DE1130079B - Semiconductor component for switching with a semiconductor body made up of three zones of alternating conductivity type - Google Patents

Description

GERMAN

PATENT OFFICE

T17373 Vmc / 21g

REGISTRATION DATE: OCTOBER 21, 1959

NOTICE
DEH REGISTRATION
AND ISSUE OF
EDITORIAL: MAY 24, 1962

The invention relates to a semiconductor component for switching off with a semiconductor body three consecutive zones of alternating conductivity type, a first and a second low-resistance non-rectifying electrode on the two outer zones and a third, rectifying one Electrode on the outer zone connected to the second electrode, close to the middle one Zone.

There are known junction transistors of this type, in which to achieve special properties, for example a negative resistance or to superimpose signals, additional rectifying Electrodes are attached to one or both of the outer zones.

In a known semiconductor component of the type specified at the outset, the third electrode is a gold wire spaced 0.05 to 0.127 mm from the central zone on one outer zone is alloyed. This creates a hook transistor whose current gain is greater than 1 is. If a suitable feedback is used, a flip-flop circuit can then be formed that automatically holds itself in one or the other of two stable states in which it is brought about by a briefly applied pulse.

In contrast, the aim of the invention is a semiconductor component that has the properties of a thyratron and is therefore particularly suitable for switching.

According to the invention, this is achieved in the case of a semiconductor component of the type specified at the outset achieves that the shortest occurring distance between the pn junction at the third, rectifying Electrode and the adjacent pn junction of the middle zone approximately equal to a diffusion length for the minority carriers in the outer zone connected to the third electrode, and that for Achieving a thyratron-like behavior for igniting a voltage pulse between the first and third electrode is applied and to erase the voltage between the first electrode and the second electrode is interrupted.

If in the semiconductor component according to the invention a sufficiently large pulse between the First and the third electrode is applied, a current flow is created, which is essentially through the external circuit is determined and cannot be influenced by the voltage at the second electrode is. This process can therefore be compared to the ignition of a thyratron. The ignition point can

Semiconductor component for switching

with a semiconductor body made up of three zones

alternating conductivity type

Applicant:

Texas Instruments Incorporated,
Dallas, Tex. (V. St. A.)

Representative: Dipl.-Ing. E. Prince

and Dr. rer. nat. G. Hauser, patent attorneys,

Munich-Pasing, Bodenseestr. 3 a

Claimed priority:
V. St. v. America October 24, 1958 (No. 769 473)

Chester Cameron Allen, Grapevine, Tex.,

Tillery Townsend, Carrolton, Tex.,

and William Nunley, Richardson, Tex. (V. St. A.),

have been named as inventors

shifted by the voltage on the second electrode.
By briefly removing the voltage supplied to the first electrode, the component is returned to the idle state. This corresponds to the deletion of a thyratron. The semiconductor component can also be erased by applying a very large pulse to the second electrode.

The semiconductor component according to the invention thus enables considerable currents to be switched with which, for example, relays can be operated directly. For such switches there is technology a great need.

The drawing shows an embodiment of a semiconductor component according to the invention.

The semiconductor component shown in the drawing consists of a body 10 made of semiconductor material, for example silicon or germanium, in

5 "shape of a rod made from a grown single crystal was obtained. Suitable methods for producing grown single crystals are general

209 601/354

known. The body 10 has two outer zones 11 and 12 of conductivity type n, which act as a collector or serve as a base, as well as a relatively narrow middle zone 13 of conductivity type p, which lies between zones 11 and 12. When the semiconductor crystal grows, the pn junctions become 14 and 14 'formed by any convenient method such as double doping, rate growth or diffusion growth. To form the zone 13, indium is preferably used as the acceptor material. As a result of his low Diffusion coefficient, the use of indium ensures a sharp pn junction 14. A first metal electrode 15 is in low-resistance, non-rectifying contact with the collector zone

11 of type n, and a similar second electrode 16 is in low-resistance, non-rectifying contact with the base zone 12 of type n. A third Electrode 17, which represents the emitter electrode, is in rectifying contact with the base zone

12 at a critical distance from the adjacent pn junction 14 '.

