The structural and optical properties of rf magnetron-sputtered GaN thin films on p ϩ -Si substrates have been accessed as a function of rapid thermal annealing ͑RTA͒ temperatures from 800 to 1000°C. The evidence has revealed that higher RTA temperatures not only assist the GaN films in recrystallizing into stable hexagonal form but also enhance the near-band-edge emission of GaN films in the photoluminescence spectrum. Moreover, a deep electron trap (E t ) with activation energy E c ϪE t Х0.39 eV detected at the surface of higher-RTA-temperature-treated GaN films was asserted to be a nitrogen-vacancy-related defect that takes a defect-assisted-tunneling role in the forward conduction process of Au/GaN Schottky diode. The greater reverse leakage current and lower breakdown voltage are suggested to be due to the effects of a lower barrier height and higher ideality factor that occurred in the higher-RTA-temperature-treated samples.

Dielectric properties of barium titanate-based internal capacitors characterized by capacitance, dissipation factor, and temperature change in capacitance are reported. A capacitance of about 10 nF/cm2 with the dissipation factor of 2.3% is obtained for the BaTi0.975O3+2 wt% LiF internal capacitor after being co-fired with low dielectric constant ceramic substrates at 900°C. The percent change of capacitance is confined within ±10%. The dissipation factor is stable and decreases with increasing temperature.

Barium–calcium–aluminum–borosilicate glass is added as a sintering promoter to reduce the sintering temperature of barium titanate. The dielectric properties of the glass-added barium titanate-based internal capacitors are investigated. The dielectric constants of the composites were found to increase with sintering temperature. A capacitance of about 2.3 nF/cm2 with the dissipation factor of 2.9% is obtained for a 20 wt% glass-added BaTiO3 internal capacitor after being cofired with low dielectric constant ceramic substrate at 950°C. The percent change of capacitance is confined within ±10% and the dissipation factor is stable in the measured temperature range.

A strobe method to control LED lighting source for machine vision inspection is a better design than that of traditional method that let LED always ON but adjustable brightness. A successful image processing depends on whether can retrieve a clear image which is the key work of the image processing. This paper introduces how to design a well strobe controller, to optimize the strobe control strategy to obtain a clear image, and is conducive to the establishment of a complete machine vision system.

The microstructural properties and reliability of spnttered Taz05 films treated by various temperaturcs of rapid thermal annealing (ICIA) in O2 atmosphere have been systematically investigated. Analytical rcsnlts rcvcaled that whenever the ICrA temperature was >650T, the noncrystallinity of as-grown Ta205 film would be effectively improved from an amorphous phasc to the p-Ta20s phase. Leakage currcnt mcasurcmcnt indicated that leakage current decreases with increasing anilealing temperature in a low RTA temperatiire range (<6BOT) and, contrarily, increases with increasing anncaling temperature in a high IlTA temperature range (650 to 950°C). Thc fortncr result was asserted that reducing pinholes and oxygen vacancies played bey factors. However, thc latter result was snggcstcd to arise due to significant Si diffusion into the Ta20s film, cawing a leaky transition laycr andlor being distributed along tlic grain boimdary to form the leakage path. Finally, thc time-dependent dielectric-breakdown experiments revealed that 950°C O2 ~T A treated Ta20s film possessed the supcrior crystallinity, crcating less interfacial hole trap states at the junction of Ta20s1Si and exhibiting the best long-term reliability ffects of Rapid Thermal Annealing 011 Rr-sputtered Films IEEE Tixisactioris oii Dielectrics arid Electrical Insulation Vol. 7 N o . 3, rune 2000 323