Low-temperature (≤200 °C) plasma enhanced atomic layer deposition of dense titanium nitride thin films

Abstract

Titanium nitride (TiN) has been widely used in the semiconductor industry for its diffusion barrier and seed layer properties. However, it has seen limited adoption in other industries in which low temperature (<200 °C) deposition is a requirement. Examples of applications which require low temperature deposition are seed layers for magnetic materials in the data storage (DS) industry and seed and diffusion barrier layers for through-silicon-vias (TSV) in the MEMS industry. This paper describes a low temperature TiN process with appropriate electrical, chemical, and structural properties based on plasma enhanced atomic layer deposition method that is suitable for the DS and MEMS industries. It uses tetrakis-(dimethylamino)-titanium as an organometallic precursor and hydrogen (H2) as co-reactant. This process was developed in a Veeco NEXUS™ chemical vapor deposition tool. The tool uses a substrate rf-biased configuration with a grounded gas shower head. In this paper, the complimentary and self-limiting character of this process is demonstrated. The effects of key processing parameters including temperature, pulse time, and plasma power are investigated in terms of growth rate, stress, crystal morphology, chemical, electrical, and optical properties. Stoichiometric thin films with growth rates of 0.4–0.5 Å/cycle were achieved. Low electrical resistivity (<300 μΩ cm), high mass density (>4 g/cm3), low stress (<250 MPa), and >85% step coverage for aspect ratio of 10:1 were realized. Wet chemical etch data show robust chemical stability of the film. The properties of the film have been optimized to satisfy industrial viability as a Ruthenium (Ru) preseed liner in potential data storage and TSV applications.

Tuning Material Properties of Oxides and Nitrides by Substrate Biasing during Plasma-Enhanced Atomic Layer Deposition on Planar and 3D Substrate Topographies

“…For film deposition without any biasing, a GPC of 0.47 ± 0.02 Å was obtained (Figure a) which is comparable to that reported for TiN x deposited using TDMAT and Ar + H 2 plasma at this temperature . The film had a resistivity of 1960 ± 60 μΩcm and a mass density of 3.9 ± 0.2 g/cm 3 (Figure b and c, respectively).…”

“…The precursors, plasma gases and other PEALD process conditions for depositing the six materials are shown in Table . Existing PEALD processes for these six materials − were used for the runs without any biasing where the substrate table was grounded during the plasma exposure step. For the runs performed with substrate biasing, the PEALD processes were modified by applying an RF bias signal to the substrate table during the plasma exposure step.…”

Room-temperature plasma-enhanced atomic layer deposition of ZnO: Film growth dependence on the PEALD reactor configuration

“…4(c), together with the appearance of (110) peak at 56 • (2θ) (not shown). The peak shift towards smaller angles may indicate change in the residual stress of the films when the higher plasma power is applied [50,51].…”

Influence of the plasma nitriding conditions on the chemical and morphological characteristics of TiN coatings deposited on silicon

“…TiN coating is also used in integrated circuits, solar cells, transparent films, and photothermal conversion 19 . Various deposition methods have been employed to deposit TiN coatings, such as dip-coating, sol-gel, thermal oxidation, e-beam, sputtering, chemical vapor deposition (CVD), plasma-enhanced CVD, metalorganic CVD, and molecular beam epitaxy 14,[20][21][22][23][24][25][26][27][28][29][30] .…”