| 摘要 |
<p>940,787. Semi-conductor devices. SIEMENS & HALSKE A.G. May 3, 1961 [May 5, 1960], No. 16018/61. Heading H1K. In a device comprising a PN tunnel junction in a semi-conductor material having a forbidden band energy gap less than that of germanium, the sum of the energy gap # n between the Fermi level and the lower limit of the conduction band of the N zone and # p between the Fermi level and the upper limit of the valence band of the P zone is less than the sum of the forbidden band energy gap and either # n or # p . The valley current of the junction is reduced by this means and by operating at a low temperature. The voltage range over which the negative resistance region extends may be increased by making # n and # p equal and their sum as large as possible, and the maximum tunnel current increased by a reduction of the forbidden band gap. If the effective masses of holes and electrons differ in the semi-conductor material the device should be designed so that at the minimum current the hole and electron currents are balanced. This is done by making # n greater than # p , when m n is less than mp, and approximately equal to kT log. m p /m n . In an example, Fig. 3, in which large and small area degenerate N zones 4, 2 are formed by alloying to a P-type body 1, the large area is soldered to a liquid cooled plate 6. The device is used with the smaller PN junction forward biased.</p> |
