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We present block copolymer multiple patterning as an efficient and truly scalable nanolithography for sub-20 nm scale patterning, synergistically integrated with conventional ArF lithography. The directed assembly of block copolymers on chemically patterned substrates prepared by ArF lithography generated linear vertical cylinder arrays with a 20 to 30 nm diameter, enhancing the pattern density of the underlying chemical patterns by a factor of two or three. This self-assembled resolution enhancement technique affords a straightforward route to highly ordered sub-20 nm scale features via conventional lithography.

Photobleachable deep UV resists were designed by introducing diazoketo groups in polymer side chains. The diazoketo groups undergo the Wolff rearrangement upon irradiation in the deep UV, affording ketenes that react with water to provide base-soluble photoproducts. The polymers were synthesized by radical copolymerization of 2-(2-3-oxo-butyryloxy)-ethylmethacrylate, 2-hydroxyethyl methacrylate, and γ-butyrolacton-2-yl methacrylate. The component resist showed 0.7 μm line and space patterns using a mercury-xenon lamp in a contact printing mode.

A new positive-working polyimide having photosensitive o-nitrobenzyl ester group as side substituent, poly{1,4-phenyleneoxy-1,4-phenylene-3,6-di[4-(o-nitrobenzyloxy)carbonylphenyl]pyromellitimide} (ODA-PI-Nb), was prepared and its aqueous alkali-developability and photosensitivity were investigated. ODA-PI-Nb was synthesized by the esterification reaction of poly[1,4-phenyleneoxy-1.4-phenylene-3,6-di(4-carboxylphenyl)pyromellit imide] (ODA-PI) with o-nitrobenzyl bromide in the presence of triethylamine (Et3N). ODA-PI-Nb obtained was characterized by FT-IR and 1H-NMR spectroscopy. The degree of esterification reaction was found from 1H-NMR absorption of CH2 proton to be over 95 mol%. Upon photo-irradiation ODA-PI-Nb transformed to the freely aqueous alkali-soluble ODA-PI under formation of o-nitrosobenzaldehyde. The thickness loss of thin ODA-PI-Nb films upon post-baking at 400°C was in the 10–15% range. ODA-PI-Nb showed positive-tone behavior in characteristic sensitivity curve and positive patterns were obtained using a typical lithographic process using aqueous tetramethylammonium hydroxide developer. The patterns with excellent resolution were observed and evaluated by optical microscopy and scanning electron microscopy. Copyright © 2005 John Wiley & Sons, Ltd.

Malignant transformation of mature cystic teratoma is an uncommon complication. While any of the constituent tissues of a teratoma has the potential to undergo malignant transformation, squamous cell carcinoma is the most commonly associated cancer. We present an unusual case of a postmenopausal woman with synchronous mucinous adenocarcinoma and strumal carcinoid tumor from one of two ovarian mature cystic teratomas (one in each ovary) with synchronous cervical cancer. We suggest that malignant transformation of mature cystic teratoma and synchronous cervical cancer be treated by hysterectomy, chemotherapy, and radiotherapy.

Directed self-assembly (DSA) process of block copolymers (BCPs) has been considered as a candidate for sub-20nm contact patterning. In recent years the semiconductor manufacturers have been interested in use DSA in production. DSA is based on the intrinsic property of the BCPs which is phase-separation in the molecular scale, but significant problems remain for device application. Process time, high process temperature, defect, and CD distribution make the using of DSA difficult in mass production. One of the most considered problems for DSA is the CD Distribution. A guide material for grapho-epitaxy DSA process requires resistance against high temperature and solvent. We use negative tone develop (NTD) photoresist (PR) guide for simple process and thermal resistance, and additional treatment for resistance against high temperature and solvent. The CD distribution of DSA is highly related to the phase separation itself. In order to get better performance, the polymer chains should have sufficient mobility under heating above their glass temperature. Therefore, film thickness and molecular weight of BCPs are very important parameters for CD distribution of DSA process. From the results, it is proven that guide materials, film thickness of BCPs, and molecular weight of BCPs are significant parameter in order to improve CD distribution of DSA patterns.

