We developed an embossing/imprinting based nanofabrication technique, dubbed Sequential Stretching Lithography (SSL). In this process, a master pattern is imprinted into an elastomer containing a film of uncured elastomer. The elastomer is cured and then elongated to increase feature density and reduce feature size. Replication of this substrate yields a new master that can be used in further reduction steps. One-dimensional grating features with a pitch size below 200 nm were fabricated from 750 nm-pitch grating lines. This process gives us a faithful pattern miniaturization in all aspects and, as a result, a much effective control on density and dimension regulation.

Nanopatterning and nanomachining of PMMA coated wafers was performed using table top extreme ultraviolet lasers. Features below 100 nm were imprinted with short (50-60 s) exposure times.

The striped nano-channel structure (about 10nm in depth) was formed on the NiO film surface by thermal annealing of the film deposited on the sapphire(0001) substrate with periodic straight atomic steps. The interval of each nano-channel was about 100nm in average and well corresponding to the separation of atomic steps on the used sapphire(0001) substrate. Effects of annealing temperature and impurity doping into NiO upon the nanochannel formation were examined in order to control the depth. The depth of nano-channels formed on the alkali-metal(Li or Na) doped NiO films were found to be larger than that of nano-channels on the non-doped NiO films and enlarged with increasing annealing temperature in the range of 500∼900°C. Atomic-scale cross sectional structure of the nano-channel was characterized by transmission electron microscopy with focused on the film/substrate interface.

Since industry has been seeking for advanced nanotechnology, development of new nano-materials and nanofabrication techniques has been a key contributor to satisfy our growing demands on miniaturization. This will present technological emergences in fabrications of novel optoelectronic devices by developing new materials since nanotechnology is a part of chemical domain. It will cover up as how chemists can contribute to this area to fabricate functional nanofabrications for information technology. For example, we developed a new class of PDMS stamps to overcome the limitations and thus to extend current soft lithography to advanced level for developing nanoscale-devices. Patterns fabricated using functional polymers also have many information technology applications to integrate optoelectronic devices.

The affordable and reproducible creation of nanoscale functional material layers is a key desire towards the progressing miniaturization of devices and the continuous increase of data storage densities. While top-down structuring costs are exploding, the self-assembly [1] of dedicated building blocks in functional molecular layers provides an alternative to produce structures in the few nanometer range. Several different approaches, exploit characteristic materials properties for this purpose: A) the dedicated assembly of two dimensional molecular layers on prepatterned surfaces provides the basis for structural transitions involving only some hundred molecules. These transitions can be reversibly triggered by an electric field. [2] B) The complex balance of inter-molecular interactions with adsorbate-adsorbent interactions provides the basis for tuning the assembly. Long range ordering is a crucial requirement to match self-assembled functional devices with top-down manufactured methods for addressing and operation. [3] C) Using larger molecular entities and conformational flexure [4], even larger periodicity functional arrays can be manufactured by extending site blocking mechanisms to nearest neighbour interactions. [5] D) By a hierarchical two step approach, i.e. the initial assembly of a specific host-layer and the second step assembly of molecular guests upon this host layer, a wealth of new molecular properties is achievable in extended supra-molecular layers. [6] All these new supra-molecular self-assembled systems offer a valid alternative toward the fabrication of reproducibly identical and addressable “molecular switches” which are impossible to achieve by using established lithographic methods.

An article is given of research of SEM, AFM and optic data of pure and doped strontium titanate as bulk single crystals and nano-scale sized samples before and after plasma treatment. Quasi-ordered system of nano-scale sized triangle piramids was discovered on surface of separate doped samples after plasma treatment

A modeling methodology based on computational fluid dynamics (CFD) has been developed that is appropriate for the global regime of lithographically directed, evaporation driven self-assembly. The modeling technique has been experimentally verified through comparison with the well-known benchmark case of evaporation driven self-assembly associated with the evaporation of a colloidal, self-pinned droplet. The predicted evolution of the particle distribution during evaporation is compared to optical experimental measurements of the particle distribution within an evaporating droplet containing fluorescing nanoparticles.

