JP2000268740A - Ion generator, ion radiator, ion radiation method and manufacture of semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable generation of low melting point metal material ions stably over a long period of time by leading the ions generated by sputtering a material plate containing an ion generation element retained at an inner wall surface of a box-like vessel by means of the plasma generated by the gas led into the vessel, out of the vessel, and holding a generated liquid. SOLUTION: A material plate 29 mounted demountably in a slit 31 of an inner wall of an arc chamber 21 of an ion source chamber of a Burnus type is subjected to sputtering of Ar gas by the plasma generated by thermoelectron from a filament to thereby generate ions which are led out from a drawing outlet 23. Only In ions in the ions from the material 29 of high melting point InSb monocrystal type is implanted into a sample after they are separated by a separation electromagnet. The In made excessive by evaporation of Sb having a high evaporation Te is melted and flows to a lower inclination 31B of the slit 31 passing through a through hole 31D from an upper inclination 31A of the slit 31. Since the filament is not close to an opposite electrode 24, no abnormal electric discharge is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an ion generator,
The present invention relates to an ion irradiation apparatus, an ion irradiation method, and a method for manufacturing a semiconductor substrate.

[0002]

2. Description of the Related Art An ion implantation method (ion irradiation method) is widely used as a method for forming a PN junction by introducing impurities such as boron (B), phosphorus (P), and arsenic (As) into a semiconductor substrate. ing. According to this ion implantation method, the impurity concentration and depth can be precisely controlled and introduced into a target location.

[0003] The ion source chamber, which is the heart of an ion implantation apparatus (ion irradiation apparatus), is roughly classified into a Freeman type using a hot electrode, a Bernas type, and a microwave type using a magnetron.

FIG. 4 shows a conventional burner type (Burnus type).
FIG. 2A shows a cross-sectional structure of a type ion source chamber. FIG. 1A shows a cross section parallel to the upper surface of the chamber, and FIG. 2B shows a cross section parallel to a side surface of the chamber. . A tungsten filament 27 is provided on one end face of the arc chamber 21 via an insulating support 25 and a reflector (spacer) 26, and a counter electrode 24 is provided on the other end face of the arc chamber 21 via the insulating support 25. Is provided.

Next, a method for extracting ions by using this apparatus will be described. The gas chamber 22 supplies, for example, Ar gas, emits thermoelectrons from the tungsten filament 27, and deflects the direction of motion of the thermoelectrons by the counter electrode 24 in a direction opposite to the direction emitted from the filament, thereby forming an arc chamber. Ionization is performed by increasing the probability of collision between the Ar gas introduced into 21 and thermionic electrons. While ions are extracted from the ion extraction port 23 provided in the front plate 28, FIG. 5 shows a cross-sectional structure of a conventional Freeman Type ion source chamber, and FIG.
Is a cross section parallel to the upper surface of the chamber, and FIG. 2B is a cross section parallel to the side surface of the chamber. A reflector 46 is provided on each of the opposing surfaces of the arc chamber 41 via an insulating support portion 45, and a rod-shaped tungsten filament 47 is provided between the opposing reflectors 46.

Next, a method of extracting ions using this apparatus will be described. For example, Ar gas is supplied from the gas introduction port 42, and at the same time, thermal electrons are emitted from the tungsten filament 47 to generate plasma. At the same time, a magnetic field parallel to the filament 47 and a rotating magnetic field due to the filament current are generated by the electromagnet 50, and the reflector 46
The electrons move in the arc chamber 41 in a complicated manner by the action of
The collision probability between the thermoelectrons emitted from the gas and the gas supplied from the gas inlet 42 is increased. Then, ions are extracted from the ion extraction port 43 provided in the front plate.

FIG. 6 is a sectional structural view of a microwave type ion source chamber. In order to extract ions using this apparatus, a microwave is generated by a magnetron 61 and the generated microwave is transmitted to a waveguide 62.
Through the discharge chamber 63 to generate plasma in the discharge chamber 63 corresponding to the above-described arc chamber, and extract ions through the extraction electrode 64.

