JP3453325B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a Schottky junction and a method for manufacturing the semiconductor device.

[0002]

2. Description of the Related Art At present, a Schottky diode is used as one of semiconductor devices which are components of integrated circuits (ICs) and large scale integrated circuits (LSIs). A Schottky diode is one type of semiconductor device using a Schottky junction, and is formed by making a semiconductor layer made of a semiconductor material and an electrode in Schottky contact. In the Schottky diode on the silicon substrate, the configuration of the portion where the semiconductor layer and the electrode are in Schottky junction is improved while various problems are solved,
It has reached today.

An electrode for Schottky junction with a semiconductor layer is conventionally formed by patterning an aluminum thin film formed by an evaporation method. In recent years, due to the reduction in design rules accompanying the high integration of integrated circuits, a method of forming a Schottky junction electrode by patterning a thin film of aluminum formed by a sputtering method has become mainstream. It is becoming. The electrode formed by using the sputtering method is superior to the electrode formed by using another method in the step coverage, the film thickness uniformity, and the film quality uniformity.

Japanese Unexamined Patent Publication (Kokai) No. 5-243556 discloses a Schottky diode in which an anode electrode and a cathode electrode are arranged on one plane of a semiconductor substrate. The anode electrode and the cathode electrode are interposed between the semiconductor substrate and the electrode for Schottky junction and external wiring or the like. Between the anode electrode and the semiconductor substrate, an electrode for Schottky junction, which is a metal layer for Schottky junction with the semiconductor substrate, is interposed. Conventionally, the cathode electrode has been in direct ohmic contact with the semiconductor substrate. In the Schottky diode disclosed in JP-A-5-243556, a metal layer that makes a Schottky junction with the semiconductor substrate is interposed between the cathode electrode and the semiconductor substrate. During operation of the Schottky diode, the metal layer between the cathode electrode and the semiconductor substrate becomes equivalent to a resistor having a small resistance value, so that the cathode electrode and the semiconductor substrate make ohmic contact. The Schottky diode disclosed in Japanese Patent Laid-Open No. 5-243556 has a metal layer for Schottky junction interposed between the cathode electrode which may be directly ohmic-joined to the semiconductor substrate and the semiconductor device. The number of parts is increasing.

In integrated circuits and large scale integrated circuits,
The semiconductor layer of the Schottky diode is an electrode for connecting the Schottky diode and the wiring, or the wiring itself,
Ohmic contact. Aluminum, which is the material of the Schottky junction electrode, is also used as the material of the connecting electrode and wiring. Generally, in the process of manufacturing a circuit, the Schottky junction electrode and the wiring are formed at the same time. In the case where the Schottky junction electrode and the wiring are formed at the same time, not only the portion where the Schottky junction electrode and the semiconductor layer form the Schottky junction but also the portion where the wiring and the semiconductor layer form the ohmic junction, silicon absorption There are problems such as aluminum spikes caused by the increase. In order to solve such a problem, an aluminum alloy containing 0.1% to 9% or several weight% of silicon (hereinafter referred to as "Al-Si") is used as a material for wiring and electrodes.
Is often used.

[0006]

In the manufacturing process of a semiconductor device, the film forming conditions in the sputtering process are set according to the intended use of the thin film to be formed. When an electrode for Schottky junction is formed by patterning an Al-Si thin film formed based on the conventional film forming conditions, the electrical characteristics of the Schottky diode including the electrode vary. Occurs. In particular, when a plurality of Schottky diodes are provided on the substrate of a single integrated circuit, the distribution of the forward voltage of the Schottky diodes in the substrate plane becomes worse than the distribution allowed in the integrated circuit. Therefore, it is desired to improve the variation in the electrical characteristics of the Schottky diode provided with the electrode made of Al-Si. Japanese Patent Laid-Open No. 5-243556 does not describe improvement of variations in electrical characteristics of Schottky diodes.

An object of the present invention is to provide a semiconductor device and its manufacturing method capable of improving the variation in electrical characteristics.

[0008]

The present invention includes a semiconductor layer made of a semiconductor material containing silicon, and a Schottky junction part made of a conductive material containing silicon and making a Schottky junction with the semiconductor layer. The Schottky junction component is formed by a first step of forming a thin film of a conductive material containing silicon on a surface of a semiconductor layer and a second step of removing a part of the formed thin film. Is a semiconductor device containing silicon particles so that the silicon particles remain uniformly in a region of the surface of the semiconductor layer where the thin film has been removed.

According to the present invention, in the semiconductor device having the Schottky junction, the Schottky junction component is formed by the step of forming a thin film made of a conductive material containing silicon and the step of patterning the thin film. .
In this specification, the distribution state of silicon particles, that is, silicon residues remaining on the surface of the semiconductor layer when a part of the thin film is removed is used as an index indicating the content state of silicon particles in the thin film. The thin film that is the source of the Schottky junction component contains silicon grains so that the silicon residue remains uniformly in the region of the surface of the semiconductor layer where there is no Schottky junction component. When a Schottky junction component is formed from a thin film containing silicon particles so that silicon residues remain uniformly, variation in electrical characteristics of a plurality of semiconductor devices manufactured simultaneously on one semiconductor wafer can be suppressed. . In this case, the reproducibility of the electrical characteristics of the semiconductor device of the present invention is more reproducible than that of the semiconductor device of the prior art having a Schottky junction component formed of a thin film containing silicon grains so that non-uniform silicon residues are left. improves.

Further, in the semiconductor device of the present invention, the silicon particles contained in the thin film are distributed such that the silicon particles remain in a chain shape in a region of the surface of the semiconductor layer where the thin film is removed. And

According to the present invention, in a semiconductor device having a Schottky junction, in a thin film which is a source of a component for the Schottky junction, silicon residues are distributed in chains.
Contains silicon grains. As a result, variations in electrical characteristics of a plurality of semiconductor devices manufactured simultaneously on one semiconductor wafer can be further suppressed. In this case, the reproducibility of the electrical characteristics of the semiconductor device of the present invention is more reproducible than that of the semiconductor device of the prior art having a Schottky junction component formed of a thin film containing silicon grains so that a non-uniform silicon residue is left. Further improve.

In the semiconductor device of the present invention, the thin film is
Silicon particles are contained such that the occupied area per unit area of the silicon particles remaining in the region where the thin film on the surface of the semiconductor layer is removed is selected to be 5% or more and 10% or less of the unit area. And

According to the present invention, in a semiconductor device having a Schottky junction, a thin film which is a source of a component for the Schottky junction has an occupied area of silicon residue per unit area of 5% or more and 10% or less of the unit area. The silicon particles are included so that the area becomes. As a result, variations in electrical characteristics of a plurality of semiconductor devices simultaneously manufactured on one semiconductor wafer are further suppressed, and reproducibility of electrical characteristics of the semiconductor devices is further improved. When the semiconductor device is a Schottky diode, the occupied area of silicon residue per unit area is 5% or more and 10% or more of the unit area.
As described below, if the thin film contains silicon grains, the forward voltage of the Schottky diode will be lower than the forward voltage of the prior art Schottky diode.

