JPS6267826A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enable the surface of semiconductor to be cleaned up with excellent reproducibility by a method wherein gas plasma of hydrogen compound of V group element contained in the semiconductor is brought into contact with the surface to be cleaned. CONSTITUTION:Within an electron-cyclotron plasma producer, a divergence magnetic field is generated to carry plasma to a surface cleaning chamber 4 with extremely low accelerating energy (around -15eV) colliding with the surface of a semiconductor 5 inserted into the chamber 4 at moderately low speed so that a surface denatured layer may be removed efficiently by the actions compounded of the high etching and reducing capacities of hydrogen ion and hydrogen radical and the moderate physical shock. Simultaneously ion radicals of arsenic and phosphorus are compounded of oxygen, hydrogen and water to produce an arsenide and a phosphide. Finally the arsenide and the phosphide are coevaporated to be discharged out of the surface cleaning chamber 4 not sticking on the surface of semiconductor with surface denatured layer removed. Through these procedures, the surface of semiconductor can be cleaned up with excellent reproducibility.

Description

[Detailed Description of the Invention] [Summary] Gallium arsenide, gallium aluminum arsenide, indinium phosphorus, indinium arsenide, indium gallium arsenide phosphorus antimony, etc., which contain aluminum, gallium or indinium, and arsenic or phosphorous as components. - This is an improvement in the process of cleaning the surface of a V group compound semiconductor.

Cleans the surface of ■-V group compound semiconductors containing aluminum, gallium, or indinium and arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphorous, indinium arsenide, indinium gallium arsenide phosphorus antimony, etc. This is a surface cleaning method in which the surface of these m-■ group compound semiconductors is brought into contact with a gaseous plasma of a hydrogen compound of a group V element (arsenic or phosphorus) contained in these group ■-v semiconductors. , which is characterized by excellent reproducibility.

[Industrial application field]

The present invention relates to a method for manufacturing a semiconductor device. In particular, ■-V containing aluminum, gallium or indinium and arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphorous, indinium arsenide, indinium gallium arsenide phosphorus antimony, etc.
This invention relates to improvements in manufacturing methods for group compound semiconductors. More specifically, the present invention relates to an improvement that improves the reproducibility of the surface purification method for compound semiconductors.

[Conventional technology]

M-V group compound semiconductors containing aluminum, gallium, or indinium and arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphide, indinium arsenide, and indinium gallium arsenide phosphide antimony, should not be left in the atmosphere. When this happens, a surface metamorphic layer is easily formed. That is, it is easily oxidized to form a natural oxidation layer, and is also contaminated with moisture and organic matter. Since the property of forming this surface alteration layer cannot be controlled, a surface cleaning step is essential in the manufacturing method of semiconductor devices.

Gallium arsenide, gallium aluminum arsenide, indinium phosphorus, indinium arsenide, indinium gallium arsenide phosphide antimony, etc.

Conventionally, a method using hydrogen plasma is known as a method for cleaning the surface of an m-v group compound semiconductor containing aluminum, gallium, or indium and arsenic or phosphorus as components. This method applies hydrogen to ■-V group compound semiconductors containing aluminum, gallium, or indium, and arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphorous, indinium arsenide, indinium gallium arsenide phosphorus antimony, etc. This method brings plasma into contact, and utilizes the excellent sputter etching properties unique to hydrogen atoms and the strong reducing properties unique to hydrogen atoms and hydrogen radicals, allowing surface modification of the semiconductor surface without causing significant damage to the semiconductor surface. It has the feature of being able to effectively remove layers.

[Problem that the invention seeks to solve]

m-V containing aluminum, gallium or indinium and arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphorous, indinium arsenide, indinium gallium arsenide phosphorus antimony, etc., produced using C1 hydrogen plasma. Surface cleaning methods for group compound semiconductors have the disadvantage that reproducibility is not necessarily good. This drawback can be confirmed by measuring the reproducibility of characteristics such as pinch-off voltage of transistors and barrier diodes manufactured by forming a semiconductor layer or a metal layer on a semiconductor layer using this cleaning method. sell. Taking the height of a Schottky barrier as an example, its average value is 780 mV.
In the case of , the standard deviation is 3 (about 1 mV).
Take the N value as an example.

