Atom probe tomography of SRAM transistors: Specimen preparation methods and analysis

Different FIB-based sample preparation methods for atom probe analysis of transistors have been proposed and discussed. A special procedure, involving device deprocessing, has been used to analyze by APT a sub-30 nm transistor extracted from a SRAM device. The analysis provides three dimensional compositions of Ni-silicide contact, metal gate and high-k oxide of the transistor gate. ⺠We discussed several sample preparation methods for APT analysis of transistors. ⺠The more effective method consists in deprocessing the device prior to FIB-milling. ⺠We analyzed by APT a sub-30 nm transistor extracted from a SRAM device. ⺠We obtained 3D chemical compositions of the transistor gate.