JPH03289037A - Mass spectrometry device of metal vapor and evaporation device including this mass spectrometry device - Google Patents

Abstract

PURPOSE:To find an existing rate of a cluster and single atoms as well as respective density in a metal vapor even when ions are existing in metal vapor by providing a means of removing ion particles in metal vapor and a means of supplying energy for ionization. CONSTITUTION:A removing electrode 6 able to remove ion particles in metal vapor as occasion demands is set up while providing an energy generation means 9 for ionization working in a fixed synchronous relation with this removing electrode 6. Thereby, neutral particles to be contained by metal vapor and ion particles can be separately measured while being able to identify an atomic number constituting respective particles so that neutral single atoms, clusters, ion density and existence rate of these call be found.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a metal vapor mass spectrometer and an evaporation device including this mass spectrometer, and particularly relates to a metal vapor mass spectrometer that is heated and evaporated by irradiating an electron beam. The present invention relates to a mass spectrometer and an evaporation device including the mass spectrometer.

[Conventional technology]

As a technology related to a conventional metal vapor mass spectrometer, there is a technology disclosed in Patent Application Publication No. 1-501583. The technique disclosed in this publication relates to an apparatus that generates a cluster beam and prevents damage caused to a substrate by the cluster beam when forming a thin film on the substrate. In relation to the present invention, its characteristic configuration is as follows: A cluster beam is generated by a cluster supply source, this cluster beam is ionized by an electron beam, and large mass cluster ions are ionized using a blocking electric field of an electrostatic separator. was configured to pass through the substrate and deposit it on the substrate to form a thin film on the substrate.

[Problem to be solved by the invention]

The above-mentioned conventional technology discloses a technology for selecting clusters with large masses, but it is difficult to determine the size of clusters present in a cluster beam, that is, the number of atoms constituting a cluster, or to distinguish between clusters and single clusters. Nothing is disclosed about the technology for determining the abundance ratio of atoms or their respective densities. Furthermore, the above technical problem cannot be achieved even based on the description thereof.

Particularly when ions are originally present in the metal vapor, there is a problem in that it is difficult to determine the abundance ratio of clusters and single atoms in the metal vapor and their respective densities.

The purpose of the present invention is to determine the size of clusters present in metal vapor, to determine the abundance ratio of clusters and monoatoms in metal vapor, and their respective densities, and furthermore, even when ions are present in metal vapor, An object of the present invention is to provide a mass spectrometer for metal vapor that can determine the proportion of clusters and clusters and their respective densities in metal vapor.

Another object of the present invention is to constantly monitor, for example, the amount of neutral particles in the metal vapor using a metal vapor mass spectrometer capable of achieving the above-mentioned object, and to analyze the signals obtained by this monitor by using a metal vapor mass spectrometer that can achieve the above-mentioned objects. An object of the present invention is to provide an evaporation device configured to feed back to an electron beam power source for use in order to adjust the output of the power source to maintain the amount of neutral particles in metal vapor at a required constant value.

[Means to solve the problem]

A first metal vapor mass spectrometer according to the present invention is a mass spectrometer that analyzes the mass of metal vapor evaporated by heating with an electron beam, and includes an ionization chamber that takes in the metal vapor, and an ionization chamber in front of the ionization chamber. an ion particle removal electrode that is disposed in the path of the metal vapor and generates an electric field for removing ion particles in the metal vapor; an energy generation means that supplies ionization energy to the ionization chamber; a control means for controlling the removal electric field generation operation and the ionization energy generation operation of the energy generation means;
A lens system means for extracting ion particles existing in the ionization chamber, a drift tube for making the extracted ion particles fly a predetermined distance, a detection means for detecting the extracted ion particles, and a detection signal from the detection means for detecting the ion particles contained in the metal vapor. A feature of the present invention is that it is equipped with a signal calculation processing means that distinguishes between neutral particles and ionic particles, and measures the differentiated neutral particles and ionic particles to determine their respective densities and abundance ratios.

In the second metal vapor mass spectrometer according to the present invention, in the first configuration, when the control means does not cause the ion particle removal electrode to generate an removal electric field, the energy generation means is not operated, and the ion particle removal electrode A feature of the present invention is that when the removal electric field is generated, the energy generating means is controlled to generate ionization energy.

In the third metal vapor mass spectrometer according to the present invention, in the second configuration, a voltage is periodically applied to the ion particle removal electrode to generate an electric field for removing ion particles in the metal vapor. A distinctive feature of this method is that it distinguishes between neutral particles and ionic particles contained in metal vapor.

A fourth metal vapor mass spectrometer according to the present invention is characterized in that, in the third configuration, the voltage applied to the ion particle removal electrode has a square waveform.

In the fifth metal vapor mass spectrometer according to the present invention, in the configuration according to any one of the first to fourth aspects, the energy generating means generates energy from the binding energy of a cluster consisting of two or more atoms contained in the metal vapor. It is also an ionization means that generates small energy, and its feature is that neutral particles in metal vapor are ionized by this ionization means.

