Atomic-scale planarization of Ge (111), (110) and (100) surfaces

The Ge surfaces are planarized in H₂ annealing with atomically flat manner on (110) and (100) surfaces in addition to that on (111) surface. The terrace widths on (111) and (110) are almost controlled by the off-angle of the initial surface. The low thermal budget of 500°C in H₂ to form the atomically flat surface is advantageous for the device fabrication on Ge (111) and (110) surfaces, because these surface orientations fortunately are expected to facilitate the high electron and hole mobility for n- and p-FETs, respectively.