US Patent 7304728 Test device and method for laser alignment calibration

A novel test device and method for calibrating the alignment of a laser beam emitted from a laser metrology tool with respect to a target area on a substrate. The test device includes a laser-sensitive material having a calibration pattern that includes a target point. When the tool is properly adjusted, the laser beam strikes the target point and is released to production. If the laser beam misses the target point, the tool is re-adjusted and re-tested until the laser beam strikes the target point.