A first evaporator according to the present invention is an evaporator that irradiates a metal with an electron beam output from an electron gun to generate metal vapor, and the first evaporator that detects the amount of neutral particles contained in the metal vapor. Compare the detection signal of a mass spectrometer having one of the configurations in 5 with the set standard, and if the set standard is not met, adjust the position and output of the electron beam to meet the set standard. The feature is that it consists of a control means for controlling.

A second evaporation device according to the present invention is an evaporation device that irradiates metal with an electron beam output from an electron gun to generate metal vapor, and the second evaporation device detects the amount of neutral particles and ion particles contained in the metal vapor. A mass spectrometer having any one of the configurations 1 to 5, and adjusting the position and output of an electron beam based on the detection signal of the mass spectrometer to detect the presence of neutral clusters and ion particles contained in metal vapor. The feature is that it is comprised of a control means for controlling the ratio to decrease.

[Effect]

In the metal vapor mass spectrometer according to the present invention, an ion particle removal electrode is installed immediately before the ionization chamber for the purpose of determining the abundance ratio and density of neutral single atoms and clusters existing in the metal vapor, as well as the abundance ratio and density of these ion particles. However, when no voltage is applied to the removal electrode, monatomic and cluster ions originally existing in the metal vapor are measured, and when voltage is applied to the removal electrode to remove ions from the metal vapor,
The ionization chamber is configured to apply ionization energy to ionize neutral particles, and use the ion particles to measure neutral monatomic atoms and clusters.

The flight time of the ion particles drawn from the ionization chamber and flying through the drift tube depends on the ratio of mass to charge of the ion particles, so the size of single atoms and clusters can be identified from the flight time of the ion particles. . Further, the density of ion particles and neutral particles can be determined from the peak value of the ion detection signal and a predetermined relational expression.

By periodically applying a removal voltage to the removal electrode, it is possible to repeatedly obtain detection data, and from this, the detection data can be averaged.

In the evaporator according to the present invention, by using the mass spectrometer according to the present invention, it is possible to monitor the amount of only neutral particles or the amount of neutral particles and ion particles, and using this monitor signal, for example, Controls the electron beam power supply and performs necessary control regarding the position and output of the electron beam.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a front view showing the configuration of a metal vapor mass spectrometer according to the present invention, and also shows a related control system electric circuit section. FIG. 2 is a plan view of the main parts of the mass spectrometer.

In FIG. 1, 1 is a crucible, and a metal 2 is housed in this crucible 1. The metal 2 in the crucible 1 is irradiated with an electron beam 3 for evaporating the metal 2, which is supplied from an electron beam generator (not shown). The metal 2 is heated by the electron beam 3, and a portion of the metal 2 evaporates to generate metal vapor 4. The generated metal vapor 4 moves upward.

An ionization chamber 5 and a removal electrode 6 disposed in the path of metal vapor in front of the ionization chamber 5 are disposed above the crucible 1. An ion source 7 is formed by the ionization chamber 5 and the removal electrode 6. The metal vapor 4 that has moved upward enters the ionization chamber 5 through the electric field space formed by the removal electrode 6 and the vapor passage holes 8 in the ionization chamber 5 . An electron beam generator 9 is attached to the ionization chamber 5 for irradiating an ionizing electron beam 20 onto the chamber. Further, a measurement chamber 10 is provided adjacent to the ionization chamber 5.
is provided. In the measurement chamber 10, a lens system 11, a drift tube 12, and a detector 13 are sequentially provided from the ionization chamber 5 side. A required electric field is applied between the ionization chamber 5 and the lens system 11, and the ion particles present in the ionization chamber 5 can be drawn out from the ionization chamber 5 to the drift tube 12 by this electric field. Lens system 1
1, the energy and trajectory of the ion particles extracted from the ionization chamber 5 can be adjusted.

Although illustration of the detailed structure of this adjustment mechanism is omitted in FIG. 1, it will be specifically explained later with reference to FIG. 2.

The detector 13 is provided with a secondary electron multiplier tube 14 .

15 is an amplifier that amplifies the output signal of the detector 13.

The ionization chamber 5 and the measurement chamber 10 are provided with a metal shield member 16.
This shield member 16 prevents the metal vapor 4 from adhering to the ionization chamber 5, lens system 11, drift tube 12, and detector 13 and causing insulation defects, and also prevents the detection of the detector 13. This prevents noise from entering the signal.

Further, 17 is a driver for driving the electron beam generator 9, and 18 is a power source for applying a voltage for setting the removal electrode 6 to a required potential. The driving operation of the driver 17 and the voltage application operation of the power supply 18 are controlled by a controller 19.