The emitter electrode 17 is preferably an aluminum wire, the end 19 of which to form a rectifying transition 20 is fused to the base zone 12 that the distance 18 between the pn junction of this electrode and the adjacent pn junction 14 'of a diffusion length of the load carrier delivered to the aluminum, d. H. Holes, corresponds. In the case of aluminum, this is the case Distance 18 from a diffusion length between 0.005 and 0.008 mm. The aluminum wire could also be in wrapped around the perimeter of zone 12 at the critical distance of 0.005 to 0.008 mm from transition 14 ' be, but the formation of the contact by melting the end of the wire is preferred.

Other suitable emitter electrodes 17 can be made by using a gold-gallium wire or of an indium spot can be obtained. In any case, it is essential that the emitter electrode 17 in one rectifying contact with the base zone 12 is, which extends so that the emitter zone of the type ρ of the pn junction 14 'is at a distance which is equal to a diffusion length of their charge carriers, ie is the minority carrier in base zone 12.

If a constant base voltage is applied, the component is turned off by a negative one Signal pulse of predetermined voltage fed between the emitter and the collector is turned on or ignited, and it stays on until the base zone is much larger Voltage is applied or until the collector voltage is completely removed.

It is not absolutely necessary that a grown junction transistor is used, because it can also from other semiconductor components known in the art pnpn arrangements with three Electrodes are formed. These include arrangements in which three layers are formed by solid diffusion be formed in a doped wafer of semiconductor material. In another useful arrangement two zones are formed by solid diffusion and a further zone by alloying.

Claims (8)

PATENT CLAIMS: 1. Semiconductor component for switching with a semiconductor body consisting of three consecutive zones of alternating conductivity type, a first and a second low-resistance non-rectifying electrode on the two outer zones and a third, rectifying electrode on the outer zone connected to the second electrode close to the middle zone, thereby characterized in that the shortest occurring distance (18) between the pn junction (20) on the third electrode (17) and the adjacent pn junction (14 ') of the central zone (13) is approximately equal to a diffusion length for the minority carriers in the is connected to the third electrode (17) outer zone (12), and that to achieve a thyratron-like behavior for ignition, a voltage pulse is applied between the first electrode (15) and the third electrode (17) and the voltage between the first to extinguish Electrode (15) and the second electrode (16) is interrupted. 2. Semiconductor component according to claim 1, characterized in that with the first Electrode (15) connected outer zone (11) as a collector zone and with the second electrode (16) connected outer zone (12) serve as the base zone. 3. Semiconductor component according to claim 2, characterized in that the third electrode (17) serves as an emitter electrode. 4. Semiconductor component according to one of claims 1 to 3, characterized in that the third electrode (17) is an aluminum wire attached to the surface of the second electrode (16) connected outer zone (12) is alloyed at a point that is about 0.005 to about 0.008 mm from the central zone (13). 5. Semiconductor component according to one of the preceding claims, characterized in that that the two outer zones (11, 12) have the conductivity type η. 6. Semiconductor component according to claim ^, characterized in that to achieve sharp pn transitions between the zones the middle zone (13) with an acceptor material is doped, which has a small diffusion coefficient Has. 7. Semiconductor component according to claim 6, characterized in that the middle zone (13) is doped with indium. 8. Semiconductor component according to one of the preceding claims, characterized in that that the semiconductor body is a grown germanium crystal. Considered publications:
German Patent Nos. 949 512, 956 434;
German Auslegeschriften No. 1060498, W11064 VHIa / 21a ² (published on August 23, 1956);
Belgian Patent No. 540 342;
U.S. Patent Nos. 2709787, 2,852,677. 1 sheet of drawings © 209 601/354 5.62