In the semiconductor device of the present invention, the thin film is
Silicon particles are contained such that the occupied thickness of the silicon particles remaining in the region where the thin film on the surface of the semiconductor layer is removed is selected to be 5% or more and 10% or less of the film thickness of the thin film. And

According to the present invention, in a semiconductor device having a Schottky junction, a thin film which is a source of a component for the Schottky junction has an occupied thickness of silicon residue of 5% or more and 10% or less of the film thickness of the thin film. It contains silicon grains so as to have a thickness. As a result, variations in electrical characteristics of a plurality of semiconductor devices simultaneously manufactured on one semiconductor wafer are further suppressed, and reproducibility of electrical characteristics of the semiconductor devices is further improved. When the semiconductor device is a Schottky diode, the forward voltage of the Schottky diode is required if the thin film contains silicon grains so that the occupied thickness of the silicon residue is 5% or more and 10% or less of the film thickness of the thin film. However, it is lower than the forward voltage of the prior art Schottky diode.

Further, according to the present invention, in a method of manufacturing a semiconductor device having a Schottky junction, a thin film of a conductive material containing silicon is formed on the surface of a semiconductor layer made of a semiconductor material containing silicon by using a magnetron sputtering device. A magnetic field of a magnetron sputtering apparatus including a first step of forming a film and a second step of removing a part of the formed thin film and leaving a Schottky junction component for Schottky junction with the semiconductor layer on the semiconductor layer. The state is that the silicon particles remain uniformly on the region where the thin film on the surface of the semiconductor layer is removed,
A method of manufacturing a semiconductor device is characterized in that a thin film to be formed is set to contain silicon grains.

According to the present invention, in the method of manufacturing a semiconductor device having a Schottky junction, the state of inclusion of silicon grains contained in the thin film which is the source of the component for the Schottky junction is such that the magnetron at the time of film formation of the thin film. It is controlled by the state of the magnetic field of the sputtering device. The state of the magnetic field of the magnetron sputtering apparatus is set so that the silicon particles are contained in the thin film to be formed so that the silicon particles can remain uniformly in the region where the thin film is removed in the surface of the semiconductor layer. . In order to uniformly leave the silicon particles on the region of the semiconductor layer surface where the thin film is removed, for example, the state of the magnetic field may be set so that the thin film to be formed contains silicon particles uniformly. . When the conductive material of a part of the thin film formed in the magnetic field in such a state is removed by etching treatment, the silicon particles contained in the thin film are converted into silicon in the region where the part of the thin film is removed. It remains uniformly as a residue. When a Schottky junction component is formed from a thin film formed so that silicon residues remain uniformly, variations in the electrical characteristics of a plurality of semiconductor devices manufactured simultaneously on one semiconductor wafer are It is less than if technology manufacturing methods were used. When the Schottky junction component contains silicon particles so that the silicon residue remains uniformly, the reproducibility of the electrical characteristics of the semiconductor device is improved as compared with the semiconductor device manufactured by using the conventional manufacturing method. .

The semiconductor device manufacturing method of the present invention is characterized in that the strength of the magnetic field of the magnetron sputtering apparatus is always maintained at a predetermined strength during the sputtering.

According to the present invention, in the method of manufacturing a semiconductor device having a Schottky junction, the strength of the magnetic field during sputtering is always maintained at a predetermined strength. The thin film formed under the condition of such a magnetic field surely contains silicon grains so that the silicon residue remains uniformly. When a plurality of semiconductor devices are simultaneously manufactured on one semiconductor wafer by using such a manufacturing method, it is possible to further suppress variations in the electrical characteristics of the semiconductor devices. Further, in this case, the reproducibility of the electrical characteristics of the semiconductor device can be further improved.

[0020]

1 is an enlarged sectional view of a semiconductor device 22 using a Schottky junction according to the present invention. In the example of FIG. 1, a semiconductor device using a Schottky junction is a Schottky diode (hereinafter abbreviated as “diode”) 2.
2, the diode 22 is one of the components of the integrated circuit 21. The diode 22 is generally a semiconductor layer 23 made of a semiconductor material containing silicon.
And an electrode 28 which is a Schottky junction component made of a conductive material containing silicon. The semiconductor layer 23 and the electrode 28 form a Schottky junction. Semiconductor layer 2
The region 29 in the surface of No. 3 where the electrode 28 is absent is hereinafter referred to as "removed region 29".

The electrode 28 for Schottky junction is formed by a first step of forming a thin film of a conductive material containing silicon on the surface of the semiconductor layer 23, and removing a part of the formed thin film to form the electrode 28. It is formed by a second process that is left on the semiconductor layer 23. The removed region 29 corresponds to the region where the thin film formed in the first step is removed in the second step. The electrode 28 for Schottky junction contains silicon grains.

In order to improve the electrical characteristics of the diode 22, especially the forward voltage, the electrode 28 for Schottky junction is used.
The silicon particles contained in contribute. Since there is a correlation between the silicon particle content state of the electrode 28 and the distribution state of the silicon residue 30, the distribution state of the silicon residue and the semiconductor device 2
There is a correlation with the electrical characteristics of 2. The silicon residue 30 means silicon particles remaining in a region where the thin film is removed when a part of the thin film made of a conductive material containing silicon is etched so as to remove the conductive material. In the present specification, the silicon remaining in the removal region 29 after the electrode 28 is formed is used as an index indicating the content state of silicon particles in the electrode 28 and the thin film (hereinafter referred to as “original thin film”) that is the source of the electrode 28. The distribution state of the residue 30 is used.

The electrode 28, that is, the original thin film, contains silicon particles so that the silicon residue 30 remains uniformly in the removal region 29. The original thin film preferably contains silicon particles so that the silicon residue 30 remaining on the removed region 29 is distributed in a chain shape. In order for the silicon residue 30 to remain uniformly and in a chain shape, it is preferable that the area occupied by the silicon residue per unit area is within the range of 5% to 10% of the unit area. The thin film contains silicon grains. Further, preferably, in order for the silicon residue 30 to remain uniformly and in a chain shape, the occupied thickness of the silicon residue is within a range of 5% to 10% of the thickness of the removed portion of the original thin film. As described above, the original thin film contains silicon grains. Most preferably, the occupied area is 5% or more and 10% or less of the unit area, and the occupied thickness is 5% or more and 10% of the thickness of the removed portion of the original thin film.
As described below, the original thin film contains silicon grains.

This embodiment is an example in which the conductive material forming the Schottky junction electrode 28 is realized by an aluminum alloy containing silicon (hereinafter referred to as “Al—Si”). There is. When the Schottky junction electrode 28 is formed of Al-Si, silicon is formed in the surface of the semiconductor layer 23 other than the region where the Schottky junction is formed with the electrode 28, particularly in the region where ohmic junction is formed with another conductive component. It prevents the generation of aluminum spikes and the like due to the sucking of aluminum.

