High density bump-less Cu-Cu bonding with enhanced quality achieved by pre-bonding temporary passivation for 3D wafer stacking

Author

Peng, L. ; Li, H.Y. ; Lim, D.F. ; Lo, G.Q. ; Kwong, D.L. ; Tan, C.S.

Author_Institution

Inst. of Microelectron., A*STAR (Agency for Sci., Technol. & Res.), Singapore, Singapore

fYear

2011

fDate

25-27 April 2011

Firstpage

1

Lastpage

2

Abstract

Face-to-face stacking of wafer-on-wafer is demonstrated successfully using bump-less Cu-Cu bonding. Using self-assembled monolayer passivation and in-situ desorption, Cu-Cu bond is enhanced in shear strength and bonding uniformity. Excellent specific contact resistance of 0.30 Ω.μm² is obtained. Continuous daisy chain of at least 6,000 contacts at 15μm pitch is connected successfully. This provides inter-IC connection density of 4.4 × 10⁵ cm^-2 suitable for wafer level 3D integration to augment Moore Law´s scaling.

Keywords

bonding processes; passivation; shear strength; 3D wafer stacking; bonding uniformity; contact resistance; enhanced quality; face-to-face stacking; high density bump-less Cu-Cu bonding; pre-bonding temporary passivation; self-assembled monolayer passivation; shear strength; Bonding; Copper; Integrated circuits; Surface cleaning; Surface contamination; Three dimensional displays; 3D IC; Cu-Cu bonding; face-to-face; self-assembled monolayer; wafer-on-wafer;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Technology, Systems and Applications (VLSI-TSA), 2011 International Symposium on

Conference_Location

Hsinchu

ISSN

1524-766X

Print_ISBN

978-1-4244-8493-5

Type

conf

DOI

10.1109/VTSA.2011.5872226

Filename

5872226