Comparison of GaN epitaxial films on silicon nitride buffer and Si(<f>1 1 1</f>)

The crystalline GaN films were grown on Si(1 1 1) or using <f>Si3N4</f> as a buffer layer by hot wall chemical vapor deposition. X-ray diffraction (XRD), photoluminescence (PL) and spreading resistance were sued to characterize the crystalline GaN films with or without a <f>Si3N4</f> buffer. The XRD indicated that the GaN epilayer was in a wurtzite structure. The PL spectrum at room temperature exhibited a strong emission of the GaN epilayer with a silicon nitride buffer at the wavelength of 365 nm and no yellow luminescence (YL) was present, but the PL spectrum of the GaN directly on silicon was not so strong and yellow luminescence was present. The <f>Si3N4</f> buffer layer was a high resistivity layer by spreading resistance. This simple but effective technique not only suppressed the YL but also made it possible to grow high-quality GaN on Si substrate. [Copyright &y& Elsevier]