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High permittivity hafnium titanate thin films deposited by chemical vapor deposition have been studied systematically as gate insulators. The electrical and physical characteristics of the films were analyzed using a variety of techniques. It was observed that the films with higher Ti content are more resistant to crystallization when subjected to high temperature annealing. The capacitance-voltage curves for devices with hafnium titanate displayed relatively low (∼50 mV) hysteresis. When the concentration of Hf is comparable to the concentration of Ti, both the interfacial layer equivalent oxide thickness and permittivity of HfxTi1-xO2 increase linearly with increasing Ti content. The sample with higher Hf content showed weaker temperature dependence of the current. In metal-oxide-semiconductor field-effect transistor devices with hafnium titanate films, normal transistor characteristics were observed. The devices exhibited electron mobility degradation. The thermodynamic stability of stoichiometric films in contact with Si was also studied. [ABSTRACT FROM AUTHOR]

The photo- and cathodoluminescence properties of epitaxial lithium-doped zinc gallate thin-film phosphors grown on (100) MgO single crystal substrates using pulsed laser ablation were investigated. The addition of lithium to both undoped and Mn-doped ZnGa[sub 2]O[sub 4] films significantly enhanced the photo- and low-voltage cathodoluminescent intensity. Cathodoluminescent efficiencies for as-deposited undoped and Mn-doped lithium zinc gallate films as high as 0.21 1m/W and 0.29 1m/W, respectively, were achieved for 1 kV and 2.26 µA/cm[sup 2]. Based on these results, lithium-doped zinc gallate thin-film phosphors appear to be attractive for applications in low-voltage field emission display devices. [ABSTRACT FROM AUTHOR]

We report that precursor HfCl4 plays an important role in optimizing atomic-layer-deposition HfO2 bulk trapping characteristics. By systematic study, it has been observed that, under certain optimized precursor pulse time condition (450 ms pulse as compared to standard 150 ms), bulk trapping characteristics could be improved significantly without affecting the equivalent oxide thickness and leakage current characteristics of the devices. Slight improvement in mobility of the devices could also be obtained. Secondary-ion-mass-spectroscopy analysis shows that increase in the chlorine composition by increasing precursor pulse time could be attributed to the observed improvement. Drastic increase in pulse time (1500 ms) negates the benefit. [ABSTRACT FROM AUTHOR]