Zirconium dioxide (ZrO2) films in the thickness range of 500-8000A havc been prepared by chemical vapor deposition in the temperature range of 800 ~ 1000~ The films were identified as fine-grained (~325A), nearly stoichiometric, monoclinic ZrO2, using electron microprobe analysis, infrared absorption, and transmission electron microscopy. The films exhibited r e m a r kable resistance to most aqueous acids and bases, although slight etching occurred in hot (220~ phosphoric acid. The deposits had an index of refraction of 2.1 -+ 0.1 at 546 nm and an optical energy gap of 5.12 eV. ZrO2 deposited on silicon offered little resistance to Na diffusion at 600~ while films deposited on thermal SiO2 were a good barrier due to pile-up of the Na near the ZrO2/SiO2 interface. The current density, J, depended on the field, E, as J -~ A E n, where n was 6 for the metal biased negatively and 2.75 or 5, depending on the magnitude of the field, for the opposite polarity. The dielectric constant in the frequency range of 5 x 10 S to 1 x l0 s Hz was relatively independent of frequency near 300~ and equal to approximately 18, however some dispersion was noted near 573~ The a-c conductivity could be represented by =ac ~ Cy~ where 5 is the measuring frequency and ~ a temperature dependent parameter, decreasing from ~1 at 300~ to ~0.5 at 573~ The dielectric strength of the films varied between 1 to 2 x 106 V/cm, independently of thickness and polarity. High frequency (1 MHz) C-V measurements indicated the presence of negative surface charge, which varied between --6 x 10 n to --1 x 1012 cm -2. The structures exhibited instability under negative bias, indicative of negative charge being injected into the insulator. C-V measurements on the double dielectric system (ZrO2/SiO2) showed that the presence of ZrO2 caused a flatband voltage displacement ~ +0.8V. In addition, the flatband voltage shifted as a function of time under negative bias and was found to obey the relationship aVFB -'-K log t.Recent developments in microelectronics, such as integrated circuit passivation and IGFET technology, have engendered extensive research in the preparation and characterization of insulating thin films (1). Much of the effort has been directed to SiO2, SlaY4, and Al203. Recently, alternatives to these materials have been sought. TiO2 (2) and Nb205 (3) have been investigated. It has been found that chemical vapor deposition (CVD) in the temperature range of 600 ~ 1000~ produces films with the most desirable properties for the above applications.A refractory oxide that has not been investigated in detail is zirconium dioxide (ZrO2). T h i s material is characterized by low electrical conductivity and extreme chemical inertness. Much of the information available on ZrO2 has been obtained on relatively impure bulk, sintered material. This paper reports on the preparation of ZrO2 films by CVD, and a survey of the optical, chemical, electrical, and interfacial properties of the resulting films. Film PreparationThe preparation of oxide films by CVD has been...

FLUORESCENCE PROPERTIES OF OXYANIONS 91shifts have a lower quenching temperature. For example, as can be seen in Fig. 9f and g, in Sr apatite the 450 nm emission is thermally quenched at a much lower temperature than the 610 nm emission. This is unusual, since Blasse et al. (3) have shown that in Eu2+-activated silicates the emissions that have the larger Stokes shifts usually have a much lower quenching temperature, due to a higher probability of crossover between the ground state and excited state of the activator ion.Sr orthophosphate system.--The Sr3 (PO4)2 lattice also provides two divalent metal ion sites which have slightly higher symmetries (D3d, C3v) than those in the apatite and spodiosite structures. The emission of Yb 2+ in Sr3(PO4)e shows only one main absorption band at room and liquid nitrogen temperatures. In this compound the emission intensity vs. temperature curve ( Fig. 9a) is not complex, and therefore there probably is emission from predominantly only one site. AcknowledgmentsThe authors are grateful to J. Ragusin for his assistance in the experimental work. Helpful discussions with C. S. Wiggins, S. Natansohn, and R. Amster are acknowledged. The use of a computer program to apply the correction functions to the recorded spectra was supplied by O. J. Sovers. The C.R. decay measurements were recorded by V. D. Meyer.ABSTRACT A CO2-112-AICI3-SiCI4 process used to deposit various compositions of aluminosilicate films on a silicon substrate held at various temperatures is described. The film deposition rate with a total vapor (0.42 A12C16 + 0.58 SIC14) concentration of 0.12 v/o (volume per cent) in the gas phase is 2500 A/rain at ll00~ and 150 A/min at 880~ with an activation energy of 42.5 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.205.114.91 Downloaded on 2015-06-30 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.205.114.91 Downloaded on 2015-06-30 to IP Vol. 117, No.