METHOD AND STRUCTURE FOR ADHESION OF INTERMETALLIC COMPOUND (IMC) ON CU PILLAR BUMP

摘要

Cu provides a method and structure for excellent adhesion of the intermetallic compound (IMC) on the pillar bumps. The method to form a deposition of a Cu layer and Cu-pillar, depositing a diffusion barrier layer on top of the Cu layer and the filler, to include depositing a cap layer on top of the Cu diffusion barrier layer, where the intermetallic compound (IMC ) is formed between the diffusion preventing layer is, the Cu cap layer and the solder layer placed on top of the Cu cap. The IMC has a good adhesion to the Cu-pillar structure, the thickness of the IMC can be controlled by the thickness of the Cu cap layer, and the diffusion prevention layer is limited to Cu is in the Cu from diffusing into the solder layer filler layer. The method may also include depositing a thin layer for improving the wettability to the top of the diffusion barrier layer before depositing the Cu cap. ;