DE1052573B - Method for producing a semiconducting electrode system, in particular a transistor - Google Patents

Description

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GERMAN MRSf ^ PATENT OFFICE

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INTERNAT. KL. H 01 1

EXPLAINING EDITORIAL 1052 573

51

N 13359 VIII c / 21g

REGISTRATION DATE: FEBRUARY 26, 1957

NOTICE ΟΠΟ 1) 1 / ft C

deranmeldunW J U D 3 l / U d

AND ISSUE OF THE

EDITORIAL: MARCH 12, 1959

The invention relates to a method for producing a semiconducting electrode system, in particular a transistor in which a semiconducting body, e.g. B. of germanium or silicon with at least a rectifier electrode and an ohmic connection and the structure etched on it and is housed in an envelope which is closed vacuum-tight.

It can be seen that the method according to the invention brings about an increase in the current amplification factor a _c i in transistors, which is determined by the equation

«Ob =

oil,

is defined.

I _c and I _b designate the collector and base currents measured at constant collector voltage V _c.

It is already known that the current amplification factor of germanium and in particular of silicon transistors can be increased by adding an oxidizing layer to the semiconducting surface Materials, e.g. B. red lead, zinc chromate or strontium chromate is coated; it is on known that organic compounds can also be used for this purpose. Have attempts however, transistors produced in this way, especially at higher temperatures, are often not stable.

With the present method, a transistor or the like with a high current gain factor can be used and a very high stability. It also gives the advantage that in a simple manner very thin on the surface of the semiconducting body, which bring about these beneficial effects Layers - the thickness of which can even have molecular dimensions - can be attached.

According to the invention, after the etching process, the semiconducting body with rectifier electrode (s) and ohmic connection brought into an environment containing at least one of the halogens and / or contains at least one of its compounds with hydrogen, with the exception of elemental fluorine. That elemental fluorine is excluded as it is unusable due to its great aggressiveness. In the In practice it has been found that an increase in the current amplification factor occurs almost immediately, if the space in which the semiconducting body with rectifier electrode (s) and ohmic connection is introduced, only a very small amount of vapor λ on at least one of these elements or compounds contains. The effect is thus also achieved when the environment has a decomposing Süb process for the production

a semiconducting electrode system,

especially a transistor

Applicant:

NV Philips' Gloeilampenfabrieken,
Eindhoven (Netherlands)

Representative: Dr. rer. nat. P. Roßbach, patent attorney,
Hamburg 1, Mönckebergstr. 7th

Claimed priority:

Netherlands 29 February 1956

Louis Marius Nijland and Jan Adrianus Manintveld,

Eindhoven (Netherlands),
have been named as inventors

contains punch that develop a noticeable vapor tension of the halogens and / or the hydrogen halogens can.

Hydrogen chloride and hydrogen fluoride prove to be particularly suitable. The effect will still be increased if the environment also contains water vapor.

A particular embodiment of the method according to the invention consists in that the semiconducting body with rectifier electrode (s) and ohmic connection only reaches an environment in the vacuum-tight sealed envelope which contains at least one of the halogens and / or at least one of their compounds with hydrogen, with the exception of elemental fluorine. Water vapor can also be present in the envelope. According to a further expedient embodiment, an additional effect can be achieved in that the gas mixture contained therein is partially pumped out again before the final closure of the envelope, preferably up to a pressure of less than 10 ~ ² mm of mercury.

Although the present method does not apply to any particular semiconducting Limited substance, it is particularly suitable for alloy transistors, their semiconducting body consists of silicon, as the usual means, the values for germanium are already practically satisfactory

Claims (7)

Γ052 573 of the current amplification factor did not give satisfactory results with silicon. The method according to the invention is explained in more detail below with reference to a few exemplary embodiments. Example 1 An alloy transistor, the semiconducting body of which is made of p-type silicon, was placed in a glass envelope containing dry hydrogen chloride after the etching process. The current amplification factor acb, which was 4.5 after the etching process, increased almost immediately to 27 as a result of this treatment. During the pumping, acb increased further and reached a maximum value of 31.4 at a pressure of about 10-1 mm of mercury, whereupon the glass envelope was melted shut. The whole was then heated, with αφ increasing continuously and reaching a value of 37 at 180 ° C. While cooling to room temperature, the same route was run in reverse order. Example 2 After the etching process, an alloy transistor, the semiconducting body of which consists of p-type silicon, was moved into an environment which contained not only hydrogen fluoride but also water vapor. Before this treatment, the current amplification factor was ac & = 6; after the treatment it rose to 25. The transistor was then placed in a vacuum-tight sealed envelope and heated to 180 ° C., at which temperature acj, reached 35. After cooling to room temperature, acb was again 25. Example 3 After the etching process, the current amplification factor of an alloy transistor with a semiconducting body of p-type silicon was acb = 5. The transistor was then placed in an environment containing dry hydrogen chloride. After this treatment, acb had risen to 27. The addition of water vapor increased acb further to a value of 30. Example 4 An alloy transistor, the semiconducting body of which consists of germanium of the η type, had a current amplification factor ae $ = 30 after the etching process. It was then placed in a glass envelope melted down, which contained hydrogen chloride and water vapor. After this treatment, acb had increased to 90. During the subsequent heating, acb rose and at 70 ° C. the value 300 was reached. While cooling to room temperature, the same route was run in reverse order. Example 5 After the etching process, the current amplification factor of an alloy transistor whose semiconducting body consists of p-type silicon was atb = 2.7. He was then placed in a shell that contained not only bromine vapor but also water vapor ίο. As a result, acb rose to 18.5. During the subsequent heating, aeb increased further, and at 180 ° C a value of 24 was reached. After cooling to room temperature, acb had dropped to 17.5. Patents 1. A method for producing a semiconducting electrode system, in particular a transistor, in which a semiconducting body, e.g. B. of germanium or silicon, strand with at least one rectifier electrode and an ohmic connection and the structure is etched on it and housed in a shell which is sealed vacuum-tight, characterized in that the semiconducting body with rectifier electrode (s) and ohmic connection after The etching process is brought into an environment which contains at least one of the halogens and / or at least one of their compounds with water . mri exception of the elementary 2. The method according to claim 1, characterized in that the mentioned environment Chjox; contains hydrogen. 3TVerfahren according to claim 1, characterized in that said environment contains fluorine hydrogen. Method according to Claim 1, 2 or 3, characterized in that the aforementioned environment also contains water vapor . 5. The method according to any one of the preceding claims, characterized in that the semiconducting body with rectifier electrodes and Ohmic connection only enters an environment in the vacuum-tight sealed envelope, the at least one of the halogens and / or at least one of their compounds with hydrogen contains, with the exception of elemental fluorine, possibly in the presence of water vapor. 6. The method according to claim 5, characterized in that before the final closure Gas mixture of the envelope is partially pumped out. 7. The method according to claim 6, characterized in that the gas mixture is ^{pumped out of the envelope up to a pressure of less than 10 ~ 2} mm of mercury. © 80ί769> / 452 3.59