#### Analysis of local stresses in Si around Cu through-silicon via for 3D integrated circuit = 3차원 집적회로의 수직 관통 구리 전극 주변 실리콘 스트레스 특성 분석

Cited 0 time in Cited 0 time in
• Hit : 318
Through Silicon Via is one of the key elements of the next generation electronic, microelectromechanical systems (MEMS), and systems with high bandwidth interconnections. However, incorporation of TSVs, where the Cu via is formed via electroplating process and several processing steps at elevated temperatures are implemented, poses a significant challenge in maintaining device reliability due to the stress distribution introduced in silicon. The residual stress from the Cu deposition, thermal stresses from the processing steps at elevated temperatures, and stresses from the deposition of passivating overlayers can all affect the stresses in Si that can unexpectedly result in difference in mobility of the charge carriers. Therefore, finding the keep off zone, where the stress distribution near the Cu via is minimized, is of critical importance. In this work, In this study, local Si stress distribution near Cu TSVs with various via sizes with and without passivation layers were characterized using micro-Raman spectroscopy and compared against finite element modeling and analysis using technology computer-aided design software. Effects of thermal cycling on the local Si stress distribution around Cu TSVs were characterized after depositing transparent $SiO_2$ and SiN thin films (>11 layers) on top of Cu TSVs. Si stresses, which are dependent on TSV size and density, were characterized and discussed from the perspective of the microstructural change in the Cu TSV. This is the first report on using micro Raman method to non-destructively characterize and analyze the stresses in Si as a function of via size then again as a function of processing steps. It should be noted that the Cu TSVs explored in this study is in the range of 4-8 $\mu m$, which is practical dimension for high density 3-D memory packaging, known as high bandwidth memory, that is currently being developed in the industry.
Han, Seung Minresearcher한승민researcher
Description
한국과학기술원 :EEWS대학원,
Publisher
한국과학기술원
Issue Date
2017
Identifier
325007
Language
eng
Description

학위논문(박사) - 한국과학기술원 : EEWS대학원, 2017.8,[vi, 94 p. :]

Keywords

Cu TSV▼aSi Stress▼amicro-Raman▼aTCAD; 3차원 적층 반도체▼a열 응력▼a마이크로 라만 분광

URI
http://hdl.handle.net/10203/241619