Particle Beam Positioning by Means of a Laser Beam
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
Simultaneous irradiation of a biased MOS-like semiconductor target 7 with a particle beam 1 and a focussed laser beam 5 generates a maximum substrate current if both beams are positioned in coincidence. The particle beam 1 with its intensity profile 4 may be an ion beam (e.g., of a secondary Ion Mass Spectroscopy (SIMS) apparatus or an ion implantation system) or a neutral particle beam; it impinges on substrate 7 which is covered with a thin isolating layer 6 and biased to approximately -50 V by voltage source 9. A sensitive ammeter 8 records a current whenever laser beam 5, which is focussed by lens 2 and raster-deflected by deflection unit 3, overlaps particle beam 1.