This work demonstrated the monolithic 3D (M3D) integrated red micro-LED display on Si CMOS driver IC. We achieved a very high pixel density of 1600 PPI by epitaxial layer engineering and low-temperature process design for the micro- display application. M3D sequential integration on pre- fabricated Si CMOS driver IC allows lithographic alignment for the pixel definition, providing high-resolution and the largest emission area per pixel pitch. Furthermore, the low-temperature process provided the lowest standby power among ever reported micro-LED displays. We believe that this work would be one of the milestones for future ultra-high-resolution displays.