Influence of a SiN mask on GaN layer by metalorganic chemical vapor deposition

GaN layers with an in-situ SiN mask were grown by metalorganic chemical vapor deposition (MOCVD) and the physical properties of the GaN layer were examined. Also, PN junction light emitting diode (LED) was fabricated to investigate the effect of the SiN mask on its optical property. When inserting a SiN mask, (102) the full width at half maximum (FWHM) decreased from 480 to 409 arcsec and threading dislocation (TD) density decreased from 3.21 × 10⁹ to 9.7 × 10⁸ cm⁻². The photoluminescence (PL) peak intensity of the sample with a SiN mask increased two times than that of the sample without a SiN mask. The output power of the LED with a SiN mask increased from 198 to 392 mcd at 20 mA, too. We found that a SiN mask improved significantly the physical and optical properties of the GaN layer.