The integrated circuit 21 includes, in addition to the diode 22,
It has an insulating layer 24. Diode 22 in integrated circuit 21
The specific configuration of is as follows. Semiconductor layer 23
Is an N-type semiconductor layer 25 and an N-type epitaxial layer 26 on the N-type semiconductor substrate 25.
It is composed by stacking. The semiconductor substrate 25 also serves as the substrate of the integrated circuit 21. The insulating layer 24 is laminated on the N-type epitaxial layer 26. The insulating layer 24 is realized by, for example, a thin film of silicon oxide. Contact openings 27 are provided in the insulating layer 24. Diode 22
At least a portion of the Schottky junction electrode 28 is in contact with the N-type epitaxial layer 26 through the contact opening 27. The remaining portion of the electrode 28 is laminated on the insulating layer 24. The portion where the electrode 28 and the semiconductor layer 23 are in direct contact functions as the diode 22.

The original thin film of the electrode 28 of the diode 22 is preferably formed by a sputtering method using a magnetron sputtering device 31. FIG. 2 is a sectional view of the magnetron sputtering apparatus 31. The magnetron sputtering device 31 includes a target 33 and a storage container 3.
4, a power source 35, and a magnetic force source 36.
The target 33 is formed of a thin film material to be formed on the surface of the semiconductor wafer 38 which is the film formation target. The storage container 34 stores the gas that is the raw material of the plasma, the target 33, and the semiconductor wafer 38. Power source 35
Generate an electric field between the target 33 and the semiconductor wafer 38. The magnetic force source 36 generates a magnetic field orthogonal to the electric field between the target 33 and the semiconductor wafer 38. It is preferable that the magnetron sputtering apparatus 31 further has a heating mechanism 39 for heating the semiconductor wafer 38 to a predetermined temperature. The heating mechanism 39 may have any heating method, for example, a lamp heating method or a gas heating method is used. The magnetron sputtering device 31 of the present embodiment uses a lamp heating system.

The magnetic force source 36 has a double magnetic pole type electromagnet 41 and a coil power source 42. The target 33 is arranged between the double magnetic pole type electromagnet 41 and the semiconductor wafer 38.
The double magnetic pole type electromagnet 41 is composed of two cylindrical electromagnet coils 43 and 44 arranged concentrically. The coil power supply 42 supplies electric power to the electromagnet coils 43 and 44, respectively. Hereinafter, the current flowing through the electromagnet coil 43 inside the double magnetic pole electromagnet 41 is referred to as “inside current Ii”.
And an electromagnet coil 44 outside the double-pole electromagnet 41.
The current flowing through is called "outside current Io".

The magnetron sputtering apparatus 31 is used in the process of manufacturing the semiconductor device 22 using the Schottky junction and in the process of forming the original thin film of the electrode 28 for the Schottky junction included in the semiconductor device 22. For this,
The semiconductor wafer 38, which is the film formation target, is specifically realized by a silicon wafer. The target 33 is made of the material of the Schottky junction electrode 28, Al in the present embodiment.
-Si is formed. Further, in the present embodiment, for example, argon gas is used as a gas that is a raw material of plasma.

Further, in the present embodiment, the power source 35 is
The double-pole electromagnet 41 is used as the cathode, and the semiconductor wafer 38
Is used for the anode. In this case, the double magnetic pole type electromagnet 41
Becomes a sputter cathode during sputtering. While the current flows through the electromagnet coils 43 and 44, the sputtering cathode 4
In No. 1, a magnetic field is created, and argon gas, which is a discharge substance, is collected in the magnetic field for efficient discharge. The double magnetic pole type electromagnet 41 also serves as the cathode (cathode) of the power source 35 and the magnetic force source 36 during execution of sputtering. Semiconductor wafer 3
If 8 is grounded, power source 35 and coil power source 4
2 may be integrated, and the power source 35 may supply power to the two electromagnet coils 43 and 44.

In the present embodiment, the magnetic field formed during sputtering has the strongest discharge concentration in the region where the magnetic field has a vertical component and a horizontal component on the surface of the target 33 and the vertical component is zero. It is formed under such conditions. The magnetron discharge concentrates most strongly in the region where the vertical component of the magnetic field is zero in the space where the magnetic field is formed. In the region where the vertical component of the magnetic field is zero, the horizontal component of the magnetic field is maximum. In this specification, the direction parallel to the surface of the disk-shaped semiconductor wafer 38 is referred to as “horizontal direction”, and the direction perpendicular to the surface of the wafer 38 is referred to as “vertical direction”. The two-dot chain line LL in FIG.
Indicates an arbitrary magnetic force line of the magnetic field generated by the double magnetic pole type electromagnet 41.

The steps of forming a thin film of Al--Si on the semiconductor wafer 38 using the magnetron sputtering apparatus 31 of FIG. 2 are roughly as follows. The target 33 is stored in the storage container 34 in advance. First, the semiconductor wafer 38 and the plasma source gas are sealed in the storage container 34, and the pressure in the storage container 34 is adjusted to a prescribed pressure. The position of the semiconductor wafer 38 in the storage container 34 is adjusted so that the center of the semiconductor wafer 38 and the center axis of the magnetic field coincide with each other. Enclosed wafer 38
Is heated to a predetermined temperature by the heating mechanism 39,
The temperature after heating is maintained. Then, the electric power source 35 produces an electric field between the double magnetic pole type electromagnet 41 and the semiconductor wafer 38, and the magnetic force source 36 produces a magnetic field orthogonal to the electric field. As a result, the electrons emitted from the cathode ionize the raw material gas while being trapped in the space where the electric field and the magnetic field are generated, so that high density plasma is formed near the surface of the target 33. The formed plasma is the target 33.
Since the surface is sputtered, the surface of the semiconductor wafer 38 is
A thin film made of the target material is formed.

The Al—Si thin film thus formed is processed into the electrode 28 of the diode 22. Al-S
When the i thin film is formed by the conventional thin film manufacturing method using the magnetron sputtering apparatus, which part of the Al—Si thin film is used as the electrode 28 for the electrical characteristics of the diode 22, especially the forward voltage? Change according to. A
The variation in the electrical characteristics of the diode 22 based on which part of the l-Si thin film is used as the electrode 28 is hereinafter referred to as "in-plane variation". In the manufacturing process of the diode 22, one Al—Si thin film is processed to form the electrodes 28 of the plurality of diodes. In the semiconductor device manufacturing process using the conventional thin film manufacturing method, a plurality of diodes 2
2 causes in-plane variations in electrical characteristics, the reliability of the diode 22 is reduced, and the reproducibility of the diode 22 is reduced.

