Materials and processes for advanced lithography applications

textStep and Flash Imprint Lithography (S-FIL) is a high resolution, next-generation lithography technique that uses an ambient temperature and low pressure process to replicate high resolution images in a UV-curable liquid material. Application of the S-FIL process in conjunction with multi-level imprint templates and new imprint materials enables one S-FIL step to reproduce the same structures that require two photolithography steps, thereby greatly reducing the number of patterning steps required for the copper, dual damascene process used to fabricate interconnect wirings in modern integrated circuits. Two approaches were explored for the implementation of S-FIL in the dual damascene process: sacrificial imprint materials and imprintable dielectric materials. Sacrificial imprint materials function as a pattern recording medium during S-FIL and a three-dimensional etch mask during the dielectric substrate etch, enabling the simultaneous patterning of both the via and metal structures in the dielectric substrate. Development of sacrificial imprint materials and the associated imprint and etch processes are described. Application of S-FIL and the sacrificial imprint material in a commercial copper dual damascene process successfully produced functional copper interconnect structures, demonstrating the feasibility of integrating multi-level S-FIL in the copper dual damascene process. Imprintable dielectric materials are designed to combine the multi-level patterning capability of S-FIL with novel dielectric precursor materials, enabling the simultaneous deposition and patterning of the interlayer dielectric material. Several candidate imprintable dielectric materials were evaluated: sol-gel, polyhedral oligomeric silsesquioxane (POSS) epoxide, POSS acrylate, POSS azide, and POSS thiol. POSS thiol shows the most promise as functional imprintable dielectric material, although additional work in the POSS thiol formulation and viscous dispense process are needed to produce functional interconnect structures. Integration of S-FIL with imprintable dielectric materials would enable further streamlining of the dual damascene fabrication process. The fabrication of electronic devices on flexible substrates represents an opportunity for the development of macroelectronics such as flexible displays and large area devices. Traditional optical lithography encounters alignment and overlay limitations when applied on flexible substrates. A thermally activated, dual-tone photoresist system and its associated etch process were developed to enable the simultaneous patterning of two device layers on a flexible substrate.Chemical Engineerin

Materials modeling and development for use in double-exposure lithography applications

The current optical photolithography technology is approaching the physical barrier to the minimum achievable feature size. To produce smaller devices, new resolution enhancement technologies must be developed. Double-exposure lithography has shown promise as a potential pathway that is attractive because it is much cheaper than double-patterning lithography and can be deployed on existing imaging tools. However, this technology is not possible without the development of new materials with nonlinear response to exposure dose. The performance of existing materials such as reversible contrast enhancement layers (rCELs), and theoretical materials such as intermediate state two-photon (ISTP) and optical threshold layer (OTL) materials in double-exposure applications have been investigated through computer simulation. All three materials yielded process windows in double-exposure mode. OTL materials showed the largest process window (depth of focus (DOF) 0.14 µm, exposure latitude (EL) 5.1%). ISTP materials had the next-largest process window (DOF 0.12 µm, EL 3.2%), followed by the rCEL (0.11 µm, 0.58%). This study is an analysis of the feasibility of using the materials in double-exposure mode

Double Exposure Materials: Simulation Study of Feasibility

Double patterning and double exposure techniques have been proposed as possible methods for reducing half pitch resolution below k1=0.25. Both methods have the potential to reduce the theoretical lithographic half pitch to k1=0.125. Double patterning is a process-intensive method that requires multiple coat, develop, and etch steps to achieve the low k1 imaging. Double exposure processes have been proposed that do not require multiple coat, develop, or etch steps. Potentially, double exposure processes will have a lower cost of ownership that double patterning. However, double exposure materials have not yet been proven to work experimentally. Before applying significant effort to develop double exposure materials, their feasibility can be determined using rigorous simulation techniques. This work presents a feasibility study of four types of double exposure materials and their potential process windows

An analysis of double exposure lithography options

The current optical photolithography technology is approaching the physical barrier to the minimum achievable feature size. To produce smaller devices, new resolution enhancement technologies must be developed. Double exposure lithography has shown promise as potential pathway that is attractive because it is much cheaper than double patterning lithography and it can be deployed on existing imaging tools. However, this technology is not possible without the development of new materials with nonlinear response to exposure dose. The performance of existing materials such as reversible contrast enhancement layers (rCELs) and theoretical materials such as intermediate state two-photon (ISTP) and optical threshold layer (OTL) materials in double exposure applications was investigated through computer simulation. All three materials yielded process windows in double exposure mode. OTL materials showed the largest process window (DOF 0.137 µm, EL 5.06 %). ISTP materials had the next largest process window (DOF 0.124 µm, EL 3.22 %) followed by the rCEL (0.105 µm, 0.58 %). This study is an analysis of the feasibility of using the materials in double exposure mode

The Grizzly, March 1, 1994

Up \u27Til Noone to Play at The Trappe • Last Semester\u27s Blood Drive a Success • Kane Encourages Support for Blood Drive • CIA Officer and his Wife Accused of Spying • Professor Profile: Keith Brand • Broughton Exhibit to Open in Berman • Senior Profile: Alan McCabe • The Snow Closing Debates, Continued • Letter to the Editor • To All Administrators, Faculty, Staff, and Other Interested Parties • Women\u27s Hoops Have Best Season Everhttps://digitalcommons.ursinus.edu/grizzlynews/1332/thumbnail.jp

