Process for electroplating copper thick films on two sides of ultrathin wafer

Abstract

The invention discloses a process for electroplating copper thick films on two sides of an ultrathin wafer. The process comprises the following steps: S1, bonding a glass carrier plate structure withan annular edge on the front surface of a wafer, and thinning the back surface of the wafer; S2, plating a metal layer on the back surface of the wafer after ion implantation; S3, coating a PI film, performing exposing and development according to a cutting channel pattern, and forming a latticed PI;S4, removing the thinner part and an adhesive layer in the middle of the glass carrier plate, and manufacturing an opening pattern of electroplating copper on the front surface; S5, electroplating Cu thick films on two sides; S6, after removing a front photoresist and a back PI film, performing etching to remove a metal layer outside a thick film copper region; S7, using SF6 plasma for etching off cut crystal grains, and completing crystal grain cutting; and S8, cutting off the annular area. According to the invention, the glass carrier plate with the annular edge is bonded with the wafer, and the netty PI stress buffer and support of the back cutting channel are formed on the back of the wafer by using the photosensitive PI thick film, so that the two sides of the ultrathin wafer are stably supported, and the thick film can be electroplated on the two sides without being damaged due tothe fact that the wafer is too thin.

Description

technical field [0001] The invention relates to the field, specifically. Background technique [0002] With the development of the semiconductor industry, the requirements for the utilization of wafers are getting higher and higher, and the electroplating of wafers is also developing from single-sided electroplating to double-sided electroplating. Wafer electroplating is an important part of the chip manufacturing process, and the quality of the electroplating effect directly affects the performance and use of the chip. At present, the electroplating of wafers is generally single-sided vertical rack plating, while high-end wafers have begun to use double-sided rack plating. The ultra-thin wafer structure combined with double-sided electroplated copper heat dissipation wires can greatly improve the performance of power components, but it is difficult to implement double-sided thick-film copper plating on ultra-thin wafers with current process equipment. [0003] The current...

AI Technical Summary

Problems solved by technology

Ultra-thin wafer structure combined with double-sided electroplated copper heat dissipation wires can greatly improve the performance of power components, but it is difficult to implement double-sided thick-film copper plating on ultra-thin wafers on current process equipment

[0003] The current technology cannot produce double-sided electroplating copper thick film technology on ultra-thin wafers, because in addition to the difficulty of making thin wafer patterns on both sides, the stress generated by electroplating thick copper films will lead to serious warping of thin wafers, and at the same time The thinning thickness of the wafer is also very limited. If a traditional glass carrier is used, it must overcome the complicated debonding thickness removal cleaning and cutting process, which has a great risk of fragmentation. If the glass carrier is not used but the traditional Taico technology, that is, there is a thick ring on the edge of the wafer, which cannot be used for the double-sided plating process of thick film copper, and because of the serious step difference on the back side, it is not suitable for the yellow light pattern process on the front side.

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