There is a growing need for digital and power electronics to deliver higher power for applications in batteries for electric vehicles, energy sources from wind and solar, data centers, and microwave devices. The higher power also generates more heat, which requires better thermal management. Diamond thin films and substrates are attractive for thermal management applications in power electronics because of their high thermal conductivity. However, deposition of diamond by microwave plasma enhanced chemical vapor deposition (MPECVD) requires high temperatures, which can degrade metallization used in power electronic devices. In this research, titanium (Ti)–aluminum (Al) thin films were deposited by DC magnetron sputtering on p-type Si (100) substrates using a physical mask for creating dot patterns for measuring the properties of the contact metallization. The influence of processing conditions and postdeposition annealing in argon (Ar) and hydrogen (H2) at 380 °C for 1 h on the properties of the contact metallization is studied by measuring the I-V characteristics and Hall effect. The results indicated a nonlinear response for the as-deposited films and linear ohmic contact resistance after postannealing treatments. In addition, the results on contact resistance, resistivity, carrier concentration, and Hall mobility of wafers extracted from Ti–Al metal contact to Si (100) are presented and discussed.
This content will become publicly available on June 1, 2025
Single-walled carbon nanotube (SWCNT) thin films were synthesized by using a floating catalyst chemical vapor deposition (FCCVD) method with a low flow rate (200 sccm) of mixed gases (Ar and H2). SWCNT thin films with different thicknesses can be prepared by controlling the collection time of the SWCNTs on membrane filters. Transmission electron microscopy (TEM) showed that the SWCNTs formed bundles and that they had an average diameter of 1.46 nm. The Raman spectra of the SWCNT films suggested that the synthesized SWCNTs were very well crystallized. Although the electrical properties of SWCNTs have been widely studied so far, the Hall effect of SWCNTs has not been fully studied to explore the electrical characteristics of SWCNT thin films. In this research, Hall effect measurements have been performed to investigate the important electrical characteristics of SWCNTs, such as their carrier mobility, carrier density, Hall coefficient, conductivity, and sheet resistance. The samples with transmittance between 95 and 43% showed a high carrier density of 1021–1023 cm−3. The SWCNTs were also treated using Brønsted acids (HCl, HNO3, H2SO4) to enhance their electrical properties. After the acid treatments, the samples maintained their p-type nature. The carrier mobility and conductivity increased, and the sheet resistance decreased for all treated samples. The highest mobility of 1.5 cm2/Vs was obtained with the sulfuric acid treatment at 80 °C, while the highest conductivity (30,720 S/m) and lowest sheet resistance (43 ohm/square) were achieved with the nitric acid treatment at room temperature. Different functional groups were identified in our synthesized SWCNTs before and after the acid treatments using Fourier-Transform Infrared Spectroscopy (FTIR).
more » « less- PAR ID:
- 10556445
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Nanomaterials
- Volume:
- 14
- Issue:
- 11
- ISSN:
- 2079-4991
- Page Range / eLocation ID:
- 965
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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