Deposition of silicon dioxide and silicon nitride by remote plasma enhanced chemical vapor deposition

Abstract

We have developed a low temperature process for the deposition of thin films of silicon dioxide and silicon nitride. The process consists of four steps: (a) excitation of an oxygen or nitrogen-containing molecule in an RF plasma; (b) transport of the excited oxygen or nitrogen species out of the plasma region; (c) mixing of the transported excited species with silane (or disilane) out of the plasma region to form precursor species; and (d) a CVD reaction at a heated substrate to form the desired thin film. We call this process remote plasma enhanced CVD (RPECVD). Silicon rich oxide films have been grown at substrate temperatures (Ts) between 100 and 350 °C using an excited O2/He mixture. Two different ‘‘silicon nitrides’’ have been deposited depending on the excited gas, NH3 or an N2/He mixture, and Ts. Using either nitrogen source and Ts greater than 450 °C, we obtain near stoichiometric films of Si3N4. On the other hand, films grown from NH3 and deposited with Ts of about 50 to 100 °C are silicon diimide [Si(NH)2], which is isostructural with respect to SiO2 with bridging NH groups substituted for the bridging oxygen atoms. Films grown from the NH3 source and at Ts between 150 and 450 °C are solid solutions of silicon nitride and silicon diimide. We discuss the application of these dielectric films in device structures.

Improvements in Silicon Oxide Dielectric Loss for Superconducting Microwave Detector Circuits

“…Poor quality Nb films, however, can occur from corrosion of the sputter target, or other contaminants in the deposition chamber. These poor quality Nb films can exhibit a lower critical temperature than pure Nb, and can result in temperature dependence of the kinetic inductance and a poor fit to (1). Qualitatively, this deviation to the fitting curve can appear as a slight downturn of the frequency versus temperature curve at temperatures near and above 1 K.…”

“…It can be deposited amorphously by sputtering, electron beam evaporation, or by electron-cyclotronresonance plasma-enhanced chemical-vapor deposition (ECR-PECVD) [1], [2]. With ECR-PECVD, deposition parameters such as stoichiometry, temperature, voltage, power, and pressure can all be carefully controlled, making it possible to deposit silicon oxide films with different characteristics.…”

“…Much theoretical and experimental progress has already been made in understanding TLS loss mechanisms [3], [4]. However, until recently, it was assumed that deposition of stoichiometric silicon dioxide (SiO 2 ) would be the most stable and lowest-loss silicon oxide film [1], [2]. However, studies in the ECR-PECVD deposition of silicon nitride have shown that more silicon-rich films can exhibit much lower loss than nitrogen-rich films in microwave resonators [5].…”

Physical and Chemical Methods for Thin-Film Deposition and Epitaxial Growth

“…Plasma-enhanced chemical vapor deposition (PECVD) (33) is used extensively to deposit a large variety of films, usually compounds such as oxides or nitrides. In the electronics industry PECVD is particularly used for depositing insulating films on integrated circuits.…”

Characterization of LPCVD and PECVD silicon oxynitride films

“…Special attention will be paid to those phenomena which may be important for the understanding of oxynitrides in general. Apart from recent developments in the deposition of these materials [26] these PECVD oxynitrides contain a large amount of H and should therefore, strictly speaking, not be considered as oxynitrides. However.…”