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.


This content will become publicly available on September 1, 2026

Title: Chemical vapor deposition of zirconium(IV) sulfide on flexible polymers
The emerging optoelectronic material family of transition metal dichalcogenides may be useful in flexible electronics. However, only MoS2 has been grown directly as thin films on polymer substrates, owing in part to the high deposition temperatures typically required to prepare these materials. Changing vapor deposition chemistry can allow much lower film growth temperatures. We show that when using tetrakis(dimethylamido)zirconium(IV), Zr(NMe2)4, and H2S as precursors, low-temperature chemical vapor deposition affords films of zirconium(IV) sulfide (ZrS2) directly on polymer substrates. Stoichiometric and crystalline ZrS2 films can be deposited with good adhesion on polyimide (Kapton) and polyether ether ketone (PEEK) substrates at 150–200 °C. The films deposited on polydimethylsiloxane (PDMS) substrates were stoichiometric and crystalline, but not well adhered. Films on all substrates were polycrystalline with small (20–30 nm) grains, highly oriented in the [001] direction of the 1T ZrS2 phase. The films grown on PEEK have resistivities ca. 625 Ω cm, two orders of magnitude higher than ZrS2 films deposited at 800–1000 °C from ZrCl4 and sulfur. The films grown on Kapton are similarly conductive, whereas films on PDMS are not conductive.  more » « less
Award ID(s):
2224949
PAR ID:
10615889
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
AIP Publishing
Date Published:
Journal Name:
Journal of Vacuum Science & Technology A
Volume:
43
Issue:
5
ISSN:
0734-2101
Page Range / eLocation ID:
053402
Subject(s) / Keyword(s):
Semiconductor growth Polymers Thin films X-ray photoelectron spectroscopy Chemical vapor deposition Transition metal dichalcogenides Zirconium(IV) sulfide
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. We analyzed the surface of a freshly exfoliated single crystal of zirconium(IV) sulfide, ZrS2. Survey spectra and high-resolution spectra from the core levels Zr 4p, Zr 4s, Zr 3d, Zr 3p, Zr 3s, S 2p, S 2s, O 1s, and C 1s were acquired. The binding energies and peak area ratios of a stoichiometric ZrS2 single crystal provide a pure reference of well-defined composition for material deposited by chemical or physical vapor deposition methods. 
    more » « less
  2. Abstract The structural properties of co-deposited ultrathin PtSe 2 films grown at low temperatures by molecular beam epitaxy on c-plane Al 2 O 3 are studied. By simultaneously supplying a Se flux from a Knudsen cell and Pt atoms from an electron-beam evaporator, crystalline (001)-oriented PtSe 2 films were formed between 200 °C and 300 °C. The long separation between substrate and electron beam evaporator of about 60 cm ensured minimal thermal load. At optimum deposition temperatures, a ten times or even higher supply rate of Se compared to Pt ensured that the pronounced volatility of the Se was compensated and the PtSe 2 phase was formed and stabilized at the growth front. Postgrowth anneals under a Se flux was found to dramatically improve the crystalline quality of the films. Even before the postgrowth anneal in Se, the crystallinity of PtSe 2 films grown with the co-deposition method was superior to films realized by thermal assisted conversion. Postgrowth annealed films showed Raman modes with narrower peaks and more than twice the intensity. Transmission electron microscopy investigations revealed that the deposited material transitioned to a two-dimensional layered structure only after the postgrowth anneal. PtSe 2 growth was found to start as single layer islands that preferentially nucleated at atomic steps of the substrate and progressed in a layer-by-layer like fashion. A close to ideal wetting behavior resulted in coalesced PtSe 2 films after depositing about 1.5 PtSe 2 layers. Detailed Raman investigation of the observed PtSe 2 layer breathing modes of films grown under optimized co-deposition conditions revealed an interlayer coupling force constant of 5.0–5.6 × 10 19 N m −3 . 
    more » « less
  3. Typical titanium oxide (TiO2) films are transparent in the visible range, allowing for their index of refraction and thickness to be extracted by single-angle spectroscopic ellipsometry (SE) using a Cauchy model. However, TiO2 films grown by atomic layer deposition (ALD) from tetrakis(dimethylamino)titanium (IV) (TDMAT) and H2O at 350 °C absorb in the visible range due to the formation of Ti-O-N/Ti-N bonds. Single-angle SE is inadequate for extracting the optical constants of these films, as there are more unknowns (n, k, d) than measurable parameters (ψ, Δ). To overcome this limitation, we combined SE with transmission (T) measurements, a method known as SE + T. In the process, we developed an approach to prevent backside deposition on quartz substrates during ALD deposition. When applying a B-spline model to SE + T data, the film thicknesses on the quartz substrates closely matched those on companion Si samples measured via standard lithography. The resulting optical constants indicate a reduced refractive index, n, and increased extinction coefficient, k, when compared to purer TiO2 thin films deposited via a physical vapor deposition (PVD) method, reflecting the influence of nitrogen incorporation on the optical properties. 
    more » « less
  4. Abstract This work reports on the correlation between structure, surface/interface morphology and mechanical properties of pulsed laser deposited (PLD)β-Ga2O3films on transparent quartz substrates. By varying the deposition temperature in the range of 25 °C–700 °C, ∼200 nm thick Ga2O3films with variable microstructure and amorphous-to-nanocrystalline nature were produced onto quartz substrates by PLD. The Ga2O3films deposited at room temperature were amorphous; nanocrystalline Ga2O3films were realized at 700 °C. The interface microstructure is characterized with a typical nano-columnar morphology while the surface exhibits the uniform granular morphology. Corroborating with structure and surface/interface morphology, and with increasing deposition temperature, tunable mechanical properties were seen in PLD Ga2O3films. At 700 °C, for nanocrystalline Ga2O3films, the dense grain packing reduces the elastic modulus Erwhile improving the hardness. The improved crystallinity at elevated temperatures coupled with nanocrystallinity, theβ-phase stabilization is accounted for the observed enhancement in the mechanical properties of PLD Ga2O3films. The structure-morphology-mechanical property correlation in nanocrystalline PLDβ-Ga2O3films deposited on quartz substrates is discussed in detail. 
    more » « less
  5. We report the growth of nanoscale hafnium dioxide (HfO2) and zirconium dioxide (ZrO2) thin films using remote plasma-enhanced atomic layer deposition (PE-ALD), and the fabrication of complementary metal-oxide semiconductor (CMOS) integrated circuits using the HfO2 and ZrO2 thin films as the gate oxide. Tetrakis (dimethylamino) hafnium (Hf[N(CH3)2]4) and tetrakis (dimethylamino) zirconium (IV) (Zr[N(CH3)2]4) were used as the precursors, while O2 gas was used as the reactive gas. The PE-ALD-grown HfO2 and ZrO2 thin films were analyzed using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM). The XPS measurements show that the ZrO2 film has the atomic concentrations of 34% Zr, 2% C, and 64% O while the HfO2 film has the atomic concentrations of 29% Hf, 11% C, and 60% O. The HRTEM and XRD measurements show both HfO2 and ZrO2 films have polycrystalline structures. n-channel and p-channel metal-oxide semiconductor field-effect transistors (nFETs and pFETs), CMOS inverters, and CMOS ring oscillators were fabricated to test the quality of the HfO2 and ZrO2 thin films as the gate oxide. Current-voltage (IV) curves, transfer characteristics, and oscillation waveforms were measured from the fabricated transistors, inverters, and oscillators, respectively. The experimental results measured from the HfO2 and ZrO2 thin films were compared. 
    more » « less