JP4221524B2 - Mass analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mass analyzer that mainly measures the mass of gaseous molecules, and more particularly to a mass analyzer that operates even in a high-pressure atmosphere during a process such as sputtering.
[0002]
[Prior art]
The principle of mass measurement of gaseous molecules is that after ionizing a molecule to be measured, the ions are subjected to electromagnetic mass separation so that only ions having a specific mass / charge value reach the collector, and the current is Measure.
[0003]
As an electromagnetic mass separation method, a method using only a high-frequency electric field, a magnetic field, and a magnetic field and an electrostatic field is known, and representative mass analyzers include a mass filter type, a sector type, an E × B type, and the like. There is.
[0004]
In order to operate a mass analyzer in a high pressure atmosphere during a process such as sputtering, in addition to the requirements for a normal mass analyzer, 1) a short process of ions to be mass separated (mass analyzer) 2) It is necessary that stray ions scattered by gas molecules or electrodes do not reach the collector.
[0005]
The condition of 1) is necessary for ions to be mass separated to reach the collector without colliding with high-pressure, that is, high-density atmosphere gas, and this stroke is approximately the same as the mean free stroke of the gas. Is required. In an ordinary sputtering process, an Ar atmosphere of about 1 Pa is used, so that the ion stroke in the mass analyzer needs to be shortened to about 10 mm.
[0006]
As a mass analyzer that satisfies such conditions, there is a mass filter type mass analyzer that has an ultra-small overall size. However, in the case of a mass filter type mass spectrometer, the accuracy of the quadrupole pole is as severe as about 1 micron, and the frequency of the applied high frequency is as high as about 10 MHz, which makes the production cost very high. Yes. Moreover, since the energy of ions passing through the quadrupole pole must be as low as about 10 eV, it is difficult to distinguish between scattered stray ions and normally mass-separated ions, and sufficient performance is achieved. Not.
[0007]
The mass analyzer, also known as the E × B (Ecrosby) type, also known as the Wien filter type, allows ions to pass through a space (electromagnetic field) where the magnetic field and the electric field are orthogonal to each other and has a specific mass / charge value. This is a method for performing mass spectrometry by moving only straight, and has the advantages that the structure is simple and the precision and electrical control are not strict.
[0008]
However, the E × B type mass analyzer has a difficulty in generating a magnetic field in practical use, and is not widely used as a mass analyzer. Slightly used to purify irradiated ions with ion implantation equipment. In this case, since the mass of the impurity mixed with the irradiation ions is greatly different, it is sufficient that the mass resolution (width) is about 10 mass units (amu). Usually 10^-FourSince it is used in an atmosphere having a low pressure of Pa or less, the ion stroke in the mass analyzer is about 100 mm and the magnetic pole gap is about 30 mm in most cases.
[0009]
In a mass analyzer that uses only a magnetic field, such as a sector-type mass analyzer, the magnetic field generation space, that is, the magnetic pole gap, can be considerably narrowed, so that the electromagnet and magnet are not so large. However, in the E × B mass spectrometer, the magnetic field and the electrostatic field must be orthogonalized, so that the magnetic pole gap becomes large and the electromagnet and magnet become large.
[0010]
7A and 7B show conventional examples of the electromagnetic field portion of the E × B mass spectrometer. In FIG. 7A, reference numeral 1 denotes a yoke, reference numerals 2 and 3 denote magnets, and reference numerals 51 and 52 denote electrodes. In FIG. 7 (a), an enlarged view of the portion indicated by the broken line 104 is shown in FIG. 7 (b), which is indicated by reference numeral 100 surrounded by the magnets 2, 3 and the electrodes 51, 52. The space to be generated is an electromagnetic field portion, and the inside of a circle indicated by reference numeral 101 is a range through which the ion beam passes. Further, in FIG. 7B, electric lines of force are generated as indicated by reference numeral 102, and magnetic lines of force are generated as indicated by reference numeral 103. The distance between the magnets 2 and 3 in the electromagnetic field portion corresponds to the magnetic pole gap. Here, a permanent magnet is used for generating a magnetic field, and the magnet directly faces the electromagnetic field portion without using the magnetic pole. The ions that are mass-separated progress from the back side to the front side of the paper perpendicular to the paper surface, and the diameter thereof is represented as a circle 101. As indicated by the electric field lines 102 and the magnetic field lines 103, the magnetic field is formed in the vertical direction and the electric field is formed in the horizontal direction.
[0011]
The basic operation of the E × B type mass analyzer is that the intensity of the magnetic field and electric field is uniform within the range through which the ion beam passes, that is, inside the circle denoted by reference numeral 101 in FIG. Must be orthogonal. If this condition is satisfied, only the ion beam having a specific mass / charge amount travels straight from the back side of the paper surface toward the front side perpendicular to the paper surface. The beam is deflected in the left-right direction. Changing the intensity of the magnetic field and electric field changes the mass / charge amount of the ion beam that travels straight. Therefore, if an aperture and a collector electrode are installed at a position where the ion beam goes straight, mass separation can be performed. If the strength of the electric field and magnetic field is not uniform, the sensitivity and resolution are deteriorated.
