ROOM TEMPERATURE DEPOSITED SiN: CHARACTERISATION AND APPLICATIONS IN MMICs

摘要

We present the mechanical and electrical characterisation of novel, high quality room temperature ammonia-free silicon nitride (SiN) films deposited using inductively coupled plasma enhanced chemical vapour deposition technique (ICP-CVD). Ultra thin 5 nm SiN Metal Insulator Metal (MIM) capacitors with 100% wafer yield were realised with a capacitance of 6.7 fF/μm~2 and a breakdown electric field of more than 3 x 10~6 Vcm~(-1). An increase in capacitance per unit area by more than thirteen fold with a reduction in RF loss was observed as the SiN film thickness was reduced from 120nm to 5nm. Comparison with high temperature conventional 300℃ PECVD SiN was also investigated; a comparable breakdown voltage, and leakage current was demonstrated. We also present the effect of the 5 nm SiN film deposited as an interface layer between the semiconductor and the metal of a Schottky contact for a sub 100nm gate length SiGe MODFETs. Finally, we report on an array-based design methodology for the realisation of Ⅲ-Ⅴ Monolithic Millimetre-wave Integrated Circuits (MMICs) enabled by the low temperature SiN deposition technique.