Epitaxy and recrystallization kinetics of TaC thin films on SiC for high temperature processing of semiconductor devices

Abstract

Articles you may be interested inA quantitative analysis of room temperature recrystallization kinetics in electroplated copper films using high resolution x-ray diffractionThe authors report the epitaxial growth of cubic TaC thin films on 4H-SiC ͑0001͒ substrates by pulsed laser deposition and their recrystallization kinetics. The growth temperature for epitaxy was found to be 1000°C. The activation energy for the recrystallization was 1.5 eV. High temperature annealing produced changes in the surface morphology which caused grain growth and created pinholes through a recrystallization process in the films deposited at lower temperatures. The films deposited at higher temperatures remained virtually unchanged. Implications of these results are discussed in the context of the development of future high temperature and high-power electronic devices.

Epitaxial growth of tantalum carbides by low carbon flow carburizing

“…It is interesting to note that epitaxial surface structures on substrates are generally obtained through CVD [44], PVD [45] or PLD [46]. It is therefore possible to obtain epitaxial tantalum carbides on substrates by low-pressure carburizing, with a device that limits the carbon flow towards the tantalum.…”

Growth of GaN films on PLD-deposited TaC substrates

“…Samples 8 mm  6 mm in size were cut from on-axis, and 3120 00 6H or 813 00 off-axis towards the (1 1 2 0), 4H-SiC wafers, and 200-500 nm thick TaC films were deposited on them by PLD at temperatures ranging from 950 to 1200 1C under conditions described elsewhere [10]. Briefly, a KrF (l ¼248 nm, t¼20 ns) laser was used for the ablation of a stoichiometric TaC (99.995% purity) target.…”

“…The SiC substrates were first degreased sequentially in acetone, methanol, and then dilute HF, and heated to the growth temperature in a base vacuum of 2 Â 10 À 8 Torr. The minimum deposition temperature was chosen to be the lowest temperature at which epitaxy occurred; at lower deposition temperatures the TaC films would ball up on the surface when they were annealed at a temperature, T A Z1200 1C [10]. The highest temperature is the upper limit for our system.…”

“…Its relatively small thermal conductivity [9] also would be a problem. One possible solution for creating a TaC substrate is to deposit it by pulsed laser deposition (PLD) [10]. It is true that the PLD TaC films will probably have poorer crystalline quality than wafers cut from a bulk crystal because of the lattice mismatch (2.27%), but it will have the advantage of breaking the mismatch up into two steps.…”

Fabrication of Tantalum and Hafnium Carbide Fibers via ForcespinningTM for Ultrahigh‐Temperature Applications

“…Due to the thermal limitation of carbon and silicon carbide fibers handicapping ultrahigh-temperature performance, RTM-C materials for use in high-temperature environments have been identified as viable replacements [4]. RTM-C materials possess strong covalent bonding and degrees of metallic bonding that lead to high melting points (>3700°C (4000 K)), high hardness, good high-temperature strength, high resistance to oxidation, excellent electrical conductivity, and exceptional resistance to harsh chemical and thermal environments [2,[5][6][7].…”