[0012]
7A and 7B, the width of the electrode is increased in order to ensure the uniformity of the electric field. Due to the presence of this large width electrode, the magnetic pole gap is necessarily increased. Even in this large magnetic pole gap, the widths of the magnets 2 and 3 are increased in order to ensure the uniformity of the magnetic field. For these reasons, the magnets 2 and 3 and the yoke 1 must be very large.
[0013]
For this reason, an E × B type mass analyzer is rarely used as a normal mass analyzer. Moreover, an E × B type mass analyzer has never been used as a mass analyzer that can operate in a high pressure atmosphere during a process such as sputtering.
[0014]
As for conventional E × B type mass analyzers, in order to improve the uniformity of the magnetic field, Japanese Patent Application Laid-Open Nos. 4-351840 and 7-161337 using a plurality of electromagnets and a voltage applied to the magnetic poles are used. Japanese Patent Laid-Open No. 6-132007 exists in which an ion beam is deflected in a direction perpendicular to the mass separation direction.
[0015]
[Problems to be solved by the invention]
An object of the present invention is to realize a mass spectrometer that can be operated in a high pressure atmosphere during a process such as sputtering, has sufficient performance, and is low in manufacturing cost.
[0016]
In order to operate in a high pressure atmosphere, it is required that the ion process in the mass analyzer is very short as described above. In order to achieve this, it is necessary to make the magnetic pole gap of the E × B mass analyzer very small. This is due to the following two reasons.
[0017]
The first reason is the end face (fringe) effect, which is a problem common to all mass analyzers. That is, in the vicinity of the end face of the electromagnetic field space, the electromagnetic field strength becomes weak due to the influence of the outer space where no electromagnetic field exists, and mass separation cannot be performed in that part. That is, the ion passing direction length that can effectively perform mass separation is shortened. Specifically, it is known that effective mass separation is not performed for the length of about half of the electrode gap and the magnetic pole gap inside the respective end faces of the inlet and outlet. For a sputtering process of about 1 Pa, the length of the mass separator must be about 10 mm. Therefore, in order to secure a length for effective mass separation of about 7 mm, the electrode gap and the magnetic pole gap must be very small, about 3 mm.
[0018]
The second reason is to achieve the required strong magnetic field strength. In order to perform mass separation with a short mass separation portion of about 10 mm (effectively about 7 mm) and sufficient resolution, a strong magnetic field strength is required. Water (18 amu), which is a particular problem in the sputtering process, becomes the background Ar²⁺In order to perform measurement separately from (40 amu), a magnetic field strength of 5 to 10 kGauss is required. In order to achieve such a strong magnetic field strength without using an extremely large electromagnet or magnet, the magnetic pole gap needs to be very small, about 3 to 5 mm.
[0019]
However, if the E × B type mass analyzer is kept in the conventional structure and is shortened to about 3 mm in the magnetic pole gap, a large performance problem occurs. This state is shown in FIG. In FIG. 8, the uniformity of the magnetic field is maintained, but the uniformity of the electric field is not ensured. In other words, since the magnetic pole gap is reduced, the widths of the electrodes 51 and 52 are reduced, and a circle indicated by reference numeral 101 is a range through which an ion beam traveling from the back side to the front side of the paper passes perpendicularly to the paper. The surfaces of the magnets 2 and 3 exist in the immediate vicinity. When the magnet is a conductor, the surface of the magnets 2 and 3 becomes a certain voltage, and when the magnet is an insulator, the surface becomes a random potential in terms of time and place. It is not a uniform electric field in which the potential surface is parallel to the electrode surface, but a distorted electric field distribution that is strongly influenced by the potential of the magnet.
[0020]
[Means for Solving the Problems]
The inventor paid attention to an E × B type mass analyzer as a mass analyzer operable at a high pressure. That is, it was considered that the E × B type mass analyzer is essentially suitable for a high-pressure mass analyzer because of its simple structure and high ion energy of 100 to 1000 eV. In particular, high ion energy means that stray ions that form a background and ions that have been mass-separated normally can be easily separated with a separate electrostatic type deflector. As a great advantage. Therefore, the inventors have invented an electromagnetic field forming technique and attempted to solve the above-mentioned problems by causing the magnetic poles or the surface of the magnet for forming the magnetic field in the E × B mass spectrometer to function as electrodes for forming an electric field. Is.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
  In order to solve the above problems, the present inventor proposesMass analyzerIs as follows.
[0022]
  That is,This invention
  A magnetic field formed by a pair of magnets
  The voltage applied to the pair of electrodes located between the pair of magnets and 10 arranged on the opposite side of the pair of magnets ⁵ -10 ⁹ An electric field formed by applying a voltage to a pair of conductor films having a sheet resistance of Ω,
  In the electromagnetic field space formed by
  Pass the measured molecular ion in the ionized sputtering process and analyze the mass of the measured molecular ion
  It is characterized byMass spectrometer.
  Also,
  A magnetic field formed by a pair of magnets;
  The sheet resistor 10 having voltage application terminals at both ends, which are disposed on opposite sides of the pair of magnets. ⁵ -10 ⁹ Electric field formed by Ω conductor film and
  In the electromagnetic field space formed by
  Pass the measured molecular ion in the ionized sputtering process and analyze the mass of the measured molecular ion
  It is characterized byMass spectrometer.
Here, the conductor film is a silicon carbide film.
