Study On The Properties Of HfO₂ High-K Gate Dielectic Materials Prepared By Atomic Layer Deposition

With the rapid development of microelectronics industry, the feature size of CMOS device is scaling down. Silicon dioxide as conventional gate dielectric material has reached the limit thickness and will not meet the requirements of the integrated circuit technology. So we have to find high-k dielectric to replace silicon dioxide. HfO2 is considered as a perspective high-permittivity material for silicon-based metal-oxide-semiconductor devices. In this thesis, the work was presented in two aspects.(1) An electroluminescence and photoluminescence measurement system of semiconductor materials and devices was setup by American National Instrument Company's virtual instrument environment. The whole test system connects semiconductor laser, spectrometer, lock-in amplifier, data acquisition device, digital source meter with computer by GPIB bus port and USB serial port. The available experiments including EL Spectra, EL I-V, EL Lifetime, PL Spectra and PL Excitation are designed for t he work's automation and integration.(2) The 50nm thick HfO2 films were grown by atomic layer deposition on Si (100) substrates with the precursors of Hf[N(CH3)2]4 and H2O. The physical and chemical characters of as-deposited and annealed films were studied by AFM, XRD, XPS, and the EL & PL spectra system. These results indicate that:The HfO2 films synthesized by atomic layer deposition system with hafnium tetrakis(dimethylamide) have higher breakdown fields than that prepared by Hafnium halides; The roughness and crystallinity of the films actually became lager with the increasing in annealing temperatures.