摘要
通过将压阻加速度计上帽与结构片的键合 ( 36 5℃保温 10min) ,再进行下帽与结构片的键合 ( 380± 10℃保温2 0min) ,成功进行了三层键合 .测得的键合强度约为 2 30MPa.硅片 基体 /SiO2 /Cr/Au层和硅片之间键合时 ,SiO2 溶解而形成CrSi2 硅化物 .共晶反应因Cr层而被推迟 ,键合温度高出共晶温度 2 0℃左右 ,从而避免了由于Au元素向硅中扩入而造成的污染 ,进而避免可能造成的对集成微电子器件性能的影响 .试验还证明硅基体 SiO2 /Cr/Au/Poly Si/Au键合层结构设计模型也遵循这一键合过程中的原子扩散理论 .
A piezoresistive accelerometer is bonded successfully.It is completed by two steps:the cap and frame wafer are first bonded together at 365 ℃ for 10min.The base plate is then bonded with them by annealing at 380±10℃ for 20min.The eutectic bonding strength is measured to be as high as 230 MPa.The bonding between wafer/Cr/Au and Si wafer is also studied.The bonding begins as soon as the dissolving of the SiO 2 layer by silicidation of the Cr barrier layer.An excess annealing temperature (about 20℃ ) should be used to avoid gold contamination of the silicon die with the possible deteriorating effect on integrated microelectronic device properties.A Si-substrate/SiO 2/Cr/Au/Poly-Si/Au eutectic solder,which is also fabricated,is in agreement with this atom diffusion theory.
基金
国家重点基础研究发展规划资助项目 (合同号 :G19990 3310 8)~~
关键词
金
硅
共晶键合
压阻式加速度计
封装
gold
silicon
eutectic bonding
piezoresistive accelerometer
