Cathodoluminescence Study of Hafnium Oxide

Hafnium dioxide (HfO2) is increasingly being used in place of silicon oxide as a gate insulator in field effect transistors. This is primarily due to its high dielectric constant, $\kappa $, of 25. Samples of HfO$_{2}$ were grown by either atomic layer deposition (ALD) or pulsed laser deposition (PLD), with the PLD samples having assorted substrate temperatures during deposition (300\r{ }C, 500\r{ }C, and 750\r{ }C). Cathodoluminescence (CL) was chosen as the technique used for studying these HfO$_{2}$ samples. The CL system used was capable of beam energies ranging from 1 keV to 20 keV and beam currents ranging from 10 $\mu $A to 50 $\mu $A. A Monte Carlo calculation using CASINO software was performed in order to determine the beam energy for the desired depth of penetration. Measurements were taken at sample temperatures ranging from 7K (closed cycled cryostat) to 300K (room temperature), as well as at various beam energies and beam currents. Comparison will be made between the PLD and ALD spectra.