It is about 1.1+0.2. In either case, this variation exceeds a practically acceptable limit.

The purpose of the present invention is to eliminate this drawback, and the present invention aims to solve this problem by combining aluminum, gallium, or indinium with arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphorous, indinium arsenide, indinium gallium arsenide phosphorus antimony, etc. m−v
An object of the present invention is to provide an improvement that improves the reproducibility of a surface cleaning method for group compound semiconductors.

[Means for solving problems]

The means taken by the present invention to achieve the above object are based on the combination of aluminum, gallium or indinium, and arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphorous, indinium arsenide, indinium gallium arsenide phosphorus antimony, etc. The ingredients are ■
- On the surface of the V group compound semiconductor, a hydrogen compound (AsH2 or P
H3) was brought into contact with the gas plasma.

The gas plasma of the hydrogen compound of the above group V element is used as a component containing aluminum, gallium or indinium, and arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphorous, indinium arsenide, indinium gallium arsenide phosphorus antimony, etc. ■-When contacting the surface of a group V compound semiconductor, a parallel plate type plasma generator may be used to clean the surface by loading the semiconductor therein, or a parallel plate type plasma generator may be used. The plasma generated during use may be transferred from the plasma chamber to a surface cleaning chamber using a strong electric field, and the semiconductor may be charged into this surface cleaning chamber to perform surface cleaning.
In either case, the ion energy in the plasma is several 100
eV, which is quite high, and therefore does not necessarily provide an optimal surface cleaning effect.

Therefore, in order to achieve the optimal surface cleaning effect, it is necessary to
Since a plasma velocity of eV can be used, it is desirable to use an electron cyclotron resonance type plasma generator.

[Effect]

Hydrogen plasma is applied to the surface of a ■-V group compound semiconductor containing aluminum, gallium, or ininium and arsenic or phosphorus, such as gallium arsenide, gallium aluminum arsenide, indinium phosphide, indinium arsenide, indinium gallium arsenide phosphide antimony, etc. The drawback of the large variations in the conventional surface cleaning method using contact is that substances etched by hydrogen plasma, such as hydrogen, may re-deposit on the semiconductor, or hydrogen ions may be adsorbed on the semiconductor. It is assumed that this is due to the following. Therefore, if oxygen, hydrogen, etc. are prevented from being attached or adsorbed to the semiconductor, the above-mentioned drawbacks should be able to be overcome.

In the present invention, the plasma of arsenic hydride or phosphorous hydride can be used to combine plasma of arsenic hydride or phosphorous hydride with gallium arsenide, gallium aluminum arsenide, indinium phosphorous, indinium arsenide, indinium gallium arsenide phosphorus antimony, etc. The arsenic hydride and phosphorus hydride are brought into contact with the surface of the component semiconductor of the group (1)-v compound, but these arsenic hydrides and phosphorous hydrides are in the states of arsenic ions, arsenic radicals, hydrogen ions, and hydrogen radicals.

Since hydrogen ions or hydrogen radicals have strong sputter etching and reducing properties, they are effective in removing surface alteration layers on semiconductor surfaces. On the other hand, arsenic ions and arsenic radicals are composed of oxygen, moisture, hydrogen, and compounds (AgOlA s
H3, etc.) and co-evaporates, it is thought that this effectively prevents oxygen, hydrogen, etc. from re-adhering to the surface of the semiconductor.

Note that since the semiconductor is kept in an arsenic atmosphere during the surface cleaning process, there is also the secondary effect that evaporation of arsenic can be prevented even if the semiconductor contains arsenic such as gallium arsenide.

〔Example〕

Hereinafter, a method for manufacturing a semiconductor device according to an embodiment of the present invention will be further described with reference to the drawings.

The reference figure in Figure 1 shows a surface cleaning device using an electron cyclotron resonance type plasma generator. In addition to normal plasma generating gases such as oxygen, nitrogen, and argon, arsine, that is, arsenic hydride (AsH), phosphorus hydride (PH3), and the like are supplied from the plasma generating gas supply port 11.

