A new method of fabricating three dimensional ( 3D) paper-based microfluidics chip by clips

提出一种利用回形针来制作三维微流控纸芯片的方法,能够适应多种不同的微流控纸芯片;利用自制的纸芯片比色检测装置,已用于牛血清白蛋白,Fe~(2+)的快速定量检测。牛血清白蛋白的线性范围是5~50μmol/L,检出限为0.13μmol/L,R~2=0.994。Fe~(2+)的线性范围是0.6~12μmol/L,检出限为0.15μmol/L,R~2=0.992。在所规定的范围内,都获得了较好的线性关系,验证了基于回形针的3D微流控纸芯片可用于实际样品检测的可能性

面向高性能GaN基功率電子的器件物理研究

氮化鎵(GaN)功率電子器件具有高擊穿電壓、高工作頻率、高電流輸出能力以及耐高溫等優點,有望成為下一代高效電源管理系統芯片的最佳候選之一.本文從界面態起源、極化能帶工程以及可靠性機理等角度分析了GaN基功率電子器件所面臨的器件物理挑戰,包括柵極閾值不穩定性、高壓動態導通電阻退化、高閾值柵技術和柵介質長期可靠性等關鍵科學問題和技術瓶頸.分析指出(Al)GaN表面的無序氧化可能是GaN基器件表/界面態的主要來源,并有針對性地介紹了界面氮化插入層、極性等離子增強原子層沉積AlN薄膜(Plasma-Enhanced Atomic Layer Deposited AlN,PEALD-AlN)鈍化、F離子注入與高溫柵槽刻蝕增強型技術,以及低壓化學氣相沉積SiNx(Low-Pressure Chemical Vapor Deposited SiNx,LPCVD-SiNx)和O3-Al2O3高絕緣柵介質等提高GaN基增強型器件性能的新型工藝技術.系統分析了國際有關高性能GaN功率電子器件研究的最新進展,及未來面臨的機遇和挑戰. Gallium-nitride-based power electronic devices, with the inherent high breakdown voltage, high working frequency, high output current density and high temperature operating capability, are promising candidates for next-generation high-efficiency and compact power management systems. In this work, the scientific and technical challenges towards high-performance GaN power devices, including threshold voltage instability, dynamic ON-resistance degradation, enhancement-mode gate techniques and long-term reliability of gate dielectrics, are investigated based on in-depth analysis of the physical origin of interface states and high-voltage current collapse. Oxidation of (Al) GaN surface are suggested to be the primary cause for the surface/interface states in GaN-based power devices. State-of-the-art device technologies, including nitridation-interficial-layer to suppress dielectric/(Al) GaN interface oxidation, polarized PEALD-AlN passivation for compensation of deep interface states, E-mode techniques of fluorine plasma ion implantation and high-temperature low-damage gate-recess, high-breakdown-strength LPCVD-SiNx and O3-sourced ALD-Al2O3 gate dielectrics are introduced for fabrication of high performance and reliability GaN-based power electronic devices