第四章 微纳制造工艺2半导体料与制备.ppt

Single Crystal Wafer Grind Ingot to defined diameter Saw – off Ingot ends using a diamond saw Saw ingot into wafers (0.5mm – 0.75mm) Edge Grind wafers Lap wafers – flaten and ensure faces are parallel Wet Etch to remove surface damage Polish – remove residues and planarise locally Final Wet Clean 硅的电阻测量 Polysilicon (多晶硅)-MEMS中基本的结构材料 生长方法：LPCVD（高于晶化温度） 特性：压阻, 热阻 应用：微机械结构（微梁，横隔膜 ）, p-n结二极管，加速度计， 非晶硅 生长方法：LPCVD （低于晶化温度） 特性：压阻, 光敏，气敏 应用：太阳能电池、气敏传感器、光传感器等 多孔硅 生长方法：电化学 特性：易腐蚀 应用：牺牲层 其他材料 Silicon oxide and nitride-SiO2 生长方法：CVD，溅射 绝热，绝缘材料，掩膜材料（碱性溶液湿法腐蚀Si），支撑结构 Polymers-Polyimides, photoresist, epoxy resin，BCB Glass and quartz substrate Thin metal films Silicon carbide and diamond 具有压阻特性 GaAs, AlGaAs, GaN 光电子器件 Shape-memory alloys actuators Carbon nanotubes 晶体平面 2 a1 a3 a2 (1 1 0) plane (0 1 1) plane (1 0 1) plane Families of planes ±h, ±k, ±l represented by curly brackets {h k l} 晶体平面 3 a1 a3 a2 (1 1 1) plane 晶体平面4 [0 0 0] (1 -1 -1) planes conventionally written as (1 1 1) a1 a3 a2 晶体平面 5 a1 a3 a2 The plane shown here runs parallel to the a1 and a3 direction and intercepts a2 at 0.5 It is therefore the (0 2 0) plane This is related to the (0 1 0) plane in that it runs parallel to it, but the separation of the planes is half that of the (0 1 0) plane. 周期表 Hexagonal closed packed (hcp) face-centered cubic (fcc) body-centered cubic (bcc) Crystal Lattices 硅的晶体结构 晶体缺陷 ? 点缺陷：影响掺杂和扩散；? 线缺陷：影响热处理；? 面缺陷和体缺陷：影响成品率 点缺陷(0-dimensional) An avenue for atomic motion within the lattice, in response to an external mechanical or electrical load In stainless steel, carbon, which makes it a steel, is an interstitial impurity in the iron lattice (and chromium, which makes it stainless, is a substitutional impurity) In semiconductors, substitutional impurities are called dopants, and control the amount of charge carriers Intrinsic (vacancies) Extrinsic (interstitial and substitutional impurity atoms) Alter the mechani