Electrical Conductivity of Silicon Dioxide Thermally Grown on Silicon

DC and ac electrical conductivities of silicon dioxide thermally grown on p- (boron-doped) and n-type (phosphorous-doped) silicon have been measured in the temperature range of 25~176 Total dc conductivities varied from 10-9 to 10-~6 ~-lcm-1 in the temperature range of 25~176 Arrhenius plots for total dc conductivities of SiO2 grown on both the substrates exhibit two regions. Below 450 ~ the conductivities were independent of temperature and are suggested to be governed by impurities. Above 450 ~ the total dc conductivities increased with increase in temperature. The acti-vation energies of conduction in the temperature ange 500~176 were estimated to be 1.65 and 2.10 eV for SiO2 grown on p- and n-type silicon, respectively. DC polarization measurements carried out in this temperature ange suggest that conduction in SiO2 is ionic as well as electronic. The ionic conduction is believed predominantly to be due to the trans-port of oxygen ions. AC conductivities were also measured in the temperature ange of 550~176 The activation ener-gies for the conduction in this temperature ange were estimated to be 1.55 eV for SiO2 on p-type silicon and 1.86 eV for SiO2 on n-type silicon. These values are in close agreement with the values reported in the literature. AC conductivity of SiO2 grown on n-type silicon was found to be lower than that of SiO2 grown on p-type silicon. In semiconductor and integrated circuit devices, silicon dioxide is g rown thermally on silicon where it is used not