Scanning x-ray microscopy imaging of strain relaxation and fluctuations in thin patterned SiGe-on-insulator nanostructures

Abstract : Strain engineered performance enhancement in SiGe channels for p-MOSFETs is one of the main drivers for the development of microelectronic technologies. Thus, there is a need for precise and accurate strain mapping techniques with small beams. Scanning X-RayDiffraction Microscopy (SXDM) is a versatile tool that allows measuring quantitative strain maps on islands as thin as 13 nm quickly. From the high velocity and robustness of the technique, statistical information can be extracted for a large number of individual islands of different sizes. In this paper, we used the advantages of SXDM to demonstrate the effectiveness of the condensation method used to grow ultra-thin layers of strained SiGe and to determine their relaxation lengths at patterned interfaces.