| 摘要 |
PURPOSE:To inject carriers effectively by crossing quantum well planes consisting of specific semiconductors in a latticed manner and forming quantum barrier regions composed of semiconductors having potential energy higher than the semiconductors around the quantum well planes. CONSTITUTION:A plurality of quantum well planes 11 composed of a semiconductor, thickness of which extends over approximately the de Broglie wavelength (several dozen nm) of electrons, are shaped, these quantum well planes 11 are crossed in a latticed manner, and quantum barrier regions 12 made up of a semiconductor having potential energy higher than the semiconductor constituting the quantum well planes 11 are formed around the quantum well planes 11. Consequently, carriers injected into the quantum well planes 11 quickly spread over the whole superlattice through the intersections of the quantum well planes 11. As a result, carrier density in the quantum well planes 11 is kept approximately constant regardless of positions. Accordingly, the semiconductor superlattice is used as an active layer in a semiconductor layer, thus reducing oscillation threshold currents. |
