Area-Selective Low-Pressure Thermal Atomic Layer Deposition of Aluminum Nitride

This work demonstrates intrinsic area-selective deposition of AlN films by thermal atomic layer deposition (ALD). Using sequential pulses of trimethylaluminum and NH3 at a substrate temperature of 623 K, polycrystalline AlN was selectively formed on a thin layer of sputtered AlN that was patterned on thermal SiO2 grown on Si substrates. A pretreatment to remove native AlOxNy facilitated the selective growth of ALD-AlN. Transmission electron microscopy, X-ray photoelectron spectroscopy, spectroscopic ellipsometry, and atomic force microscopy examined the interfaces and layer thickness. As reported in this article, the deposition of AlN exhibits intrinsic selectivity, a trait that can be exploited to grow other III-nitrides selectively, such as GaN.</p

Electrical characterization of hot-wire assisted atomic layer deposited Tungsten films

In this work, we applied conventional Van der Pauw and circular transmission line method (CTLM) test structures to determine the sheet and contact resistance of ultra-thin (1-10 nm) tungsten films grown by Hot Wire assisted Atomic Layer Deposition, as well as their temperature coefficient of resistance (TCR). We finally explored the field effect (FE) in these layers

Conduction and electric field effect in ultra-thin tungsten films

Ultra-thin tungsten films were prepared using hotwire assisted atomic layer deposition. The film thickness ranged from 2.5 to 10 nm, as determined by spectroscopic ellipsometry and verified by scanning electron microscopy. The films were implemented in conventional Van der Pauw and circular transmission line method (CTLM) test structures, to explore the effect of film thickness on the sheet and contact resistance, temperature coefficient of resistance (TCR), and external electric field applied. All films exhibited linear current-voltage characteristics. The sheet resistance was shown to considerably vary across the wafer, due to the film thickness non-uniformity. The TCR values changed from positive to negative with decreasing the film thickness. A field-induced modulation of the sheet resistance up to 4.6&#x2219;10-4 V-1 was obtained for a 2.5 nm thick film, larger than that generally observed for metals

Electrical behavior of ALD-molybdenum films in the thin-film limit

Test structures were designed and fabricated to investigate the electrical properties of ultra-thin molybdenum films obtained by atomic layer deposition. The films were incorporated in conventional Van der Pauw and circular transmission line method test structures to explore the effect of film thickness on the resistivity, temperature coefficient of resistance, contact resistivity, and external electric field applied. The resistivity was shown to depend strongly on film thickness, while the temperature coefficient of resistance changed from positive to negative, indicating a change in the dominant conduction mechanism. A modest field effect was observed for the films in their thickness limit.</p

Area-Selective Low-Pressure Thermal Atomic Layer Deposition of Aluminum Nitride

This work demonstrates intrinsic area-selective deposition of AlN films by thermal atomic layer deposition (ALD). Using sequential pulses of trimethylaluminum and NH3 at a substrate temperature of 623 K, polycrystalline AlN was selectively formed on a thin layer of sputtered AlN that was patterned on thermal SiO2 grown on Si substrates. A pretreatment to remove native AlOxNy facilitated the selective growth of ALD-AlN. Transmission electron microscopy, X-ray photoelectron spectroscopy, spectroscopic ellipsometry, and atomic force microscopy examined the interfaces and layer thickness. As reported in this article, the deposition of AlN exhibits intrinsic selectivity, a trait that can be exploited to grow other III-nitrides selectively, such as GaN