Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degr...Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degree centrality, betweenness centra- lity and closeness centrality are taken into consideration in the proposed method. Numerical examples are used to illustrate the effectiveness of the proposed method.展开更多
With the relentless densification of interconnected circuitry dictated by Moore’ s Law,the CMP manufacture of such delicate wafers requires the significant reduction of polishing pressure of integrated circuits,not o...With the relentless densification of interconnected circuitry dictated by Moore’ s Law,the CMP manufacture of such delicate wafers requires the significant reduction of polishing pressure of integrated circuits,not only globally,but also locally on every tip of the pad asperities.Conventional diamond disks used for dressing the polyurethane pads cannot produce asperities to achieve such uniformity.A new design of diamond disk was fabricated by casting diamond film on a silicon wafer that contains patterned etching pits. This silicon mold was subsequently removed by dissolution in a hydroxide solution.The diamond film followed the profile of the etching pits on silicon to form pyramids of identical in size and shape.The variation of their tip heights was in microns of single digit that was about one order of magnitude smaller than conventional diamond disks for CMP production.Moreover,the diamond film contained no metal that might contaminate the circuits on polished wafer during a CMP operation.The continuous diamond film could resist any corrosive attack by slurry of acid or base.Consequently,in-situ dressing during CMP is possible that may improve wafer uniformity and production throughput.This ideal diamond disk(IDD) is designed for the future manufacture of advanced semiconductor chips with node sizes of 32 nm or smaller.展开更多
Low stress polishing is required for the manufacture of advanced integrated circuits(IC) with node sizes of 45 nm and smaller.However,the CMP community achieved the low stress by reducing the down force that press the...Low stress polishing is required for the manufacture of advanced integrated circuits(IC) with node sizes of 45 nm and smaller.However,the CMP community achieved the low stress by reducing the down force that press the wafer against a rotating pad.The reduced down force also decrease the removal rate of the wafer. As a result,the productivity suffers.In order to cope with this problem,an electrical potential is applied to the copper layer during polishing,in this case,the chemical oxidation is accelearated and hence the removal rate. Alternatively,the rotating pad must be softened to minimize the defects of wafers caused by CMP. In this research,we report a simpler solution to achieve low stress polishing without investing in new equipment and in developing new pad materials.The conventional CMP is proceeded by dressing the pad with a PCD dresser that can form 10×more asperities on the pad surface.The fluffy surface can then polish delicate IC without using the brutal force.As a result,the removal rate of wafers can be maintained without causing defectivity on the IC layer.展开更多
基金supported by the National Natural Science Foundation of China(61174022)the National High Technology Research and Development Program of China(863 Program)(2013AA013801)+2 种基金the Open Funding Project of State Key Laboratory of Virtual Reality Technology and Systems,Beihang University(BUAA-VR-14KF-02)the General Research Program of the Science Supported by Sichuan Provincial Department of Education(14ZB0322)the Fundamental Research Funds for the Central Universities(XDJK2014D008)
文摘Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degree centrality, betweenness centra- lity and closeness centrality are taken into consideration in the proposed method. Numerical examples are used to illustrate the effectiveness of the proposed method.
文摘With the relentless densification of interconnected circuitry dictated by Moore’ s Law,the CMP manufacture of such delicate wafers requires the significant reduction of polishing pressure of integrated circuits,not only globally,but also locally on every tip of the pad asperities.Conventional diamond disks used for dressing the polyurethane pads cannot produce asperities to achieve such uniformity.A new design of diamond disk was fabricated by casting diamond film on a silicon wafer that contains patterned etching pits. This silicon mold was subsequently removed by dissolution in a hydroxide solution.The diamond film followed the profile of the etching pits on silicon to form pyramids of identical in size and shape.The variation of their tip heights was in microns of single digit that was about one order of magnitude smaller than conventional diamond disks for CMP production.Moreover,the diamond film contained no metal that might contaminate the circuits on polished wafer during a CMP operation.The continuous diamond film could resist any corrosive attack by slurry of acid or base.Consequently,in-situ dressing during CMP is possible that may improve wafer uniformity and production throughput.This ideal diamond disk(IDD) is designed for the future manufacture of advanced semiconductor chips with node sizes of 32 nm or smaller.
文摘Low stress polishing is required for the manufacture of advanced integrated circuits(IC) with node sizes of 45 nm and smaller.However,the CMP community achieved the low stress by reducing the down force that press the wafer against a rotating pad.The reduced down force also decrease the removal rate of the wafer. As a result,the productivity suffers.In order to cope with this problem,an electrical potential is applied to the copper layer during polishing,in this case,the chemical oxidation is accelearated and hence the removal rate. Alternatively,the rotating pad must be softened to minimize the defects of wafers caused by CMP. In this research,we report a simpler solution to achieve low stress polishing without investing in new equipment and in developing new pad materials.The conventional CMP is proceeded by dressing the pad with a PCD dresser that can form 10×more asperities on the pad surface.The fluffy surface can then polish delicate IC without using the brutal force.As a result,the removal rate of wafers can be maintained without causing defectivity on the IC layer.
