skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Selective phosphorus doping of polycrystalline silicon on glass using self-assembled monolayer doping (MLD) and flash anneal
Title: Selective phosphorus doping of polycrystalline silicon on glass using self-assembled monolayer doping (MLD) and flash anneal
We report doping of thin (~60 nm) amorphous silicon (a-Si) on glass substrate to form n + polycrystalline silicon on glass in selective regions using Monolayer doping (MLD) via Flash Lamp Annealing (FLA). The phosphorus monolayer was formed on the exposed regions of SiO2 patterned a-Si, through functionalization with chemically bound Diethyl vinylphosphonate (DVP) dopant molecules. The samples were capped with SiO2 and annealed using a single xenon flash pulse (5.0 J/cm2, 250 μs) to simultaneously crystallize a-Si, incorporate and activate phosphorus dopants. SIMS results show an average concentration of 8x1019 cm−3 in the 60 nm of thin silicon on glass. Electrical results show a resistivity of ~6.60x10−2 Ω.cm in doped regions. N-channel field effect transistor devices are successfully demonstrated using this MLD-FLA technique.  more » « less
Award ID(s):
1842635
PAR ID:
10346912
Author(s) / Creator(s):
; ; ; ;
Editor(s):
Aldo R. Boccaccini
Date Published:
Journal Name:
Materials letters
Volume:
305
Issue:
130780
ISSN:
0167-577X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. (, Microelectronic engineering)
    Lanza, Mario (Ed.)
    A conformal and controlled semiconductor doping is needed for applications in next generation nanoscale devices,low contact resistivity metal semiconductor junctions such as selective emitters in solar cells. Molecular monolayer doping (MLD) in silicon is a novel technique based on the formation of self-assembled monolayer of dopant – containing molecules on surface of crystalline silicon, followed by rapid thermal anneal. The technique is capable of forming ultra-shallow junctions with high atomic accuracy and minimum defects in silicon. A container and process was developed which successfully doped 6 in. diameter silicon wafers using MLD for the in-house CMOS fabrication facility. The phosphorus monolayer is grafted on hydrogen terminated p-type silicon followed by rapid thermal anneal. Average sheet resistance ~670 Ω/sq. and junction depth ~25 nm are achieved. N + P junctions are fabricated using MLD and current-voltage characteristics are measured and analyzed using unified diode model. 
    more » « less
  2. ; ; ; ; ; (, Materials letters)
    Aldo R. Boccaccini (Ed.)
    Monolayer Doping (MLD) is a technique involving the fmmation of a self-assembled dopant-containing layer on the substrate. The dopant is subsequently incorporated into the substrate by annealing, fmming a diffused region. Following MLD, samples were capped with silicon dioxide and rapid the1mal annealed (RTA). In this work, gallium doping using MLD has been demonstrated. Gallium containing compound Tris (2,4 pentanedionato) gallium(III) was synthesized, and shown to be suitable for monolayer doping silicon subsa-ates and deposited thin film polysi!icon. Seconda1y ion mass spectroscopy (SIMS) and spreading resistance probe (SRP) measurements were performed to determine the dopant profiles and dopant elecu-ical activation. TI1ese results showed that a dose of l.6*1015 atoms/cm2 was received, and the gallium dopant produced a 0.2 µm junction in 11-type silicon. For polysilicon, tlle entire 0.4 µm film was evenly doped, witll a concenu-ation greater than 1019 atoms/cm3 tllroughout. 
    more » « less
  3. ; ; ; ; ; ; ; ; (, Advanced Functional Materials)
    Abstract The development of novel doping strategies compatible with high‐resolution patterning and low cost, large‐scale manufacturing is critical to the future development of electronic devices. Here, an approach to achieve nanoscale site‐specific doping of Si wafer using DNA as both the template and the dopant carrier is reported. Upon thermal treatment, the phosphorous atoms in the DNA diffuse into Si wafer, resulting in doping within the region right around the DNA template. A doping length of 30 nm is achieved for 10 s of thermal treatment at 1000 °C. Prototype field effect transistors are fabricated using the DNA‐doped Si substrate; the device characteristics confirmed that the Si is n‐doped. It is also shown that this approach can be extended to achieve both n‐type and p‐type site‐specific doping of Si by using DNA nanostructures to pattern self‐assembled monolayers. This work shows that the DNA template is a dual‐use template that can both pattern Si and deliver dopants. 
    more » « less
  4. ; ; ; ; (, Advanced Electronic Materials)
    Abstract Source/Drain extension doping is crucial for minimizing the series resistance of the ungated channel and reducing the contact resistance of field‐effect transistors (FETs) in complementary metal–oxide–semiconductor (CMOS) technology. 2D semiconductors, such as MoS2and WSe2, are promising channel materials for beyond‐silicon CMOS. A key challenge is to achieve extension doping for 2D monolayer FETs without damaging the atomically thin material. This work demonstrates extension doping with low‐resistance contacts for monolayer WSe2p‐FETs. Self‐limiting oxidation transforms a bilayer WSe2into a hetero‐bilayer of a high‐work‐function WOxSeyon a monolayer WSe2. Then, damage‐free nanolithography defines an undoped nano‐channel, preserving the high on‐current of WOxSey‐doped FETs while significantly improving their on/off ratio. The insertion of an amorphous WOxSeyinterlayer under the contacts achieves record‐low contact resistances for monolayer WSe2over a hole density range of 1012to 1013cm−2(1.2 ± 0.3 kΩ µm at 1013cm−2). The WOxSey‐doped extension exhibits a sheet resistance as low as 10 ± 1 kΩ □−1. Monolayer WSe2p‐FETs with sub‐50 nm channel lengths reach a maximum drain current of 154 µA µm−1with an on/off ratio of 107–108. These results define strategies for nanometer‐scale selective‐area doping in 2D FETs and other 2D architectures. 
    more » « less
  5. ; ; ; ; ; (, Frontiers in Nanotechnology)
    This paper reports the fabrication of silicon PN diode by using DNA nanostructure as the etching template for SiO2and also as then-dopant of Si. DNA nanotubes were deposited ontop-type silicon wafer that has a thermal SiO2layer. The DNA nanotubes catalyze the etching of SiO2by HF vapor to expose the underlying Si. The phosphate groups in the DNA nanotube were used as the doping source to locallyn-dope the Si wafer to form vertical P-N junctions. Prototype PN diodes were fabricated and exhibited expected blockage behavior with a knee voltage ofca.0.7 V. Our work highlights the potential of DNA nanotechnology in future fabrication of nanoelectronics. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email