GaAs HBT中测信号防护处理

Protection Processing of CP Signal in GaAs HBT

在集成电路前段代工厂制作完成后,为确保出货电性及封装良率,客户会要求出货前对器件进行电性及可靠度测试。由于HBT砷化镓芯片高集成度及高频等因素,在中测时存在振荡与干扰,无法得到真实的电性良率,而且不同于手动探针台每次只测试单一测试项,中测要对晶粒同时进行所有电性测试,进一步造成电性良率失真。针对此问题,对中测探针卡进行改良,通过比较TaN片电阻均匀性与手动探针台测量结果,以及观察电流值的高斯分布,证实中测结果的合理性。结果表明,对探针卡进行电磁屏蔽及电路匹配后,改善前后电性良率有显著提升,能满足快速且准确的检测目的。

After the production of the previous generation of integrated circuits is completed,customers will require the electrical property and reliability test of the devices before shipment to ensure the electrical property and packaging yield.Due to factors such as high integration and high frequency of HBT GaAs chip,there is oscillation and interference during the CP test,which can not obtain the real electrical yield.Moreover,unlike manual probe station which only tests a single test item at a time,the CP test needs to perform all electrical tests on the crystal grains at the same time,further causing electrical yield distortion.In order to solve this problem,the probe card under test was improved.The rationality of the test result was verified by comparing the uniformity of TaN sheet resistance with manual probe station measurement results and observing the Gaussian distribution of current values.The results show that after electromagnetic shielding and circuit matching are carried out on the probe card,the electrical yield before and after improvement is significantly improved,and the rapid and accurate detection purpose can be satisfied.