US Patent Issued to Carl Zeiss SMT on Sept. 29 for "End point determination by means of contrast gas" (German Inventor)

ALEXANDRIA, Va., Sept. 30 -- United States Patent no. 12,748,347, issued on Sept. 29, was assigned to Carl Zeiss SMT GmbH (Oberkochen, Germany).

"End point determination by means of contrast gas" was invented by Daniel Rhinow (Frankfurt am Main, Germany).

According to the abstract* released by the U.S. Patent & Trademark Office: "The present invention encompasses a method of repairing a defect on a lithography mask, comprising the following steps: (a.) directing a particle beam onto the defect to induce a local etching operation on the defect; (b.) monitoring the etching operation using backscattered particles and/or secondary particles and/or another free-space signal generated by the etching operation, in order to detect a transition fr...