skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Direct-Liquid-Evaporation Chemical Vapor Deposition of Nanocrystalline Cobalt Metal for Nanoscale Copper Interconnect Encapsulation

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [1]; ORCiD logo [3]
  1. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
  2. John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
  3. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States; John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Center for Next Generation of Materials by Design: Incorporating Metastability (CNGMD)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1388998
DOE Contract Number:
AC36-99GO10337
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Applied Materials and Interfaces; Journal Volume: 9; Journal Issue: 12; Related Information: CNGMD partners with National Renewable Energy Laboratory (lead); Colorado School of Mines; Harvard University; Lawrence Berkeley National Laboratory; Massachusetts Institute of Technology; Oregon State University; SLAC National Accelerator Laboratory
Country of Publication:
United States
Language:
English
Subject:
solar (photovoltaic), solar (fuels), solid state lighting, phonons, thermoelectric, hydrogen and fuel cells, defects, charge transport, optics, materials and chemistry by design, synthesis (novel materials)

Citation Formats

Feng, Jun, Gong, Xian, Lou, Xiabing, and Gordon, Roy G. Direct-Liquid-Evaporation Chemical Vapor Deposition of Nanocrystalline Cobalt Metal for Nanoscale Copper Interconnect Encapsulation. United States: N. p., 2017. Web. doi:10.1021/acsami.7b01327.
Feng, Jun, Gong, Xian, Lou, Xiabing, & Gordon, Roy G. Direct-Liquid-Evaporation Chemical Vapor Deposition of Nanocrystalline Cobalt Metal for Nanoscale Copper Interconnect Encapsulation. United States. doi:10.1021/acsami.7b01327.
Feng, Jun, Gong, Xian, Lou, Xiabing, and Gordon, Roy G. Thu . "Direct-Liquid-Evaporation Chemical Vapor Deposition of Nanocrystalline Cobalt Metal for Nanoscale Copper Interconnect Encapsulation". United States. doi:10.1021/acsami.7b01327.
@article{osti_1388998,
title = {Direct-Liquid-Evaporation Chemical Vapor Deposition of Nanocrystalline Cobalt Metal for Nanoscale Copper Interconnect Encapsulation},
author = {Feng, Jun and Gong, Xian and Lou, Xiabing and Gordon, Roy G.},
abstractNote = {},
doi = {10.1021/acsami.7b01327},
journal = {ACS Applied Materials and Interfaces},
number = 12,
volume = 9,
place = {United States},
year = {Thu Mar 16 00:00:00 EDT 2017},
month = {Thu Mar 16 00:00:00 EDT 2017}
}
  • In nature, cells perform a variety of complex functions such as sensing, catalysis, and energy conversion which hold great potential for biotechnological device construction. However, cellular sensitivity to ex vivo environments necessitates development of bio–nano interfaces which allow integration of cells into devices and maintain their desired functionality. In order to develop such an interface, the use of a novel Sol-Generating Chemical Vapor into Liquid (SG-CViL) deposition process for whole cell encapsulation in silica was explored. In SG-CViL, the high vapor pressure of tetramethyl orthosilicate (TMOS) is utilized to deliver silica into an aqueous medium, creating a silica sol. Cellsmore » are then mixed with the resulting silica sol, facilitating encapsulation of cells in silica while minimizing cell contact with the cytotoxic products of silica generating reactions (i.e. methanol), and reduce exposure of cells to compressive stresses induced from silica condensation reactions. Using SG-CVIL, Saccharomyces cerevisiae (S. cerevisiae) engineered with an inducible beta galactosidase system were encapsulated in silica solids and remained both viable and responsive 29 days post encapsulation. By tuning SG-CViL parameters, thin layer silica deposition on mammalian HeLa and U87 human cancer cells was also achieved. Thus, the ability to encapsulate various cell types in either a multi cell (S. cerevisiae) or a thin layer (HeLa and U87 cells) fashion shows the promise of SG-CViL as an encapsulation strategy for generating cell–silica constructs with diverse functions for incorporation into devices for sensing, bioelectronics, biocatalysis, and biofuel applications.« less
  • In nature, cells perform a variety of complex functions such as sensing, catalysis, and energy conversion which hold great potential for biotechnological device construction. However, cellular sensitivity to ex vivo environments necessitates development of bio–nano interfaces which allow integration of cells into devices and maintain their desired functionality. In order to develop such an interface, the use of a novel Sol-Generating Chemical Vapor into Liquid (SG-CViL) deposition process for whole cell encapsulation in silica was explored. In SG-CViL, the high vapor pressure of tetramethyl orthosilicate (TMOS) is utilized to deliver silica into an aqueous medium, creating a silica sol. Cellsmore » are then mixed with the resulting silica sol, facilitating encapsulation of cells in silica while minimizing cell contact with the cytotoxic products of silica generating reactions (i.e. methanol), and reduce exposure of cells to compressive stresses induced from silica condensation reactions. Using SG-CVIL, Saccharomyces cerevisiae (S. cerevisiae) engineered with an inducible beta galactosidase system were encapsulated in silica solids and remained both viable and responsive 29 days post encapsulation. By tuning SG-CViL parameters, thin layer silica deposition on mammalian HeLa and U87 human cancer cells was also achieved. Thus, the ability to encapsulate various cell types in either a multi cell (S. cerevisiae) or a thin layer (HeLa and U87 cells) fashion shows the promise of SG-CViL as an encapsulation strategy for generating cell–silica constructs with diverse functions for incorporation into devices for sensing, bioelectronics, biocatalysis, and biofuel applications.« less
