Exposure system based on control of principal component of space image

Abstract

The invention relates to an exposure system based on the control of the principal component of a space image, sequentially comprising an illuminator, a masking plate, a projection objective lens and a silicon wafer table along the light propagation direction. A measuring unit used for measuring the space image information is arranged on the silicon wafer table. At least one movable lens of which the position can be adjusted is arranged in the projection objective lens. The exposure system based on the control of the principal component of the space image further comprises a control module. The control module is used for establishing a matrix of conversion from the position of the movable lens in the projection objective lens to the principal component of the space image according to the space image information measured by the measuring unit and calculating the position adjustment quantity of the movable lens according to the matrix of conversion so as to control the displacement of movable lens.

Description

technical field [0001] The invention relates to the field of photolithography, in particular to an exposure system in a photolithography machine. Background technique [0002] In the existing lithography equipment, in order to ensure a good exposure effect and the uniformity of the feature size to meet the process requirements, it is usually necessary to reduce the wave aberration of the projection optical system as much as possible, and at the same time reduce the wave image in the optical field of view as much as possible. Poor distribution difference, to ensure that the distribution characteristics of the spatial light intensity at the imaging end are as close to the ideal state as possible. At the same time, due to the drift of optical system performance parameters such as wave aberration caused by changes in the use environment, as well as the process characteristics of the exposure pattern, illuminator settings and other factors, during the use of the lithography machi...

AI Technical Summary

Problems solved by technology

[0004] Due to the large number of Zernike coefficient items that need to be independently controlled, the number of movable degrees of freedom of the projection objective lens is large, and the conversion matrix from movable degrees of freedom to Zernike coefficients is huge. The manufacturing and assembly of the projection objective lens is extremely difficult. Extremely difficult to design and calibrate

[0005] At the same time, the usual projection objective lens is only designed and controlled for wave aberration, and there is no conversion relationship from wave aberration to silicon wafer surface image quality, so it is impossible to realize the conversion from movable lens surface shape and adjustment amount to silicon wafer surface image quality Complete closed-loop control of

The usual practice is to make the Zernike coefficient as small as possible through movable lens compensation. On the one hand, it increases the difficulty of designing and adjusting the projection objective lens; on the other hand, it cannot fully guarantee the exposure image quality of the silicon wafer.

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