METHOD OF GROWING GALLIUM NITRIDE CRYSTAL AND METHOD OF MANUFACTURING GALLIUM NITRIDE CRYSTAL

In a method of growing GaN crystal in one aspect, the following steps are performed. An underlying substrate is prepared. Then, a mask layer having an opening portion and composed of SiO2 is formed on the underlying substrate. Then, GaN crystal is grown on the underlying substrate and the mask layer. The mask layer has surface roughness Rms not greater than 2 nm or a radius of curvature not smaller than 8 m. In a method of growing GaN crystal in one aspect, the following steps are performed. An underlying substrate is prepared. Then, using a resist, a mask layer having an opening portion is formed on the underlying substrate. Then, the underlying substrate and the mask layer are cleaned with an acid solution. Then, after of cleaning with an acid solution, the underlying substrate and the mask layer are cleaned with an organic solvent. Then, GaN crystal is grown on the underlying substrate and the mask layer.