Effect of F doping on capacitance–voltage characteristics of SiCOH low-k films metal–insulator–semiconductor structure

Abstract

This paper investigates the capacitance–voltage (C–V) characteristics of F doping SiCOH low dielectric constant films metal–insulator–semiconductor structure. The F doping SiCOH films are deposited by decamethylcyclopentasiloxane (DMCPS) and trifluromethane (CHF3) electron cyclotron resonance plasmas. With the CHF3/DMCPS flow rate ratio from 0 to 0.52, the positive excursion of C–V curves and the increase of flat-band voltage VFB from −6.1 V to 32.2 V are obtained. The excursion of C–V curves and the shift of VFB are related to the change of defects density and type at the Si/SiCOH interface due to the decrease of Si and O concentrations, and the increase of F concentration. At the CHF3/DMCPS flow rate ratio is 0.12, the compensation of F-bonding dangling bond to Si dangling bond leads to a small VFB of 2.0 V.