Sucker and method for eliminating wafer exposure defocus defects

Abstract

The invention provides a sucker and method for eliminating wafer exposure defocus defects. The sucker is flat in upper surface and is used for supporting a wafer. The sucker comprises a plurality of vacuum suction holes and a plurality of thermoelectric couples, the vacuum suction holes are densely distributed in the upper surface of the sucker, all parts of the wafer are absorbed into the same plane by the vacuum suction holes, the thermoelectric couples are densely distributed at the bottom of the sucker, the thermoelectric couples and the vacuum suction holes are alternatively arranged, and the thermoelectric couples are used for heating the wafer. By means of the sucker and method, the thermoelectric couples densely distributed at the bottom of the sucker and the vacuum suction holes densely distributed in the upper surface of the sucker are arranged, the upper surface of the sucker is flat, stress in the wafer is slowly released in the heating process, vacuum suction force, acting on the wafer, of the vacuum suction holes enables the wafer to be attached to the flat upper surface of the sucker, buckling deformation defects of the wafer are accordingly reduced, the surface of the wafer is flattened, the defocus defects in the exposure process are further eliminated, and the exposure quality and the product yield are improved.

Description

Technical field [0001] The invention relates to the field of semiconductor technology, and in particular to a sucker for eliminating out-of-focus defects of wafer exposure and a method for eliminating out-of-focus defects of wafer exposure. Background technique [0002] In the semiconductor manufacturing process, after undergoing multiple processes, a large amount of stress will inevitably accumulate on the wafer, which will cause the wafer to warp and deform. Such as figure 1 Shown is a schematic diagram of the wafer test height difference, figure 1 In the middle, the dark color indicates upward or downward warpage, and the larger the number, the greater the deformation. Wafer warping will affect the quality of the exposure process. Specifically, the exposure equipment cannot fully compensate the focus depth, making the exposure out of focus, such as figure 2 As shown, figure 2 Is an exposure schematic diagram of a wafer with out-of-focus defects, figure 2 In the middle, the...

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Problems solved by technology

Patent Publication No. CN 103367217A discloses a silicon wafer adsorption device and its adsorption method. Although the suction cup has vacuum suction holes to adsorb the wafer, the wafer does not have warping deformation or warping deformation is small In some cases, it can meet the requirements of fixing the wafer and improving the warpage of the wafer. However, in the case of serious warpage, simply relying on increasing the vacuum degree to increase the mechanical force applied to the wafer will be due to the force If it is too large, it will lead to the breakage of the wafer and reduce the product yield; under the condition of increasing the vacuum degree, it is impossible to completely eliminate the defect of wafer warping and deformation, so the defect of exposure out-of-focus will still exist

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