In these conventional ion source chambers, ions to be irradiated are generally obtained by introducing a gas or a vapor obtained by sublimating an individual into an arc chamber, and ionizing with a plasma. Was. That is, in the above-described conventional ion source chamber, it is essential that ions to be irradiated be supplied as vapor (gas). However, for high melting point metals such as B (boron) and Ti (titanium), for example, Ti needs to be heated to 1400 ° C. or more in order to obtain a vapor pressure of about 10 ⁻⁴⁰ Torr required for ion implantation. In fact, ion implantation by this method was impossible.

On the contrary, indium has a melting point of about 15
Since it was too low at 6 ° C., it was easily melted in plasma, and was extremely inconvenient. On the other hand, a method of ion implantation using a chloride gas, an oxide gas, a fluoride gas or the like of these metals has been developed, and these high melting point metals can be used. However, in this method, corrosion of the inner wall of the arc chamber and the filament for thermionic emission due to chlorine, fluorine or a chlorine compound, a fluorine compound, or the like due to chloride gas or fluoride gas was inevitable.

For In, a method using a chloride gas has been attempted. For example, when ionization is performed by introducing vapor obtained by heating InCl ₃ to 330 ° C. into the conventional ion source chamber shown in FIG.
Other chlorine ions or radicals dissociated from l ₃ etches the inner wall of the arc chamber composed mainly of tungsten, since even tungsten filament etches, leading to increased resistance to thinning of the filament remarkably arc The control required for discharge can no longer be performed. Further, the extraction electrode was also etched, so that stable extraction of ions could not be performed. As a result, abnormal discharge frequently occurred in about 5 hours, and ion implantation became impossible.

As described above, as long as the high-melting point metal and In are ionized using the chlorine-based compound, the inner wall of the arc chamber and the tungsten filament are etched by chlorine ions and chlorine radicals generated by the ionization. Could not be avoided.

Further, when a chloride gas such as indium chloride and a fluoride gas such as boron fluoride and germanium fluoride are alternately introduced into the same arc chamber and ionized, for example, fluorine is introduced when boron fluoride is introduced. Adsorbs on the wall surface and reacts when chloride gas is introduced to form chlorine fluoride, a strong oxidizing agent, and tungsten, molybdenum,
Despite being made of a stable high melting point material such as graphite, there is a problem that the corrosion of the inner wall of the arc chamber and the filament for emitting thermoelectrons is accelerated. Further, there is a problem that fluorine and chlorine in the exhaust gas need to be removed, which increases the cost of the apparatus. In the case of an oxide gas, carbon (graphite) -based members used for an ion generator or an ion irradiation device, particularly an electrode for extracting ions, are oxidized, and the life of the device is significantly shortened. There was a problem.

In particular, the filament is corroded by chlorine and fluorine, and it is difficult to obtain a stable arc discharge for a long period of time. In addition, ion implantation of noble metals such as gold and platinum from which chlorides cannot be easily obtained was still extremely difficult.

Furthermore, solid fluorides are deliquescent, and are extremely inconvenient to use, for example, reacting with water in the atmosphere and melting while filling in a heating oven for vaporization. Was.

In response to the above-mentioned problems, the present inventors have shown in FIG. 7 that a plate-like material 29 made of a desired ion source is provided in an arc chamber 21 as shown as an example of an improved version of the Bernus type ion source chamber. And a method in which plasma is generated in the arc chamber 21 and the material 29 is sputtered to generate desired ions (hereinafter referred to as sputtered ions).
188833). This method was extremely excellent in that ions of a high melting point metal, which were practically impossible with each of the above methods, could be easily generated. Here, in the above description of FIG. 7, the same parts as those of the ion source chamber shown in FIG. 4 are denoted by the same reference numerals, and the description is omitted.

However, even with the above-mentioned method using sputtering ions, a metal having a low melting point, such as In, or Sb
As described above, it is still very difficult to stably perform ion implantation of a metal in which a single solid is unstable.

On the other hand, in the conventional method of manufacturing a semiconductor substrate, P
When ion-implanting a type impurity and an N-type impurity, it is usual to use another ion implantation apparatus or to exchange a source gas and a solid source as an ion source. For this reason, when another apparatus is used, two or more ion implantation apparatuses are required for the same semiconductor processing, and when performing ion implantation by exchanging the ion source, the ion implantation can be stably performed after the exchange. Preparation time was needed to check the conditions. In any case, there has been a problem in reducing the manufacturing cost of the semiconductor device.

