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Title: Bottom-Up Copper Filling of Millimeter Size Through Silicon Vias

Abstract

This work demonstrates void-free Cu filling of millimeter size Through Silicon Vias (mm-TSV) in an acid copper sulfate electrolyte using a combination of a polyoxamine suppressor and chloride, analogous to previous work filling TSV that were an order of magnitude smaller in size. For high chloride concentration (i.e., 1 mmol/L) bottom-up deposition is demonstrated with the growth front being convex in shape. Instabilities in filling profile arise as the growth front approaches the freesurface due to non-uniform coupling with electrolyte hydrodynamics Filling is negatively impacted by large lithography-induced reentrant notches that increase the via cross section at the bottom. In contrast, deposition from low chloride electrolytes, proceeds with a passive-active transition on the via sidewalls. For a given applied potential the location of the transition is fixed in time and the growth front is concave in nature reflecting the gradient in chloride surface coverage. Application of a suitable potential wave form enables the location of the sidewall transition to be advanced thereby giving rise to void-free filling of the TSV.

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [2];  [2]; ORCiD logo [1]
  1. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). Materials Science and Engineering Division
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Microsystems and Engineering Sciences Applications (MESA) Complex
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
SPP-funded work; USDOE
OSTI Identifier:
1490759
Alternate Identifier(s):
OSTI ID: 1492359
Report Number(s):
SAND-2018-14027J
Journal ID: ISSN 0013-4651; 670913
Grant/Contract Number:  
AC04-94AL85000; NA0003525
Resource Type:
Journal Article: Published Article
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 166; Journal Issue: 1; Journal ID: ISSN 0013-4651
Publisher:
The Electrochemical Society
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Josell, Daniel, Menk, Lyle Alexander, Hollowell, Andrew E., Blain, Matthew G., and Moffat, Thomas P. Bottom-Up Copper Filling of Millimeter Size Through Silicon Vias. United States: N. p., 2019. Web. doi:10.1149/2.0321901jes.
Josell, Daniel, Menk, Lyle Alexander, Hollowell, Andrew E., Blain, Matthew G., & Moffat, Thomas P. Bottom-Up Copper Filling of Millimeter Size Through Silicon Vias. United States. doi:10.1149/2.0321901jes.
Josell, Daniel, Menk, Lyle Alexander, Hollowell, Andrew E., Blain, Matthew G., and Moffat, Thomas P. Sat . "Bottom-Up Copper Filling of Millimeter Size Through Silicon Vias". United States. doi:10.1149/2.0321901jes.
@article{osti_1490759,
title = {Bottom-Up Copper Filling of Millimeter Size Through Silicon Vias},
author = {Josell, Daniel and Menk, Lyle Alexander and Hollowell, Andrew E. and Blain, Matthew G. and Moffat, Thomas P.},
abstractNote = {This work demonstrates void-free Cu filling of millimeter size Through Silicon Vias (mm-TSV) in an acid copper sulfate electrolyte using a combination of a polyoxamine suppressor and chloride, analogous to previous work filling TSV that were an order of magnitude smaller in size. For high chloride concentration (i.e., 1 mmol/L) bottom-up deposition is demonstrated with the growth front being convex in shape. Instabilities in filling profile arise as the growth front approaches the freesurface due to non-uniform coupling with electrolyte hydrodynamics Filling is negatively impacted by large lithography-induced reentrant notches that increase the via cross section at the bottom. In contrast, deposition from low chloride electrolytes, proceeds with a passive-active transition on the via sidewalls. For a given applied potential the location of the transition is fixed in time and the growth front is concave in nature reflecting the gradient in chloride surface coverage. Application of a suitable potential wave form enables the location of the sidewall transition to be advanced thereby giving rise to void-free filling of the TSV.},
doi = {10.1149/2.0321901jes},
journal = {Journal of the Electrochemical Society},
issn = {0013-4651},
number = 1,
volume = 166,
place = {United States},
year = {2019},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1149/2.0321901jes

Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

Figures / Tables:

Figure 1 Figure 1: Cross-sectioned mm-TSV after 1 hr Cu deposition at the indicated applied potentials in low Ct electrolyte containing 80 μmol/L Cl- + 40 μmol/L TET. All were preceded by 2 min at -0.40 V to mix electrolyte into the alcohol-prewetted features. The patterned substrates were rotating at 400 rpmmore » during deposition. Insets are at 2× relative magnification.« less

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Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.