Effects of plasma exposure on defects in novel dielectric materials

Summary form only given. During plasma processing of microelectronic devices, plasma exposure can cause damage to dielectric materials, resulting in defects in the thin dielectric layer. Effects of plasma exposure on defect concentrations in high- and low-k thin dielectric films deposited on high-resistivity silicon were measured with electron-spin resonance (ESR) spectroscopy. For high-k dielectric films, plasma parameters, including pressure and power, were varied to minimize the defect concentrations. For low-k dielectric films, during argon electron cyclotron resonance (ECR) plasma exposure, ion and photon bombardment increased the measured defect concentrations. Dielectric samples with various dielectric constants were examined showing that as the value of the dielectric constant was lowered, the defect concentrations were shown to increase significantly. To investigate further the nature of the defect concentrations and locations, defect states in different dielectric materials with crystalline and amorphous structures were investigated with two models, the Broer model and the Bloch model. For crystalline structures as in hafnium oxide, the defects were found to fit well with the Broer model due to strong local magnetic-field-orientation dependency. In amorphous materials, for example, organosilicate glass, the defects were found to fit to the Bloch model as seen in the field-broadening effects. Using the two models, the behaviors of the defects can be explained as a result of electron spins.