Dielectrics for very large scale integration (VLSI)

Dielectric films are an integral part of the integrated circuits. Key applications can be classified as, (i) dielectrics for growing semiconductor films e.g., silicon on insulator, (ii) layer of dielectric films which do not appear in the finished device e.g., dielectrics for diffusion and ion implantation masks, and (iii) permanent dielectric films which play a key role in the electrical operation of the circuit e.g., gate dielectric in a MOSFET. In this paper a review is presented of the dielectrics with main emphasis on the permanent dielectric films. Techniques for forming dielectric films reviewed are evaporation, sputtering, plasma depostion, thermal process and various types of chemical vapor depositions. A comparitive study of alternative deposition techniques for various dielectric films is presented. Materials and techniques that have potential for achieving performance and reliability goals of submicron integrated circuits are evaluated in depth.