method for the continuous change of the electrical properties of at least a part of a halfgeleiderlichaam of germanium or silicon by a ionenbombardement and halfgeleiderlichaam vervaardigd by application of the method.

摘要

1,035,151. Semi-conductor devices. NORTH AMERICAN AVIATION Inc. Jan. 20, 1964 [Jan. 18, 1963; Sept. 9, 1963], No. 2467/64. Heading H1K. A semi-conductor 32 is heated whilst being bombarded with ions 37 of atoms required to be introduced into the semi-conductor as interstitial impurities. The ions are of sodium, potassium, rubidium or caesium and the temperature to which the body is heated is a temperature in the range 300‹ to 700‹ C. such that the damage to the semiconductor crystal lattice, which could otherwise be occasioned by the ionic bombardment, is avoided. Semi-conductors produced, or having their conductivity modified, in this way are stated to absorb the alkali metals as interstitial impurities and to be produceable-depending on the energy and duration of the bombardment, the temperature, the orientation of the semi-conductor crystal &c. -with a variety of characteristics suitable for application to field effect transistors, nuclear particle detectors, non-linear capacitors, and PN junction photo-cells. The detailed description is particularly concerned with the introduction of caesium and sodium into borondoped silicon. The host material may, however, be germanium or an alloy thereof with silicon, and it may be intrinsic or pre-doped with aluminium, gallium, indium, phosphorus, arsenic or antimony. The treatment chamber of Fig. 1 comprises a support 31 for the semi-conductor crystal, a heater 30, a source 22 of the ions and a source 41 of either heated caesium or an inert gas. Before treatment, the chamber is gettered with caesium and/or flushed with the inert gas. During treatment the valve 42 is closed and a vacuum pump connected to outlet 26.