Properties of TaN Films for ULSIs Prepared by Reactive Sputter Deposition

Abstract

Tantalum Nitride (TaN) thin films were deposited onto n-type Si(100) and (111) substrates with SiO 2 films at room temperature by radio frequency (RF) magnetron sputtering under Ar-N 2 plasma using a tantalum target. We observed the formation of TaN thin films with a wide range of the electrical resistivity as a function of the N 2 gas flow ratio, working pressure and the sputtering power, and their origins are discussed based upon the structural properties and chemical compositions of TaN thin films before Cu films deposition. In this study, we first observed that the TaN thin films with lower resistivity exhibited TaN (200) preferentially oriented structures and had larger grain sizes. It was also found that the formation of TaO(002) made the resistivity of TaN thin films higher because of the diffusion of oxygen from SiO 2 films during deposition.

Deposition of TaN Films by RF Sputtering and Their Barrier Properties in Cu/TaN/Dielectrics/Si MIS Structures

“…2. There is a tendency that the electrical resistivity increases with increasing TaN (111) peak intensity, which is the same with our previous observation that the electrical resistivity of TaN(200) preferentially oriented films was lower than that of TaN(111) preferentially oriented films [7]. At 600…”

“…• C), low electrical resistivity and high thermal conductivity [1][2][3][4][5][6][7], which make it possible to use as a diffusion barrier between Copper (Cu) wiring and interlayer dielectric film in ultra large scale integrated circuits (ULSIs) [2][3][4][5][6][7][8][9][10]. TaN can also be used in wide variety of applications such as corrosion-resistant materials, write-head materials in high-density magnetic recording and high-speed thermal printing head as well as thin film resistors.…”

“…Moreover, in recent years work function of TaN has received considerable attention for commonly used metal source/drain and metal gate electrodes of group III-V/Ge CMOS technologies with heterogeneous integrations on Si platform [11]. So far, TaN thin films have been prepared typically by sputtering tantalum in the argon and nitrogen gas mixture [1][2][3][4][5][6][7]. TaN has a defective structure [12], and deviations from stoichiometry are common.…”

“…So far we have investigated the influence of the resistivity of TaN thin films deposited by RF magnetron sputtering on the N 2 gas flow ratio and sputtering power, and the results were compared with their structural properties and chemical compositions before Cu film deposition [7]. In this study we focus on the barrier properties of TaN ISSN …”

Effects of Nitrogen Flow Rate on the Structural, Morphological and Optical Properties of TaN Thin Films Grown by the DC Magnetron Sputtered Technique

“…The high hardness of ≈ 61.9 GPa corresponds to orthorhombic Ta 4 N phase. Tajima et al [11] have also shown that the resistivity, film thickness, and crystallographic structure of TaN thin films could be controlled by changing N 2 gas flow ratio, working pressure and sputtering power for the application to ultra large-scale integration (ULSI). Kwang et al [12] studied optical properties and X-ray photoelectron spectroscopy of TaN thin films prepared by means of a reactive RF sputtering method on borosilicate glass substrates.…”