| 摘要 |
PURPOSE:To maintain high-speed properties by forming a collector-side potential- barrier layer composed of a substance, potential-energy difference thereof between a lower lever and an upper lever is larger than (AlGa)As. CONSTITUTION:A collector-side potential-barrier layer 34 is formed by InP, and a base layer 35 is constituted by InGaAs in order to lattice-match with the layer 34. Since potential-energy difference between valleys consisting of InP such as potential-energy difference between a GAMMA valley and an L valley normally takes 0.54[eV] and is far higher than that in (AlGa)As, possibility of which hot-electrons passing through the base layer 35 are subject to an inter- valley scattering in a collector-side potential-barrier layer 36 and are transitted to the L valley from the GAMMA valley is eliminated completely, thus making transit time shorter than a high-speed semiconductor device. Accordingly, a HET having high speed properties can be acquired. |
