IC工艺技术2--光刻.ppt

IC工艺技术系列讲座第二讲 PHOTOLITHOGRAPHY 光刻 讲座提要 1. General 2. Facility (动力环境) 3. Mask (掩膜版) 4. Process step highlight (光刻工艺概述) 5. BCD 正胶工艺 6. History and 未来的光刻工艺 1. General MASKING Process (光刻工艺) Photolithography (光学光刻) ----Transfer a temporary pattern (resist) Defect control Critical dimension control Alignment accuracy Cross section profile Etch (腐蚀) ----Transfer a permanent pattern (Oxide, Nitride, Metal…) 2.0 Facility requirement Temperature (温度) 70 oF Humidity (湿度) 45% Positive pressure (正压) 0.02in/H2O Particle control (微粒) Class 100 Vibration (震动) Yellow light environment (黄光区) DI water (去离子水) 17mhom Compress air and Nitrogen (加压空气,氮气) In house vacuum(真空管道) 3.0 Mask (掩膜版) Design PG tape Mask making Plate --- quartz, LE glass, Soda line glass Coating --- Chrome, Ion oxide, Emulsion Equipment --- E-beam, Pattern generator Mask storage ---Anti static Box Pellicle Pellicle protection 4.0 光刻工艺概述 Prebake and HMDS (前烘) Resist coating (涂胶) EBR (去胶边), soft bake, 3. Exposure (曝光) Alignment (校正) 4. Develop (显影) Post e-bake, Hard bake, backside rinse 5. Develop inspection (显检) 4.1 Prebake and HMDS treatment Purpose of Pre-bake and HMDS treatment is to improve the resist adhesion on oxide wafer. HMDS is adhesion promoter especially designed for positive resist. HMDS (Hexamethyldisilane) can be applied on the wafers by 1. Vapor in a bucket 2. vapor in a vacuum box 3. Directly dispense on wafer 4. YES system --- in a hot vacuum system 5. Vapor in a hot plate (with exhaust) Too much HMDS will cause poor spin, vice versa will cause resist lifting 4.2 Resist Coating (涂胶) Resist coating specification (指标） Thickness（厚度）0.7u – 2.0u (3.0以上for Pad layer) Uniformity（均匀度）+ 50A – +200A Size of EBR （去胶边尺寸） Particle（颗粒）20 per wafer Backside contamination(背后污染） 三个主要因数影响涂胶的结果 Resist Product (产品） Viscosity （粘度） Spinner Dispense method （涂胶方法） Spinner speed (RPM) （转速） Exhaust （排气） Soft bake temperature （烘温） Facility Temperature （室温） Humility