Infinite lateral growth of (001) single crystal strip in Ge film on SiO2 by micro-chevron laser scanning method

Abstract

Abstract A single crystal strip of Ge, exhibiting a predominant crystal orientation of (001), was successfully grown within a 60 nm thick sputtered Ge film using the micro-chevron laser scanning method. The continuous lateral growth of the Ge strip was achieved through the strategic implementation of a thick cap layer and a SiO2 interlayer between the Ge layer and cap layer. The thick cap layer was pivotal as a heat sink, effectively extending the period during which the Ge film remained molten, preventing unwanted nucleation. Yaw rotation of (001) crystal orientations, which typically trigger the formation of grain boundaries in Si, was found to be negligible in Ge. This observation offers compelling evidence for the potential for infinite lateral growth of (001)-oriented Ge strips. The Raman shift of the single crystal strip was measured at 297.4 cm−1, indicating that the film exhibited tensile stress.