Inline characterization of SiGe structures on 8 inch Si wafers using the Bede QC200 x-ray diffractometer

Inline characterization of SiGe and SiGe:C heterobipolar transistors places stringent requirements on x-ray diffraction set-ups: (i) precise mounting and positioning of 8 inch wafers for single position scans and area mapping ; (ii) high beam intensity in a small spot; and (iii) low background to rea lize a dynamic range better than five orders of magnitude for precise rocki ng curve simulation. The Bede QC200 x-ray diffractometer, which applies a n ovel micro-focus x-ray source and a novel beam conditioning optics to a dou ble-crystal x-ray diffraction system, meets these requirements. Data collec ted on SiGe structures with the QC200 are compared with data collected at a synchrotron source. We demonstrate that reliable depth? profiles of Ge con tent can be obtained in structures of 500 x 500 mum(2) size in an automatic operation mode at different positions over an 8 inch wafer in a well defin ed grid. Two automatic fitting programs, one involving a generic algorithm, are used to extract material information from simulation of the high-resol ution diffraction scans. Rapid, reliable convergence on the global minimum gives objective fitting, suitable for quality control in a SiGe technology. Finally, we show how the lateral distribution of Ge content and layer thic kness can be mapped over an 8 inch wafer.