3 is a waveguide means for supplying microwaves, approximately 2.45GH
z microwave is supplied. 4 is a surface cleaning chamber, the surface of which is cleaned of gallium arsenide, gallium aluminum arsenide, indinium phosphorus, indinium arsenide, indinium gallium arsenide phosphide antimony, etc.
A 1-V group compound semiconductor layer 5 containing aluminum, gallium, or indinium and arsenic or phosphorous is charged.

In the plasma generator I, charged particles undergo circular motion under the Lorentzian force caused by a static magnetic field of 875 Gauss. When a 2.45 GHz microwave is applied here, a resonance absorption phenomenon occurs, and the electric field energy is efficiently absorbed by the charged particles, promoting plasma formation even at low temperatures.
Hydrogen ions, hydrogen radicals, arsenic ions or phosphorus ions, arsenic radicals or arsenic ions, etc. are efficiently generated. Moreover, in the electron cyclotron plasma generator, a diverging magnetic field is generated, and the plasma is transferred to the surface cleaning chamber 4 with extremely low acceleration energy (about -15 eV), and the plasma is transferred to the surface of the semiconductor layer 5 charged therein. collides at a moderately low speed, producing hydrogen ions and
Due to the combined effect of the high etching and reducing properties of hydrogen radicals and this moderate physical impact, the surface modified layer is efficiently removed, and arsenic and phosphorus ions and radicals combine with oxygen, hydrogen, and water. Then, arsenide and phosphide are formed with these, and these arsenide and phosphide co-evaporate and are removed from the surface cleaning chamber 4 and attached to the surface of the semiconductor from which the surface modified layer has been removed. Since there is no surface cleaning, surface cleaning can be performed with good reproducibility.

In addition, since there are no corrosive objects such as filaments or electrodes in the plasma generation chamber of the electron cyclotron plasma generator, even if corrosive gases such as arsine or phosphorus hydride are used, no consideration should be given to corrosion. Totally unnecessary.

Furthermore, if the semiconductor contains gallium arsenide, indinium phosphide, arsenic, phosphorus, etc., the atmosphere contains not only hydrogen, etc., but also arsenic, phosphorus, etc., which have high partial pressures, so arsenic, phosphorus, etc. evaporate. This also prevents water damage and provides an excellent surface cleaning effect.

In order to confirm the effectiveness of this surface cleaning method, we manufactured a prototype similar to that described in the section on the problems to be solved by the invention and conducted an experiment.
In the case of 80 Peng V, the standard deviation was less than 5 m1J. Furthermore, the N value was 1.1±0.05, and significant effects were confirmed in both cases.

〔Effect of the invention〕

As explained above, in the method of manufacturing a semiconductor device made of a ■-V group compound semiconductor containing aluminum, gallium, or indium and arsenic or phosphorus according to the present invention, on the surface of a semiconductor layer, Since the process involves surface cleaning by contacting gaseous plasma of hydrogen compounds of elements, in addition to hydrogen plasma's excellent etching and reducing properties, group V plasma has oxygen-hydrogen,
The property of reacting with water, etc. to create arsenide and phosphide, which co-evaporates, and eliminates oxygen, hydrogen, water, etc. from the surface cleaning area is utilized, so the surface has excellent reproducibility. The Purification Law is realized.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a surface cleaning apparatus using an electron cyclotron plasma generator used to carry out a surface cleaning process according to the gist of a method for manufacturing a semiconductor device according to an embodiment of the present invention. . l...Plasma generation chamber, 11...Gas supply port for plasma generation, No. 2...Magnetic field generator, 3φ...Wave guide means for microwave supply, 4.Q.For non-explosion Fig. 1

Claims (1)

[Scope of Claims] [1] A method for manufacturing a semiconductor device made of a III-V group compound semiconductor containing aluminum, gallium, or indium and arsenic or phosphorus, wherein the surface of the semiconductor is made of a group V compound semiconductor included in the semiconductor. 1. A method for manufacturing a semiconductor device, comprising the step of cleaning a surface by bringing it into contact with a gaseous plasma of an elemental hydrogen compound. [2] Using electron cyclotron resonance method,
2. The method of manufacturing a semiconductor device according to claim 1, wherein the V group element is brought into contact with the III-V group compound semiconductor.