Method for planarizing the surface of polymer dielectric layer in redistribution layer by using cmp

Abstract

In the re-wiring layer technology, the requirement for surface evenness of the first polymer dielectric layer is not high, however, after the first layer of copper is deposited and the second polymer dielectric layer is subjected to spin coating or spraying, the surface evenness of the second polymer dielectric layer enables unevenness of the first polymer dielectric layer and the first copper deposition layer to be overlaid and enlarged. The invention provides a method for flattening the surface of the second uneven polymer dielectric layer, even all uneven polymer dielectric layers after the second layer in the re-wiring technology through a CMP. The surface evenness after flattening can be smaller than 1%. Two to three times of CMP grinding with the grinding speed from high to low is adopted, and washing is carried out after grinding. The method has the advantages that high-density and small-line-width integration can be more easily realized on the surfaces of polymers with good surface evenness.

Description

technical field [0001] The invention relates to a method for planarizing the surface of a polymer dielectric layer in a rewiring layer by using CMP, and belongs to the technical field of semiconductor manufacturing. Background technique [0002] Redistribution layer technology is currently widely used in the field of semiconductor packaging. In the redistribution layer (RDL), the process cost of using polymers (such as: polyimide polyimide or benzocyclobutene BCB) as the dielectric layer is low and the process is simple, but the surface uniformity of the polymer is poor, especially As the number of RDL layers increases, the surface uniformity of polymer spin coating will become worse and worse, which restricts the continued extension and development of high-density packaging. Therefore, the currently common RDL process can only achieve two layers, and the RDL process with more than three layers becomes very difficult due to the constraints of surface uniformity. However, t...

AI Technical Summary

Problems solved by technology

In the redistribution layer (RDL), the process cost of using polymers (such as: polyimide polyimide or benzocyclobutene BCB) as the dielectric layer is low and the process is simple, but the surface uniformity of the polymer is poor, especially As the number of RDL layers increases, the surface uniformity of polymer spin coating will become worse and worse, which restricts the continued extension and development of high-density packaging

Therefore, the current common RDL process can only achieve two layers, and the RDL process with more than three layers becomes very difficult due to the constraints of surface uniformity.

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