According to the present invention,Facing the electromagnetic spaceMagneticBy making the surface of the stone function as an electrode for forming an electric field, it is possible to correct the electric field in the electromagnetic field, or to generate and correct the electric field.MagneticEven if stones are brought close to each other to reduce the magnetic pole gap, a uniform electric field can be formed in which the equipotential surface between the electrodes is parallel to the electrode surface.
[0023]
  In the above, facing the electromagnetic field spaceMagneticTo make the surface of the stone function as an electrode that forms an electric field, MagnetismA configuration in which a quasi-conductor film is provided on the surface of the stone facing the electromagnetic field space can be employed. Semi-conductor film, for example, a thin film made of silicon carbide having a uniform sheet resistance valueThe magnetBy providing it on the surface of the stone facing the electromagnetic field space, the electric potential of the surface can be changed at a constant rate of increase or decrease along the electric field direction, and the electric field correction of the electromagnetic field space or the electric field of the electromagnetic field space Both generation and electric field correction are performed.
[0026]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to the embodiments described in the following embodiments, and the creation of the technical idea described in the present specification. Various changes can be made within the range.
[0027]
[Example 1]
FIG. 1 is a diagram showing a schematic configuration of a first embodiment of the present invention.
[0028]
Conductor magnets 2 and 3 are arranged so that the opposite poles face each other, and non-magnetic electrodes 51 and 52 to which + V and −V voltages are respectively applied are arranged. ing.
[0029]
Between the magnets 2 and 3 and the electrodes 51 and 52, non-magnetic insulating films 53 and 54 and non-magnetic silicon carbide films 55 and 56, and silicon carbide films 55 and 56 are electrode 51, 52 are provided so as to be in electrical contact with each other.
[0030]
In FIG. 1, a space surrounded by magnets 2 and 3 and electrodes 51 and 52 and denoted by reference numeral 100 is an electromagnetic field portion. Further, the inside of a circle represented by reference numeral 101 is a range through which an ion beam traveling from the back surface side to the front surface side of the paper surface passes perpendicularly to the paper surface.
[0031]
Also in this embodiment, electric lines of force in the direction indicated by reference numeral 102 and magnetic lines of force in the direction indicated by reference numeral 103 are generated in FIG. 7B of the conventional example, but these are omitted in FIG. is doing. Moreover, although the yoke shown with the code | symbol 1 exists in Fig.7 (a) of a prior art example, it is abbreviate | omitting in FIG.
[0032]
The distance between the magnets 2 and 3 in the electromagnetic field portion 100 corresponds to the magnetic pole gap, and in this embodiment, this is about 3 mm.
[0033]
In the present invention, since the silicon carbide films 55 and 56 interposed between the magnets 2 and 3 and the electrodes 51 and 52 are in electrical contact with the electrodes 51 and 52, they face the electromagnetic field space 100. The surfaces of the magnets 2 and 3 function as electrodes for forming an electromagnetic field.
[0034]
Further, the silicon carbide films 55 and 56 are 10^Five-10⁹A silicon carbide film that is composed of a film having a uniform sheet resistance value of about Ω and is in contact with the surfaces of the magnets 2 and 3 via the insulating films 53 and 54 between the electrodes 51 and 52. The electric potential of 55 and 56, that is, the electric potential of the surface of the magnets 2 and 3 facing the electromagnetic field space between the electrodes 51 and 52 is from the electrode surfaces of the electrodes 51 and 52 to which voltages of + V and −V are applied. It becomes a value determined by the distance, and changes at a constant increase rate or decrease rate along the electric field direction (direction of electric lines of force not shown). As a result, the electric potential in the electromagnetic field portion 100 is uniform electric field strength obtained by equally dividing the potentials + V and −V of the electrodes 51 and 52, that is, the equipotential surface between the electrodes 51 and 52 is in relation to the surfaces of the electrodes 51 and 52. A parallel electric field is formed.
[0035]
On the other hand, the electrodes 51, 52, the insulating films 53, 54, and the silicon carbide films 55, 56 are all made of a non-magnetic material. Various magnetic field strengths are obtained.
[0036]
In this way, in this embodiment, an ideal electromagnetic field portion in which the strength of the magnetic field and the electrolysis is uniform and orthogonal is formed in the electromagnetic field portion 100 even though the magnetic pole gap is reduced to about 3 mm. Has been.
[0037]
In this embodiment, the insulating films 53 and 54 are used. This is because the magnets 2 and 3 used in this embodiment are conductors. When the magnets 2 and 3 are insulators, the insulating films 53 and 54 are interposed between the silicon carbide films 55 and 56 that are in electrical contact with the electrodes 51 and 52 and the surfaces of the magnets 2 and 3. do not have to.
[0038]
Further, the yoke 1 not shown in FIG. 1 is effective in improving the strength of the magnetic field and decreasing the strength of the leakage magnetic field to the outside, but is not necessarily indispensable.
[0039]
[Example 2]
FIG. 2 is a diagram showing a schematic configuration of the second embodiment of the present invention.
[0040]
Conductor magnets 2 and 3 are arranged so that the opposite poles face each other, and non-magnetic silicon carbide films 55 and 56 are disposed on these surfaces via non-magnetic insulating films 53 and 54, respectively. Is provided.
