Method for improving thick metal layer LIFT OFF technology pattern abnormality

Abstract

The invention belongs to the technical field of a semiconductor integrated circuit technology, and relates to a method for improving thick metal layer LIFT OFF technology pattern abnormality, and specifically is photoresist coating-photoresist exposure-photoresist developing-thick metal layer deposition-blue film attachment, blue film stripping-photoresist stripping. According to a LIFT OFF technology provided by the invention, in a process of metal deposition, collapse of the photoresist is avoided through a low temperature technology, a multi-evaporation technology with slow-speed of revolution is used, and in combination with a blue film assistant stripping method, thickness of the photoresist is reduced, moreover, pattern abnormality caused by collapse of a relatively thick metal layer(more than 3 microns) on the photoresist and cracks of the photoresist is avoided, and consequently, the thick layer LIFT OFF technology is realized.

Description

technical field [0001] The invention relates to a method for a LIFT OFF process, in particular to a method for improving the pattern abnormality of a thick metal layer LIFT OFF process, and belongs to the technical field of semiconductor integrated circuit technology. Background technique [0002] In the integrated circuit process, the metal titanium-nickel-silver (Ti-Ni-Ag) needs to be selectively covered (that is, it needs to be patterned), and the dry etching cannot remove the metal nickel-silver by etching, and the patterned metal titanium-nickel silver cannot be obtained. Silver, wet etching Because there is metal aluminum on the surface of the wafer, the aluminum will be corroded at the same time, and the uniformity of the corrosion is poor, so it is difficult to realize the mass production process. In order to solve this problem, the current processing technology adopts the metal LIFT OFF process, that is, the metal photoresist stripping technology. [0003] The conv...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to provide a method for improving the pattern abnormality of the thick metal layer LIFT OFF process aimed at the problems of the LIFT OFF process in the current semiconductor integrated circuit process. In the metal deposition process, the low temperature process is used to avoid the photoresist collapse , using low-speed multiple evaporation process, combined with the blue film-assisted stripping method, not only reduces the thickness of the photoresist, but also avoids the tilting and collapse of the thicker metal layer (above 3um) on the photoresist and photoresist cracks The resulting pattern is abnormal, so that the thick metal layer LIFT OFF process is finally realized

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