Novel Scalable Transfer Approach for Discrete III-Nitride Devices Using Wafer-Scale Patterned h-BN/Sapphire Substrate for Pick-and-Place Applications

The mechanical release of III-nitride devices using h-BN is a promising approach for heterogeneous integration. Upscaling this technology for industrial level requires solutions that allow a simple pick-and-place technique of selected devices for integration while preserving device performance. An advance that satisfies both of these requirements is demonstrated in this work. It is based on a lateral control of the h-BN quality, using patterned sapphire with a SiO2 mask, to achieve localized van der Waals epitaxy of high-quality GaN based device structures. After process fabrication, the devices can be individually picked and placed on a foreign substrate without the need for a dicing step. In addition, this approach could reduce delamination of h-BN on large diameter substrates because each h-BN region is smaller, with independent device structures. Discrete InGaN LEDs on h-BN are grown and fabricated on 2 in. patterned sapphire using a SiO2 mask. A set of devices are selectively released and transferred to flexible aluminum tape. The transferred LEDs exhibit blue light emission around 435 nm. The approach presented here is scalable on any wafer size, can be applied to other types of nitride-based devices, and can be compatible with commercial pick-and-place handlers for mass production.