基于OTP修调功能的芯片量产方法研究

Research on chip mass production method based on OTP modification function

在实际生产中,受制造工艺的影响,芯片内部的基准电压模块会有一定的偏差。在芯片量产测试时,需通过一种内嵌存储单元修调电路,写入trim code来控制芯片内部电路,从而对芯片的参数进行微调。在测试过程中存在一些因素导致测试失效,需要进行复测提高良率。如果使用传统的方式进行一次性可编程(OTP)烧写,由于量产测试时重复烧写,会造成修调位错误烧写,导致芯片失效。基于自动化测试设备(ATE)设计了一种改进的OTP修调算法,测量初始电压、频率,并经过测试修正得出最合适的trim code,在复测时避免了对芯片重复烧写OTP。所提出方法提高了芯片测试良率,降低了生产成本。通过对两片晶圆上8000颗die的测试结果进行分析,验证了所提算法的可行性。

In actual production,being affected by the manufacturing process,the reference voltage module inside the chip will have a certain deviation.During the chip mass production test,a kind of embedded memory unit trimming circuit is used to write trim code to control the chip’s internal circuits and fine-tune the parameters of the chip.As there are some factors that cause the test to fail during the test,retests are needed to improve the yield.However,if the traditional programming method is used for one time programmable(OTP)programming,the trim and program will be incorrectly programmed due to repeated programming during mass production testing,which will result in chip failure.Therefore,an improved OTP tuning algorithm is designed based on the automatic test equipment(ATE),which measures the initial voltage and frequency,and then tests and corrects the most appropriate trim code to avoid the repeated burning of OTP on the chip during retest.The proposed algorithm can improve the chip and reduce the production costs as well.The feasibility of the algorithm is verified by analyzing the test results of 8000 die on two wafers.