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FAIR DEAL Grand Challenge Overview

Allemang, Christopher R.; Anderson, Evan M.; Baczewski, Andrew D.; Bussmann, Ezra B.; Butera, Robert; Campbell, DeAnna M.; Campbell, Quinn C.; Carr, Stephen M.; Frederick, Esther; Gamache, Phillip G.; Gao, Xujiao G.; Grine, Albert D.; Gunter, Mathew M.; Halsey, Connor H.; Ivie, Jeffrey A.; Katzenmeyer, Aaron M.; Leenheer, Andrew J.; Lepkowski, William L.; Lu, Tzu-Ming L.; Mamaluy, Denis M.; Mendez Granado, Juan P.; Pena, Luis F.; Schmucker, Scott W.; Scrymgeour, David S.; Tracy, Lisa A.; Wang, George T.; Ward, Dan; Young, Steve M.

While it is likely practically a bad idea to shrink a transistor to the size of an atom, there is no arguing that it would be fantastic to have atomic-scale control over every aspect of a transistor – a kind of crystal ball to understand and evaluate new ideas. This project showed that it was possible to take a niche technique used to place dopants in silicon with atomic precision and apply it broadly to study opportunities and limitations in microelectronics. In addition, it laid the foundation to attaining atomic-scale control in semiconductor manufacturing more broadly.

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TYPE SAND Report YEAR 2021
DOIOSTI

Quantum dots with split enhancement gate tunnel barrier control

Applied Physics Letters

Rochette, S.; Rudolph, Martin R.; Roy, A.M.; Curry, Matthew J.; Eyck, G.A.T.; Manginell, Ronald P.; Wendt, J.R.; Pluym, Tammy P.; Carr, Stephen M.; Ward, Daniel R.; Lilly, M.P.; Carroll, Malcolm

We introduce a silicon metal-oxide-semiconductor quantum dot architecture based on a single polysilicon gate stack. The elementary structure consists of two enhancement gates separated spatially by a gap, one gate forming a reservoir and the other a quantum dot. We demonstrate that, in three devices based on two different versions of this elementary structure, a wide range of tunnel rates is attainable while maintaining single-electron occupation. A characteristic change in the slope of the charge transitions as a function of the reservoir gate voltage, attributed to screening from charges in the reservoir, is observed in all devices and is expected to play a role in the sizable tuning orthogonality of the split enhancement gate structure. The all-silicon process is expected to minimize strain gradients from electrode thermal mismatch, while the single gate layer should avoid issues related to overlayers (e.g., additional dielectric charge noise) and help improve the yield. Finally, reservoir gate control of the tunnel barrier has implications for initialization, manipulation, and readout schemes in multi-quantum dot architectures.

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TYPE Journal Article YEAR 2019
DOIOSTIScopus

Spectroscopy of Multielectrode Tunnel Barriers

Physical Review Applied

Carroll, Malcolm; Shirkhorshidian, Amir; Gamble, John K.; Maurer, Leon M.; Carr, Stephen M.; Dominguez, Jason J.; Ten Eyck, Gregory A.; Wendt, J.R.; Nielsen, Erik N.; Jacobson, Noah T.; Lilly, Michael L.

Despite their ubiquity in nanoscale electronic devices, the physics of tunnel barriers has not been developed to the extent necessary for the engineering of devices in the few-electron regime. This problem is of urgent interest, as this is the specific regime into which current extreme-scale electronics fall. Here, we propose theoretically and validate experimentally a compact model for multielectrode tunnel barriers, suitable for design-rules-based engineering of tunnel junctions in quantum devices. We perform transport spectroscopy at approximately T=4 K, extracting effective barrier heights and widths for a wide range of biases, using an efficient Landauer-Büttiker tunneling model to perform the analysis. We find that the barrier height shows several regimes of voltage dependence, either linear or approximately exponential. Effects on threshold, such as metal-insulator transition and lateral confinement, are included because they influence parameters that determine barrier height and width (e.g., the Fermi energy and local electric fields). We compare these results to semiclassical solutions of Poisson's equation and find them to agree qualitatively. Finally, this characterization technique is applied to an efficient lateral tunnel barrier design that does not require an electrode directly above the barrier region in order to estimate barrier heights and widths.

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TYPE Journal Article YEAR 2018
DOIOSTIScopus

Single-electron-occupation metal-oxide-semiconductor quantum dots formed from efficient poly-silicon gate layout

Physical Review Applied

Carroll, Malcolm; Rochette, Sophie; Rudolph, Martin R.; Roy, A.M.; Curry, Matthew J.; Ten Eyck, Gregory A.; Manginell, Ronald P.; Wendt, J.R.; Pluym, Tammy P.; Carr, Stephen M.; Ward, Daniel R.; Lilly, Michael L.; Pioro-Ladriere, Michel

We introduce a silicon metal-oxide-semiconductor quantum dot structure that achieves dot-reservoir tunnel coupling control without a dedicated barrier gate. The elementary structure consists of two accumulation gates separated spatially by a gap, one gate accumulating a reservoir and the other a quantum dot. Control of the tunnel rate between the dot and the reservoir across the gap is demonstrated in the single electron regime by varying the reservoir accumulation gate voltage while compensating with the dot accumulation gate voltage. The method is then applied to a quantum dot connected in series to source and drain reservoirs, enabling transport down to the single electron regime. Finally, tuning of the valley splitting with the dot accumulation gate voltage is observed. This split accumulation gate structure creates silicon quantum dots of similar characteristics to other realizations but with less electrodes, in a single gate stack subtractive fabrication process that is fully compatible with silicon foundry manufacturing.

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TYPE Journal Article YEAR 2017
OSTI
Results 1–25 of 59
Results 1–25 of 59