氮化镓器件芯片表面银迁移抑制方法研究  

A Method for Silver Migration Inhibition on the Chip Surface of GaN HEMT Devices

作　　者：别业楠[1] 裴轶 赵树峰 BIE Ye-nan;PEI Yi;ZHAO Shu-feng(ZTE Corporation;Dynax Semiconductor Corporation)

机构地区：[1]中兴通讯股份有限公司无线研究院 [2]苏州能讯高能半导体有限公司

出　　处：《中国集成电路》2022年第10期55-60,共6页China lntegrated Circuit

基　　金：国家重点研发计划项目(2021 YFB3602400)。

摘　　要：封装贴片所用烧结银胶中的银元素有可能在高温高湿度条件下转化为离子并在高电场作用下沿芯片表面迁移从而导致器件电极间漏电甚至短路。本研究工作采用高加速应力实验(HAST)作为加速检验手段,通过对失效样品的物理分析,首先确认了银迁移是引起所观察到失效的根源。器件表面电场模拟结果显示,引入适当的环形屏蔽电极可以有效降低关键区域的电场强度。实验结果证实采用了带有优化设计屏蔽电极芯片的产品其芯片表面的银迁移现象得到了充分抑制,极大提高了采用烧结银胶贴片工艺生产的氮化镓器件的可靠性(栅漏电异常比例由48%降为0%),使其达到满足实际工业应用的水平。the silver element in the sintered silver paste used for packaging may be converted into ions under high temperature and humidity conditions and migrate along the chip surface under high electric field,resulting in leakage or even short circuit between the electrodes of the device.In this study the high accelerated stress test(HAST)is used as the fast evaluation method.Based on the physical analysis results of the failed samples,it is confirmed at first that silver migration was the root cause of the observed failure.The simulation results of the electric field on the device surface show that by introducing annular shield electrode the electric field intensity in the critical region of the chip can be effectively reduced.The experimental results show that the migration of silver on the surface of the chips with optimized shielding electrodes is fully suppressed,which greatly improves the reliability of the GaN devices produced with the sintered silver glue process to a satisfactory level for industrial applications.

关 键 词：氮化镓 器件芯片 烧结银胶 银迁移 

分 类 号：TN386[电子电信—物理电子学] TN405