[0041]
The terminals 57 and 58 are electrically connected to the right end and the left end of the silicon carbide film 55 in FIG. 2, and similarly, the terminals 59 and 60 are connected to the right end and the left end of the silicon carbide film 56 in FIG. Electrically connected.
[0042]
In FIG. 2, the space between the silicon carbide films 55 and 56 provided on the surfaces of the magnets 2 and 3 is the electromagnetic field portion 100. Further, the inside of a circle represented by reference numeral 101 is a range through which an ion beam traveling from the back surface side to the front surface side of the paper surface passes perpendicularly to the paper surface.
[0043]
Also in this embodiment, electric lines of force in the direction indicated by reference numeral 102 and magnetic lines of force in the direction indicated by reference numeral 103 are generated in FIG. 7B of the conventional example, but these are omitted in FIG. Has been. Moreover, although the yoke shown with the code | symbol 1 exists in Fig.7 (a) of a prior art example, it is abbreviate | omitted in FIG.
[0044]
The distance between the magnets 2 and 3 in the electromagnetic field portion 100 corresponds to a magnetic pole gap, and in this embodiment, it is about 4 mm.
[0045]
As shown in FIG. 2, a voltage of + V is applied to the terminals 57 and 59, and a voltage of −V is applied to the terminals 58 and 60, respectively. Thus, the silicon carbide films 55 and 56, that is, the surfaces of the magnets 2 and 3 facing the electromagnetic field space function as electrodes that form an electromagnetic field.
[0046]
Further, the silicon carbide films 55 and 56 are formed in the same manner as in the first embodiment shown in FIG.^Five-10⁹It is composed of a film having a uniform sheet resistance value of about Ω, so that the potential of the silicon carbide films 55 and 56, that is, the potential of the surfaces of the magnets 2 and 3 facing the electromagnetic field space is + V. Is a value internally divided by the distance from the terminals 57 and 59 to which a voltage of −V is applied and the terminals 58 and 60 to which a voltage of −V is applied, and is constant along the electric field direction (direction of electric field lines not shown). It will change at an increasing rate or decreasing rate. Therefore, the electric potential in the electromagnetic field portion 100 has a uniform electric field strength obtained by equally dividing + V and −V by the widths of the magnets 2 and 3.
[0047]
Further, as in the first embodiment, since the insulating films 53 and 54 and the silicon carbide films 55 and 56 are all made of a non-magnetic material, the magnetic field generated by the magnets 2 and 3 is changed into the insulating films 53 and 54 and the carbonized films. The magnetic field is uniform without being disturbed by the silicon films 55 and 56.
[0048]
In this way, even in this embodiment, an ideal electromagnetic field portion in which the strength of the magnetic field and the electrolysis is uniform and orthogonal is formed in the electromagnetic field portion 100 even though the magnetic pole gap is reduced to about 4 mm. Has been.
[0049]
The reason why the insulating films 53 and 54 are used in the second embodiment is the same as that in the first embodiment. When the magnets 2 and 3 are insulators, the insulating films 53 and 54 are replaced with the silicon carbide film 55. 56 and the surfaces of the magnets 2 and 3 do not need to be interposed.
[0050]
The yoke 1 (not shown in FIG. 2) is effective in improving the strength of the magnetic field and reducing the strength of the leakage magnetic field to the outside, but is similar to the first embodiment in that it is not always essential.
[0051]
Compared with the first embodiment shown in FIG. 1, the configuration of the second embodiment has an advantage that the deflected ion beam does not scatter on the electrode because the electrode is unnecessary.
[0052]
(Reference Example 1)
  FIG. 3 illustrates the present invention.Be helpfulIt is a figure showing the outline composition of an example.
[0053]
The conductor magnets 4, 5, 6, and 7 are electrically insulated from each other, and the magnets 6 and 7 are also electrically insulated. The same polarity comrades are arranged side by side, and the set of magnets 4 and 5 arranged side by side and the set of magnets 6 and 7 arranged side by side are arranged so as to face each other. Yes.
[0054]
Between the magnets 4 and 5 and the magnets 6 and 7 arranged in this way, non-magnetic electrodes 51 and 52 to which voltages of + V and −V are applied, respectively, are arranged.
[0055]
Further, as shown in FIG. 3, a voltage of + V / 2 is applied to the magnet 4 and the magnet 6, and a voltage of −V / 2 is applied to the magnet 5 and the magnet 7. In this way, the magnets 4, 5, 6, 7 are applied with a voltage so that an electric field is formed between the magnets 4 and 5 and between the magnets 6 and 7. The magnet 5, the magnet 6 and the magnet 7 are electrically insulated and juxtaposed. In this embodiment, electrical insulation is achieved by providing a gap between the magnet 4 and the magnet 5, and between the magnet 6 and the magnet 7, respectively. It is sufficient that the electric field can be maintained without generating a discharge between them. Further, without providing a gap, an insulating film can be interposed between the magnet 4 and the magnet 5 and between the magnet 6 and the magnet 7 for electrical insulation.
[0056]
In FIG. 3, a space surrounded by magnets 4, 5, 6, 7 and electrodes 51, 52 and indicated by reference numeral 100 is an electromagnetic field portion. Further, the inside of a circle represented by reference numeral 101 is a range through which an ion beam traveling from the back surface side to the front surface side of the paper surface passes perpendicularly to the paper surface.
