Imaging structure and composition homogeneity of 300 mm SiGe virtual substrates for advanced CMOS applications by scanning X-ray diffraction microscopy

摘要

Advanced semiconductor heterostructures are at the very heart of many modern technologies, including aggressively scaled complementary metal oxide semiconductor transistors for high performance computing and laser diodes for low power solid state lighting applications. The control of structural and compositional homogeneity of these semiconductor heterostructures is the key to success to further develop these state-of-the-art technologies. In this article, we report on the lateral distribution of tilt, composition, and strain across step-graded SiGe strain relaxed buffer layers on 300 mm Si(001) wafers treated with and without chemical−mechanical polishing. By using the advanced synchrotron based scanning X-ray diffraction microscopy technique K-Map together with micro-Raman spectroscopyand Atomic Force Microscopy, we are able to establish a partial correlation between real space morphology and structuralproperties of the sample resolved at the micrometer scale. In particular, we demonstrate that the lattice plane bending of thecommonly observed cross-hatch pattern is caused by dislocations. Our results show a strong local correlation between the strain field and composition distribution, indicating that the adatom surface diffusion during growth is driven by strain field fluctuations induced by the underlying dislocation network. Finally, it is revealed that a superficial chemical mechanical polishing of cross-hatched surfaces does not lead to any significant change of tilt, composition, and strain variation compared to that of as-grown complementary metal oxide semiconductor transistors for\udhigh performance computing and laser diodes for low power solid state lighting applications. The\udcontrol of structural and compositional homogeneity of these semiconductor heterostructures is the\udkey to success to further develop these state-of-the-art technologies. In this article, we report on the\udlateral distribution of tilt, composition, and strain across step-graded SiGe strain relaxed bu\udff\uder layers\udon 300 mm Si(001) wafers treated with and without chemical\ud−\udmechanical polishing. By using the\udadvanced synchrotron based scanning X-ray di\udff\udraction microscopy technique K-Map together with micro-Raman spectroscopy\udand Atomic Force Microscopy, we are able to establish a partial correlation between real space morphology and structural\udproperties of the sample resolved at the micrometer scale. In particular, we demonstrate that the lattice plane bending of the\udcommonly observed cross-hatch pattern is caused by dislocations. Our results show a strong local correlation between the strain\udfi\udeld and composition distribution, indicating that the adatom surface di\udff\udusion during growth is driven by strain\udfi\udeld\udfl\uductuations\udinduced by the underlying dislocation network. Finally, it is revealed that a super\udfi\udcial chemical\ud−\udmechanical polishing of cross-\udhatched surfaces does not lead to any significant change of tilt, composition, and strain variation compared to that of as-grown samples