Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Abstract

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

Characterization of Ferroelectric Characteristics for Hafnium Zirconium Oxide Capacitors with Refractory Electrodes

“…28 the TaN x electrode may evolve gradually from TaN to Ta 3 N 5 as the nitrogen content of TaN x is increased. 29 The broad peak may also correspond to the mixture of TaN (111), Ta 3 N 5 (130), or Ta 3 N 5 (040) due to the mixture of the two-phases (i.e. TaN and Ta 3 N 5 ).…”

Co-W Barrier Layers for Metallization of Copper Interconnects: Thermal Performance Analysis

“…Considering that TaN can exhibit resistivity values of 0.3 Ω∙cm at 2 nm thickness [ 26 ] or the 1.5689 × 10 −3 Ω∙cm for a 97.64 nm thick film [ 27 ], it is worth noting that a Cu/TaN system is bound to exhibit higher resistivity values at similar thicknesses. In this way, while this Cu/Ta system displayed lower values than the Cu/Co-W alternative, a conventional dual-layer system comprised of a Ta adhesion layer with a TaN barrier layer should yield a higher sheet resistivity than that observed for the Co-W system at equivalent thickness due to the aforementioned TaN electrical properties.…”

Challenges in scaling of IPVD deposited Ta barriers on OSG low‐k films: Carbonization of Ta by CHx radicals generated through VUV‐induced decomposition of carbon‐containing groups

“…The material properties of ionized PVD (IPVD) deposited Ta and TaN are discussed in Hecker and colleagues. [12,14] It has been shown that Ta well meets the requirements for the application as a Cu diffusion barrier. Intermetallic Cu-Ta compounds are nonexistent, [15,16] and the solubility of tantalum in copper is very small.…”