Daniel M Mccarthy

US Patent:

6392242, May 21, 2002

Filed:

May 27, 1999

Appl. No.:

09/320673

Inventors:

F. Keith Perkins - Alexandria VA
Daniel McCarthy - Ellicott City MD
Martin C. Peckerar - Silver Spring MD
Christie R. K. Marrian - Marbury MD
Eric S. Snow - Springfield VA

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

G01I 100

US Classification:

2504911, 250361 R

Abstract:

A fiducial beam monitor includes a patterned diode layer on a semiconducting substrate. An electrical field between the diode (or diodes) on the diode layer and the semiconducting substrate modulates the size of the depletion layer formed by the diode or diode. A high energy beam incident upon a diode on the diode layer produces a greater current than a high energy beam incident upon a non-diodic region of the same layer. In use, the beam monitor is typically fixed to the backside of a workpiece such as a semitransparent membrane being patterned by a focused high energy beam that is translated with respect to workpiece and attached monitor. The changes in current during translation are then correlated with the position of the beam with respect to the pattern on the diode layer.