Abstract
Dopants modify the electronic properties of semiconductors, including their susceptibility to etching. In semiconductor nanowires doped during growth by the vapor-liquid-solid (VLS) process, it has been shown that nanofaceting of the liquid-solid growth interface influences strongly the radial distribution of dopants. Hence, the combination of facet-dependent doping and dopant selective etching provides a means to tune simultaneously the electronic properties and morphologies of nanowires. Using atom-probe tomography, we investigated the boron dopant distribution in Au catalyzed VLS grown silicon nanowires, which regularly kink between equivalent «112» directions. Segments alternate between radially uniform and nonuniform doping profiles, which we attribute to switching between a concave and convex faceted liquid-solid interface. Dopant selective etching was used to reveal and correlate the shape of the growth interface with the observed anisotropic doping.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 4518-4525 |
| Number of pages | 8 |
| Journal | Nano letters |
| Volume | 17 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 12 2017 |
Funding
The local-electrode atom-probe tomograph (LEAP 4000X Si) at the Northwestern University Center for Atom-Probe Tomography (NUCAPT) was acquired and upgraded with equipment grants from the MRI program of the National Science Foundation (Grant DMR-0420532) and the DURIP program of the Office of Naval Research (Grants N00014-0400798, N00014-0610539 N00014-0910781). NUCAPT is a Research Core Facility of the Materials Research Center of Northwestern University supported by the National Science Foundation's MRSEC Program (Grant DMR-1121262). Additional instrumentation at NUCAPT was supported by the Initiative for Sustainability and Energy at Northwestern (ISEN). Our research also made use of the EPIC facility (NUANCE Center), which receives support from the Materials Research Science and Engineering Center (MRSEC) program (NSF DMR-1121262); the International Institute for Nanotechnology (IIN); the State of Illinois and through the IIN. NUCAPT received some additional support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF NNCI-1542205). We thank the anonymous reviewer for comments that helped us to improve parts of the text.
Keywords
- Nanowire
- atom-probe tomography
- dopant
- liquid-solid interface
- selective etching
- vapor-liquid-solid growth
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Bioengineering
- General Chemistry
- General Materials Science