DE1158181B - Diffusion process for doping a semiconductor body for semiconductor components - Google Patents

Description

GERMAN

PATENT OFFICE

S 71055 Vmc / 21g

REGISTRATION DATE: OCTOBER 28, 1960

NOTICE THE REGISTRATION AND ISSUE OF THE

EDITORIAL: NOVEMBER 28, 1963

The invention relates to a diffusion method for doping a semiconductor body for semiconductor components, especially for a silicon transistor.

Conventionally, diffusion type semiconductor devices have been manufactured by a method at which an oxide film on the surface of z. B. n-silicon was formed, whereupon an impurity, which represented an acceptor, let diffuse into the silicon, which penetrated into the oxide film, to form a diffused P-type impurity layer. Then you removed one Part of this oxide film and allowed a donor impurity to diffuse into that part of the silicon from which the oxide film was removed to leave a diffusion layer with an N-type impurity form. This created an npn transistor.

In such a conventional method, a treatment time of 1 or 2 hours is required for the formation of the oxide film to oxidize the surface of the semiconductor, and a treatment time of 1 or 2 hours for the diffusion process for the diffusion of an impurity penetrating into the oxide film .

So five such process are these two process steps required, so that it is of little use especially in mass production.

According to the invention, the doping of a semiconductor body can now be carried out in a single method step be carried out so that on the surface of a semiconductor body of the one, first conductivity type a doping impurity of the opposite, second conductivity type is applied and then the semiconductor body is heated in a heated oxidizing atmosphere, so that the contamination diffuses into the semiconductor material to form a pn junction and at the same time Oxide film is formed that the oxide film is removed from a part of the redoped semiconductor surface and that a second impurity of the first conductivity type is diffused into this part.

It is particularly expedient to deposit the first doping impurity on the semiconductor body.

An example embodiment of the method according to the invention is shown below Hand of the drawing explained, in the single figure, the implementation of the method according to the invention is indicated schematically.

This exemplary embodiment of the invention is explained below. _______

It becomes a semiconductor body 1, ζ. B. a silicon wafer, prepared on one or both surfaces Diffusion process

for doping a semiconductor body

for semiconductor components

Applicant:
Sony Corporation, Tokyo

Representative: Dr. F. Zumstein,

Dipl.-Chem. Dr. rer. nat. E. Assmann

and Dipl.-Chem. Dr. R. Koenigsberger,

Patent Attorneys, Munich 2, Bräuhausstr. 4th

Claimed priority:
Japan October 29, 1959 (No. 34155)

Yoshiyuki Kawana and Toshio Misawa, Tokyo,
have been named as inventors

the platelet, an impurity is deposited or applied beforehand, which is opposite to the Semiconductor acts as an acceptor or donor, so that an impurity layer 2 is formed on this semiconductor body. When the semiconductor body consists of n-silicon, then boron, gallium or the like, which can act as an acceptor, can be an impurity to get voted. In the case of p-silicon, in contrast, phosphorus, arsenic, antimony or the like is used. selected to act as a donor. The fact that an impurity is pre-deposited on the surface means that an n-type silicon wafer z. B. in a vapor atmosphere of boron oxide in a temperature range from 700 to 1100 ° C, preferably at 900 ° C, heated to the boron easily diffuse into or adhere to the silicon wafer or its surface. In this method, the contamination cannot be removed even if the semiconductor body is with it Hydrofluoric acid is treated.

No matter what impurity is pre-deposited or applied, the amount or the thickness the layer 2 is diffused according to the thickness or surface concentration of the following contaminant plant certainly. Then the semiconductor body, which carries the contamination layer 2, in a

309 750/299

heated hot oxidizing atmosphere, the temperature of which is in the range of 1000 to 1300 ° C, preferably at 1200 ° C. Moist oxygen, moist hydrogen and moist nitrogen, drier Oxygen can be used to build up the oxidizing atmosphere.

It takes about 1 to 2 hours to warm up.

Thus, the impurity on the surface of the semiconductor diffuses into the surface or into one limited inner part in the vicinity of the surface and forms an impurity diffusion layer 3. At the same time, the surface of the semiconductor body is oxidized to form an oxide film.

If n-silicon is used and boron is the impurity then becomes a P-type impurity diffusion layer on the n-type silicon layer and another oxide film layer is formed thereon.

After manufacturing such a semiconductor body with the diffusion impurity layer S and of the oxide film layer 4, a part of the oxide film is removed and an impurity that is an acceptor or donor according to the diffused impurity of the layer 3 is formed a second impurity layer 5 diffuses.

Such a diffusion treatment can be carried out as usual after the oxide film 4 after has been removed by a method known per se, e.g. B. according to the so-called photoresistive method.

According to the method described here, a diffusion-type silicon transistor of the npn or vom pnp type.

According to the method according to the invention find a reaction in which an impurity in a Semiconductor body diffuses, and another reaction in which an oxide film forms on the surface of the Forms semiconductor body, held at the same time in a single process stage.

The method according to the invention for producing such a semiconductor component of the diffusion type is therefore, compared with the known methods, very simple, so that such methods are significantly improved by the invention.

Although the invention is mainly explained using the specific example of a silicon semiconductor was, so can other semiconductors such. B. germanium, can be used, and the impurity is selected depending on the semiconductor material, so that the inventive method can be performed as explained above.

Claims (4)

PATENT CLAIMS: 1. Diffusion method for doping a semiconductor body for semiconductor components, characterized in that a doping impurity of the opposite, second conductivity type is applied to the surface of a semiconductor body of the one, first conductivity type and then the semiconductor body is heated in a heated oxidizing atmosphere, so that the impurity in the semiconductor material diffuses to form a pn junction and, at the same time, an oxide film is formed, that the oxide film is removed from a part of the redoped semiconductor surface and that a second impurity of the first conductivity type is diffused into this part. 2. Diffusion method according to claim 1, characterized in that the first doping Impurity is deposited on the semiconductor body. 3. Diffusion method according to claim 1, characterized in that the first doping Impurity is applied or painted on the semiconductor body. 4. Diffusion method according to one of claims 1 to 3, characterized in that the Platelet-shaped semiconductor body is made of silicon and in the oxidizing atmosphere 1 to 2 hours at a temperature of about 1200 ° C is heated. Considered publications:
German Auslegeschrift No. 1 080 697;
French Patent No. 1,211,756;
U.S. Patent No. 2,802,760. 1 sheet of drawings © 309 750/299 11.63