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Wafer-scale synthesis of p-type TMD films is critical for its commercialization in next-generation electro/optoelectronics. In this work, wafer-scale intrinsic n-type WS2films and in situ Nb-doped p-type WS2films were synthesized through atomic layer deposition (ALD) on 8-inchα-Al2O3/Si wafers, 2-inch sapphire, and 1 cm2GaN substrate pieces. The Nb doping concentration was precisely controlled by altering cycle number of Nb precursor and activated by postannealing. WS2n-FETs and Nb-doped p-FETs with different Nb concentrations have been fabricated using CMOS-compatible processes. X-ray photoelectron spectroscopy, Raman spectroscopy, and Hall measurements confirmed the effective substitutional doping with Nb. The on/off ratio and electron mobility of WS2n-FET are as high as 105and 6.85 cm2 V-1 s-1, respectively. In WS2p-FET with 15-cycle Nb doping, the on/off ratio and hole mobility are 10 and 0.016 cm2 V-1 s-1, respectively. The p-n structure based on n- and p- type WS2films was proved with a 104rectifying ratio. The realization of controllablein situNb-doped WS2films paved a way for fabricating wafer-scale complementary WS2FETs.
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This content will become publicly available on June 1, 2027
Scaling nanoribbon transistors with monolayer transition metal dichalcogenides
Abstract Nanoscale transistors demand aggressive scaling of all channel dimensions—length, width and thickness. Two-dimensional semiconductors (2DS) provide the ultimate thickness limit, yet good device performance has largely remained restricted to micrometre-wide channels. Here we report monolayer 2DS nanoribbon transistors with both n- and p-type operation, fabricated by a top-down multipatterning process that includes ‘anchored’ contacts to limit nanoribbon delamination. This approach achieves channel lengths and widths down to 25–30 nm, with minimal edge degradation confirmed through nanoscale characterization, including tip-enhanced photoluminescence. Integrated with thin high-κgate dielectrics, the devices deliver on-state currents up to 560, 420 and 130 µA µm−1at a drain-to-source voltage of 1 V for n-type MoS2, n-type WS2and p-type WSe2, respectively. These results exceed prior single-gated 2DS nanoribbon reports, with WS2improving by more than two orders of magnitude, even for normally off (enhancement-mode) operation. Overall, these findings position top-down patterned 2DS nanoribbons as promising building blocks for future nanosheet transistor architectures.
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- Award ID(s):
- 2425218
- PAR ID:
- 10703184
- Publisher / Repository:
- Springer Nature
- Date Published:
- Journal Name:
- Nature Nanotechnology
- Volume:
- 21
- Issue:
- 6
- ISSN:
- 1748-3387
- Page Range / eLocation ID:
- 803 to 809
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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