Method for improving photolithography exposure energy homogeneity using grey level compensation

The invention discloses a method for using gray scale compensation to improve photo-etching exposure energy uniformity, with wide application in non-mask photo-etching machine which uses spatial light modulator as image generator. The non-mask photo-etching machine provided with a spatial light modulator as image generator uses the gray scale modulation of the spatial light modulator, according to the image light strength distribution information of photo-etching objective lens collected by a CCD to modulate the light output of each pixel unit of the spatial light modulator to change the emission light field distribution on the image plane of the photo-etching objective lens. The invention uses the light strength distribution measured in the integration of some time or uses the energy distribution of the light emitted from each image plane position in a certain exposure time to make the exposure energy of each position uniform on the image plane. The invention can effectively reduce the design and assembly hardness of the lighting system of traditional photo-etching machine and reach better exposure energy uniformity.