[0018]

As described above, in the conventional ion implantation apparatus, a metal having a low melting point such as In, Sb
However, it is still very difficult to stably perform ion implantation of a material in which a single solid is unstable.

In the conventional method of manufacturing a semiconductor device, P
When ion implantation of a type impurity and an N type impurity is performed, two or more ion implantation devices are required for the same semiconductor processing when using different devices. Requires a preparation time for checking conditions so that ion implantation can be stably performed after the replacement. In any case, there is a problem that the manufacturing cost of the semiconductor device cannot be reduced.

The present invention has been made to solve the above-mentioned problems, and is an ion generating apparatus and an ion irradiating apparatus capable of stably ion-implanting a metal having a low melting point or a material in which a single solid is unstable. And an ion irradiation method.

Further, the present invention provides a semiconductor device which can separate P-type impurities and N-type impurities without preparing time without exchanging an ion source when ion-implanting P-type impurities and N-type impurities. It is intended to provide a manufacturing method.

[0022]

In order to solve the above-mentioned problems, in an ion generator according to the present invention, a container formed in a box shape and a material containing an element generating the ions are formed on an inner wall surface of the container. Holding means for holding a plate, plasma generating means for generating desired ions by sputtering a material plate held by the holding means by generating plasma in the container, and plasma used for the sputtering Gas introducing means for introducing a gas capable of generating a gas into the container, a liquid holding unit for holding a liquid generated by the sputtering, and ion deriving means for extracting ions generated by sputtering on the material plate to the outside of the container. It is characterized by having.

Further, the invention is characterized in that the holding means doubles as the liquid holding portion. Next, in the ion irradiation apparatus according to the present invention, a container formed in a box shape, holding means for holding a material plate containing the element generating ions on the inner wall surface of the container, and Plasma generating means capable of generating desired ions by sputtering a material plate held by the holding means by generating plasma, and gas introduction for introducing a gas capable of generating plasma used for the sputtering into the container. Means, a liquid holding unit for holding a liquid generated by the sputtering,
An ion deriving means for deriving ions generated by sputtering on the material plate out of the container, and an ion deriving means for inducing the ions derived by the ion deriving means to a sample to be irradiated with the ions. I do.

Further, in the ion irradiation method according to the present invention,
A step of introducing a gas into a container holding a solid material composed of two or more elements therein, and irradiating the gas with the gas in the container and irradiating the material, and sputtering the material with its constituent elements. An ion generating step of generating certain ions, a liquid storing step of storing, in a liquid holding unit, a liquid composed of the constituent elements of the material generated on the material surface in the ion generating step, and drawing the ions out of the container The method is characterized by comprising an ion deriving step, an ion deriving step of inducing ions extracted outside the container to a sample to be irradiated, and an ion irradiating step of irradiating a desired sample with the induced ions.

Further, in the ion irradiation method according to the present invention, a step of introducing an inert gas into a container holding therein a material comprising two or more elements and capable of generating desired ions, and introducing nitrogen into the container. A step of introducing a gas, generating plasma in the container, converting the inert gas to the nitrogen gas into plasma, irradiating the material, and sputtering the material to generate ions as constituent elements thereof. An ion generating step, a nitriding step of nitriding a liquid composed of one of the constituent elements of the material generated on the material surface in the ion generating step with the nitrogen gas, and an ion deriving step of leading the ions out of the container. An ion inducing step of inducing ions led out of the container to a sample to be irradiated, and an ion irradiation step of irradiating a desired sample with the induced ions. Characterized in that it has and.

The above-mentioned ion irradiation method is particularly characterized in that the liquid has a melting point of 800 ° C. or less. Finally, in the method of manufacturing a semiconductor device according to the present invention, in the method of manufacturing a semiconductor device having a first impurity region and a second impurity region into which different impurities are implanted, a desired ion comprising two or more elements A step of introducing a gas into a container holding a material capable of generating a gas, and irradiating the material with the gas by generating a plasma in the container to irradiate the gas, and sputtering the material. An ion generating step of generating two or more types of ions that are elements, an ion deriving step of extracting the two or more types of ions out of the container,
A first step of forming the first impurity region in the semiconductor device formation scheduled region on the semiconductor substrate surface by mass-separating and accelerating desired first ions from ions of at least one kind and irradiating the semiconductor substrate surface with the first ions An ion implantation step, and mass separation of desired second ions from two or more kinds of ions led out of the container, acceleration of the second ions, and irradiation of the semiconductor substrate surface with the semiconductor device formation region on the semiconductor substrate surface A second ion implantation step of forming the second impurity region.