[0057]
Also in this embodiment, electric lines of force in the direction indicated by reference numeral 102 and magnetic lines of force in the direction indicated by reference numeral 103 are generated in FIG. 7B of the conventional example, but these are omitted in FIG. is doing. Moreover, although the yoke shown with the code | symbol 1 exists in Fig.7 (a) of a prior art example, it abbreviate | omits in FIG.
[0058]
The distance between the magnets 4 and 5 and the magnets 6 and 7 in the electromagnetic field portion 100 corresponds to the magnetic pole gap, and is about 5 mm in this embodiment.
[0059]
Although the surface potential of the magnets 4, 5, 6, and 7 facing the electromagnetic field portion 100 is not equal to the potential as in the first and second embodiments shown in FIGS. Since the voltages of + V / 2 and −V / 2 are applied as described above, the potentials are intermediate values of the electrodes 51 and 52 to which the voltages of + V and −V are applied.
[0060]
In addition, the corners of the magnets 4, 5, 6, and 7 directed toward the electromagnetic field portion 100 are illustrated so that the distance from the range 101 through which the ion beam passes is increased to help improve the uniformity of the electric field and magnetic field. 3 As shown, each is cut.
[0061]
As a result, a substantially uniform electric field is formed in the electromagnetic field portion 100.
[0062]
On the other hand, considering the magnetic field in the electromagnetic field unit 100, the magnets 4 and 5 are electrically at different potentials, but magnetically, the magnets 4 and 5 are arranged in parallel with only a slight gap at the center. Since the angle toward the direction of the field part 100 is only cut, the magnets 4 and 5 arranged side by side perform substantially the same operation as the magnet 2 in the first embodiment shown in FIG. The same applies to the magnets 6 and 7 arranged opposite to each other, and the magnets 6 and 7 arranged in parallel perform substantially the same operation as the magnet 3 in the first embodiment shown in FIG.
[0063]
In addition, since the electrodes 51 and 52 are made of a non-magnetic material, the magnetic fields generated by the magnets 4, 5, 6, and 7 are not disturbed by the electrodes 51 and 52 and have a uniform magnetic field strength.
[0064]
Therefore, also in this embodiment, a substantially uniform magnetic field is formed in the electromagnetic field portion 100.
[0065]
Therefore, in this embodiment, an ideal electromagnetic field portion in which the strength of the magnetic field and the electric field is uniform and orthogonal is formed in the electromagnetic field portion 100 even though the magnetic pole gap is reduced to about 5 mm. .
[0066]
3 is compared with the first and second embodiments (FIGS. 1 and 2), carbonization is performed so that the surface of the magnet itself facing the electromagnetic field space functions as an electrode for forming an electric field. There is an advantage that it is not necessary to use a silicon film.
[0067]
(Reference Example 2)
  FIG. 4 illustrates the present invention.Other helpfulIt is a figure showing the outline composition of an example.
[0068]
The magnets 8, 9, 10, and 11 of the conductor are arranged so that the magnets 8 and 9 are electrically insulated from each other and the same polarity is adjacent to each other, and the magnets 10 and 11 are also electrically connected to each other. The magnets 8 and 9 are arranged in parallel so that the same poles are adjacent to each other, and the magnets 10 and 11 arranged in parallel are different from each other. They are arranged to face each other.
[0069]
Between the magnets 8 and 9 and the magnets 10 and 11 arranged in this way, non-magnetic electrodes 61 and 62 to which + V and −V voltages are applied are interposed as spacers. The electrode 61 and the magnets 8 and 10 and the electrode 62 and the magnets 9 and 11 are electrically connected to each other.
[0070]
Unlike the third embodiment shown in FIG. 3, the surface potential of the magnets 8, 9, 10, and 11 facing the electromagnetic field portion 100 is not the intermediate potential of the electrodes 61 and 62. As described above, since the electrodes 61 and 62 are electrically connected to each other, they have the same potential as the electrodes 61 and 62.
[0071]
Thus, the magnet 8 and the magnet 9, and the magnet 10 and the magnet 11 are respectively formed so that an electric field is formed between the magnets 8 and 10 and the magnets 9 and 11 that have the same potential as the electrodes 61 and 62, respectively. They are electrically insulated and juxtaposed. In this embodiment, electrical insulation is achieved by providing a gap between the magnet 8 and the magnet 9, and between the magnet 10 and the magnet 11, respectively. It is sufficient that the electric field can be maintained without generating a discharge between them. Further, without providing a gap, an insulating film can be interposed between the magnet 8 and the magnet 9 and between the magnet 10 and the magnet 11 to achieve electrical insulation.
[0072]
In FIG. 4, a space surrounded by magnets 8, 9, 10, 11 and electrodes 61, 62 and indicated by reference numeral 100 is an electromagnetic field portion. Further, the inside of a circle represented by reference numeral 101 is a range through which an ion beam traveling from the back surface side to the front surface side of the paper surface passes perpendicularly to the paper surface.
[0073]
Also in this embodiment, electric field lines in the direction indicated by reference numeral 102 and magnetic field lines in the direction indicated by reference numeral 103 in FIG. 7B of the conventional example are generated, but these are omitted in FIG. is doing. Moreover, although the yoke shown with the code | symbol 1 exists in Fig.7 (a) of a prior art example, it abbreviate | omits in FIG.
