System and method for producing oscillating magnetic fields in working gaps useful for irradiating a surface with atomic and molecular ions

摘要

Deflection apparatus is shown for high perveance ion beams, operating at 20 Hz fundamental and substantially higher order harmonics, having a magnetic structure formed of laminations with thickness in range between 0.2 and 1 millimeter. Additionally, a compensator is shown with similar laminated structures with resonant excitation circuit, operating at 20 Hz or higher, in phase locked relationship with the frequency of the previously deflected beam. Furthermore, features are shown which have broader applicability to producing strong magnetic field in magnetic gap. Among the numerous important features shown are special laminated magnetic structures, including different sets of crosswise laminations in which the field in one lamination of one set is distributed into multiplicity of laminations of the other set of coil-form structures, field detection means and feedback control system, cooling plate attached in thermal contact with number of lamination layers. Surfaces on the entry and exit sides of the compensator magnetic structure have cooperatively selected shapes to increase the length of path exposed to the force field dependently with deflection angle to compensate for contribution to deflection angle caused by higher order components. The entry and exit surfaces of the magnetic scanner and compensator structures cooperating to produce desired beam profile and desired limit on angular deviation of ions within the beam. Also shown is an accelerator comprising a set of accelerator electrodes having slotted apertures, a suppressor electrode at the exit of the electrostatic accelerator, a post-accelerator analyzer magnet having means for adjusting the angle of incidence by laterally moving the post-accelerator analyzer magnet, and a magnet to eliminate aberration created by the post- accelerator analyzer magnet. In the case of use of a spinning substrate carrier for scanning in one dimension, the excitation wave form of the scanner relates changes in scan velocity in inverse dependence with changes in the radial distance of an implant point from the rotation axis. Also an oxygen implantation method is shown with 50 mA ion beam current, the ion beam energy above 100 KeV, and the angular velocity of a rotating carrier above 50 rpm.