Si 3 N 4 etch control is one of the most critical processes for profile angle, uniformity and selectivity. We investigated the morphology and selectivity of Si 3 N 4 etch in inductively coupled ...plasmas (ICP) and capacitively-coupled plasmas (CCP), which are standardly used in fabrication industry for the etching process with Lam conductor etch (CE) Kiyo ® series and dielectric etch (DE) Flex ® series tool, respectively. In our study, Si 3 N 4 etching was performed by using CF 4 /CHF 3 based plasma and combining O 2 plasma to balance passivation when mixed with diluted gas AR or helium. We have focused on tuning ESC temperature, O 2 flow, total flow, gas ratio and power splits to improve profile angle and uniformity. In addition, the wafer edge tilting issue has also been optimized to improve extreme edge profile tilting process window in extreme edge area.
The multicast operation is used commonly in parallel applications and can be used to support several other collective communication operations. A significant performance improvement can be achieved ...by supporting multicast operations at the hardware level. In this paper, we propose two parent selecting strategies which use global information to reduce the conflict among different multicast operations on k-ary n-trees. We first define an equivalence relation to divide the switches at each stage into several equivalence classes. Then we prove that the switches, which are at the same stage and are passed through by the same multicast tree, belong to the same equivalence class. Based on the study, two least loaded parent selecting strategies are developed. The proposed strategies are evaluated through simulation experiments. The results indicate that the proposed strategies lower the multicast latency and increase the multicast throughput significantly.
Supporting multicast at hardware level is a future trend of interconnection networks, and the latency of hardware-based multicast is sensitive to network conflict. In this paper, we study the method ...to forecast and reduce the conflict between unicast and multicast traffic on k-ary n-trees. We first derive a switch grouping method to describe the relationship among switches being passed through by a unicast routing path or a multicast tree. Then we analyze the sufficient condition for conflict-free routing. Based on these observations, a look-ahead adaptive routing strategy for unicast packet is proposed. The simulation results indicate that the proposed strategy can lower the multicast latency and the unicast latency simultaneously.
Progress in SHAO 65m radio telescope antenna Biao Du; Yuanpeng Zheng; Yifan Zhang ...
2013 Proceedings of the International Symposium on Antennas & Propagation,
2013-Oct., Letnik:
1
Conference Proceeding
The SHAO 65m radio telescope is the largest fully steerable radio telescope antenna in China, operating at decimeter to millimeter wavelength. This paper describes the design, main technical feature ...and progress in construction of the telescope antenna.
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