In this embodiment, when the diode 22 is completed, the silicon residue 30 is left on the removal region 29 of the semiconductor layer 23.
The original thin film of the electrode 28 is formed so as to remain uniformly. The generation state of the silicon residue 30 is related to the film forming conditions of the Al-Si thin film. When the Al-Si thin film is formed by using the magnetron sputtering apparatus 31, the closest causal relationship between the distribution state of the silicon residue 30 and the setting condition of the magnetic field at the time of forming the Al-Si thin film. is there. The generation degree of the silicon residue 30 changes according to the change in the strength of the magnetic field during sputtering. Uniformly distributed silicon residue 3
In order to generate 0, it is preferable that the magnetic field in a predetermined state is always maintained during the Al-Si sputtering process. This makes it possible to form a thin film in which a very uniform silicon residue 30 remains in the removal region 29.

Among the thin film forming conditions using the sputtering method, the temperature condition of the semiconductor wafer 38 at the time of sputtering can be a condition for promoting the generation of the silicon residue 30. The generation degree of the silicon residue 30 changes according to the increase and decrease in the temperature of the semiconductor wafer 38. However, when the temperature of the semiconductor wafer 38 during sputtering is increased more than before, the completed diode 2
The in-plane variation of the forward voltage of 2 is hardly improved. As described above, among the optimization of the conditions for promoting the generation of the silicon residue 30, only the optimization of the setting condition of the magnetic field has the effect of improving the in-plane variation of the electric characteristics of the diode 22.

In order to form the original thin film of the electrode 28 so that the silicon residue 30 remains uniformly in the removed region 29, the magnetic field of the magnetron sputtering apparatus 31 is maintained at a predetermined strength while the original thin film is formed. Continue to drip. Silicon residue 30
When forming the original thin film so that
When the original thin film is formed so that the silicon residue 30 remains with an occupied thickness of 5% or more and 10% or less of the unit area per unit area, and with an occupied thickness of 5% or more and 10% or less of the film thickness of the original thin film. In each of the three cases of forming the original thin film so that the silicon residue 30 remains, the magnetron sputtering apparatus 3 is used.
The one magnetic field satisfies at least one of the magnetic field conditions described below.

In order to improve the content of silicon grains in the original thin film, the strength of the magnetic field and the shape of the magnetic field at the time of sputtering are the most important, and the magnetic field in a predetermined state is always maintained during the sputtering. It is preferably retained. In other words, it is important that the magnetic field does not change during sputtering and always maintains a predetermined strength and shape.
As the conditions of the magnetic field at the time of sputtering, specifically, the erosion diameter φB, the eccentric state of the magnetic field, the holding state of the magnetic field,
The strength of the magnetic field is used.

The erosion diameter φB is the diameter of the erosion region in the space where the magnetic field is formed. The erosion area is an area in which the vertical component is 0 and the horizontal component is maximum in the space. The erosion diameter φB that defines the shape of the magnetic field is determined by the ratio of the inside current Ii and the outside current Io (hereinafter referred to as “magnet current ratio Ii / Io”). Magnet current ratio Ii / Io is equal and two currents Ii, I
When there are a plurality of combinations of currents having different o values, the erosion diameter φB defined by each combination
Are equal to each other. For example, a combination in which both the inside current Ii and the outside current Io are 2A,
When comparing a combination in which both the inside current Ii and the outside current Io are 4 A, the erosion diameters φB defined by each of these two combinations are equal to each other.

The discharge shape diameter RB of the magnetic field is half the erosion diameter φB. While the sputtering is performed, the discharge shape diameter RB of the magnetic field is equal to or larger than the maximum distance (hereinafter referred to as “arrangement center diameter”) RW from the edge of the film formation object to the center axis of the magnetic field and the arrangement center diameter. It is selected as a value within an allowable range of 1.5 times or less of RW. The discharge shape diameter RB of the magnetic field is preferably selected to be a value within an optimum range of 1.2 times or more the arrangement center diameter RW and 1.3 times or less the arrangement center diameter RW. In the present embodiment, the central axis of the magnetic field penetrates the center of the semiconductor wafer 38 that is the film-forming target, so the arrangement center diameter RW is equal to the radius of the semiconductor wafer 38.

The eccentricity of the magnetic field is determined by the combination of the inside current Ii and the outside current Io. Inside current Ii and outside current Io
Are set so that the double magnetic pole electromagnet 41 generates a magnetic field having a predetermined strength without eccentricity.

The strength of the magnetic field is determined by the magnitude of the inside current Ii and the magnitude of the outside current Io. Inside current Ii and outside current Io
The larger the magnitude of, the stronger the magnetic field defined by the combination of these two currents Ii, Io. For example, when comparing a combination in which both the inside current Ii and the outside current Io are 2A and a combination in which both the inside current Ii and the outside current Io are 4A, the magnetic field defined by the former combination is compared. Is weaker than the strength of the magnetic field defined by the latter combination. The weaker the magnetic field strength during sputtering,
The in-plane variation in the electrical characteristics of the diode 22 is reduced. Inside current Ii and outside current Io
Are selected within the allowable range of 0 A or more and 2 A or less.

As described above, the shape, eccentricity, and strength of the magnetic field are determined by the combination of the inside current Ii and the outside current Io. In order to improve the state of inclusion of silicon grains in the original thin film, it is necessary to maintain a predetermined state without changing the magnetic field during the sputtering. In order to keep the magnetic field eccentric and at a predetermined strength during the sputtering, the inside current Ii
The outside current Io and the outside current Io are not changed during the execution of the sputtering and are always maintained at the values determined for the respective currents Ii and Io.

In the present embodiment, there are four conditions of the magnetic field during the execution of sputtering, that is, the discharge shape diameter of the magnetic field, the magnetic field holding state, the magnetic field eccentricity state, and the magnetic field strength.
The magnetron sputtering device 31 may generate a magnetic field so as to satisfy at least one of these four magnetic field conditions. The more the magnetic field conditions are satisfied, the more the in-plane variation in the electrical characteristics of the Schottky diode can be suppressed. It is most preferable that the magnetic field is generated so as to satisfy all four magnetic field conditions, and the in-plane variation of the electrical characteristics of the Schottky diode can be suppressed most.

In this embodiment, the inside current Ii is 2A and the outside current Io is set to 2A, so the magnet current ratio Ii / Io is 2A / 2A.
= 1. As a result, the silicon residue 30 can be uniformly distributed on the entire surface of the semiconductor layer 23, so that the electrical characteristics of the diode 22 are improved and, at the same time, the in-plane variation of the diode 22 is suppressed to the minimum. As shown in FIG. 7 described later, the forward voltage of the diode 22 decreases as the occupied thickness of the silicon residue 30 increases. Contrary to the above description, when the magnetic field forming conditions of the magnetron sputtering apparatus 31 at the time of forming the original thin film are changed, the in-plane variation of the diode 22 formed on one wafer 38 becomes large. By using one wafer 38, a plurality of diodes 22 having different forward voltages can be obtained.

FIG. 3 is a schematic process diagram for explaining the manufacturing process of the diode 22 of the integrated circuit 21 of FIG. In the process diagram of FIG. 3, a part of the semiconductor wafer 38 having the N-type epitaxial layer formed on one surface corresponds to the semiconductor layer 23.

