide of anodized aluminum (AAO). [6,7] Extensive studies have shown that ordered pores of diameters ranging from 25 to 300 nm can be generated by controlling the anodizing conditions. While anodized alumina usually provides closed-end pores, attempts to remove the nanoporous alumina from the underlying Al surface and use the free-standing nanoporous alumina membrane as an etch mask for plasma etching of organic films have been reported. [8][9][10] However, it involves multiple process steps that include electrochemical anodization and requires careful control over volume expansion during oxidation to control pore size and interpore distance. The other common approach to nanoporous templates is to use microphase separated thin films of block copolymers. [11,12] As a classic example, asymmetric diblock copolymers of polystyrene and poly(methyl methacrylate) (PS-b-PMMA) with cylindrical PMMA microdomains have been used to create nanoporous templates by removing PMMA domains from the thin films. [2,13,14] The size of the pores is governed by the molecular weight of the block copolymer and pores of 15-50 nm in diameter can be easily obtained by this approach. [15] However, this approach also involves multiple steps that include interfacial energy control between the substrate and the block copolymer, and a long thermal annealing step. Moreover, it still remains a challenge to make high aspect-ratio uniform nanoporous templates over large areas with block copolymer thin films. [2,[16][17][18] A simple and reproducible method for fabricating nanoporous templates with controlled pore dimensions, high aspect-ratio, and uniformity over a large area is, therefore, highly desirable. Previously, a method to create high aspect-ratio (approximately 15 nm in pore diameter, 320 nm in pore length), normally oriented nanoporous structures on silicon wafers was reported using self-assembly of an organic block copolymer and an organosilicate precursor.[19] The method gives thermally and mechanically robust nanoporous films that can be used as a nanotemplate for high-temperature processes such as inorganic nanowire growth. [20] However, the process requires extensive annealing time under controlled solvent vapor. Herein, a simple method that generates nanoporous templates with controlled aspect-ratio and uniformity over a large area is reported. This approach provides nanoporous templates of diameters that range from 8 to 25 nm very reproducibly.A bilayer approach was used that consisted of a top self-assembled layer which serves as a high silicon-containing etch mask (hereafter called the pattern layer) and an underlying or...

Transparent mesoporous silica films were prepared by sol-gel spin coating on silicon wafers at room temperature. An erbium complex, erbium tris 8-hydroxyquinoline (ErQ), was homogeneously impregnated into the pores of the mesoporous silica films, and its concentration was easily controlled by using a solution immersing technique. The ErQ-impregnated mesoporous silica films show a room-temperature photoluminescence at 1.5 m.Erbium-doped material films have received growing interest over the last decade due to their multiple applications such as use in integrated lasers or amplifiers for telecommunications.1 Since planar optical amplifiers have a smaller interaction length with respect to erbiumdoped fiber amplifiers, higher erbium concentration is required to obtain a sufficient optical gain. However, high doping levels of erbium quench the fluorescence emission and reduce the performance of the amplifier. Especially, the clustering of Er 3+ ions is a main obstacle preventing concentration quenching because a silicabased inorganic matrix is fabricated by high-temperature processes such as flame hydrolysis deposition and chemical vapor deposition.2 To reduce concentration quenching, erbium ions should disperse uniformly on a molecular level. When Er 3+ ions are surrounded by bulky organic ligands, the average minimum distance between Er 3+ ions increases due to the steric hindrance. Thus, introduction of an erbium complex can be a solution to reducing concentration quenching. Er complex is generally used with a polymer matrix because of its solubility and the processing temperature. There have been several reports concerning room-temperature photoluminescence in polymer/Er complex systems.3,4 However, the polymer matrix is largely composed of a linear CH chain and thus large CH quenching can occur. Therefore, a general polymer matrix is not suitable to the incorporation of an Er complex. Theoretically, the most effective method for uniform dispersion is the periodic arrangement of erbium ions in a matrix when high doping levels of Er 3+ ions are required. Thus, we selected mesoporous materials as the host matrix. Mesoporous materials were developed for constructing a periodic pore structure, which has pores of a few nanometers in size.5 They can also be made of various inorganic components, such as silica and alumina, which have low optical losses.Recently, mesoporous materials were used for encapsulating organic dyes to prevent aggregation of the dye molecules.6 Impregnation of Er complex into mesoporous silica has some advantages over incorporation of Er complex in the matrix. First, the mesoporous silica has a periodic pore distribution such that the impregnated Er ions are expected to be uniformly dispersed. Moreover, the absorption cross section can increase compared to Er 3+ ion by doping Er complex into a low loss silica matrix.7 Although the mesoporous film is fabricated through a high-temperature process, there is no temperature restriction to impregnate Er complex because it can be impregnated by a solut...