[0027]

Embodiments of the present invention (hereinafter, abbreviated as embodiments) will be described below with reference to the drawings. First, with reference to FIG. 1, an outline of the entire configuration of an ion irradiation apparatus, an ion generation method, and an irradiation method will be described. The present invention has a significant feature in an ion source chamber 1 (arc chamber) serving as an ion generator as described later, and the other configuration shown in FIG. 1 is the same as the configuration of the conventional ion irradiation apparatus. .

In the ion irradiation apparatus shown in FIG. 1, ions are first generated in the ion source chamber 1 (the details will be described later). Next, the ions are extracted by the extraction electrode 2 adjacent to the ion source chamber 1 and introduced into the separation electromagnet 3, where they are mass-separated for each ion species according to charge and mass. The ions that have passed through the separation electromagnet 3 are subsequently introduced into the slit 4, where only desired ion species are completely separated. The separated desired ion species is accelerated or decelerated by the accelerator 5 to a desired final energy. Then, an ion beam having a desired energy is applied to the sample 12 by the quadrupole lens 6.
It is focused so that it has a focusing point on the surface of a (for example, a semiconductor substrate). Subsequently, scanning is performed by the scanning electrodes 7 and 8 so that the injection amount becomes uniform over the entire sample surface. Then, in order to remove neutral particles generated by collision with the residual gas, the deflection electrode 9 is used.
As a result, the ion beam is bent, and the surface of the sample 12 is irradiated with the ion beam through the mask 10. 11 is a ground.

Hereinafter, the ion source chamber 1 shown in FIG.
(Ion generating device) and an ion generating method using the same,
Details of the ion irradiation method and the like will be described with reference to the drawings.

(First Embodiment) First, referring to FIG.
A first embodiment of the present invention will be described. FIG. 2 shows a cross-sectional structure when the material plate 29 is placed in the burner-type ion source chamber according to the first embodiment of the present invention, and FIG. 2A is parallel to the upper surface of the chamber. Cross section,
FIG. 4B shows a cross section parallel to the lateral side surface of the chamber, and FIG. 5C shows a cross section parallel to the vertical side surface of the chamber.

The basic configuration is the same as that of the conventional burner type ion source chamber shown in FIG. That is, a tungsten filament 27 is provided on one end face of an arc chamber 21 composed mainly of tungsten via an insulating support 25 and a reflector 26 (spacer), and an insulating face is provided on the other end face of the arc chamber 21. The counter electrode 24 is provided via the support 25. Then, Ar gas is supplied from the gas inlet 22, and desired ions are extracted from the ion extracting port 23 provided in the front plate 28.

The ion source chamber (arc chamber) 21 usually has an ion outlet 23 as an upper surface,
The gas inlet 22 is placed so as to be located on the lower surface. In the ion generator of the present embodiment, a slit 31 is provided along the inner wall of the arc chamber 21, and a material plate 29 for extracting desired ions is detachably provided in the slit 31. Therefore, the material plates can be easily replaced according to the ions to be extracted. Then, thermal electrons are emitted from the filament 27 to generate plasma, and desired ions can be extracted from the material plate 29 by sputtering of Ar gas.

The material plate 29 may be provided on at least a part of the inner wall surface of the arc chamber 21. Preferably, the material plate 29 has four inner surfaces other than the pair of opposing surfaces to which the filament 27 and the opposing electrode 24 are attached. It is desirable to be installed on at least one or more of the walls. Further, the material plate 29 may be provided on at least a part of the installation surface, but the sputtering efficiency is better if the material plate 29 is provided on the entire surface.