First, in step A1, the semiconductor wafer 3
The surface of the N-type epitaxial layer 26 of No. 8 is coated with a thin film of an insulating material. When the insulating material is silicon oxide, the insulating material thin film is the N-type epitaxial layer 2
It is obtained by oxidizing the surface of 6. Step A
In step 2, a part of the predetermined position in the formed thin film of the insulating material is removed, so that the contact opening 27 is formed. An etching process using a photoresist is used for forming the contact openings 27. As a result, the insulating layer 24 is formed on the semiconductor wafer 38. In step A3, the semiconductor wafer 38 on which the insulating layer has been formed is subjected to pretreatment for forming the original thin film. The pretreatment is performed using plasma, for example.

In step A4, the preprocessed semiconductor wafer 38 is stored in the container 34 of the magnetron sputtering apparatus 31.
It is carried in and heated to a predetermined temperature. After the semiconductor wafer is loaded, the storage container 34 is evacuated. In step A5, the magnetron sputtering apparatus 31 uses the original thin film of Ai-Si for the preprocessed semiconductor wafer 3
8 is deposited on the insulating layer 24. The strength of the magnetic field generated by the magnetron sputtering apparatus 31 is always maintained at a predetermined strength during the Al-Si sputtering. In step A6, the formed Ai-Si thin film is patterned. For patterning the Al-Si thin film, an etching process using, for example, a photolithography method is used. As a result, the electrode 28 of the diode is formed on the semiconductor wafer 38, so that the diode 22 is completed.

At the time of patterning in step A6, Al is used.
-Electrode 2 for Schottky junction of diode in Si thin film
In addition to leaving the portion to be 8 as well, other constituent parts of the integrated circuit 21, for example, portions to be wiring and other electrodes may be left. This provides the electrode 28 as well as other components of the integrated circuit 1. When another component of the integrated circuit 21 is formed of an Al—Si thin film, sintering is performed on the semiconductor wafer 38 after completion of the diode in a hydrogen atmosphere. After all the components of the integrated circuit 21 are formed on the semiconductor wafer 38, the semiconductor wafer 38
The portion in which all the components are arranged is cut out. As a result, the integrated circuit 21 is completed.

One of the optimum examples of specific conditions in the manufacturing process of the diode 22 is as follows. The material of the electrode 28 for Schottky junction is Al-Si containing 1% by weight of silicon. Both the inside current and the outside current given to the double magnetic pole type electromagnet 41 during the sputtering process have a current value of 2 A, and the DC component voltage of both currents is 500V. Storage container 3 after vacuuming
The degree of vacuum in 4 is 0.6 Pa. The heating temperature of the substrate by the heating mechanism 39 is 100 ° C. Patterning of the Al-Si thin film is performed using a general photoetching technique. The heating temperature during sintering is about 420 ° C., and the heating time is 1 hour. Sintering is performed in a hydrogen atmosphere.

In order to evaluate the diode 22 of this embodiment, first and second experiments described below were conducted.
The first experiment is as follows. In the first experiment, FIG.
The Al-Si thin film is formed on the surface of each of the plurality of semiconductor wafers 38 based on the thin film forming step in the manufacturing process of the semiconductor device described above, and the formed Al-Si thin films are respectively processed, and the processed Al- The physical properties related to the electrical characteristics of the diode are measured based on the Si thin film. As the film forming conditions in the manufacturing process of the Al-Si thin film, there are film forming conditions set based on the conventional thin film manufacturing method and film forming conditions set based on the thin film manufacturing method of the present embodiment. The Al-Si thin films are formed on at least one semiconductor wafer 38 under each of the two conditions.

[0050]

[Table 1]

Table 1 shows film forming conditions set based on the conventional thin film manufacturing method and film forming conditions set based on the thin film manufacturing method of the present embodiment. Of the forming conditions of the diode 22 other than the film forming conditions shown in Table 1, Al-
The silicon content of the Si target 33 is 1% by weight, and the distance D between the target 33 and the wafer 38 is 55 mm.
And the sintering temperature is set to 420 ° C. The semiconductor wafer 38 is a 4-inch silicon wafer and has a diameter of 100 mm.

In the first experiment, each semiconductor wafer 38 was formed based on the film forming conditions of the conventional technique and this embodiment.
The Al-Si thin film formed on the surface is further processed to form a plurality of diodes 22 for each semiconductor wafer 38,
The forward voltage of each diode 22 formed is measured. The forward voltage of the diode 22 is
2 is defined by the voltage value when a current of 10 μA is applied in the forward direction. The area of the electrode of the diode 22 is 10 μm × 10 μm.

Further, in the first experiment, at the time when a part of the Al-Si thin film was partially peeled during the formation of the diode,
The thickness and area of the silicon residue 30 remaining on the removed region 29 are measured. Silicon residue 3 on the removal area 29
The thickness of 0 is measured using a step measuring device. The first
The thickness of the Al-Si thin film in the experiment of about 1.4 μm
Is. The occupying area of the silicon residue 30 on the removal region 29 indicates the generation status of the silicon residue 30 on the removal region 29.
It is observed and measured by an optical microscope and a scanning electron microscope. Silicon residue for a predetermined unit area 3
The ratio of the occupied area of 0 is defined by the ratio of the measured area of the silicon residue 30 to the area of the visual field of the scanning electron microscope when the magnification is 10,000 times.

In one semiconductor wafer 38, the diode 22 to be measured is the tip portion of the wafer 38, the wafer 3
8 and a facet portion of the wafer 38 in the three measuring portions. For this reason, the removal region 29 of the silicon residue 30 that is to be measured also includes the tip portion of the wafer 38, the central portion of the wafer 38, and the wafer 3.
It is in each of the three measuring parts of the eight facet parts. As shown in FIG. 4, the wafer tip 51, the wafer center 52, and the wafer facet 53 are located on the wafer 38.
Are arranged substantially parallel to the center line 55 of the. The central portion 52 is located near the center of the wafer 38, and the tip portion 51 and the facet portion 53 are located near the intersection of the edge of the wafer 38 and the center line 45.

FIGS. 5A to 5C show the removed region in the semiconductor wafer 38 after a part of the Al-Si thin film formed based on the improvement conditions in Table 1 is removed in the first experiment. FIG. 29 is an enlarged view of 29. FIG. 5A shows a state in which the removed region 29 is observed at a magnification of 500 times with an optical microscope. FIG. 5B shows a state in which the removed region 29 is observed at a magnification of 2000 times with a scanning electron microscope (SEM). FIG. 5C shows a state in which the removed region 29 is observed at a magnification of 10,000 times with a scanning electron microscope. 6A to 6C are enlarged views of the removed region in the semiconductor wafer after a part of the Al-Si thin film formed based on the conventional condition of Table 1 is removed in the first experiment. Is. In FIG. 6 (A), the removal area is 5
The state observed at a magnification of 00 is shown. 6 (B) and 6 (C) show that the removal area is 2 by a scanning electron microscope.
The state observed at magnifications of 000 and 10000 is shown.

