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PORTLAND, Ore. A novel self-assembly technique previouslydemonstrated only in the lab for regular test patterns, has beenperfected for creating the irregular patterns necessary tofabricate real semiconductors down to 14-nanometers, according toresearchers funded by Semiconductor Research Corp. (SRC). By solving one of the outstanding lithographic problems facingfurther scaling the tiny contact holes that connect semiconductorsto their substrate researchers at Stanford University havedemonstrated working circuits at 22-nanometer and a clear path to14-nanometers, as well as a bee-line on the chemistry developmentsneeded to scale to single digit sizes. "Others have demonstrated self-assembly of regular patterns," saidPhilip Wong, lead researcher at Stanford for the SRC-guidedresearch. "But this is the first time that directed self-assembly(DSA) has been successfully applied to create the critical contactholes needed for standard cell libraries on future sub-22-nanometerchips." The semiconductors fabricated by Wong's group were real workingcircuits at 22-nanometer, not just test structures, demonstratingthat DSA can be used for any irregular pattern required for futurelogic or memory chips. The group also demonstrated that they couldheal imperfections in patterns and maintain high resolutions andultra-fine features consistently across a wafer. "At SRC, we view Wong's work as the critical breakthrough needed topattern contact hole patterns at advanced nodes, which is one ofthe most difficult problems the industry is facing today," said BobHavemann, director of nanomanufacturing sciences at SRC (ResearchTriangle, N.C.). "Wong was also able to achieve the patterningusing environmentally green materials, which is another obstaclethat needed to be surmounted." Stanford's technique works by first using standard lithographytechniques to pattern the general area where the contact hole willneed to be, using features than can be more than twice the size ofthe final contact holes. For instance, if pair of contact holesbeen to be spaced 22 nanometers apart, then the template might beused to etch an oblong indentation that is 50 nanometers long.Then, in the second step, a self-assembling block-copolymer isdeposited on the wafer, where it only activates within the indentedareas. By carefully formulating the two parts of the co-polymer, itself assembles into precisely the placement pattern required toaccurately etch closely spaced side-by-side 22 nanometer holes. "Our current demonstration showed we could etch irregular patternsof 22 nanometer holes," said Linda He Yi, a researcher working onWong s team. "But our current copolymer can handle etching holesin patterns as small as 14 nanometers." The solvents used in the coating and etching process werepolyethylene glycol monomethyl ether acetates, which are considereda green alternative to conventional solvents. Other SRC projectsunderway are aiming to extend the green directed self-assemblytechnique to single-digit sizes below 10-nanometer, by perfectingdifferent copolymer formulations. Additional funding for the project was provided by the NationalScience Foundation. I am an expert from medical-hospitalbeds.com, while we provides the quality product, such as Hospital Electric Beds , Ambulance Stretcher Trolley Manufacturer, Medical Hospital Beds,and more.
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