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Mechanically robust pad structure method

IP.com Disclosure Number: IPCOM000239408D
Publication Date: 2014-Nov-05
Document File: 4 page(s) / 209K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a mechanically anchored C4 pad design and method of manufacturing.

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This is the abbreviated version, containing approximately 66% of the total text.

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Mechanically robust pad structure method

Wafer backside C4 pad delamination (white bump) in three-dimensional (3D) integration presents T0 and reliability issues.

The novel contribution is a mechanically anchored C4 pad design and method of manufacturing. The use of self-assembling Diblock (DSA) copolymer is proposed to create a random pattern in the dielectric layer, below the C4 metallic pad, without introducing an additional mask level, where the pitch of the random pattern can be adjusted by the copolymer formulation (e.g.,. in the range of 50nm to 100nm), while the density and randomness can be modified by added impurity.

A mechanically robust bump pad design eliminates T0 bump delamination and reliability concerns. The novel approach uses a self-assembling Diblock (DSA) to create a random pattern in the dielectric layer below the C4 metallic pad without introducing additional mask level. The surface area is increased between the dielectric material and metal pad by randomly shaped grooves/teeth-like trenches filled with pad metallization. The approach introduces a fabrication process to form randomly patterned dielectric grooves using a self-assembling Diblock (DSA) copolymer, without introducing extra mask. The increased surface/contact area between pad metallization and dielectric leads to improved adhesion. The incorporation of a novel self-assembled polymer technique into the Far Back End of Line (FBEOL) flow is a cost efficient method to create random...