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Search Publications by: Richard M. Silver (Fed)

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Displaying 1 - 25 of 154

DC to GHz measurements of a near-ideal 2D material: P+ monolayers

March 8, 2024
Author(s)
Neil M. Zimmerman, Antonio Levy, Pradeep Namboodiri, Joshua M. Pomeroy, Xiqiao Wang, Joseph Fox, Richard M. Silver
P+ monolayers in Si are of great scientific and technological interest, both intrinsically as a material in the "ideal vacuum" of crystalline Si, and because they are showing great promise as qubits of electron and nuclear spin. The GHz complex

Multi-scale alignment to buried atom-scale devices using Kelvin probe force microscopy

February 24, 2024
Author(s)
Pradeep Namboodiri, Jonathan Wyrick, Gheorghe Stan, Xiqiao Wang, Fan Fei, Ranjit Kashid, Scott Schmucker, Richard Kasica, Bryan Barnes, Michael Stewart, Richard M. Silver
Fabrication of quantum devices by atomic scale patterning with a Scanning Tunneling Microscope (STM) has led to the development of single/few atom transistors, few-donor/quantum dot devices for spin manipulation and arrayed few-donor devices for analog

Experimental realization of an extended Fermi-Hubbard model using a 2D lattice of dopant-based quantum dots

November 11, 2022
Author(s)
Richard M. Silver, Jonathan Wyrick, Xiqiao Wang, Ranjit Kashid, Garnett W. Bryant, Albert Rigosi, Pradeep Namboodiri, Ehsan Khatami
The Hubbard model is one of the primary models for understanding the essential many-body physics in condensed matter systems such as Mott insulators and cuprate high-Tc superconductors. Due to the long-range Coulomb interactions, accessible low

Enhanced Atomic Precision Fabrication by Adsorption of Phosphine into Engineered Dangling Bonds on H-Si Using STM and DFT

November 1, 2022
Author(s)
Jonathan Wyrick, Xiqiao Wang, Pradeep Namboodiri, Ranjit Kashid, Fan Fei, Joseph Fox, Richard M. Silver
Doping of Si using the scanning probe technique of hydrogen depassivation lithography has been shown to enable placing and positioning small numbers of P atoms with nanometer accuracy. Several groups have now used this capability to build devices that

Measurement sensitivity of DUV scatterfield microscopy parameterized with partial coherence for duty ratio-varied periodic nanofeatures

February 1, 2022
Author(s)
Taekyung Kim, Eikhyun Cho, Yoon Sung Bae, Sang-Soo Choi, Bryan Barnes, Richard M. Silver, Martin Sohn
The deep ultraviolet (DUV) scatterfield imaging microscopy technique enables accurate dimensional measurements of periodic nanostructures with sub-nanometer sensitivity to support semiconductor device manufacturing. A parametric sensitivity analysis for

Electron-electron interactions in low-dimensional Si:P delta layers

June 15, 2020
Author(s)
Joseph Hagmann, Xiqiao Wang, Ranjit Kashid, Pradeep Namboodiri, Jonathan Wyrick, Scott W. Schmucker, Michael Stewart, Richard M. Silver, Curt A. Richter
Key to producing quantum computing devices based on the atomistic placement of dopants in silicon by scanning tunneling microscope (STM) lithography is the formation of embedded highly doped Si:P delta layers (δ-layers). This study investigates the

Atomic-scale control of tunneling in donor-based devices

May 11, 2020
Author(s)
Xiqiao Wang, Jonathan E. Wyrick, Ranjit V. Kashid, Pradeep N. Namboodiri, Scott W. Schmucker, Andrew Murphy, Michael D. Stewart, Richard M. Silver
Atomically precise donor-based quantum devices are a promising candidate for scalable solid- state quantum computing. Atomically precise design and implementation of the tunnel coupling in these devices is essential to realize gate-tunable exchange

Appraising the extensibility of optics-based metrology for emerging materials

October 4, 2019
Author(s)
Bryan M. Barnes, Mark-Alexander Henn, Martin Y. Sohn, Hui Zhou, Richard M. Silver
To advance computational capabilities beyond conventional scaling limitations, novel device architectures enabled by emerging materials may be required. Optics-based methodologies, central to modern-day process control, will be pursued by the