The ratio of the occupied area of the silicon residue 30 per unit area in the removal region 29 to the unit area (hereinafter referred to as "occupied area ratio") is shown in FIGS. 5 (A) to 5 (C) and FIG. 6 (A). Calculated based on (C). The occupied area ratio of the silicon residue in the removed region 29 of the Al—Si thin film formed based on the improvement conditions shown in FIG.
30%. The occupied area ratio of the silicon residue in the removed region of the Al—Si thin film formed based on the conventional technology condition shown in FIG. 6 is 4.10%.

Referring to FIG. 6, in the removed region of the Al--Si thin film formed under the conventional technique, the silicon residue 30 is removed.
It can be seen that are distributed in the form of particles. Referring to FIG. 5, the removal region 2 of the Al-Si thin film formed under the improved condition
In No. 9, it can be seen that the silicon residue 30 is distributed in a chain. Comparing FIG. 5 and FIG. 6, the removal area of the Al—Si thin film formed under the improved condition is higher than the occupied area ratio of the silicon residue in the removal area of the Al—Si thin film formed under the conventional technology condition. The ratio of the occupied area of silicon residues in
Occupied area ratio of silicon residue is small.

[0058]

[Table 2]

Table 2 shows the 3 measured in the first experiment.
The forward voltage VF of the diode 22 in each of the measurement units 51 to 53, the thickness of the silicon residue, and the ratio of the thickness of the silicon residue to the film thickness of the Al—Si thin film (hereinafter referred to as “occupied film thickness ratio”). Indicates. In addition, Table 2 also shows the measurement results of the diode 22 formed at both side end portions 56 and 57 of the thin film formed using the conventional technology conditions.

As can be seen from Table 2, the in-plane variation of the forward voltage of the diode 22 when the thin film forming condition of the present embodiment is used is in the case where the conventional thin film forming condition is used. It is sufficiently smaller than the in-plane variation of the forward voltage of the diode. The in-plane variation in the former case is 2/5 or more and 2/7 or less of the in-plane variation in the latter case.
It is approximate. As described above, when the thin film deposition conditions of the present embodiment are used, in-plane variation of the forward voltage can be sufficiently suppressed as compared with the case where the conventional thin film deposition conditions are used.

As can be seen from Table 2, the forward voltage of the diode 22 when the thin film forming conditions of this embodiment are used is the same as the conventional thin film forming condition at any position in the wafer. It is smaller than the forward voltage of the diode. Therefore, the forward voltage of the diode 22 when the thin film deposition condition of the present embodiment is used is higher than the forward voltage of the diode when the conventional thin film deposition condition is used at any position in the wafer. Is also small. Based on these reasons, the thin film deposition conditions of the present embodiment are
It is preferable to the conventional thin film deposition conditions.

Furthermore, as can be seen from Table 2, the in-plane variation in the thickness of the silicon residue 30 when the thin film forming conditions of the present embodiment are used is based on the conventional thin film forming condition. In this case, it is sufficiently smaller than the in-plane variation in the thickness of the silicon residue 30. As described above, when the thin film deposition conditions of the present embodiment are used, the in-plane variation in the thickness of the silicon residue 30 can be sufficiently suppressed as compared with the case where the conventional thin film deposition conditions are used. Therefore, the thin film deposition conditions of this embodiment are preferable to the thin film deposition conditions of the prior art.

Considering comprehensively the results of the first experiment, like the diode 22 manufactured by the manufacturing method of the present embodiment, the silicon residues 30 are uniformly and regularly generated in the removal region 29. The diode has a lower forward voltage than the diode manufactured by the conventional manufacturing method,
Moreover, the in-plane variation of the forward voltage is also reduced. Therefore, the diode manufacturing method according to the present embodiment is preferable to the diode manufacturing method according to the related art.

FIG. 7 is a graph showing the relationship between the forward voltage of the diode 22 and the thickness of the silicon residue, based on the measurement results at eight points shown in Table 2. The eight black circles plotted show the measured silicon residue thickness against the measured forward voltage VF. The graph L1 is a graph that approximates the distribution state of the silicon residue thickness with respect to the forward voltage, and is obtained by using the measurement results at eight points and by using the least squares method. Referring to FIG. 7, the silicon residue thickness is
It can be seen that it decreases in proportion to the forward voltage VF of the diode 22.

The upper limit value of the forward voltage VF required in the diode 22 having an electrode area of 10 μm × 10 μm is 380 mV, and the effective lower limit value of the forward voltage VF of the diode 22 is about 280 mV.
Is. Referring to FIG. 7, 280 mV or more and 380 mV
In order to obtain the diode 22 having the following forward voltage VF, it is understood that the occupied film thickness ratio of the silicon residue 30 should be 5% or more and 10% or less. Thus, regardless of the method of manufacturing the Al-Si thin film, in order to set the forward voltage of the diode 22 within a predetermined range, the thin film with respect to the film thickness of the thin film which is the source of the electrode 28 of the diode 22 is formed. It is preferable that the content thickness of the silicon grains in the film is 5% or more and 10% or less of the thickness of the original thin film.

FIGS. 8A to 8C are enlarged views of the removed region 29 in the semiconductor wafer 38 after a part of the Al--Si thin film formed using the conventional technique conditions is removed.
The removed region of FIG. 8 is formed by Al-S formed under the conventional technology conditions.
The position in the i thin film differs from the removal region shown in FIG. FIG. 8A shows a state in which the removed region is observed at a magnification of 500 times with an optical microscope. 8B and 8B.
(C) shows the removal area of 200 by scanning electron microscope.
The state observed at 0 and 10000 times magnification is shown.
The occupied area ratio of the silicon residue in the removed region of the Al—Si thin film shown in FIG. 8 is 11.4%. Referring to FIG. 8, in the removal region 29 shown in FIG.
It can be seen that are distributed in a chain. Comparing FIG. 5 with FIG. 8, the chain-like distribution of silicon grains becomes clearer as the occupied area ratio of silicon residues, that is, the amount of silicon residues generated increases.

[0067]

[Table 3]

Table 3 shows the ratio of the occupied area of the silicon residue 30 to the unit area measured in the first experiment and the forward voltage of the diode 22 near the removal region where the silicon residue remains. Occupied area ratio of silicon residue is 8.3
When it is 0%, the forward voltage is included in the range of the forward voltage required for the diode 22 having the electrode 28 made of Al—Si, that is, in the range of 280 mV or more and 380 mV or less, and the diode 22. It has been confirmed that the mass production of is possible. When the occupied area ratio of the silicon residue is 4.10%, the forward voltage exceeds the range of the forward voltage required for the diode 22, and thus it is determined that the diode 22 is not suitable for mass production. There is. When the occupied area ratio of the silicon residue is 11.4%, it has been confirmed that a defect has occurred in the chip recognition test in the manufacturing process of the integrated circuit using the diode 22, which is not suitable for mass production of the diode 22. Has been determined. As described above, in order to set the forward voltage of the diode within a predetermined range and enable mass production, the unit of the thin film which is the source of the electrode of the diode 22 is irrespective of the manufacturing method of the Al—Si thin film. The area containing silicon particles per area is preferably 5% or more and 10% or less of the unit area.