[0074]
The distance between the magnets 8 and 9 and the magnets 10 and 11 in the electromagnetic field portion 100 corresponds to the magnetic pole gap, and in this embodiment, it is about 5 mm.
[0075]
Similarly to the third embodiment, the magnet 8 toward the electromagnetic field unit 100 is arranged to further improve the uniformity of the electric and magnetic fields by further increasing the distance from the range 101 through which the ion beam passes. As shown in FIG. 4, the corners 9, 10, and 11 are cut deeper.
[0076]
Accordingly, also in this embodiment, a substantially uniform electric field is formed in the electromagnetic field portion 100.
[0077]
On the other hand, when the magnetic field in the electromagnetic field unit 100 is examined, a substantially uniform magnetic field is formed in the electromagnetic field unit 100 also in this example for the same reason as in Example 3 (FIG. 3).
[0078]
Therefore, even in this embodiment, despite the fact that the magnetic pole gap is reduced to 5 mm, in the electromagnetic field portion 100, an ideal electromagnetic field portion in which the magnetic field and the strength of electrolysis are uniform and orthogonal is formed.
[0079]
When this Example 4 is compared with Example 3, it is advantageous that parts are simplified.
[0080]
(Reference Example 3)
  FIG. 5 illustrates the present invention.Other helpfulIt is a figure showing the outline composition of an example.
[0081]
Conductor magnets 12, 13, 14, 15 are electrically insulated and attached to the center of the yoke 1 via an insulator magnet attachment ring 16.
[0082]
The space surrounded by the magnets 12, 13, 14, and 15 constitutes the electromagnetic field unit 100, and the inside of the circle represented by reference numeral 101 is perpendicular to the paper surface from the back surface side to the front surface side of the paper surface. This is the range through which the ion beam that advances is passing. In FIG. 5, the lines of electric force are generated as indicated by reference numeral 102, and the lines of magnetic force are generated as indicated by reference numeral 103.
[0083]
In this embodiment, as shown in FIG. 5, the magnets 12 and 13 are arranged so that the same poles are adjacent to each other in a perpendicular direction. Similarly, the magnets 14 and 15 are also arranged so that the same poles are adjacent to each other in a perpendicular direction. And the magnet 12 and the magnet 14 and the magnet 13 and the magnet 15 are arrange | positioned so that different polars may face each other.
[0084]
The four magnets have the same shape and are arranged rotationally symmetrical four times with respect to the center.
Such an arrangement configuration of the magnets 12, 13, 14, and 15 is similar to a quadrupole lens known as a strong focus lens, but the direction of the magnetic poles is different.
[0085]
Due to the arrangement of the magnets as described above, the lines of magnetic force represented by reference numeral 103 are from bottom to top in FIG. 5 in the range 101 through which the ion beam passes in the space surrounded by the magnets 12, 13, 14 and 15. As a result, a substantially uniform magnetic field is formed in this space.
[0086]
The magnets 12, 13, 14, and 15 are respectively applied with voltages V1, V2, V3, and V4 shown below, and not only mass separation as E × B but also an ion beam as an electrostatic deflector. The X-axis / Y-axis direction deflection and the primary astigmatism correction of the ion beam can be performed as an electrostatic astigmatism corrector.
[0087]
Magnet 12: V1 = + Vm + Vy−Vs
Magnet 13: V2 = −Vm−Vx + Vs
Magnet 14: V3 = −Vm−Vy−Vs
Magnet 15: V4 = + Vm + Vx + Vs
Here, Vm: mass separation voltage, Vx: X-axis direction deflection voltage, Vy: Y-axis direction deflection voltage, and Vs: astigmatism correction voltage.
[0088]
Focusing on + Vm and -Vm, which are mass separation voltages, in FIG. 5, the right magnets 12 and 15 are at + Vm, and the left magnets 13 and 14 are at -Vm.
[0089]
Since the magnets 12 and 15 and the magnets 13 and 14 are symmetrical with respect to the horizontal direction in FIG. 5, the lines of electric force are in the horizontal direction near the center. Therefore, a substantially uniform electric field in the horizontal direction is formed near the center due to + Vm and -Vm.
[0090]
Therefore, as described above, due to the presence of a substantially uniform magnetic field from the bottom to the top in FIG. 5 in the vicinity of the center of the magnets 12 to 15, and the presence of a generally uniform electric field in the horizontal direction near the center. , E × B, mass separation is performed.
[0091]
As described above, in order to apply different voltages to the four magnets 12 to 15 to form an electric field, the magnets 12, 13, 14, and 15 are electrically insulated as described above. Need to be.
[0092]
In this embodiment, a gap is arranged between each of the magnets 12 to 15 to achieve electrical insulation from each other. The space between the gaps is sufficient as long as no electric discharge is generated between the magnets 12 to 15 and the electric field can be maintained. It should be noted that an insulating film can be interposed between each of the magnets 12 to 15 without electrically disposing the gap, thereby achieving electrical insulation.