Assessing form-dependent optical scattering at vacuum- and extreme-ultraviolet wavelengths off nanostructures with two-dimensional periodicity

June 24, 2019
Author(s)
Bryan M. Barnes, Mark Alexander Henn, Martin Y. Sohn, Hui Zhou, Richard M. Silver
Several metamaterials and nanostructures are form birefringent, exhibiting effective refractive index differences for orthogonal polarizations due to the placement of subwavelength features if the periodicity is smaller than the incident wavelength. As the

Low-resistance, high-yield electrical contacts to atom scale Si:P devices using palladium silicide

March 29, 2019
Author(s)
Scott W. Schmucker, Pradeep Namboodiri, Ranjit Kashid, Xiqiao Wang, Binhui Hu, Jonathan Wyrick, Alline Myers, Joshua D. Schumacher, Richard M. Silver, Michael Stewart
Scanning tunneling microscopy (STM) enables the fabrication of 2-D delta-doped structures in Si with atomistic precision, with applications from tunnel field effect transistors to qubits. The combination of a very small contact area and the restrictive

STM patterned nanowire measurements using photolithographically defined implants in Si(100)

January 29, 2018
Author(s)
Aruna N. Ramanayaka, Hyun Soo Kim, Ke Tang, Xiqiao Wang, Richard M. Silver, Michael D. Stewart, Joshua M. Pomeroy
Using photolithographically defined implant wires for electrical connections, we demonstrate measurement of a scanning tunneling microscope (STM) patterned nanoscale electronic device on Si(100), eliminating the onerous alignment procedures and electron

Quantifying Atom-scale Dopant Movement and Electrical Activation in Si:P Monolayers

January 26, 2018
Author(s)
Xiqiao Wang, Joseph A. Hagmann, Pradeep N. Namboodiri, Jonathan E. Wyrick, Kai Li, Roy E. Murray, Frederick Meisenkothen, Alline F. Myers, Michael D. Stewart, Richard M. Silver
Doped semiconductor structures with ultra-sharp dopant confinement, minimal lattice defects, and high carrier concentrations are essential attributes in the development of both ultra- scaled conventional semiconductor devices and emerging all-silicon

Weak localization thickness measurements of embedded phosphorus delta layers in silicon produced by PH3 dosing

January 23, 2018
Author(s)
Joseph A. Hagmann, Xiqiao Wang, Pradeep N. Namboodiri, Jonathan E. Wyrick, Roy E. Murray, Michael D. Stewart, Richard M. Silver
The key building blocks for devices based on the deterministic placement of dopants in silicon are the formation of phosphorus dopant monolayers and the overgrowth of high quality crystalline Si. Lithographically defined dopant delta-layers can be formed

Towards single atom devices for quantum information and metrology: weak localization in embedded phosphorus delta layers in silicon

June 29, 2017
Author(s)
Joseph A. Hagmann, Xiqiao Wang, Pradeep N. Namboodiri, Jonathan E. Wyrick, Roy E. Murray, Michael D. Stewart, Richard M. Silver, Curt A. Richter
The key building block for devices based on the deterministic placement of dopants in silicon is the formation of phosphorus dopant monolayers and the overgrowth of high quality crystalline Si. Lithographically defined dopant delta-layers can be formed

Combining model-based measurement results of critical dimensions from multiple tools

April 7, 2017
Author(s)
Nien F. Zhang, Bryan M. Barnes, Hui Zhou, Mark Alexander Henn, Richard M. Silver
Model-based measurement techniques use experimental data and simulations of the underlying physics to extract quantitative estimates of the measurands of a specimen based upon a parametric model of that specimen. The uncertainties of these estimates are

Assessing the wavelength extensibility of optical patterned defect inspection

March 29, 2017
Author(s)
Bryan Barnes, Hui Zhou, Mark-Alexander Henn, Martin Sohn, Richard M. Silver
Qualitative comparisons have been made in the literature between the scattering off deep- subwavelength-sized defects and the scattering off spheres in free space to illustrate the challenges of optical defect inspection with decreasing patterning sizes