The growth of Internet traffic facilitates our daily life. From e-commerce, online game, to online video, our daily activities are full of interactions with Internet and an information based display (or a smart display) will be an important component in this scenario. In our lab, we focus our efforts on one of the important topics of this next generation displays: semiconductor based micro LEDs. Two important material systems are used for red, green, and blue color generations: Gallium nitride based (InGaN, AlGaN, GaN), and AlGaInP based materials (a finished device is shown in Fig. 1). The benefit to use semiconductor as the main host of technology is its mature fabrication and highly efficient light-emitting capability. In our lab, we demonstrated devices as small as 2 micrometers in size and emission wavelengths from ultra-violet to red can be realized[1-3]. However, to achieve high resolution in a display, we need to reduce the size of each pixel, whose sizes are determined by each LED of different colors. Another important issue that needs to be addressed is that the reduction of light emitting efficiency (or called external quantum efficiency, EQE) is inevitable when we reduce the size of the devices. This is because of the increase of the sidewall leakage and non-radiative recombination inside the devices[1-4]. To alleviate this problem, an atomic layer deposition system was used to passivation the sidewalls of the devices, as shown in Fig. 2. This passivation can effectively reduce the leakage current and boost up the illumination efficiency of the devices. The light field angular intensity is also an interesting topic for these devices[5]. Because each color has its own far field pattern, as shown in Fig. 3, the overall result needs to be investigated and modified to improve the angular uniformity of the colors in a micro-LED based display such that you will not see angle-dependent color variation. We can use chip design to compensate this variation and to achieve better uniformity.