The second experiment is as follows. In the second experiment, the forward voltage of each of the plurality of diodes 22 manufactured from one Al—Si thin film formed on the basis of the prior art conditions in the first experiment was measured, and each diode 22 was measured. The amount of silicon contained in the inner electrode 28 is measured. The measurement procedure of the forward voltage of each diode is
Equivalent to the first experiment. The amount of silicon contained in the Al-Si thin film is determined by elemental identification using an electron probe microanalyst analysis method. In the electron probe microanalyst analysis method, Al- deposited on a semiconductor wafer is used.
The surface of the Si thin film is irradiated with an electron beam. The energy of the electron beam is 7 keV and the measurement time is 100 seconds.

[0070]

[Table 4]

[0071]

[Table 5]

[0072]

[Table 6]

FIG. 9 shows the first Al-S used for manufacturing the diode 22 having a forward voltage VF of 327 mV.
This is the spectrum of the i thin film. Table 4 shows the first Al-
The element identification result of a Si thin film is shown. FIG. 10 is a spectrum of the second Al—Si thin film used for manufacturing the diode 22 having the forward voltage VF of 389 mV. Table 5 shows the element identification results of the second Al-Si thin film.
FIG. 11 is a spectrum of the third Al—Si thin film used for manufacturing the diode 22 having the forward voltage VF of 482 mV. Table 6 shows the element identification results of the third Al-Si thin film. 9 to 11, the vertical axis represents
It is the count number of the detected element and is displayed logarithmically, and the horizontal axis is energy. In Tables 4 to 6, elements with [◯] are analyzed as having a high possibility of existing in the Al—Si thin film.

[0074]

[Table 7]

Table 7 shows the relationship between the content ratio [%] of silicon in the Al-Si thin film and the forward voltage VF of the diode 22 having the Schottky junction electrode 28 formed from the Al-Si thin film. Show. The content ratio of silicon in the Al-Si film is the ratio of the count number of silicon (Si) to the count number of aluminum (Al).

As shown in FIGS. 8 to 11 and Tables 4 to 7, the lower the forward voltage of the diode 22, the lower the forward voltage of the diode 22, the silicon of the Al--Si thin film forming the electrode 28 for Schottky coupling in the diode 22. Shows a tendency for the content ratio of to increase. As the forward voltage of the diode 22 is lower, the silicon in the Al-Si thin film formed by sputtering is concentrated near the interface of the Al-Si thin film.
The -Si thin film behaves like a conductive thin film formed by epitaxial growth.

Based on the experimental results described in FIGS. 5 to 11, in the diode 22, the ratio of the occupied area of the silicon residue 30 to the unit area and the ratio of the thickness of the silicon residue 30 to the film thickness of the Al—Si thin film are It is understood that the content is preferably 5% or more and less than 10% regardless of the manufacturing method of the semiconductor device. This is based on the above experimental results and the following reasons.

The silicon particles in the electrode 28 are
In addition to improving the in-plane variation of the forward voltage of 2,
It also contributes to the leakage current at the portion where the semiconductor layer 23 and the electrode 28 make a Schottky junction. The leakage current increases as the amount of the silicon residue 30 increases. In the diode 22, the ratio of the silicon residue 30 on the removed region 29 is 10%.
When it exceeds%, the silicon particles are not distributed in a chain in the electrode 28 and instead occupy the entire surface. As a result, the effect of increasing the leakage current of the Schottky junction in the diode 22 due to the silicon particles appears more strongly than the effect of improving the in-plane variation of the forward voltage of the diode 22 due to the silicon particles. The reliability of the diode 22 as a device is impaired. When the ratio of the silicon residue 30 on the removal region 29 exceeds 10%, the diode 22 is affected by the influence of the silicon residue 30.
In the manufacturing process of 1 or the die bonding process in the manufacturing process of the integrated circuit 21, the recognition failure of the semiconductor chip is likely to occur.

When the ratio of the silicon residue 30 is less than 5%, the silicon residue 30 on the removal region 29 is not distributed like a chain and is distributed in a broken state. In this case, the number of chain-like portions of the silicon residue 20 on the removed region 29 also decreases. In such a state, the forward voltage of the diode 22 becomes higher than the maximum forward voltage allowed for the device. When the ratio of the silicon residue 30 is less than 5%, the in-plane variation of the electrical characteristics of the diode 22 is larger than the maximum in-plane variation allowed in manufacturing. Based on the above reason, both the area ratio and the thickness ratio of the silicon residue 30 on the removal region 29 are preferably 5% or more and less than 10%.

The semiconductor device and the method for manufacturing the same described above are examples of the semiconductor device and the method for manufacturing the same according to the present invention, and can be implemented in various other forms as long as the main structures are the same. Particularly, the detailed processing of the semiconductor device and the manufacturing method thereof is performed if the thin film which is the source of the component for the Schottky junction contains silicon grains as described above.
The configuration is not limited to the configuration described in the present embodiment, and may be realized by other configurations.

The detailed structure of the magnetron sputtering apparatus is not limited to the structure shown in FIG. 2 and may be realized by another structure as long as the magnetic field is formed so as to satisfy the above-mentioned conditions. The magnetic force source may have a configuration other than the configuration including the double magnetic pole type electromagnet, for example, a configuration using a permanent magnet, as long as the discharge shape diameter of the magnetic field can be set within a predetermined range. Good. If the shape of the film-forming target 8 is variable, it is preferable that the magnetic force source has a configuration capable of changing the strength of the magnetic field and the shape of the magnetic field. The shape of the film-forming target 8 is not limited to a substantially disk-shaped plate, and may be another shape, and the material of the film-forming target is not limited to silicon. The source gas for plasma is not limited to argon gas.

Target material, that is, semiconductor device 2
The material of the electrode 28 for Schottky junction No. 2 is not limited to Al-Si and may be another material as long as it is a metal material that can be a material of the electrode and can make good ohmic contact. . The magnetic field conditions described in this embodiment are most effective for Al-Si. The electrode 28 of the diode 22 is formed by sputtering using Al.
-When it is formed from a Si thin film, the step coverage of the electrode is higher than when the electrode is formed from another material and when the electrode is formed from a thin film formed by another thin film forming method. Since the uniformity of the electrode film thickness and the uniformity of the electrode film quality are excellent, it is preferable.

The thin film of the conductive material formed by the above-mentioned manufacturing method is not limited to the electrodes of the Schottky diode, but may be processed into other parts such as wirings and electrodes in the integrated circuit. The semiconductor device having the Schottky junction manufactured by using the above-described manufacturing method is not limited to the Schottky diode and may be a semiconductor device having another configuration.

