Semiconductor circuit elements

摘要

989,118. Semi-conductor devices. INTERNATIONAL BUSINESS MACHINES CORPORATION. April 18, 1962 [April 20, 1961], No. 15036/62. Heading H1K. [Also in Division H3] A circuit element has a body with two or more adjoining semi-conductive portions, the two adjoining portions, or an adjoining two of the portions, being of different basic semiconductor material; the body also has a region of semi-conductive material which adjoins each of the portions of the body and forms a rectifying junction with at least one of them. The embodiment shown in Fig. 2 has an intrinsic portion 3 of GaAs (pn 5 x 106 ohm.cms.) on which an N+ Ge portion 2 is epitaxially deposited. A large area ohmic contact 5 is provided on the lower face of the composite body. To the upper surface of the body is alloyed a pellet 4 of a Ga/Sn alloy. The Ga converts the recrystallized Ge region 6 to P+ conductivity, thus producing a Ge tunnel diode supported by intrinsic GaAs (except for a small region 7 converted to N+ conductivity by Sn from the alloy). A portion 8 of the N+ Ge portion may be etched away, as shown, to reduce the junction area of the diode and obtain a correspondingly low capacitance. In the embodiment of Fig. 3 a composite body having successive portions 2, 4, 3 of P+ GaAs, intrinsic GaAs, and N + Ge has a broad area ohmic contact 8 provided on one face and on its opposite face has an epitaxially deposited layer 5 of N+ Ge to which an ohmic contact 9 is attached. The junction between portion 2 and layer 5 may be reduced by etching if desired. This construction provides an oscillator in which the equivalent circuit contains a capacitance and shunt negative resistance associated with the heterojunction tunnel diode formed by portion 2 and layer 5, positive resistance associated with portion 3, and inductance, which is mainly associated with layer 5. The embodiment of Fig. 4 (not shown) is similar to that of Fig. 3, but instead N+ Ge portion 3 it has a portion of P+ Ge. This produces a hetero-junction tunnel diode in parallel with a homo-junction tunnel diode, thus providing a device in which one diode is designed to act as a load on the other which operates as a class C oscillator at low power levels. Specification 886,393 is referred to.