Next, the ion generating method and the ion irradiating method according to the present embodiment will be described in detail with reference to the method of generating and irradiating indium (In) ions. In this embodiment, an InSb single crystal substrate is used as a material plate serving as an ion source. The InSb substrate has a high melting point, unlike single indium metal (melting point: 156 ° C.). It is industrially available and stable at room temperature. Furthermore, since it is a single crystal, the composition is extremely stable.

In the present embodiment, this InSb is processed into a plate shape and installed on three surfaces of a pair of side walls and a bottom surface of the inner wall surface of the tungsten arc chamber 21. Next, after performing a predetermined start-up operation, Ar gas is supplied from the gas inlet 22 and thermions are emitted from the filament 27. The Ar gas is turned into plasma, and the sputtering effect of the plasma particles causes the material to become material. Plate (InSb)
Sb and In were derived from 29 and ionized by discharge. Generated Sb ion, In ion and Ar
The ions were extracted through the extraction port 23. Among them, only the In ions were extracted by the separation electromagnet,
The sample was ion implanted.

In this case, the acceleration voltage is about 4 m at 180 KeV.
A beam current of A was stably obtained for about 50 hours (10 times the conventional value). As shown in the above conventional example, when the vapor obtained by heating InCl ₃ to 330 ° C. is introduced into the conventional ion source chamber to perform ionization, abnormal discharge frequently occurs in about 5 hours. Then, ion implantation could not be performed.

By adopting the configuration of the present invention, it has become possible to carry out ionization extremely stably for a long time. In addition,
The present invention is not limited to the embodiment described above.

In the embodiment described above, In or Sb is used as the metal to be ionized. However, there is a possibility of melting in other ion chambers, and ions of many metal elements capable of forming a stable compound are formed. Applicable for injection. For example, aluminum (Al: melting point 660)
C), gallium (Ga: melting point 30 ° C.), thallium (T
l: Melting point 303 ° C), tin (Sn: melting point 232 ° C), lead (Pb: melting point 328 ° C), zinc (Zn: 420 ° C), cadmium (Cd: melting point 321 ° C), etc. . In particular, Group 3 element metals are easily used because they form stable compounds with Group 5 elements.
Various Group 35 compounds such as GaAs can be used. In particular, InSb, GaAs, and the like can be used as a compound semiconductor crystal and can stably generate ions. Similarly, Zn and Cd are also group 2 compounds, such as ZnSe and CdT.
By using e or the like, ions can be generated stably. Sn and Pb are Group 5 elements, but Sn oxide, Pb
It is possible to form a compound having a higher melting point than pure Sn and Pb as an oxide, and it can be used as an ion generating material.

It is not necessary to use one kind of material, and a material plate using different materials (such as GaAs and InSb) may be provided on each inner wall surface. In this case, many kinds of elements can be ionized at the same time, and ions can be selected by mass separation using an ionizing magnet.

(Second Embodiment) According to the above-described embodiment, it has become possible to stably and continuously carry out the generation of In ions for about ten times as long as that of the conventional one.

However, even if the above method is used, if the generation of ions is continued for more than 50 hours, problems such as abnormal discharge occur. As a result of repeated studies by the present inventors on the above problem, it has been found that when an abnormal discharge occurs, In metal remains even though the simple In is not used on the inner wall of the arc chamber. . Also, when In metal was found around the filament and the electrode, the abnormal discharge seemed to be particularly large.

The above phenomenon is caused by the fact that as a result of continuing discharge using InSb as a material, Sb having a high vapor pressure evaporates little by little first, resulting in an excess of In, and furthermore, a single In metal is formed, and the inside of the arc chamber is formed. It was considered that the material melted and moved. In particular, it was presumed that when In moved and came around the filament and the electrode, a discharge path was formed locally and abnormal discharge frequently occurred. As a result of analysis by the present inventors, under the above conditions (180 V, 4 mA), when the size of the chamber is 220 ml (total volume of tungsten as a chamber material is 100 ml), the temperature inside the chamber is raised from 500 ° C. to 800 ° C. Estimated,
It was expected that not only In but also the above-mentioned low melting point metal would be almost melted.

To solve the above problem, nitrogen gas was introduced into the arc chamber in addition to Ar gas at the time of ion generation. Introducing nitrogen gas causes InS
The excessive In remaining on the surface b was nitrided to form InN and became a solid, and did not move from the surface.

