Impact of microbump induced stress in thinned 3D-LSIs after wafer bonding

Mariappan Murugesan, Yuki Ohara, Jichoru Be, Kanuku Ri, Takafumi Fukushima, Tetsu Tanaka, Mitsumasa Koyanagi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

Micro-Raman spectroscopic technique has been employed to study the induced stress/strain by the metal microbumps in 3D-LSI Si die/wafer after wafer thinning and bonding, and the impact of bump spacing, bump size, bonding temperature and bonding force in the stress distribution in such a microbump bonded LSIs has been investigated. It is inferred that (i) the Si present at the interface (between CuSn and LSI die/wafer) is under compressive stress, and it decreases exponentially in the cross-sectional direction both in the die and the wafer; (ii) in the lateral direction, the compressive stress produced by the adjacent microbumps overlapped to each other at the region of bump-spacing; (iii) qualitatively, the residual mechanical stress/strain increases with the bonding temperature and the size of the microbump, i.e. it is large for the higher bonding temperature (as high as >300 MPa @300°C) than for the non-bonded microbump (a maximum of only +125 MPa @ 280°C); (iv) the metal microbump exerted a large compressive stress up to the depth of >10 μm in the bonded 3D-LSI die/wafer.

Original languageEnglish
Title of host publicationIEEE 3D System Integration Conference 2010, 3DIC 2010
DOIs
Publication statusPublished - 2010 Dec 1
Event2nd IEEE International 3D System Integration Conference, 3DIC 2010 - Munich, Germany
Duration: 2010 Nov 162010 Nov 18

Publication series

NameIEEE 3D System Integration Conference 2010, 3DIC 2010

Other

Other2nd IEEE International 3D System Integration Conference, 3DIC 2010
CountryGermany
CityMunich
Period10/11/1610/11/18

ASJC Scopus subject areas

  • Control and Systems Engineering

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