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Title: In situ study on low-k interconnect time-dependent-dielectric-breakdown mechanisms

An in situ transmission-electron-microscopy methodology is developed to observe time-dependent dielectric breakdown (TDDB) in an advanced Cu/ultra-low-k interconnect stack. A test structure, namely a “tip-to-tip” structure, was designed to localize the TDDB degradation in small dielectrics regions. A constant voltage is applied at 25 °C to the “tip-to-tip” structure, while structural changes are observed at nanoscale. Cu nanoparticle formation, agglomeration, and migration processes are observed after dielectric breakdown. The Cu nanoparticles are positively charged, since they move in opposite direction to the electron flow. Measurements of ionic current, using the Triangular-Voltage-Stress method, suggest that Cu migration is not possible before dielectric breakdown, unless the Cu/ultra-low-k interconnect stacks are heated to 200 °C and above.
Authors:
 [1] ;  [2] ; ; ; ; ;  [3] ;  [1] ; ; ; ;  [4]
  1. GLOBALFOUNDRIES, Fab8, 400 Stonebreak Rd. Extension, Malta, New York 12020 (United States)
  2. (Germany)
  3. Fraunhofer Institute for Ceramic Technologies and Systems, Maria-Reiche-Str. 2, D-01109 Dresden (Germany)
  4. GLOBALFOUNDRIES Dresden Module One LLC and Co. KG, Wilschdorfer Landstr. 101, D-01109 Dresden (Germany)
Publication Date:
OSTI Identifier:
22271180
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AGGLOMERATION; BREAKDOWN; COPPER; DIELECTRIC MATERIALS; ELECTRIC CURRENTS; ELECTRIC POTENTIAL; ELECTRONS; NANOSTRUCTURES; PARTICLE SIZE; PARTICLES; STRESSES; TIME DEPENDENCE; TRANSMISSION ELECTRON MICROSCOPY