IC工艺技术3--刻蚀.ppt

IC工艺技术系列讲座第三讲 ETCHING 刻蚀 讲座提要 1. General 1.1 Isotropic/Anisotropic etch (无定向/定向刻蚀) 1.2 Facility(动力环境) 2. Wet etch 2.1 Wet etch mechanism （湿化刻蚀机理） 2.2 BOE etch （氧化硅刻蚀) 2.3 Aluminum etch (铝刻蚀) 2.4 Nitride etch (氮化硅刻蚀) 2.5 Poly/silicon etch (多晶硅/单晶硅刻蚀) 2.6 DI water rinse and dry 3. Dry etch 3.1 Plasma Theory and application (等离子理论和应用) 3.2 Type of plasma etch (等离子刻蚀种类) 3.3 Etching gases and pressure (刻蚀气体和低压） 3.4 Etch process highlight (刻蚀工艺简介) 3.5 Etch process parameter (刻蚀工艺参数) 3.6 Ion milling (离子铣) 3.7 BCD plasma etching equipment and application 5. Next etch process 未来的刻蚀工艺 1.1 General Isotropic etch (无定向刻蚀) Etching has no direction. Wet etch or a plasma etch without side wall passivation process. It causes undercut during the etching and change critical dimension. Anisotropic etch (定向刻蚀) Etch with direction or side wall protection Ion milling, RIE or the plasma etch with enough side wall passivation process. After etch, critical dimension has no change or very slightly difference. Isotropic etch (无定向刻蚀) 1.2 Facility DI water (去离子水) 17mhom Drain(排水) Special chemical dispose system Exhaust(排风) Compress air and Nitrogen (加压空气,氮气) In house vacuum(真空管道) Cooling water(冷却水) Gas cabinet / Gas line (气柜,气体管道) Gas bottle(气瓶) 2.0 Wet etch Advantage and disadvantage Chemical etch (化学刻蚀）--- isotropy CD loss （线宽变小） High particle contamination （高颗粒） Unable for small geometry (不能用于小尺寸工艺) Higher process cost （工艺费用高） Most of wet etch process have high selectivity to the under layer （高选择比） Fast throughput （产量高） Low equipment (investment) cost （投资少） 2.1.1 Wet etch mechanism （湿化刻蚀机理） Wafer surface wetting and contact with etch chemical Chemical reaction takes place, soluble byproduct formation. Remove by product from wafer surface The etch rate (and uniformity) affects by Temperature The slowest step of one of above step 2.1.2 Wet etch byproduct (副产物) Part of byproduct will be converted to water soluble material. (水溶性) Part of byp