Study on nitride semiconductor microstructure growth for uniform quantum dot array and full color light emitting devices

Abstract

After III-nitride semiconductor materials are used by the blue light-emitting diode, these semiconductors are used for many different types of parts. These III-nitride semiconductors have physically and chemically stable properties, can tunable wavelengths from ultraviolet to near-infrared, and are possible for electrical operation. For mass production of these III-nitride semiconductors, optical lithography is necessary to make micro-sized structures. By using optical lithography, a mask opening can be created, and by using this mask structure, the 3D structure can be grown. Metalorganic chemical vapor deposition is used to grow 3D structures and with a self-limited growth mechanism and site-controlled growth mechanism, we can control the site and size of the pyramid apex. However, by using a self-limited growth mechanism, uniformity and 6-fold symmetry of 3D structure can be degraded. Lateral overgrowth which degrades the symmetry of the pyramid apex should be reduced by controlling the growth mechanism, especially for carrier gas during growth. Also, by site-controlled growth mechanisms with different sizes and spacing, it is possible to grow different 3D structures with different heights and spacing. In this situation, due to different surface migration lengths of In and Ga adatom, In the composition of the InGaN layer can be modified. Therefore, red, green, and blue which are the three primary colors of light can simultaneously emit at the same sample and finally make while light emitting sample. From this result, it is possible to make quantum structures with a quantum well that emit red, green, and blue in different positions.