Electrical and structural properties of high-k Er-silicate gate dielectric formed by interfacial reaction between Er and SiO2 films

The authors investigate the electrical and structural properties of high-k Er-silicate film formed by the interfacial reaction between Er and SiO2 films. The increase in rapid thermal annealing temperature leads to the reduction of the interface trap density by one order of magnitude, indicating the improvement in the interface quality of Er-silicate gate dielectric. The increased capacitance value of Er-silicate gate dielectric with thermal treatment is attributed in part to the reduction of SiO2 thickness and to the increase in the relative dielectric constant of Er-silicate film caused by the chemical bonding change from Si-rich to Er-rich silicate.