The embodiment of the invention relates to the field of semiconductors, and provides a method for obtaining a compensation
mask of a
photomask, an
exposure method and an
exposure system. The method for obtaining the compensation
mask of the
photomask comprises the steps that: the
photomask is provided, wherein the photomask comprises a photosensitive layer and a graphical shading layer, and the graphical shading layer is located on the surface of the photosensitive layer; a
critical dimension deviation test is performed on the photomask by using an
exposure machine to obtain a deviation area of the
feature dimension of the photomask and a deviation value of the deviation area; and based on the deviation area and the deviation value, a compensation
mask corresponding to the exposure
machine table is formed, the compensation mask is internally provided with an attenuation area, the compensation mask is located between the photomask and an exposure
light source in the exposure
processing period through the photomask, and the attenuation area is right opposite to the deviation area, the attenuation area is used for attenuating the illumination intensity of light emitted by the exposure
light source and reaching the deviation area through the attenuation area, and at least the
critical dimension uniformity of the photomask can be improved.