Crystal Structure and Surface Morphology of GaN Thin Films Grown on Different Patterned AlN Substrate Surfaces

Gallium nitride (GaN) is frequently used as the primary material for manufacturing high-brightness light-emitting diodes (LEDs). Recently, atomic layer deposition has become increasingly prevalent across microelectronics, optoelectronics, and nanotechnology as a method for thin-film growth. Gaining insights into the process of thin-film growth can significantly enhance the device performance. Herein, molecular dynamics was used to simulate GaN thin film growth on substrates with different patterned surfaces. Results showed that GaN thin films grown on cone- and dome-patterned substrate surfaces have smoother surfaces than those grown on a flat substrate. Moreover, the GaN thin films grown on flat surfaces exhibited an optimal crystalline quality compared to those grown on patterned substrate surfaces. However, the GaN thin films grown on flat surfaces showed strain levels higher than those grown on patterned substrate surfaces, potentially affecting the performance of the optoelectronic devices. This study reveals the impact of different patterned substrate surfaces on GaN thin films and provides guidance on the design of substrate patterns for different GaN thin film application scenarios.