Strain induced changes in gate leakage current and dielectric constant of nitrided Hf-silicate metal oxide semiconductor capacitors

Uniaxial-mechanical-stress altered gate leakage current and dielectric constant of silicon metal-oxide-semiconductor (MOS) devices with nitrided Hf-silicate (HfSiON) dielectric are measured as a function of uniaxial stress applied using four-point wafer bending along the [110] direction. The gate leakage current and dielectric constant are found to increase by ∼2% per 100 MPa of tensile and compressive stresses. A decrease in hole trap activation energy in hafnium oxide-based dielectric is used to explain the mechanical stress altered gate leakage. It is proposed that the HfSiON dielectric constant increase results from band gap narrowing caused by strain induced N p band splitting.