Electron spin resonance study of interface defects in atomic layer deposited hafnium oxide on Si

We report electron spin resonance (ESR) observation of interface defects at the HfO2/(111)Si boundary for HfO2 films deposited via atomic layer chemical vapor deposition using Hf(NO3)4 as a precursor. We observe several signals, dominated by one due to a silicon dangling bond at the Si/dielectric interface. This center is somewhat similar to, but not identical to, Si/SiO2 interface silicon dangling bonds. Comparison between ESR and capacitance versus voltage measurements suggests that these dangling bond centers play an important role in HfO2/Si interface traps.