Performance and failure mechanisms of TiN diffusion barrier layers in submicron devices

Abstract

Defects in reactively sputtered titanium nitride diffusion barriers in submicron devices were investigated. Four different failure mechanisms could be extracted, two originating from the production of the layers, two related to foregoing process steps. The latter are contact hole overetch and topology inside the contact hole, Le., edges, created by deviating isotropic etch ratios of different dielectric layers in a post-treatment after the contact etch. The insufficiencies related to the preparation of the TiN films are microcracks due to excessive stress incorporated and encroachment caused by a Ti-rich titanium nitride on the contact hole walls, proved by an Auger electron spectroscopy analysis. Accidental accumulation of two or more of these defects in a production line can cause the barrier to fail. The process of contact degradation was investigated by transmission electron microscopy and energy-dispersive x rays. It was found that after aluminum penetration the destruction of the contact area proceeds via a ternary Alx Tiy Si z reaction until aU titanium is consumed, followed by the growth of a pure Al spike and the fatal breakdown of the contact.

LPCVD Titanium Nitride for ULSIs

“…Titanium nitride LPCVD using TIC14 and NH3 as the source materials has been studied, mainly for hard coatings (4). Recent attempts, including the authors' studies (5)(6)(7)(8)(9)(10), have confirmed the applicability of this method for ULSIs.…”

Dispersion of TiN in aqueous media

“…Because of its exceptional intrinsic properties, such as high hardness, chemical inertness, high electronic conductivity, and low friction coefficient, TiN is applicable in hard coatings, hard cutting-tool inserts, refractory cements, high-temperature materials, and diffusion barriers in very large-scale integrated (VLSI) circuits [1][2][3][4][5][6][7][8][9]. In addition, TiN is widely used as a particulate-reinforced second phase in ceramic composites [10][11][12][13][14][15][16].…”

Characteristics of YBa2Cu3O7 Thin Films Deposited on Substrates Buffered by Various TiO2 Layers

“…TiN thin films have been studied and used extensively in recent years due to their superior mechanical, thermal, and electrical properties. [1][2][3] Moreover, it has been suggested that TiN thin films not only serve as buffer layers in depositing superconducting YBa 2 Cu 3 O 7 (YBCO) thin films on various substrates such as Si, Hastelloy, Inconel and stainless steel, but also as the electrode for metallization and integration of superconductor and semiconductor devices. 4,5) In the light of these unique properties exhibited by TiN films, we previously attempted to fabricate the YBCO/TiN/substrate structure by sequential in situ pulse laser deposition (PLD) to investigate the out-of-plate (along c-axis) transport properties of YBCO thin films.…”