LUMINESCENT SiCxNy THIN FILMS DEPOSITED BY ICP-CVD

Abstract

<p>In current microelectronic interconnect technology, significant delay is incurred due to capacitances in the intermediate and global interconnect layers. To avoid capacitive effects optical interconnects can be used; however conventional technologies are expensive to manufacture. One method to address these issues is to make use of quantum confinement effects and states lying within the bandgap of the material to enhance luminescence in a CMOS compatible silicon based system. Thin SiCxNy films appear to be suitable to work as luminescent silicon based films due to their lower direct bandgap and chemical stability but have not yet been studied in great detail.</p> <p>This thesis is an exploratory work aiming to assess the suitability of SiCxNy films for the above applications and to identify future research areas. The films analyzed in this thesis were manufactured on the inductively coupled plasma-chemical vapour deposition reactor (ICP-CVD) at McMaster University. The ICP-CVD produces films of high uniformity by using a remote RF plasma and an arrangement of high vacuum pumps to attain a vacuum on the order of 10-7Torr.</p> <p>Several experimental techniques have been used to analyse the films. The complex index of refraction has been determined through the use of ellipsometry giving results typical of that of a-SiNx:H. The photoluminescence spectroscopy results show a large broad emission peak with at least one shoulder at higher energies. The precise luminescence mechanism(s) could not be identified though a strong relationship with the bonding state of nitrogen has been found. The composition and structure of the films, as determined through ion beam measurements, infrared absorption measurements, and transmission electron microscopy measurements demonstrate the formation of a two phase structure consisting of carbon rich clusters surrounded by a mostly silicon nitride matrix. These carbon rich regions have some graphitic character and act to dampen the luminescence.</p>