芯片失效分析前处理

[{"attributes":{"color":"var(--weui-FG-2)"},"insert":"失效分析 赵工"},{"insert":" "},{"attributes":{"color":"#576b95"},"insert":"半导体工程师"},{"insert":" "},{"attributes":{"color":"var(--weui-FG-2)"},"insert":"2023-02-24 10:18"},{"insert":" "},{"attributes":{"color":"var(--weui-FG-2)"},"insert":"发表于北京"},{"insert":"\n"},{"attributes":{"align":"justify"},"insert":"\n\n"},{"insert":"   由于芯片的失效往往发生在多层结构下的层间金属化或有源区，所以对芯片进行失效分析必须解决多层结构下层的可观察性和可测试性，这就需要对芯片进行去层处理。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"封装种类"},{"attributes":{"align":"justify"},"insert":"\n\n\n"},{"insert":"1、金属封装"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 采用金属作为壳体或底座，芯片直接可以或通过基板安装在外壳或底座上，引线穿过金属壳体或底座；"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 具有高速、高导热的优良性能，散热能力和电磁场屏蔽性良好；"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 适用于功能复杂、多芯片组装、输出引脚数量较少的器件。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":{"image":"https://files.eteforum.com/202302/1c7d58cead7d4bea.png"}},{"attributes":{"align":"justify"},"insert":"\n\n"},{"insert":"图1 典型金属封装—TO封装"},{"attributes":{"align":"center"},"insert":"\n"},{"attributes":{"color":"#888888"},"insert":"（图片源自网络若侵权请联系删除）"},{"attributes":{"align":"center"},"insert":"\n"},{"insert":"2、陶瓷封装"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 陶瓷封装能提供IC芯片的气密性的密封保护，使其具有优良的可靠度；"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 在电、热、机械特性等方面极其稳定，不仅可以作为封装的封盖材料，也是各种微电子产品重要的承载基板；"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 具有较高的脆性，易致应力损害。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":{"image":"https://files.eteforum.com/202302/f9adfa8ed640cdcb.png"}},{"attributes":{"align":"justify"},"insert":"\n\n"},{"insert":"图2 典型陶瓷封装—DIP封装"},{"attributes":{"align":"center"},"insert":"\n"},{"attributes":{"color":"#888888"},"insert":"（图片源自网络若侵权请联系删除）"},{"attributes":{"align":"center"},"insert":"\n"},{"insert":"3、塑料封装"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 具有低成本、薄型化、工艺较为简单、适合自动化生产等优点；"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 应用范围极广，是目前微电子工业使用最多的封装方法；"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"l 存在一些可靠性问题：吸收潮气、表面组装元件焊接加热时封装会出现爆裂。"},{"attributes":{"align":"justify"},"insert":"\n\n\n"},{"insert":{"image":"https://files.eteforum.com/202302/33882be822b5ac8e.png"}},{"attributes":{"align":"center"},"insert":"\n"},{"insert":"图3 典型塑料封装—QFP封装"},{"attributes":{"align":"center"},"insert":"\n"},{"attributes":{"color":"#888888"},"insert":"（图片源自网络若侵权请联系删除）"},{"attributes":{"align":"center"},"insert":"\n"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"开封方法"},{"attributes":{"align":"justify"},"insert":"\n\n\n"},{"insert":"1、开封的含义：Decap即开封，也称开盖，开帽，指给完整封装的IC做局部腐蚀，使得IC可以暴露出来，同时保持芯片功能的完整无损，为下一步芯片失效分析实验做准备，方便观察或做其他测试。比如EMMI,FIB,OM测试需要对裸芯片或开封后芯片操作。通过芯片开封，我们可以更为直观地观察到芯片内部结构，结合OM，SEM等设备分析判断样品的故障原因和失效的可能原因。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"2、开封方法"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"①激光开封：主要是利用激光束使被加工体表面气化达到去除器件填充料的目的。优点是开封速度快，操作方便，无危险性。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"②化学开封：选用对塑料材料有高效分解作用的化学试剂，如发烟硝酸和浓硫酸。主要操作方法：根据样品情况和材质，用调配好的化学试剂腐蚀塑封料，漏出芯片表面，不需要腐蚀的部分用铝箔保护起来。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"3、开封注意事项"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"①进行化学开封的所有操作必须在通风柜内进行，并且佩戴防毒面具，防护手套；"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"②清洗的过程中，镊子不可直接接触金丝和芯片表面，以免造成不必要的划伤。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"芯片去层"},{"attributes":{"align":"justify"},"insert":"\n\n\n"},{"insert":"   芯片开封后，可在OM下观察芯片表面有无损坏，简单判断一下芯片层数及金属材质（Al、Au或Cu），芯片没有损坏或着损坏部分不影响去层效果即可开始进行去层处理。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"1、钝化层去除：为了保护芯片，通常会在芯片的表面覆盖上一层很厚的致密磷化硅酸盐和氮化硅。芯片去层处理的第一步就是去除这层钝化层。用刻蚀机干法刻蚀的方法可以去除钝化层。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"2、金属层去除：芯片中用平面工艺加工出金属层，用电来连接各个半导体器件。金属层一般是Al或Cu。Al层的去除一般采用湿法，稀释后的硝酸、硫酸、硫酸等可将Al去除；Cu层的去除可采用干法或湿法，干法是用刻蚀机进行刻蚀，湿法是用稀释后的酸与铜反应进行去除。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"3、绝缘层去除：在各个金属层之间通常采用二氧化硅来做绝缘处理，因此在去除一层金属层后还需要去除一层绝缘层。绝缘层的去除一般由实验人员用研磨液在研磨台上进行研磨，也可用刻蚀机将绝缘层刻蚀掉。"},{"attributes":{"align":"justify"},"insert":"\n\n"},{"insert":"来源：米格实验室；作者：郑爽"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"转载有修改"},{"attributes":{"align":"justify"},"insert":"\n"},{"attributes":{"color":"var(--weui-FG-0)"},"insert":"半导体工程师"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"半导体经验分享，半导体成果交流，半导体信息发布。半导体行业动态，半导体从业者职业规划，芯片工程师成长历程。"},{"attributes":{"align":"justify"},"insert":"\n"},{"insert":"\n"}]