Document Type and Number:
Japanese Patent JPS4914106
Kind Code:
B1
Abstract:
1289701 Semi-conductor devices MITSUBISHI DENKI KK 28 Nov 1969 [28 Nov 1968] 58226/69 Heading H1K A semi-conductor device comprising a wafer of a semi-conductor material such as Ge, Si, GaP or Ga 1-x Al x As(x#0À5) having in its conductive band two valleys of different energy, is operated in such a way that the electron and hole concentrations in the active region of the device are approximately equal, producing a negative resistance characteristic when a sufficiently large electric field is applied. The essential energy band condition is that the wave vector of the valence band maximum shall be equal to that of the higher energy valley in the conduction band. The electron/hole equality occurs in intrinsic material, and it may be produced in non-intrinsic material by suitable heating or irradiation with light. In each of these eases it is merely necessary to provide a uniform wafer of the material having two ohmic electrodes. Fig. 4 illustrates an alternative method of producing approximate carrier-equality by the provision of an N + type Sb, P or As doped region 24 in one of two P+ + type (#1018 atoms/ cm.3 ) end regions 22 in a P type (#1015 atoms/ cm.3 ) B or In doped Ge wafer 20. A suitable potential applied between Al electrodes 28, 30 causes electrons to be injected into the main P type wafer 20, thereby producing near equality of electrons and holes, resulting in a negative resistance characteristic between electrodes 26 and 28. The conductivity types may be reversed. The device may oscillate analogously to a Gunn effect device.
Application Number:
JP8717768A
Publication Date:
April 05, 1974
Filing Date:
November 28, 1968
Export Citation:
International Classes:
H01L45/00; H01L29/88; H01L47/00; H01L47/02; H02G3/32; H03B9/12