Confirmation of proton beam bending in graded Si_1-xGe_x/Si layers using ion channeling

A graded composition Si_1-xGe_x/Si [001] layer, which has recently been proposed as a method for bending and extracting protons from high-energy particle accelerators, has been studied by angle-resolved ion channeling analysis using focused MeV proton and He⁺ beams. Backscattering spectrometry confirms that the composition is linearly graded and a maximum Ge concentration of 0.16 was measured at the epilayer surface. Off-normal planes {111} are curved with respect to the substrate by a total angle of 0.332° and efficient bending of channeled particles along the curved planes and into the substrate is confirmed. © 1999 American Institute of Physics.