Method for electron beam-induced processing of a defect of a microlithographic photomask

A method for electron beam-induced processing of a defect of a microlithographic photomask, including the steps of:

• providing an activating electron beam at a first acceleration voltage and a process gas in the region of a defect of the photomask, and repairing the defect at least in part by use of the process gas activated by the electron beam;
• producing a first image of the photomask, in which the region of the defect is captured at least in part, by providing an electron beam at a second acceleration voltage which differs from the first acceleration voltage;
• producing a second image of the photomask, in which the region of the defect is captured at least in part, by providing an electron beam at a third acceleration voltage which differs from the first and the second acceleration voltages;
• analyzing the first produced image of the photomask to obtain first information about a structure of the photomask at a first depth;
• analyzing the second produced image of the photomask to obtain second information about the structure of the photomask at a second depth;
• and
• determining the quality of the repaired defect based at least in part on the first and second information about the structure of the photomask at the first and second depths;
• wherein an extent of a deviation of a parameter determined from the at least one produced image of the photomask from a reference parameter determined from reference data is determined during the determination of the quality of the repaired defect, and the method comprises determining whether the determined deviation is less than a predetermined threshold value.

A method for electron beam-induced processing of a defect of a microlithographic photomask, including the steps of:

• a) providing an activating electron beam at a first acceleration voltage and a process gas in the region of a defect of the photomask for the purpose of repairing the defect, and
• b) producing a plurality of images of the photomask, in which the region of the defect is captured at least in part, by providing an electron beam at a plurality of second acceleration voltages which differ from the first acceleration voltage, for the purpose of determining a quality of the repaired defect,
• wherein the plurality of images of the photomask are produced using the electron beam at a corresponding plurality of the second acceleration voltages which differ from the first acceleration voltage and from one another, for the purpose of acquiring depth information in relation to a structure of the photomask;
• wherein the determination of the quality of the repaired defect includes:
• a determination of a contour of one or more structures in the at least one produced image of the photomask, and/or
• a determination of a dimension of the one or more structures on the basis of the determined contour;
• wherein, during the determination of the quality of the repaired defect, a deviation of the determined contour from a reference contour in reference data and/or a deviation of the determined dimension from a reference dimension in reference data are/is determined;
• wherein the deviation of the determined contour from the reference contour in the reference data and/or the deviation of the determined dimension from the reference dimension in the reference data is determined for each of the at least one second acceleration voltage.

A method for electron beam-induced processing of a defect of a microlithographic photomask, including the steps of:

• providing an activating electron beam at a first acceleration voltage and a process gas in the region of a defect of the photomask, and repairing the defect at least in part by use of the process gas activated by the electron beam;
• producing a first image of the photomask, in which the region of the defect is captured at least in part, by providing an electron beam at a second acceleration voltage which differs from the first acceleration voltage;
• producing a second image of the photomask, in which the region of the defect is captured at least in part, by providing an electron beam at a third acceleration voltage which differs from the first and the second acceleration voltages;
• analyzing the first produced image of the photomask to obtain first information about a structure of the photomask at a first depth;
• analyzing the second produced image of the photomask to obtain second information about the structure of the photomask at a second depth;
• and
• determining the quality of the repaired defect based at least in part on the first and second information about the structure of the photomask at the first and second depths;
• wherein the determination of the quality of the repaired defect includes:
• a determination of a contour of one or more structures in the at least one produced image of the photomask, and/or
• a determination of a dimension of the one or more structures on the basis of the determined contour;
• wherein, during the determination of the quality of the repaired defect, a deviation of the determined contour from a reference contour in reference data and/or a deviation of the determined dimension from a reference dimension in reference data are/is determined;
• wherein the deviation of the determined contour from the reference contour in the reference data and/or the deviation of the determined dimension from the reference dimension in the reference data is determined for each of the second and third acceleration voltages.