Mask for estimating aberration in projection lens system of exposure apparatus
AssigneeSamsung Electronics Co., Ltd.
InventorSung-Woo Lee
Life of this patent
Estimating the term…
Abstract
A mask for estimating aberration in a projection lens system of an exposure apparatus. The mask includes a mask substrate and mask patterns arranged on the mask substrate such that a critical dimension (CD), represented by the width of each of the mask patterns, and a phase of the mask patterns have a size proportional to a SINC function. Preferably the distance between the centers of the mask patterns is substantially uniform. The size and phase of light transmitted to the projection lens system during an exposure step are substantially uniform such that the aberration value in each portion of the projection lens system depending on each of the mask patterns is substantially not distorted and is substantially uniform.
Claims15
A mask for estimating aberration in a projection lens system of an exposure apparatus comprising:
- mask patterns arranged on a mask substrate such that a critical dimension and a phase of said mask patterns have a size proportional to a SINC function, said critical dimension being represented by the width of each of said mask patterns.
The mask of claim 6, wherein the size and phase of light transmitted to said projection lens system during exposure are substantially uniform.
A method for estimating aberration in a projection lens system of an exposure apparatus comprising:
- measuring a center distance between photoresist patterns transferred from mask patterns to a semiconductor wafer, said mask patterns being arranged such that a critical dimension and a phase of said mask patterns have a size proportional to a SINC function;
- measuring a center distance between said mask patterns;
- comparing said center distance between said photoresist patterns to said center distance between said mask patterns to obtain an aberration value.
Dependencies are inferred from the claim text.