Patent ID: 8110775
Filing Date: 2012-02-07
Classification: G11C,H01L

Abstract:
1. A system for determining relative position of a semiconductor substrate and at least one laser beam spot on or within the semiconductor substrate in a machine used to selectively irradiate structures on or within the semiconductor substrate using a plurality of laser beams, the system comprising: a means for producing at least a first laser beam and a second laser beam, wherein the first laser beam propagates toward the semiconductor substrate along a first laser beam propagation path having a first laser beam axis that intersects the semiconductor substrate at a first spot, and wherein the second laser beam propagates toward the semiconductor substrate along a second laser beam propagation path having a second laser beam axis that intersects the semiconductor substrate at a second spot; a means for detecting reflection of both the first and second spots from one or more reflective structures on or within the semiconductor substrate while the first and second laser beam spots move relative to the semiconductor substrate, thereby generating at least one reflection signal; and a means for determining, based on said at least one reflection signal, positions of both the first and second spots on or within the semiconductor substrate.