Contents I. Introduction
The demand for higher resolution and more realistic image quality drive display screen towards a trend of sub-micron and nano-scale miniaturization promotion [1], [2], [3]. High density GaN-based light-emitting diodes (LEDs), as promising devices of micro-display technology, are emerging as candidates for high-resolution display applications, such as augmented reality, virtual reality and smartphones [4], [5], [6], [7]. Conventional high-density LEDs are typically fabricated using techniques such as etching [8], [9], [10], epitaxial growth [11], [12], [13], and ion implantation [7], [14], [15], [16]. However, these methods are accompanied by certain disadvantages or limitations. The etching process would introduce surface/structural damages, and the fabrication process is complex and time-consuming. Moreover, the utilization of selective epitaxial growth technology has technical challenges such as lattice mismatch and defect accumulation, which would degrade device quality and performance. In addition, ion implantation requires precise parameter control and would also result in lattice damage, distortion, and impurity introduction. All of which negatively impact the optoelectronic properties of LEDs. Therefore, developing epitaxial slice damage-free process to fabricate high-density LED array has a significant meaning to micro-display technologies.