Massively Parallel Scanning Probe Microscopy is an obvious path for enhancing the acquisition speed and the imaging range of current based-AFM metrology devices. Current experimental systems, based on active probes array, would reach their limits in density and hardware complexity. This paper presents a new approach with the promise to break several of these barriers. The key idea is readout of a Scanning Probes Microscope (SPM) array by an interferometer technique called digital holography which directly gives the cantilever phase information at each pixel of a CCD array. This means that no contact line to each individual SPM probes is needed, allowing us to reach very high density of probes. The phase information is available in a parallel form in real-time. Moreover, the digital holography optical setup (Digital Holography Microscope or DHM) needs in principle no expensive components, optical (or, to a large extent, mechanical) imperfections being compensated in the signal processing, i.e. in electronics. This gives the system the potential for a low cost device with fast and large readout capability.

This work presents an annealing study of high-anisotropy (Co/Pd)N magnetic multilayers designed for bit-patterned medium recording applications. Magnetic multilayers were deposited by magnetron sputtering at 2.5mT argon pressure at room temperature and annealed at different temperatures (up to 250 °C) for up to 2 hours in atmosphere and in vacuum. Depending on the annealing time, the samples annealed in atmosphere exhibited two distinct modes of magnetization reversal. In samples annealed for a time shorter than some critical time, tc, where tc is a function of the annealing temperature, the magnetization reversal occurs by domain wall injection and propagation. In samples annealed for times longer then tc, the magnetization reversal mode switches to magnetization rotation. Using XPS, it is found that the transition is accompanied by the formation of oxidizes at the grain boundaries leading to exchange decoupling of the grains. In samples annealed at higher temperatures, the increases of the coercivity of as high as 30 times the coercivity of as prepared samples are observed. Significantly, annealing in vacuum showed only small modification of magnetic properties as manifested by relatively minor modifications of vertical M-H loops and unchanged morphology of domain patterns in AC demagnetized state.

Recently, metal nanocrystal based carbon nanotube memory has been demonstrated with sub-5V low bias programming, single electron sensitivity but poor room temperature retention. The process integration of an ultra-thin tunnel dielectric is essential for lateral, vertical scaling and reliable room temperature operation. Low defect density and conformal deposition on the nanotube are required to enhance the performance as a tunnel barrier. Additionally, Au contamination in the CNT decreases the on/off current ratio in the CNTFETs by substantially increasing the off current. Consequently, the dielectric should function as a good diffusion barrier for Au in the nanocrystals. We have explored composite tunneling dielectric film with SiO2 seed layer for conformal high-k deposition to demonstrate minimal Au contamination and improved retention. Room temperature retention of better than three days has been observed.

Block copolymer lithography is a promising method for fabricating periodical nano patterns less than 20nm by self-assembly and can be applicable for fabricating patterned magnetic media with recording density over 1Tbit/inch2. We found a simple technique to control the orientation of cylindrical microdomains in thin films. Only by mixing polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymers with the constituent homopolymer (PS or PMMA), we could align the cylindrical microdomains perpendicular to the film surface. The added homopolymer induces conformational entropic relaxation of the block chains in microdomain space and stabilizes perpendicular orientation of hexagonally packed cylindrical microdomains. Thus formed perpendicular cylinders can be readily aligned in a regular array with a grating substrate.

We propose a nonvolatile two-terminal memory with two resistance states based on the molecular tunnel junctions. This tunnel junction is composed of one or few monolayers of polar molecules sandwiched between two electrodes made of materials with different screening length. As a prototype model system we study rare earth endohedral metallofullerene molecule with reversible dipole moment sandwiched by metal and semiconducting electrodes forming a double barrier junction. We use the Thomas-Fermi model to calculate the potential profile across the device. Calculated tunneling conductance through the proposed structure changes by order of magnitude upon the reversal of the dipole orientation (due to the applied voltage). This effect originates from the difference of potential profile seen by tunneling electrons for two opposite dipole orientations.

