A heating and diffusion barrier based on TaSiNx for miniaturized IC devices

• Published in: Thin solid films 2006-11, Vol.515 (3), p.990-995
• Main Authors: CHENG, Huai-Yu, CHEN, Yi-Chen, LEE, Chain-Ming, WANG, Shuo-Hung, CHIN, Tsung-Shune
• Format: Article
• Language: English
• Subjects: Composition and phase identification; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physical properties of thin films, nonelectronic; Physics; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thermal stability; thermal effects; Thin film structure and morphology
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2006.07.091

Highly resistive TaSiNx films investigated as candidates for heating and diffusion-barrier layers for miniaturized IC devices such as a sensor or a phases-change random access memory (PCRAM). The obtained resistivity, between 0*069-1*21 Omega cm, increases with increasing nitrogen content up to 52*83%, and fulfills the requirements as a suitable heating layer. All the as-deposited films were amorphous, and the films with substantial nitrogen content showed excellent thermal stability The amorphous structure had a very smooth surface which was stable at temperatures up to 800 deg C. In addition to its heating capability, the amorphous structure with no grain boundaries was found to also act as a good diffusion barrier effect in contact with a tungsten electrode as determined by AES an TEM analysis. The barrier effect was evaluated by an annealing at 500 and 600 deg C in Ar atmosphere for 30 min, respectively. The highly resistive TaSiNx heating layer successfully obstructed the diffusion of tungsten atoms from the W electrodes even when the layer was only 10 nm thick. With increasing N content, the heating and diffusion-barrier layer for PCRAM was proposed as a typical example of many potential applications.