Method of improving outline of photoresist pattern

Abstract

The invented method is to proceed hard baking when temp. is under vitrescence transform temp. of the photic slushing agent after definiting exposure and develop steps of photic slushing agent, thus to make the photic slushing agent being been back-flow reshaped to avoid generation of point convex angle, reduce mask error factor and increased degree of uniformity of key size. The heard baking step can be substituted by two steps that to proceed back flow baking when temp. is below and super the vitrescence transform temp. of the photic slushing agent separately to achieve the same purpose.

Description

technical field [0001] The present invention relates to a method for improving the photoresist profile (Profile), and in particular to a method of using high temperature reflow (Hard Bake) to reflow the photoresist to improve its profile . Background technique [0002] The traditional method for defining a contact window or a via hole includes first forming a photoresist layer on the surface 100 where the contact window or via layer edge is to be formed, and then defining the photoresist layer to form an opening, exposing The portion of the lower layer where contact windows or via holes are to be formed. The traditional method of defining the photoresist layer, such as figure 1 As shown, including photoresist coating (Coating) 101, soft baking (SoftBake) 102, exposure (Exposure) 103, post-exposure baking (Post Exposure Bake) 104, development 105 and hard baking (Hard Bake) 106 and other steps. [0003] After exposure and development, the photoresist must go through a har...

AI Technical Summary

Problems solved by technology

It can be seen from the figure that due to the phenomenon of positive defocus, the apex angle of the opening of the photoresist forms a so-called top reentrant angle (Top Reentrant), and the opening obtained by the scanning electron microscope is much smaller than the actual need, which cannot Conforms to specifications, must be reworked (Rework)

However, if you take its cross-sectional view, you can find that the size of the photoresist opening actually meets the specifications, but the result of the top view inspection is not up to specification due to the concave angle generated by the top angle of the opening.

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