Even with such a method, since the nitrided InSb surface is constantly renewed by sputtering, there was no change in the sputter rate of each element.
By introducing nitrogen into the arc chamber in addition to Ar as described above, more stable ion generation and ion irradiation became possible.

The present embodiment is not limited to the above. For example, the discharge may be performed by using InN from the beginning on the inner wall of the arc chamber and using an inert gas or a mixed gas of an inert gas and nitrogen gas. Good. Even in such a form, the above effects can be enjoyed.

(Third Embodiment) Next, an example in which the above problem is addressed by improving the structure of an arc chamber as a third embodiment of the present invention will be described with reference to the drawings.

FIGS. 3 (a), 3 (b) and 3 (c) all correspond to a cross section parallel to the lateral side surface of the arc chamber shown in FIG. 2 (b). It is. In the following description, the same portions as those in FIG. 2B are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment shown in FIG. 3 (a), the material plates 29 are placed on opposite sides of the inner wall of the arc chamber. Also, no material plate is placed on the bottom surface.
In the present embodiment, the material plate is inserted and fixed in the slit 31. However, unlike each of the above-described embodiments, the slit 31 is formed deep, and an upper inclined portion 31A that extends upward is provided above the slit 31. Is formed. Further, in the lower portion of the slit 31, a lower slope 31B which extends downward in a direction opposite to that of the slit 31A is formed in a groove shape in a direction perpendicular to the cross section shown in FIG. The material plate fixing portion 31C is provided with a through hole 31D so as to intermittently connect 31A and 31B.
Are formed.

When ions were generated using the arc chamber according to the present embodiment, the excess In metal formed on the InSb surface passed through 31D along the slit 31A through 3D.
It flowed into 1B and did not move from there. As a result, inconveniences such as abnormal discharge could be prevented.

The present embodiment is effective even if only the slope 31A is formed. Also, there is no slope 31A part,
Only the slope 31B and a path into which the liquid (In metal) can flow may be secured. Also, the slope 31
It goes without saying that the shapes of A and 31B are not limited to the above.

FIG. 3B shows a first modification of the present embodiment. In the first modification, the material plate 29
A plate equivalent to is also placed on the bottom. However, this plate is a perforated material plate 29A having fine holes 29B formed on the entire surface.
It is. The lower part of the perforated material plate 29A is shaved to form a recess 21A. With such a configuration, the liquid such as In generated on the surface of the material plate 29 to the perforated material plate 29A flows into the depression 21A through the minute hole 29B, and is not exposed to the plasma. Was prevented. FIG. 3C shows a second modification of the present embodiment. In the present embodiment, unlike the first modification, a hole is not formed in the material plate 29, a gap 31E is secured between the material plate on the side surface and the material plate on the bottom surface, and the bottom of the arc chamber is connected to the support 21C. A part was shaved to leave a liquid reservoir such as In.

As described above, in the present embodiment and the first and second modified examples, it is necessary to avoid exposure to plasma by dropping a liquid such as In below the material plate. The form is not limited to the above.

Next, a third modification of the embodiment of the present invention will be described. The present modification is characterized in that a mesh-shaped or wire-meshed cover made of a refractory metal such as tungsten or molybdenum is provided on the surface of a material plate instead of securing a liquid holding portion such as In. By providing such a cover, a liquid such as In is condensed around a wire mesh, tungsten forming a mesh, or the like because of high surface tension, and is not scattered around. This modification is different from the above-described embodiment and the first and second modifications, and does not require processing of the arc chamber, but can be implemented only by installing a mesh-shaped cover. The mesh or wire mesh may be made of a metal having a higher melting point than the liquid generated from the material plate.
A metal having a melting point of 000 ° C. or more is desirable.

(Fourth Embodiment) Next, a method of implanting a plurality of types of ions into a semiconductor substrate by using the ion generation methods according to the first to third embodiments will be described.
FIGS. 1 and 2 show an example in which Sb ions are sequentially implanted.
This will be described with reference to FIG.

