| 摘要 |
1,144,147. Transistors. SIEMENS A.G. 2 May, 1966 [3 May, 1965], No. 19161/66. Heading H1K. In a semi-conductor device such as metal base transistor, with a metal layer between two semiconductor layers, reflection at the "collector" junction is minimized by employing a semiconductor where the wave number k at the conduction band minima is other than zero (e.g. germanium or silicon) and the average wave number vector in the semi-conductor at the end of the conduction band is made substantially equal to the average wave number vector in the metal. The metal layer is a transition metal, semi-metal (e.g. antimony or bismuth) or an alloy with its composition selected to provide the correct k-number. Orientation of the semi-conductor is utilized since this affects the k-number. Fig. 2 shows a metal base transistor with N-type emitter and collector regions 5 and 7 and intermediate metallic layer 6. The emitter and collector regions are orientated in the same direction. The metal has a high k-value compared with the material of the emitter to give a high "refracting index" in the metal relative to the semi-conductor to produce tightly bunched electron beams. At least the emitter zone should be monocrystalline. |
