Structural and Electrical Properties of Low‐Temperature, Low‐Pressure SiO2 on Si

Abstract

The physical and electrical properties of SiO2 deposited on Si at low pressure (2-10 Torr) and low temperature (100-300~ are reported. Fourier transform infrared spectroscopy (FTIR) is used to examine the chemical nature of the deposited oxide as a function of deposition and anneal temperature. Films deposited at T<200~ reveal partially oxidized silicon along with water and silanol groups. As the deposition temperature is raised to 3O0~ the FTIR spectra resemble that of thermal oxide. Annealing of films deposited at lower temperatures significantly improves the films, also causing the FTIR peaks to resemble those of thermal oxide. Capacitance-voltage measurements are used to extract fixed-charge and interface-state densities. Fixed-charge densities below 1 • 1011 cm -2 and interface-state densities below 5 • 10 TM cm -2 eV -1 are obtained after rapid thermal annealing of SiO2 on Si. Bias-temperature stressing is used to investigate slow trapping instabilities observed after rapid thermal annealing.