TY - JOUR
T1 - On-wafer thermomechanical characterization of a thin film polyimide formed by vapor deposition polymerization for through-silicon via applications
T2 - Comparison to plasma-enhanced chemical vapor deposition SiO2
AU - Fukushima, Takafumi
AU - Murugesan, Mariappan
AU - Bea, Ji Cheol
AU - Hashimoto, Hiroyuki
AU - Kino, Hisashi
AU - Tanaka, Tetsu
AU - Koyanagi, Mitsumasa
N1 - Funding Information:
JSPS KAKENHI (Multi‐year Fund), Grant‐in‐Aid for Challenging Exploratory Research, Grant/Award Number: 25630118; JSPS KAKENHI, Fund for the Promotion of Joint International Research (Fostering Joint International Research (B)), Grant/Award Number: 19KK0101 Funding information
Funding Information:
This work was partially supported by Japan Society for the Promotion of Science KAKENHI (Multi-year Fund), Grant-in-Aid for Challenging Exploratory Research: Grant Number 25630118. We would like to acknowledge Toray Research Center, Inc. for CTE measurements on Si wafers and by TMA, and BRUKER AXS, Inc. for measuring Young's moduli on Si wafers. We also thank Matsumoto Fine Chemical Co., Ltd. for kindly supplying the adhesion promotor.
Funding Information:
This work was partially supported by Japan Society for the Promotion of Science KAKENHI (Multi‐year Fund), Grant‐in‐Aid for Challenging Exploratory Research: Grant Number 25630118. We would like to acknowledge Toray Research Center, Inc. for CTE measurements on Si wafers and by TMA, and BRUKER AXS, Inc. for measuring Young's moduli on Si wafers. We also thank Matsumoto Fine Chemical Co., Ltd. for kindly supplying the adhesion promotor.
Publisher Copyright:
© 2020 The Authors. Journal of Polymer Science published by Wiley Periodicals LLC.
PY - 2020/8/15
Y1 - 2020/8/15
N2 - Thin-film polyimides were prepared by solvent-less vapor deposition polymerization (VDP) from pyromellitic dianhydride and 4,4′-oxydianiline at 200 °C for liner dielectric formation of vertical interconnects called through-silicon vias (TSVs) used in three-dimensionally stacked integrated circuit (3DICs). FTIR, synchrotron XPS, and TDS were employed for determining the imidization ratio, and in addition, the mechanical properties, coefficient of thermal expansion and Young's modulus, of the VDP polyimide were characterized on Si wafers. The VDP polyimide exhibited extremely high conformality, beyond 75%, toward high-aspect-ratio deep Si holes, compared with conventional SiO2 prepared by plasma-enhanced chemical vapor deposition. The adhesion between the VDP polyimide and Si wafer was enhanced by an Al-chelate promotor. Remarkably, the VDP polyimide TSV liner dielectrics showed much less thermomechanical stresses applied to the Si surrounding the TSVs than the plasma-chemical vapor deposition SiO2. The small keep-out zone is expected for scaling down highly reliable 3DICs for the upcoming real artificial intelligence society.
AB - Thin-film polyimides were prepared by solvent-less vapor deposition polymerization (VDP) from pyromellitic dianhydride and 4,4′-oxydianiline at 200 °C for liner dielectric formation of vertical interconnects called through-silicon vias (TSVs) used in three-dimensionally stacked integrated circuit (3DICs). FTIR, synchrotron XPS, and TDS were employed for determining the imidization ratio, and in addition, the mechanical properties, coefficient of thermal expansion and Young's modulus, of the VDP polyimide were characterized on Si wafers. The VDP polyimide exhibited extremely high conformality, beyond 75%, toward high-aspect-ratio deep Si holes, compared with conventional SiO2 prepared by plasma-enhanced chemical vapor deposition. The adhesion between the VDP polyimide and Si wafer was enhanced by an Al-chelate promotor. Remarkably, the VDP polyimide TSV liner dielectrics showed much less thermomechanical stresses applied to the Si surrounding the TSVs than the plasma-chemical vapor deposition SiO2. The small keep-out zone is expected for scaling down highly reliable 3DICs for the upcoming real artificial intelligence society.
KW - 3DIC
KW - CTE
KW - TSV
KW - keep-out zone (KOZ)
KW - polyimide
KW - vapor deposition polymerization
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U2 - 10.1002/pol.20200094
DO - 10.1002/pol.20200094
M3 - Article
AN - SCOPUS:85092435493
VL - 58
SP - 2248
EP - 2258
JO - Journal of Polymer Science
JF - Journal of Polymer Science
SN - 2642-4150
IS - 16
ER -