Samsung Electronics Co., Ltd. (KR) divulges nanofabrication process for silicon nano wires made by accurately controlling the size and distribution of nucleation regions in U.S. Patent 7,649,192. The nano wires have a PN junction structure
The method, invented by Byoung-lyong Choi and , includes forming microgrooves with a plurality of microcavities. The microgrooves form a regular pattern on a surface of a silicon substrate. A metal layer is formed on the silicon substrate by depositing a material which acts as a catalyst and forms nano wires on the silicon substrate. This is followed by agglomerating the metal layer within the microgrooves on the surface of the silicon substrate by heating the metal layer to form catalysts; and growing the nano wires between the catalysts and the silicon substrate using a thermal process.
Nano wires are currently being widely researched, and are a next-generation technology used in various devices such as optical devices, transistors, and memory devices. Materials used in nano wires include silicon, zinc oxide, and gallium nitride, which is a light emitting semiconductor. The nano wire manufacturing technique is sufficiently developed to be used for altering of the length and width of nano wires.
Quantum dots or nano light emitting devices using quantum dots are used in conventional nano light emitting (EL) devices. Organic EL devices using quantum dots have high radiative recombination efficiency but low carrier injection efficiency. GaN LEDs, which use quantum wells, have relatively high radiative recombination efficiency and carrier injection efficiency.
However, it is very difficult to produce GaN LED on a large area due to a defect caused by the difference in the crystallization structures of the GaN LED and a commonly used sapphire substrate, and thus the manufacturing costs of GaN LEDs are relatively high. A nano light emitting device using nano wires has very high radiative recombination efficiency and relatively high carrier injection efficiency.
Quantum dots or nano light emitting devices using quantum dots are used in conventional nano light emitting (EL) devices. Organic EL devices using quantum dots have high radiative recombination efficiency but low carrier injection efficiency. GaN LEDs, which use quantum wells, have relatively high radiative recombination efficiency and carrier injection efficiency.
However, it is very difficult to produce GaN LED on a large area due to a defect caused by the difference in the crystallization structures of the GaN LED and a commonly used sapphire substrate, and thus the manufacturing costs of GaN LEDs are relatively high. A nano light emitting device using nano wires has very high radiative recombination efficiency and relatively high carrier injection efficiency.
Samsung's new manufacturing process for a nano light emitting device is simple and a nano light emitting device can be formed to have a crystallization structure that is practically similar to that of a substrate, and thus it is easy to form the nano light emitting device in a large area.
