US 4,789,945 A · Method and apparatus for charged particle beam exposure

Abstract

A method and apparatus for drawing, by an electron beam, patterns on a semiconductor wafer for fabricating of an integrated circuit. Chip areas on the semiconductor wafer are each divided into rectangular blocks arrayed in rows and columns. The deflection field of the electron beam is selected slightly larger than each block. Real block marks, indicating the positions of respective blocks, are provided on every side of the chip area. The specimen is fed so that a block array starting at one corner of the chip area passes through the deflection field along one side of the array. Upon detecting the block marks at three corners of a first block of the array, correction coefficients for the block are computed based on the positions of the three detected real block marks and then an imaginary block mark is set at the remaining corner of the block on the basis of the correction coefficients. Thereafter, upon each detection of one real block mark for each block of the block array, correction coefficients are computed based on the position of the newly detected real block mark, the position of the real block mark detected for the immediately preceding block, and the position of the imaginary block mark set for the immediately preceding block. An imaginary block mark is set for the block on the basis of the correction coefficients. Pattern data for each block is corrected according to the correction coefficients thus obtained and a pattern is drawn in the block in accordance with the corrected pattern data.

Claims11

Dependent claims

A charged particle beam exposure method for exposing patterns by applying a charged particle beam, through deflection control, to one surface of a specimen on which rectangular blocks are defined in and real block marks are provided on at least two adjoining sides of the block matrix to define rows and columns thereof, said method comprising the steps of:

(a) passing the specimen through a charged particle beam deflection field along one of the two sides of the block matrix so that a first block in a first row at an intersection of two adjoining sides enters the charged particle beam deflection field;
(b) detecting the real block marks having entered the charged particle beam deflection field;
(c) detecting three real block marks at three corners of the first block;
(d) computing correction coefficients based on the positions of the three detected real block marks;
(e) placing an imaginary block mark at the one remaining corner of the first block on the basis of the computed correction coefficients;
(f) detecting the real block mark of each of the subsequent blocks;
(g) computing correction coefficients based on the position of the newly detected real block mark, the position of the real block mark detected for the immediately preceding block, and the position of the imaginary block mark placed at the one remaining corner of the immediately preceding block;
(h) placing an imaginary block mark at the remaining corner of the subsequent block on the basis of the computed correction coefficients;
(i) correcting pattern data for each of the blocks according to the correction coefficients computed therefor;
and
(j) drawing a pattern with the charged particle beam in each block in accordance with the corrected pattern data.

8 more elements

A charged particle beam exposure apparatus comprising:

a stage for carrying a specimen having a surface to be exposed on which rectangular blocks are defined in matrix form and real block marks are provided on at least two adjoining sides of the block matrix to define rows and columns of the matrix, said stage being capable of feeding the specimen in row and column directions of the block matrix;
deflection means for deflecting a charged particle beam to a desired point on the surface of the specimen mounted on said stage;
mark detection means for detecting the real block marks present in a deflection field of the charged particle beam through detection of electrons reflected from the real block marks irradiated with the charged particle beam;
coefficient computing means for computing correction coefficients on the basis of the positions of the three real and/or imaginary block marks at three corners of one block;
imaginary mark computing means for setting an imaginary block mark at one remaining corner of the block on the basis of the correction coefficients computed by said coefficient computing means;
imaginary block mark memory means for storing the positions of the imaginary block marks computed by said imaginary block mark computing means;
and
drawing control means for correcting paattern data on the basis of the correction coefficients computed by said coefficient computing means and supplying the corrected pattern data to said deflection means, thereby deflecting the charged particle beam by said deflection means in accordance with the corrected pattern data, and irradiating the specimen surface with the charged particle beam.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for charged particle beam exposure

Life of this patent

Method and apparatus for charged particle beam exposure

Life of this patent

Abstract

Claims11