In a general way, non-CARs consist of the matrix resins and photoactive compounds (PACs), and the dissolution properties of the resists are dependent on the amount of PACs. In common, I-line and G-line resists based on novolac and diazonaphthoquinone (DNQ) are typical non-CARs. But most PACs absorb much light in the deep UV, and they are poorly photobleached by deep UV exposure. This strong absorption of PACs prevents the deep UV light from reaching the bottom of the resist film, leading to scum and sloped pattern profiles. Several PACs which contain diazoketo groups have been reported for deep UV lithography. Our goal in this investigation is to find a proper resist that is processable without photoacid generator and induces both photobleaching in the deep UV regions and polarity change upon exposure. We thought diazoketo groups attached to the polymer side chains could give such effects. There is no necessity for the post-exposure bake step that is the cause of acid-diffusion. The diazoketo groups undergo the Wolff rearrangement upon irradiation in the deep UV, affording ketenes that react with water to provide base soluble photoproducts. The polymers were synthesized by radical copolymerization of 2-(2-diazo-3-oxo-butyryloxy)-ethyl methacrylate, 2-hydroxyethyl methacrylate, and γ-butyrolacton-2-yl methacrylate. The single component resist showed 0.7μm line and space patterns using a mercury-xenon lamp in a contact printing mode.

We synthesized a new type of polymers that have diazoketo groups instead of acid-labile protecting groups. The polymers do not need a photoacid generator for formulation of resists. That is, the new matrix polymers absorb UV light and produce carboxylic groups. Also, there is no necessity for a post-exposure bake step, which is the cause of post-exposure delay effects. New monomer, ethyl 2-diazo-4-methyl-3-oxo-pent-4-enoate was synthesized. This monomer was copolymerized with hydroxystyrene and adamantyl methacrylate. After UV exposure, the polymers became soluble in an aqueous base developer. The polymers showed bleaching effect after UV exposure. Thermal properties of the polymers were measured by TGA and DSC. Characterization of the polymers has been done using other techniques such as FT-IR, NMR, GPC, and UV. The resist patterns of 0.8 μm feature size were resolved using a DUV contact printer and with a tetramethylammonium hydroxide aqueous solution.

A novel nanomolecular resist based on POSS substituted with diazodiketo-functionalized cholate derivatives was successfully synthesized as a candidate for 193-nm lithography. The diazodiketo group was introduced into the cholate derivatives to provide the solubility change and to eliminate the problems of chemically amplified resists. The decomposition temperature of the resist was found to be 130°C. The initial lithographic studies showed the feasibility of the resist to be used as a candidate for 193-nm lithography.

An AlAs/GaAs/Al/sub 0.3/Ga/sub 0.7/As heterostructure on a GaAs substrate has been directly bonded on a fiber-optic plate for the first attempt of the 3rd generation transmission photocathode. The substrate is removed mechanically and etched chemically, utilizing high etching selectivities of GaAs and AlAs in potassium citrate/citric acid. The bonding strength between fiber optic and GaAs wafer exceeds 5.7 MPa without annealing, the final GaAs/Al/sub 0.3/Ga/sub 0.7/As structure on the fiber optic allows large dimension (1 cm /spl times/ 1 cm), thin (2 /spl mu/m) and uniform film thickness, and good transmission performance.

We synthesized a new type of norbornene-maleic anhydride copolymer which as diazoketo groups instead of acid labile protecting groups. The matrix polymer does not need a photoacid generator for the lithographic evaluation. And there is no necessity for the post-exposure bake step that is the cause of PED effects. Methyl 5-norbornenyl-3-oxopropionate was prepared by the reaction of acetyl norbornene with dimethyl carbonate in the presence of sodium hydride. And methyl 5-norbornenyl-2-diazo-3-oxopropionate was synthesized from the reaction between methyl 5-norbornenyl-3-oxopropionate and p-carboxybenzenesulfonyl azide. The polymer was prepared by free radical polymerization. Upon exposure to DUV light, diazoketo groups undergo a series of reactions that culminate in the formation of a carboxylic acid. The matrix polymer in the exposed region becomes soluble in the aqueous base developer. The polymer showed bleaching effect after exposure. Thermal stability of the polymer is measured by TGA and DSC. Characterization of the polymer is achieved using other techniques such as FT-IR, NMR, GPC, and UV. The resist patterns of 0.6 μm feature size were resolved using a KrF exposure tool and with a conventional developer, 2.38 wt% TMAH aqueous solution.

A novel molecular resist material based on polyhedral oligomeric silsesquioxane, possessing diazoketo groups, was successfully synthesized for deep UV lithography. The initial lithographic evaluation of the molecular resist shows the potential of the new platform for the next generation resists.