First, as shown in FIG. 2, after holding an InSb plate as a material plate 29 on the inner wall of the arc chamber 21, for example, an Ar gas is supplied from the gas inlet 22, and thermoelectrons are emitted from the tungsten filament 27. By deflecting the direction of movement of the thermoelectrons by the counter electrode 24 in the direction opposite to the direction emitted from the filament, the probability of collision between the Ar gas introduced into the arc chamber 21 and the thermoelectrons is increased to perform ionization. As a result, the ion extraction port 2 provided in the front plate 28
3, In ions and Sb ions can be extracted.

Next, as shown in FIG. 1, the In ions and Sb ions are extracted by the extraction electrode 2 adjacent to the ion source chamber 1 and introduced into the separation electromagnet 3, where only the In ions are slit 4. Are separated according to the charge and the mass as introduced into the mass. Slit 4
Are completely separated there. The separated desired In ions are accelerated or decelerated by the accelerator 5 to a desired final energy. Then, an In ion beam having a desired energy is applied to the quadrupole lens 6.
Thereby, the light is focused so as to have a focal point on the surface of the sample 12 (for example, a semiconductor substrate). Subsequently, scanning is performed by the scanning electrodes 7 and 8 so that the injection amount becomes uniform over the entire sample surface.
The ion beam is bent by the deflecting electrode 9 to remove neutral particles generated by collision with the residual gas, and the desired portion of the semiconductor device formation region on the surface of the sample 12 is irradiated with the In ion beam through the mask 10. Is done. 11
Is earth.

At this time, only a desired portion of the sample 12 to be ion-implanted is opened, and the other portion is covered with a mask. After the above-described ion implantation, the mask on the sample 12 is replaced, and the ions applied to the slit 4 are changed to Sb ions by changing the voltage applied to the separation electromagnet 3, and the ion implantation is performed again. As a result, S
b can be ion-implanted.

By using this method, without changing the material inside the arc chamber, the N
It is possible to form a p-type impurity region and a p-type impurity region. In the above embodiments, the generation of In ions has been described. However, the amount of Sb, which is a constituent element of the same material plate, is sufficient to act as an impurity in the silicon substrate. . Of course, the same impurity amount was obtained for In.

Further, even when GaAs, InAs, GaSb, or the like is used, the desired impurity amount can be similarly obtained for both the group 3 element and the group 5 element. Each embodiment described above can be applied to, for example, manufacturing (ion implantation) of a semiconductor substrate.

For example, an impurity diffusion layer of a MOS transistor can be formed by introducing In ions into a semiconductor substrate. In particular, when attempting to introduce divalent ions of In into a semiconductor substrate, in addition to the above-mentioned problems, Fe (iron) is mixed from an oven or a gas pipe in the case of ionization with InCl ₃ or an organic gas. Thus, there is a problem that this Fe is also ionized. This Fe
Is equal to the radius of curvature of the divalent ion of In.
Mass separation is extremely difficult with a separation electromagnet. When this iron is introduced into the semiconductor substrate, problems such as deterioration of the characteristics of the PN junction are caused.

Therefore, by performing the sputtering ion implantation according to the present invention, there is an effect that impurities can be extremely easily and stably introduced into the substrate without causing a contamination problem.

Further, in each of the embodiments described above, an example was described in which Ar was used as a support gas for performing sputtering. However, other support gases may be used. It is needless to say that a material other than tungsten, such as graphite, can be used for the filament and the chamber.

Further, in the embodiment described above, the method using the Bernas type ion source has been described, but it is needless to say that the present invention can be applied to other methods. In addition, the present invention can be variously modified and implemented without departing from the spirit thereof.

[0064]

According to each of the above embodiments, low melting point metal material ions can be stably generated over a long period of time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an ion irradiation apparatus.

FIG. 2 is a cross-sectional structural view when a material plate is placed in a burner type ion source chamber according to the first embodiment of the present invention.

FIG. 3 is a sectional structural view of an arc chamber according to a third embodiment of the present invention.

FIG. 4 is a view showing a cross-sectional structure of a conventional burner type ion source chamber.

FIG. 5 is a diagram showing a cross-sectional structure of a conventional Freeman-type ion source chamber.

FIG. 6 is a diagram showing a cross-sectional structure of a conventional microwave ion source chamber.

