Akihito Ohno

Demonstration of High Quality 4H-SiC Epitaxy by Using the Two-Step Growth Method

A new growth method for considerably suppressing generation of carrot and triangle defects is presented. Based on the investigation for the surfaces before and after the epitaxial growth, it becomes clear that those defects were results from micrometer-scale SiC particles. For removing the particles, pre-flow of H2 at high temperature before the growth was very effective. The density of those defects strongly depends on the condition of the pre-flow and especially decreased at Tp=1575°C and tp=180 sec.

High power 625-nm AlGaInP laser diode

Highly efficient quantum well laser diode is promising as a red light source for laser display. In the wavelength range of red light, short lasing wavelength is preferred because spectral luminous efficiency increases sharply as wavelength shortens. In this paper, we present high-power AlGaInP laser diode with remarkably short lasing wavelength of 625 nm. The fabricated device showed 220 mW and 44 lm output at 25 °C under CW operation. Efficiency was measured as 24 lm/W. Comparisons to 630-nm and 638-nm laser diodes are also presented.