[0093]
When attention is paid to + Vx and −Vx which are X-axis direction deflection voltages, the lower right magnet 15 has a potential of + Vx and the upper left magnet 13 has a potential of −Vx. Therefore, the X-axis direction deflection of the ion beam is performed by + Vx and −Vx. Similarly, the ion beam is deflected in the Y-axis direction by + Vy and −Vy.
[0094]
When attention is paid to the astigmatism correction voltages + Vs and -Vs, the potentials of the opposing magnets become equal potentials, and the potentials of the magnets in the perpendicular direction become positive and negative. Therefore, primary astigmatism correction is performed to adjust the shape of the ion beam in a one-dimensional direction by + Vs and -Vs.
[0095]
Compared with Example (FIG. 4), Example 5 is advantageous in that the parts are simpler.
[0096]
(Reference Example 4)
  FIG. 6 shows the present invention.Other helpfulIt is a figure showing the outline composition of an example.
[0097]
Conductor magnets 17, 18, 19, 20, 21, 22, 23, and 24 are electrically insulated and attached to the center of the yoke 1 via an insulator magnet attachment ring 16.
[0098]
The space surrounded by the magnets 17 to 24 constitutes the electromagnetic field unit 100, and the inside of the circle represented by reference numeral 101 advances from the back side to the front side of the page perpendicular to the page. This is the range through which the beam passes.
[0099]
As shown in FIG. 6, the magnets 17, 18, 19 and 20 are arranged so that the same poles are adjacent to each other with an angle of 45 degrees, and the magnets 21, 22, 23 and 24 also have an angle of 45 degrees. Have the same polarity comrades next to each other. And the magnet 17 and the magnet 21, the magnet 18 and the magnet 22, the magnet 19 and the magnet 23, and the magnet 20 and the magnet 24 are arrange | positioned in the form from which opposite poles mutually oppose. The eight magnets have the same shape and are rotationally symmetric with respect to the center.
[0100]
Due to the arrangement of the magnets as described above, a substantially uniform magnetic field from the bottom to the top in FIG. 6 is formed in the range 101 through which the ion beam passes in the space surrounded by the magnets 17 to 24. .
[0101]
The magnets 17 to 24 are applied with the voltages V1, V2, V3, V4, V5, V6, V7, and V8 shown below, respectively. The ion beam can be deflected in the X and Y-axis directions as a type deflector, the secondary astigmatism correction of the ion beam can be performed as an astigmatism corrector, and the ion beam can be converged in the X-axis direction as a stereofocusing mass analyzer.
[0102]
Magnet 17: V1 = + Vm + Vdx + a · Vdy + Vsx + Vf
Magnet 18: V2 = + Vm + a.Vdx + Vdy + Vsy
Magnet 19: V3 = −Vm−a · Vdx + Vdy−Vsx−Vf
Magnet 20: V4 = −Vm−Vdx + a · Vdy−Vsy−Vf
Magnet 21: V5 = −Vm−Vdx−a · Vdy + Vsx−Vf
Magnet 22: V6 = −Vm−a · Vdx−Vdy + Vsy−Vf
Magnet 23: V7 = + Vm + a.Vdx-Vdy-Vsx
Magnet 24: V8 = + Vm + Vdx−a · Vdy−Vsy + Vf
Where Vm: mass separation voltage, Vdx: X axis direction deflection voltage, Vdy: Y axis direction deflection voltage, Vsx: X axis direction astigmatism correction voltage, Vsy: Y axis direction astigmatism correction voltage, Vf: X-axis direction convergence voltage, a: Arbitrary coefficient.
[0103]
Focusing on + Vm and -Vm, in FIG. 6, the right magnets 17, 18, 23, and 24 have a potential of + Vm, and the left magnets 19, 20, 21, and 22 have a potential of -Vm. Since the magnets 17 and 18 and the magnets 23 and 24 and the magnets 19 and 20 and the magnets 21 and 22 are axisymmetric with respect to the horizontal direction in FIG. 6, the lines of electric force are in the horizontal direction near the center. . Therefore, a substantially uniform electric field in the horizontal direction is formed near the center due to + Vm and -Vm.
[0104]
Therefore, as described above, the presence of the substantially uniform magnetic field from the bottom to the top in FIG. 6 near the center of the magnets 17 to 24 and the substantially uniform electric field in the horizontal direction near the center. , E × B, mass separation is performed.
[0105]
As described above, in order to apply different voltages to the eight magnets 17 to 24 and form an electric field, the magnets 17 to 24 need to be electrically insulated as described above. .
[0106]
In this embodiment, a gap is arranged between each of the magnets 17 to 24 to achieve electrical insulation from each other. It is sufficient that the gaps have such a size that no electric discharge is generated between the magnets 17 to 24 and the electric field can be maintained. It should be noted that an insulating film may be interposed between each of the magnets 17 to 24 without electrically disposing the gap, thereby achieving electrical insulation.
[0107]
Although detailed description of + Vdx, -Vdx, + Vdy, and -Vdy is omitted, this principle of operation is well known as an 8-pole electrostatic astigmatism corrector for a large deflection angle. In conclusion, without causing a large deflection aberration, + Vdx and −Vdx perform X-axis direction deflection, and + Vdy and −Vdy perform Y-axis direction deflection.