FIG. 7 is a diagram showing a cross-sectional structure of an improved burner-type ion source chamber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ion source chamber 2 ... Extraction electrode 3 ... Separation electromagnet 4 ... Slit 5 ... Accelerator 6 ... Quadrupole lens 7, 8 ... Scanning electrode 9 ... Deflection electrode 10 ... Mask 11 ... Ground 12 ... Sample 21, 41 ... Arc chamber 21A ... Depressions 22, 42: Gas introduction ports 23, 43 ... Ion extraction ports 24 ... Counter electrodes 25, 45 ... Insulating support parts 26, 46 ... Reflectors 27, 47 ... Filament 28 ... Front plate 29 ... Material plate 29A ... Perforated material plate 29B: Micro hole 31: Slit 31A: Upper slope of slit 31B: Lower slope of slit 31C: Material plate fixing part 31D: Through hole 50: Electromagnet 61: Magnetron 62: Waveguide 63: Discharge box

Claims (7)

[Claims] 1. A container formed in a box shape, holding means for holding a material plate containing the ion-generating element on the inner wall surface of the container, and a plasma generated in the container to generate the ions. Plasma generating means for generating desired ions by sputtering a material plate held by holding means, gas introducing means for introducing a gas capable of generating plasma used for the sputtering into the container, and gas generated by the sputtering An ion generator, comprising: a liquid holding unit for holding a liquid; and ion deriving means for deriving ions generated by sputtering on the material plate out of the container. 2. The ion generator according to claim 1, wherein said holding means also serves as said liquid holding section. 3. A container formed in a box shape, holding means for holding a material plate containing the element generating ions on the inner wall surface of the container, and generating plasma in the container. Plasma generating means for generating desired ions by sputtering a material plate held by holding means, gas introducing means for introducing a gas capable of generating plasma used for the sputtering into the container, and gas generated by the sputtering A liquid holding unit for holding a liquid, ion deriving means for deriving ions generated by sputtering on the material plate out of the container, and guiding the ions derived by the ion deriving means to a sample to be irradiated with the ions; An ion irradiation device having ion induction means. 4. A step of introducing a gas into a container holding a solid material composed of two or more elements therein, and irradiating the material with the gas into plasma in the container and sputtering the material. An ion generating step of generating ions that are constituent elements thereof, a liquid storing step of storing a liquid composed of the constituent elements of the material generated on the material surface in the ion generating step in a liquid holding unit, and An ion deriving step of deriving ions extracted outside the container, an ion deriving step of directing ions extracted outside the container to a sample to be irradiated, and an ion irradiation step of irradiating a desired sample with the induced ions. An ion irradiation method characterized in that: 5. A step of introducing an inert gas into a container containing a material comprising two or more elements and capable of generating desired ions therein, and a step of introducing nitrogen gas into the container.
An ion generating step of generating plasma in the container, converting the inert gas to the nitrogen gas into plasma, irradiating the material, and sputtering the material to generate ions as constituent elements thereof; and A nitriding step of nitriding a liquid composed of one of the constituent elements of the material generated on the material surface in the generating step with the nitrogen gas, an ion deriving step of deriving the ions out of the container, and being led out of the container. An ion irradiation method, comprising: an ion induction step of inducing a sample to be irradiated with the extracted ions; and an ion irradiation step of irradiating a desired sample with the induced ions. 6. The ion irradiation method according to claim 4, wherein the melting point of the liquid is 800 ° C. or less. 7. A method for manufacturing a semiconductor device having a first impurity region and a second impurity region into which different impurities have been implanted, wherein a material comprising two or more elements and capable of generating desired ions is held inside. A step of introducing a gas into the container, and irradiating the material with the gas by generating a plasma in the container to irradiate the material, and sputtering the material to form two or more ions that are constituent elements of the material. An ion generating step to generate, an ion deriving step of deriving the two or more ions out of the container, and mass separating and accelerating a desired first ion from the two or more ions deducted out of the container A first ion implantation step of irradiating the semiconductor substrate surface to form the first impurity region in the semiconductor device formation planned region on the semiconductor substrate surface; Desired second ions are mass-separated from two or more kinds of ions led out of the chamber, accelerated, and irradiated to the surface of the semiconductor substrate, so that the second impurity is added to the semiconductor device formation planned region on the semiconductor substrate surface. A second ion implantation step of forming a region.