[0084]

According to the present invention, in a semiconductor device having a Schottky junction, the Schottky junction component is
It is formed through a step of forming a thin film made of a conductive material containing silicon and a patterning step of the thin film,
The thin film contains silicon grains so that the silicon residue is uniformly left in the region where there are no Schottky junction components on the surface of the semiconductor layer. As a result, variations in the electrical characteristics of a plurality of semiconductor devices manufactured simultaneously on one semiconductor wafer are suppressed, and the reproducibility of the electrical characteristics of the semiconductor devices is improved. Furthermore, when the semiconductor device is a Schottky diode, the forward voltage of the diode is ensured to be within the range of the forward voltage required for the Schottky diode.

Further, according to the present invention, in the semiconductor device having the Schottky junction, the thin film which is the source of the component for the Schottky junction contains the silicon particles so that the silicon residue is distributed in a chain shape. . Furthermore, according to the present invention, in the thin film which is the source of the component for Schottky bonding, the occupied area per unit area of the silicon residue is 5 unit area.
%, And silicon particles are contained so as to have an area of 10% or more. Further, according to the present invention, the thin film which is a source of the component for the Schottky junction has a thickness occupied by the silicon residue,
The thickness should be 5% or more and 10% or less of the thickness of the thin film,
Contains silicon grains. According to these inventions, variations in the electrical characteristics of a plurality of semiconductor devices manufactured simultaneously on one semiconductor wafer can be further suppressed, and reproducibility of the electrical characteristics of the semiconductor devices can be further improved.

As described above, according to the present invention, in the method of manufacturing a semiconductor device having a Schottky junction, the silicon grains contained in the thin film are formed at the time of forming the thin film which is the source of the component for the Schottky junction. The content state is controlled by the state of the magnetic field of the magnetron sputtering device. The state of the magnetic field of the magnetron sputtering apparatus is set so that the silicon particles are contained in the thin film to be formed so that the silicon particles can uniformly remain on the region where the thin film is removed in the semiconductor layer surface. There is. As a result, it is possible to suppress variations in the electrical characteristics of a plurality of semiconductor devices manufactured simultaneously on one semiconductor wafer and to improve the reproducibility of the electrical characteristics of the semiconductor devices. According to the invention, the strength of the magnetic field during the sputter is
It is always kept at a predetermined strength. As a result, variations in electrical characteristics of the semiconductor device are further suppressed, and reproducibility of electrical characteristics of the semiconductor device is further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a Schottky diode 22 which is a semiconductor device having a Schottky junction according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a magnetron sputtering apparatus 1 used for manufacturing the Schottky diode shown in FIG.

FIG. 3 is a process diagram showing a process of manufacturing the Schottky diode 22 of FIG. 1 using the magnetron sputtering apparatus of FIG.

FIG. 4 shows a forward voltage V in a single semiconductor wafer 8.
FIG. 6 is a plan view of the semiconductor wafer 8 for showing the position of the Schottky diode 22 where F is measured.

FIG. 5 is a diagram showing a state where a region 29 without a Schottky junction electrode 28 in a surface of a semiconductor layer 23 of a Schottky diode 22 manufactured by a manufacturing method of the present invention is observed by a microscope.

FIG. 6 is a diagram showing a state in which a region without a Schottky junction electrode in a surface of a semiconductor layer of a Schottky diode manufactured according to a conventional manufacturing method is observed by a microscope.

FIG. 7 is a forward voltage VF of the Schottky diode 22.
5 is a graph showing the relationship between the thickness of the silicon residue 30 and.

FIG. 8 is a diagram showing a state in which a region without a Schottky junction electrode in a surface of a semiconductor layer of a Schottky diode manufactured according to a conventional manufacturing method is observed with a microscope.

FIG. 9 is a spectrum showing a result of electron probe microanalysis analysis of the Schottky junction electrode 28 of the Schottky diode 22 having a forward voltage of 327 mV, which is manufactured by the manufacturing method of the present invention.

FIG. 10 is a Schottky diode 22 manufactured according to the manufacturing method of the present invention and having a forward voltage of 389 mV.
3 is a spectrum showing a result of electron probe microanalysis analysis of the Schottky junction electrode 28 of FIG.

FIG. 11 is a Schottky diode 22 manufactured according to the manufacturing method of the present invention and having a forward voltage of 482 mV.
3 is a spectrum showing a result of electron probe microanalysis analysis of the Schottky junction electrode 28 of FIG.

[Explanation of symbols]

22 Schottky diode 23 Semiconductor layer 28 electrodes 29 removal area 30 Silicon residue 31 magnetron sputtering equipment 33 Target 34 Storage container 35 power source 36 Magnetic source 38 Semiconductor wafer 41 double pole type electromagnet 43,44 Electromagnetic coil

Continuation of front page (51) Int.Cl. ⁷ Identification code FI // C23C 14/35

Claims (6)

(57) [Claims] 1. A semiconductor layer made of a semiconductor material containing silicon, and a Schottky junction part made of a conductive material containing silicon and forming a Schottky junction with the semiconductor layer, wherein the Schottky part is provided. First, a thin film of a conductive material containing silicon is formed on the surface of a semiconductor layer.
Formed by a step and a second step of removing a portion of the formed thin film, the thin film containing silicon particles so that the silicon particles remain uniformly in a region of the surface of the semiconductor layer where the thin film is removed. A semiconductor device characterized in that. 2. The silicon particles contained in the thin film are distributed so that the silicon particles remain in a chain shape in a region of the surface of the semiconductor layer where the thin film has been removed. Semiconductor device. 3. The thin film is made of silicon so that the area occupied by the silicon particles remaining in the region where the thin film on the surface of the semiconductor layer is removed is 5% or more and 10% or less of the unit area. The semiconductor device according to claim 2, wherein the semiconductor device contains grains. 4. The thin film is made of silicon so that the occupied thickness of silicon grains remaining in the region of the surface of the semiconductor layer where the thin film is removed is selected to be 5% or more and 10% or less of the film thickness of the thin film. The semiconductor device according to claim 2, wherein the semiconductor device contains grains. 5. A method of manufacturing a semiconductor device having a Schottky junction, wherein a thin film of a conductive material containing silicon is formed on a surface of a semiconductor layer made of a semiconductor material containing silicon by using a magnetron sputtering device. First
And a second step of removing a part of the formed thin film and leaving a Schottky junction component for Schottky junction with the semiconductor layer on the semiconductor layer. A method for manufacturing a semiconductor device, characterized in that the thin film to be formed is set to contain silicon particles so that the silicon particles remain uniformly on the region where the thin film on the layer surface is removed. 6. The method of manufacturing a semiconductor device according to claim 5, wherein the strength of the magnetic field of the magnetron sputtering apparatus is always maintained at a predetermined strength while the sputtering is performed.