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Title: In situ control of synchronous germanide/silicide reactions with Ge/Si core/shell nanowires to monitor formation and strain evolution in abrupt 2.7 nm channel length

The metal-semiconductor interface in self-aligned contact formation can determine the overall performance of nanoscale devices. This interfacial morphology is predicted and well researched in homogenous semiconductor nanowires (NWs) but was not pursued in heterostructured core/shell nanowires. Here, we found here that the solid-state reactions between Ni and Ge/Si core/shell nanowires resulted in a protruded and a leading NiSiy segment into the channel. A single Ni 2Ge/NiSi y to Ge/Si core/shell interface was achieved by the selective shell removal near the Ni source/drain contact areas. In using in situ transmission electron microscopy, we measured the growth rate and anisotropic strain evolution in ultra-short channels. We also found elevated compressive strains near the interface between the compound contact and the NW and relatively lower strains near the center of the channel which increased exponentially below the 10 nm channel length to exceed 10% strain at ~3 nm lengths. These compressive strains are expected to result in a non-homogeneous energy band structure in Ge/Si core/shell NWs below 10 nm and potentially benefit their transistor performance.
Authors:
ORCiD logo [1] ;  [2] ;  [3] ;  [4] ; ORCiD logo [5] ; ORCiD logo [6]
  1. Univ. of California, San Diego, CA (United States). Dept. of Electrical and Computer Engineering
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Center for Integrated Nanotechnologies and HRL Laboratories
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Center for Integrated Nanotechnologies; Univ. of California, Los Angeles, CA (United States). Materials Science and Engineering
  4. Sandia National Lab. (SNL-CA), Livermore, CA (United States). Center for Integrated Nanotechnologies; North Carolina State Univ., Raleigh, NC (United States). Materials Science and Engineering Program
  5. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Center for Integrated Nanotechnologies
  6. Univ. of California, San Diego, CA (United States). Dept. of Electrical and Computer Engineering, Materials Science and Engineering Program, Dept. of NanoEngineering
Publication Date:
Report Number(s):
LA-UR-17-22748
Journal ID: ISSN 0003-6951; APPLAB
Grant/Contract Number:
AC52-06NA25396; AC04-94AL85000
Type:
Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 110; Journal Issue: 21; Journal ID: ISSN 0003-6951
Publisher:
American Institute of Physics (AIP)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC). Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Material Science
OSTI Identifier:
1375878