The Grizzly, April 19, 1994

Erdrich Speaks of Cultural Struggles • Friendly Fire Over Iraq • Greeks Participate in Greek Week • U.S.G.A. Responds to Requests for a Wismer Meal Plan • Tropical Conservationist to Speak at Ursinus • President John Bartholomew Speaks Again • Tuning in to Talk Radio • Bands to Perform Saturday • It\u27s Not a Matter of Dryness • Women\u27s Lacrosse Crushes Swarthmore; Falls to Johns Hopkins • Eagles Draft Preview • George White Named New Men\u27s Basketball Coach at Ursinushttps://digitalcommons.ursinus.edu/grizzlynews/1336/thumbnail.jp

The Grizzly, September 22, 1992

It\u27s That Time Again: 1992 Sorority Pledging Gets Under Way at Ursinus • Dean Kane: On Alcohol Policy • The Axe Falls on Underage Drinking at Ursinus • Koester Named Head of SAC • Freshman Officers Elected • Freshman Facts • Rushing Views • Author Victor Hernandez Cruz to Read and Speak at Ursinus • Ursinus Radio WVOU • Jazz Great Dazzles Ursinus • Christ on Campus • Movie Review: Sneakers • Letters to the Editor • Lady Bears Play Tough • Volleyball Team Working to Improve • Intramurals • Youthful Soccer Squad Struggles • Grizzlies Split: Defense Shines • U.C. on the Sea • X-Country Runs Awayhttps://digitalcommons.ursinus.edu/grizzlynews/1298/thumbnail.jp

The structure of the tetrasialoganglioside from human brain

Autosomal dominant retinal vasculopathy with cerebral leukodystrophy is a microvascular endotheliopathy with middle- age onset. In nine families, we identified heterozygous C- terminal frameshift mutations in TREX1, which encodes a 3'-5' exonuclease. These truncated proteins retain exonuclease activity but lose normal perinuclear localization. These data have implications for the maintenance of vascular integrity in the degenerative cerebral microangiopathies leading to stroke and dementias

Change in level of productivity in the treatment of schizophrenia with olanzapine or other antipsychotics

<p>Abstract</p> <p>Background</p> <p>When treating schizophrenia, improving patients' productivity level is a major goal considering schizophrenia is a leading cause of functional disability. Productivity level has been identified as the most preferred treatment outcome by patients with schizophrenia. However, little has been done to systematically investigate productivity levels in schizophrenia. We set out to better understand the change in productivity level among chronically ill patients with schizophrenia treated with olanzapine compared with other antipsychotic medications. We also assessed the links between productivity level and other clinical outcomes.</p> <p>Methods</p> <p>This post hoc analysis used data from 6 randomized, double-blind clinical trials of patients with schizophrenia or schizoaffective disorder, with each trial being of approximately 6 months duration. Change in productivity level was compared between olanzapine-treated patients (HGBG, n = 172; HGHJ, n = 277; HGJB, n = 171; HGLB, n = 281; HGGN, n = 159; HGDH, n = 131) and patients treated with other antipsychotic medications (separately vs. haloperidol [HGGN, n = 97; HGDH, n = 132], risperidone [HGBG, n = 167; HGGN, n = 158], quetiapine [HGJB, n = 175], ziprasidone [HGHJ, n = 271] and aripiprazole [HGLB, n = 285]). Productivity was defined as functional activities/work including working for pay, studying, housekeeping and volunteer work. Productivity level in the prior 3 months was assessed on a 5-point scale ranging from no useful functioning to functional activity/work 75% to 100% of the time.</p> <p>Results</p> <p>Chronically ill patients treated with olanzapine (OLZ) experienced significantly greater improvement in productivity when compared to patients treated with risperidone (RISP) (OLZ = 0.22 ± 1.19, RISP = -0.03 ± 1.17, p = 0.033) or ziprasidone (ZIP) (OLZ = 0.50 ± 1.38, ZIP = 0.25 ± 1.27, p = 0.026), but did not significantly differ from the quetiapine, aripiprazole or haloperidol treatment groups. Among first episode patients, OLZ therapy was associated with greater improvements in productivity levels compared to haloperidol (HAL), during the acute phase (OLZ = -0.31 ± 1.59, HAL = -0.69 ± 1.56, p = 0.011) and over the long-term (OLZ = 0.10 ± 1.50, HAL = -0.32 ± 1.91, p = 0.008). Significantly more chronically ill and first episode patients treated with olanzapine showed moderately high (>50%-75% of the time) and high levels of productivity (>75%-100% of the time) at endpoint, when compared to risperidone or haloperidol-treated patients (p < .05), respectively. Higher productivity level was associated with significantly higher study completion rates and better scores on the positive, negative, disorganized thoughts, hostility and depression subscales of the Positive and Negative Symptom Scale (PANSS).</p> <p>Conclusions</p> <p>Some antipsychotic medications significantly differed in beneficial impact on productivity level in the long-term treatment of patients with schizophrenia. Findings further highlight the link between clinical and functional outcomes, showing significant associations between higher productivity, lower symptom severity and better persistence on therapy.</p> <p>Trial Registration</p> <p>clinicaltrials.gov identifier <a href="http://www.clinicaltrials.gov/ct2/show/NCT00088049">NCT00088049</a>; <a href="http://www.clinicaltrials.gov/ct2/show/NCT00036088">NCT00036088</a></p