[0108]
Detailed explanations of + Vsx, -Vsx, + Vsy, and -Vsy are also omitted, but this operating principle is well known as an octupole electrostatic stigmator. In conclusion, secondary astigmatism correction is performed to adjust the shape of the ion beam in a two-dimensional direction from + Vsx, −Vsx, + Vsy, and −Vsy.
[0109]
It is known that an E × B type mass analyzer having a uniform electromagnetic field space has an ion beam converging effect with respect to the magnetic field direction but has no converging effect with respect to the electric field direction. Accordingly, a method is known in which the electric field in the electrode field space is slightly curved using a curved electrode in order to have a converging effect in the direction of the electric field. If it demonstrates in FIG. 7 of a prior art example, the electrodes 51 and 52 shall be curved not in a flat plate but in the shape of a bow. This method achieves so-called stereo convergence in which the ion beam converges in a two-dimensional direction.
[0110]
In this embodiment, although the conductor magnets 17 to 24 that also function as electrodes have the same shape, this function can be realized. That is, when + Vf is applied to the two rightmost magnets and −Vf is applied to the four leftmost magnets, the electric field in the electromagnetic field space is slightly curved rightward. Thereby, in this embodiment, the three-dimensional focusing of the ion beam is achieved.
[0111]
As described above, the present invention described with reference to the attached drawings is essentially completely different from the technical concept disclosed in the aforementioned patent application relating to the conventional E × B mass spectrometer.
[0112]
That is, in JP-A-4-351840 and JP-A-7-161337, a plurality of magnetic poles are used, but the added magnetic poles are installed on the back side of the electrodes, and the magnetic poles themselves are used as electric fields as in the present invention. It does not generate or correct.
[0113]
In Japanese Patent Application Laid-Open No. 6-132007, a voltage is applied to the magnetic pole itself, but the electric field generated thereby functions only to deflect the ion beam, and the voltage applied to the magnetic pole as in the present invention. Thus, an electric field for mass separation perpendicular to the magnetic field is not generated.
[0116]
In Examples 1 and 2, the silicon carbide films 55 and 56 having uniform sheet resistance are formed on the surfaces of the magnets 2 and 3, but the present invention is not limited to such an embodiment. For example, a plurality of elongated conductor films can be formed by being arranged along the electric field direction in an insulated state, and a potential divided by using another silicon carbide film or a resistor can be applied to each conductor film. Alternatively, a quasi-conductor film having a small sheet resistance value can be formed to be folded along the direction of the electric field with a single stroke. In addition, in any configuration, it is sufficient that the thin film formed on the surface of the magnet facing the electromagnetic field space allows the surface potential of the magnet to change monotonously along the electric field direction.
[0120]
In the above description, the E × B apparatus of the present invention has been described as a mass analyzer that operates even in a high pressure atmosphere. However, the E × B apparatus of the present invention is not used only in such a high pressure atmosphere. Absent. It can also be used as a mass analyzer that operates in a normal pressure atmosphere or for ion beam purification.
[0121]
Furthermore, the use of the E × B apparatus of the present invention is not limited to a mass analyzer. That is, in the above-described embodiments, the case where the E × B apparatus of the present invention is used only for the purpose of mass separation of ions having the same energy has been described, but the present invention is not limited to this. It can also be used for energy separation of ions and electrons with the same mass.
[0122]
【The invention's effect】
According to the present invention, it is possible to provide a mass analyzer that can be operated in a high pressure atmosphere during a process such as sputtering, has sufficient performance, and is low in manufacturing cost.
[Brief description of the drawings]
FIG. 1 of the present inventionMass analyzerThe schematic block diagram of the 1st preferable Example of this.
FIG. 2 of the present inventionMass analyzerThe schematic block diagram of 2nd preferable Example of this.
FIG. 3 of the present inventionreferenceThe schematic block diagram of an Example.
FIG. 4 of the present inventionreferenceThe schematic block diagram of an Example.
FIG. 5 of the present inventionreferenceThe schematic block diagram of an Example.
FIG. 6 of the present inventionreferenceThe schematic block diagram of an Example.
7A is a schematic configuration diagram of a conventional E × B apparatus, and FIG. 7B is an enlarged view of a part of the E × B apparatus shown in FIG. 7A.
FIG. 8 is a schematic configuration diagram for explaining a case where a magnetic pole gap is reduced in a conventional E × B apparatus.

Claims (3)

A magnetic field formed by a pair of magnets
Formed by applying voltage to a pair of conductor films having a voltage applied to a pair of electrodes positioned between the pair of magnets and a sheet resistance of 10 ⁵ to 10 ⁹ Ω disposed on opposite sides of the pair of magnets Electric field,
In the electromagnetic field space formed by
A mass spectrometer characterized by passing a molecular ion to be measured in an ionized sputtering process and analyzing a mass of the molecular ion to be measured . A magnetic field formed by a pair of magnets;
An electric field formed by a conductor film having a sheet resistance of 10 ⁵ to 10 ⁹ Ω, which is disposed on opposite sides of the pair of magnets and has voltage application terminals at both ends ;
In the electromagnetic field space formed by
A mass spectrometer characterized by passing a molecular ion to be measured in an ionized sputtering process and analyzing a mass of the molecular ion to be measured . The mass spectrometer according to claim 1, wherein the conductor film is a silicon carbide film.

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