  • A grain-size-dependent reduction in the room-temperature thermal conductivity of nanocrystalline yttria-stabilized zirconia is reported for the first time. Films were grown by metal-organic chemical vapor deposition with controlled grain sizes from 10 to 100 nm. For grain sizes smaller than approximately 30 nm, a substantial reduction in thermal conductivity was observed, reaching a value of less than one-third the bulk value at the smallest grain sizes measured. The observed behavior is consistent with expectations based on an estimation of the phonon mean-free path in zirconia.(c) 2000 American Institute of Physics.
  • In this article, we investigate the main mechanisms of interfacial SiO{sub 2} and silicate formation during yttrium oxide deposition on Si substrates by plasma-enhanced metal-organic chemical vapor deposition using a pulsed-liquid injection delivery source. The precursor supplier system is based on a sequential injection of Y-precursor diluted in an organic solvent. A detailed study of interface thickness and chemical nature is carried out combining angle-resolved x-ray photoelectron spectroscopy, transmission electron microscopy, and electron energy loss spectroscopy. We found that the flow rate of injected reactive species, controlled by the injection frequency, has a strong effect on the plasma gas phasemore » and plays a key role in the SiO{sub 2} and silicate formation. For a 1 Hz injection frequency deposition, a silicate layer is formed on a thick SiO{sub 2} interface [Si/SiO{sub 2}({approx}3.6 nm)/Si{sub x}O{sub y}Y{sub z}], whereas deposition at 5 Hz induces an oxidized yttrium layer with an interfacial layer composed of a SiO{sub 2} and Y-silicate mixture [Si/SiO{sub 2}+Si{sub x}O{sub y}Y{sub z}({approx}2 nm)/Y{sub x}O{sub y}C{sub z}]. To understand the actual SiO{sub 2} origin, the effect of the oxygen plasma on the silicon oxidation was investigated. According to our results, the silicon oxidation by the oxygen O* species from the plasma is strongly enhanced by the presence of organic compounds in the plasma gas phase from reactions between the solvent molecule and the oxygen. This reaction is mostly favored at a low solvent flow rate, which can explain the thicker SiO{sub 2} layer observed for the 1 Hz sample compared to the 5 Hz. When introducing yttrium precursor in addition to the solvent, a Y-based silicate is formed via consumption of the SiO{sub 2} by yttrium. The silicate formation is enhanced when a large quantity of SiO{sub 2} is available, which is the case for the 1 Hz sample. According to this study, a high flow of reactive species is preferred to reduce the interface layer thickness.« less
  • We have developed a technique recently for copper chemical vapor deposition utilizing direct liquid coinjection of trimethylvinylsilane (TMVS) and the copper (I) precursor (hexafluoroacetylacetonate) Cu (TMVS). We present here an investigation of the properties of copper films deposited using this technique. The films were grown on Si[sub 3]N[sub 4] substrates at temperatures in the range of 220--250 [degree]C and characterized using several experimental techniques, with an emphasis placed on factors influencing copper film resistivity. The average as-deposited film resistivity is 1.86 [mu][Omega] cm; this value is reduced to 1.82 [mu][Omega] cm when the effects of surface scattering are taken intomore » account. The resistivity is essentially independent of film thickness for thicknesses between 0.2 and 3.5 [mu]m, and is reduced by less than 0.05 [mu][Omega] cm by annealing at 400--600 [degree]C in vacuum. The total impurity content of the films is approximately 100 parts per million. The film density is 97[plus minus]2% of the bulk copper value. The average grain size increases with film thickness and falls in the range of 0.5--1.5 [mu]m. Morphological defects are the main cause of the resistivities (after adjusting for surface scattering) being approximately 0.14 [mu][Omega] cm above the bulk copper value (1.68 [mu][Omega] cm). Comparison of thickness and resistivity measurements for rough as-deposited films and smooth chemical-mechanical polished films shows that the surface roughness causes surface profilometry to overestimate the thicknesses of the unpolished films by approximately 1300 A. This effect can lead to both artificially high resistivity values and a false dependence of resistivity on film thickness if profilometry measurements for the unpolished films are not properly corrected. [copyright] [ital 1995][ital American] [ital Vacuum] [ital Society]« less