A method for improving ILD oxide layer spalling

Abstract

The invention discloses a method for improving ILD oxide layer peeling. The method comprises the following steps: step 1, stacking an oxide layer after ILD0CMP; step 2, applying a photoresist and exposing the middle position which does not contain a crystal edge; step 3, removing the oxide layer in the exposed area in an etching manner; and step 4, removing the residual photoresist on the wafer edge to reserve the thickened oxide layer on the wafer edge. The method can effectively improve subsequent aluminum metal residues and oxide layer stripping.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuits, in particular to a method for improving the peeling off of an ILD (dielectric layer) oxide layer. Background technique [0002] Since the HK (high dielectric coefficient metal) 28nm product has a process of edge etching (2.2mm) in the STI (Shallow Trench Isolation) process, so that this area will continue to be too low and have no pattern in the middle and later processes. phenomenon, and after the zero chemical mechanical polishing of the dielectric layer, there will be a serious collapse problem, which will cause the aluminum metal residue problem after the subsequent mechanical polishing of the aluminum gate, and after the subsequent chemical mechanical polishing of the dielectric layer, Also because it is lower here, there is a thinner oxide layer left on the residual aluminum metal here, so this thinner oxide layer is not strong, and the subsequent contact hole etching proces...

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Problems solved by technology

[0002] Since the HK (high dielectric coefficient metal) 28nm product has a process of edge etching (2.2mm) in the STI (Shallow Trench Isolation) process, so that this area will continue to be too low and have no pattern in the middle and later processes. phenomenon, and after the zero chemical mechanical polishing of the dielectric layer, there will be a serious collapse problem, which will cause the aluminum metal residue problem after the subsequent mechanical polishing of the aluminum gate, and after the subsequent chemical mechanical polishing of the dielectric layer, Also because it is lower here, there is a thinner oxide layer left on the residual aluminum metal here, so this thinner oxide layer is not strong, and the subsequent contact hole etching process will destroy this structure. Causes the oxide layer to peel off, thereby blocking the subsequent hole to be filled with tungsten metal

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