Method for fabricating phase shift photomask

Abstract

The invention provides a method for fabricating a phase shift photomask, comprising the following steps of: on a phase shift photomask substrate containing a first photoresist capable of forming a hard film, forming a first layout pattern structure in the first photoresist through first photoetching; applying a polyamine compound on the first photoresist so as to solidify the first layout pattern structure in the first photoresist, heating to react the polyamine compound with the surface of the first photoresist so as to form an isolation film insoluble in a second photoresist, and removing the redundant polyamine compound; applying the second photoresist to the solidified first photoresist; performing second photoetching so as to form a second layout pattern structure in the second photoresist film; and transferring the first layout pattern and the second layout pattern in the photoresists to a partially light-pervious molybdenum silicide thin film and a light-tight chromium thin film through etching, respectively, thereby completing the fabrication of the phase shift photomask. The process is omitted from the etching step in the phase shift photomask fabrication process and is capable of effectively improving the productivity and reducing the fabrication cost.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, and more specifically, the invention relates to a method for manufacturing a phase shift photomask. Background technique [0002] Photolithography is one of the key processes for making large-scale integrated circuits. The photolithography process is to transfer the layout pattern on the photomask to the photoresist film, and the photoresist film containing the layout pattern is used as a mask for the subsequent ion implantation or etching process. Photomasks play an important role in the photolithography process. With the continuous improvement of the integration level of semiconductor chips and the continuous reduction of the feature size of transistors, the requirements for photolithography technology are getting higher and higher, and phase shift photomasks have gradually become the mainstream photomasks of high-end photolithography technology. [0003] Such as Figure 1A As shown...

AI Technical Summary

Problems solved by technology

[0007] However, the steps of the phase-shift photomask manufacturing process according to the prior art are still not simplified enough

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