A-plane GaN was grown on r -plane sapphire using a two-step growth method by hydride vapor phase epitaxy (HVPE). In the first step, a-plane GaN formed triangular stripes along the m-direction ([ 1100] direction) at a low growth temperature. Then, increasing the growth temperature enhanced the lateral growth mode to coalesce a-plane GaN in the second step. There were triangular voids formed after growth. In this work, a new method was developed to produce the voids in the a-plane GaN film using the two-step growth method without optical lithography.