Patent ID: 9691589
Date: 2017-06-27
CPC Classifications: B82Y,G03F,G06T,H01J,H04N

Claim:
1. A method for exposing a plurality of stripes of a field of a wafer using a plurality of charged particle beamlets by an electron optical column of a charged particle lithography system comprising a moveable stage, the method comprising: transmitting control signals for the charged particle beamlets by channels of a data path, wherein each channel transmits beamlet control data for a group of the beamlets, wherein each group of beamlets is arranged to scan one stripe of the field of the wafer; identifying non-functional beamlets of the charged particle lithography system among the beamlets prior to performing a first scan; calculating, by a processing unit communicatively connected to the charged particle lithography system, a first subset of the beamlets, first channels and a first wafer offset for exposing a first portion of the stripes, the first subset of the beamlets excluding the non-functional beamlets as identified prior to performing the first scan; calculating, by the processing unit, a second subset of the beamlets, second channels and a second wafer offset for exposing a second portion of the stripes, the second subset also excluding the non-functional beamlets as identified prior to performing the first scan; moving the wafer using the moveable stage to a first position based on the first wafer offset before beginning the first scan; performing the first scan for exposing the entire first portion of the stripes using the first channels; moving the wafer using the moveable stage to a second position based on the second wafer offset after the first scan and before beginning the second scan, wherein the second position is shifted with respect to the first position; and performing the second scan of the same field of said wafer to be exposed in the charged particle lithography system for exposing the entire second portion of the stripes using the second channels, wherein the first and second wafer offsets comprise shifting the wafer with respect to the electron optical column in the y-direction and/or x-direction by an amount corresponding to a number of stripes until channels with properly functioning beamlets are positioned to write the respective portions of the stripes, wherein the first and second portions of the stripes do not overlap and together comprise the complete area of the wafer to be exposed; and wherein the first subset of the beamlets is different from the second subset of the beamlets.