In recent years, with increasing the demands for next-generation visual systems such as ultra-high-resolution augmented/virtual reality (AR/VR) and hologram display, inorganic light emitting diodes (LEDs) have been intensively developed as a self-emitting light source in these applications to utilize their high quantum efficiency and robust durability. In past decades, huge efforts and developments on inorganic LEDs have led the expansion of solid-state lighting systems and outdoor digital signage. However, the development of conventional LED fabrication process has stopped dimension scaling at around a few hundred micrometers targeting mainly lighting applications using phosphor-coated blue LEDs. Differently with lighting applications, present, and future display needs high-resolution full-color LEDs for red (R), green (G), blue (B) on the same backplane to represent bright and broad color combinations. Therefore, miniaturized and low-power consuming micro-LEDs (μ-LEDs) will be a crucial technology for future high-resolution displays, which require above 2000 PPI. We are exploring the new technology to achieve extremely high ppi (>5000 ppi) display using wafer bonding and sequential device fabrication process.