适于纳米探针电性能测试的SRAM样品制备方法

Preparation Method of the SRAM Sample Suitable for Electrical Performance Test of Nanoprobes

在先进制程静态随机存储器(SRAM)单比特失效的分析过程中,SRAM样品制备是关键,传统研磨方法制备的样品其表面容易出现钨栓缺失的问题。利用离子精密刻蚀仪制备用于纳米探针电性能测试的SRAM样品。通过刻蚀仪改变刻蚀能量和刻蚀角度来制备样品,再对样品进行纳米探针电性能测试并根据测试结果得到最佳刻蚀参数。在此参数下制备的样品,其表面形貌完好并无钨栓缺失,且测得的晶体管特性曲线与传统方法制备的样品测得的晶体管特性曲线相匹配。实验结果表明,此方法可替代传统样品制备方法,并能有效提高失效分析的成功率。

In the analysis of single-bit failure for the advanced process static random access memory(SRAM), the SRAM sample preparation is the key. It was easy to miss tungsten plugs at the surface of samples prepared by traditional polishing methods. An ion precise etching instrument was applied to prepare SRAM samples for the electrical properties test of nanoprobes. The etching instrument was used to change the etching energy and etching angle to prepare a sample, and then the sample was tested for the electrical properties of nanoprobes and the optimal etching parameters were obtained according to the test results. The surface morphology of the sample prepared under these parameters is intact and no tungsten plug is missing, and the measured transistor characteristic curve matches the measured transistor characteristic curve of the sample prepared by the traditional method. Experiment results show that this method can replace traditional sample preparation methods and effectively improve the success rate of failure analysis.