Recently, the large number of investigations concerning acid-catalyzed photopolymer systems such as chemically amplified photoresists and UV-curing materials has been reported. On the other hand, analogous systems utilizing base-catalyzed reactions have received far less attention, because low quantum yields for photobase generation to lead to low photosensitivity of these systems. To improve this problem, we proposed introduction of the concept of base proliferation reactions into the photopolymer systems using base-catalyzed reactions. The concept involves the autocatalytic base-catalyzed decomposition of a compound, referred to as a base amplifier which releases a newborn amine, leading to its autocatalytic decomposition. In fact, the addition of the base amplifiers such as 9-fluorenylmethyl carbamate, phenylsulfonylethyl carbamate, and 3-nitropentane-2-yl carbamate to a photopolymer consisting of an epoxy polymer sensitized and a photobase generator (PBG) resulted in the marked improvement of photosensitivity.

However, these base amplifiers with low molecular weight are not suitable for photopatterning because of the volatility and the excessive diffusion of amines proliferated in polymer films. We report here novel base-amplifying silicone resins tethering phenylsulfonylethyl carbamoyl groups which proliferate primary amino groups or secondary amino groups in their side chains.

Base-catalyzed decomposition behavior of films of these resins containing PBG was evaluated by UV absorption measurements. A film consisting of the resin proliferating primary amino groups and 10 wt% of PBG decomposed immediately in a nonlinear manner by 365 nm irradiation and subsequent heat treatment at 120oC for 6 min. On the other hand, this film without UV irradiation was thermally stable for 18 min at 120oC. These results indicate that photoinduced base proliferation reaction of the resin proceeded. A film consisting of the resin generating secondary amino groups and PBG decomposed in a way similar to that of the resin proliferating primary amino groups. Furthermore, lithographic evaluation of the film comprising the resin to generate secondary amines and PBG obtained 7ÊS positive images with an exposure dose of 75 mJ/cm2 which shows higher sensitivity when compared to conventional base-catalyzed photopolymers.

We have carried out density functional calculations on a CoFeB/MgO/CoFeB interface with amorphous electrodes. The interface was shown to be stable with 4 mono-layers (ML) and to contain spin-polarized metal-oxigen bonds at the interface. The interfacial energy was estimated, to be used as a comparative measure of stability. In addition, the exchange-coupling indicated a favouring of the anti-paralell magnetization configuration with respect to the paralell for 4 ML.

Electron-beam mastering of templates for patterned media presents a challenge to the toolmaker to simultaneously meet throughput, resolution and placement requirements. Fundamental to tool development is the ability to measure the placement to true grid of shapes as small as 7 nm over the whole substrate. In this article we describe a technique, consisting of acquiring and analyzing scanning electron (SE) micrographs, for measuring the placement errors in lithography similar to that required for patterned media, albeit over a few square microns and without scale and orthogonality components. The method enabled the measurement of placement errors of dots in an array with accuracy down to about 2 nm. The technique was used to benchmark current X-Y tool performance and the smallest 3× standard deviation of placement error was found to be around 4.5 nm. A clearer understanding of the necessary tool improvements was obtained. The use of the technique as basis for measuring errors to true grid over the entire substrate is discussed.

Room-temperature nanoimprint lithography (RT-NIL) using spin-coated hydrogen silsesquioxane (HSQ) resin as the replication material was developed. HSQ pattern with 50 nm linewidth was successfully obtained by the RT-NIL. Postbaking temperature dependence of a HSQ imprinted depth on a mold linewidth was investigated. HSQ imprinted depth had a dependence on the mold linewidth. This revealed that the RT-NIL is suitable for the linewidths of below 1 mm. Furthermore, we have also developed a new imprinting technique that uses liquid-phase hydrogen silsesquioxane (HSQ) as an alternative to the spin-coated HSQ resin. The liquid-phase HSQ imprint technique enabled fabrication of various HSQ patterns with a wide range of linewidths from 25 nm to 300 mm. Arbitrary patterns, including both submicron and greater than 100 micron patterns, were simultaneously replicated with a one-step imprint process, something very difficult to accomplish with spin-coated HSQ. Moreover, after imprinting, the residual HSQ layer in the compressed area was less than 10 nm thick.