Next, the operation of the metal vapor mass spectrometer having the above configuration will be explained. Metal vapor 4 evaporated by irradiating metal 2 in crucible 1 with electron beam 3 moves upward and enters ionization chamber 5 . If the ion particles originally contained in the metal vapor 4 are not to be removed, no voltage is applied to the removal electrode 6, and at the same time, the electron beam generator 9 is not driven. Therefore, the ion particles originally contained in the metal vapor 4 are drawn out to the drift tube 12 by the electric field generated between the ionization chamber 5 and the lens system 11. On the other hand, when applying a voltage to the removal electrode 6 to generate a required electric field and removing ion particles in the metal vapor 4 using this electric field, the ionization electron beam generator 9 is driven to generate a predetermined cutoff. An electron beam 2o having an area is generated to ionize neutral particles contained in the metal vapor 4. Ions generated by the ionizing electron beam 20 are drawn to the drift tube 12 by the electric field formed between the ionization chamber 5 and the lens system 11 in the same manner as described above.

As mentioned above, when extracting the ionic particles originally contained in the metal vapor 4, or by removing the ionic particles originally contained in the metal vapor 4 in advance and then ionizing the neutral particles, extracting the generated ionic particles. In either case, the ion particles 21 extracted from the ionization chamber 5 have their energy and trajectory adjusted by the lens system 11, and are guided to the drift tube 12. After the ion particles 21 fly for a certain period of time in the drift tube 12, they are detected by the secondary electron multiplier 14 of the detector 13. The output signal is then input to amplifier 15, where it is amplified to the required level.

Next, a method for determining the size of neutral clusters contained in the metal vapor 4 will be explained with reference to FIG.

The lens system 11 includes an acceleration electrode 11a, a deceleration electrode 11b, a ground electrode 11c, an X-direction deflection electrode 11d, and an X-direction deflection electrode 11e. The ion particles present in the ionization chamber 5 are accelerated by the electric field between the ionization chamber 5 and the acceleration electrode 11a, and then accelerated by the electric field between the acceleration electrode 11a and the deceleration electrode 11b.
The deceleration is caused by the electric field between the deceleration electrode 11b and the earth electrode 11c. As a result, lens system 1
Ion particles 2 that entered 1 and reached the earth electrode 11c
1 has kinetic energy qv, (q: charge of the ion particle) corresponding to the potential difference V between acceleration and deceleration. The deflection electrode 11d is directed against the ion particles 21 in the X direction (for example,
The deflection electric field in the metal vapor passing direction) is
A deflection electric field in the X direction perpendicular to the direction is applied. X direction and X
When applying deflection electric fields in different directions, the strength of each deflection electric field is adjusted so that the ion detection signal monitored by the detector 13 is maximized. Note that, for example, the voltage applied to the deflection electrode lie is made into a pulse voltage, and adjustment is performed so that the ion detection signal can be monitored by the detector 13 only when this pulse voltage is applied. Here, the deflection electrode 11
The distance from e to the entrance of detector 13 (flight distance) is JF
Then, the flight time t for the ion particles ejected from the deflection electrode 11e to reach the entrance of the detector 13 can be expressed by the following equation.

t=z r (mI /2 qV+) ”'
--(1) Here, mI is the mass of the ion particle, q is the charge of the ion particle, and Vl is the acceleration voltage of the ion particle.

In the above equation, the flight time of a monovalent monatomic ion particle of a certain metal is t. Then, the flight times of divalent and trivalent monatomic ion particles are t2to /v'T: t
, =jo/n-. On the other hand, in the case of a cluster, the valence of the ion particles is considered to be 1, so the flight time of the cluster ion particles with a cluster size of 2 or 3 is t 3 =vTt o , respectively.
t4=f]-t o.

This is because in the case of a cluster, the repulsive force between positive charges is greater than the bonding force between the atoms that make up the cluster, so even if two or more atoms are ionized, they immediately separate into two or more. This is to put it away.

Next, with the application time of the deflection pulse voltage applied to the deflection electrode 11e as a reference (t=0), the time-series signals of the above-mentioned monatomic ion particles and cluster ion particles are calculated at the time t.
. - It is shown in FIG. 3(b) based on t4. As is clear from the previous equation, the flight time of a k-valent monatomic ion particle is 1
The flight time t of a valent monatomic ionic particle. , and the flight time of a cluster ion particle with a cluster size of j is t. f]- times. In this way, the flight time t of the ion particles in the drift tube 13. −
From t4, the size of the cluster and the single atoms contained in the metal vapor 4 can be determined.

In the above case, if the pulse width of the deflection pulse voltage is made too large, the pulse width of each detection signal shown in FIG. 3 will also be widened, and the resolution will deteriorate, making it difficult to distinguish between the detection signals. On the other hand, if the pulse width is made too small, for example in the case of a metal with a large mass, the deflection of the ion particles will become insufficient, making it impossible to detect the ion detection signal. Therefore, when determining the pulse voltage, it is necessary to set the optimal pulse width and pulse height value of the deflection pulse voltage while monitoring the ion detection signal.

Also, as is clear from the previous equation, in order to improve the detection resolution of the detector 13, it is necessary to increase the flight distance by 1°,
It is also effective to reduce the ion particle acceleration voltage V.

Next, neutral monatomic atoms, clusters, contained in metal vapor 4,
Also, a method for measuring the density and abundance ratio of these ion particles will be explained.

When no voltage is applied to the removal electrode 6 and the ion particles contained in the metal vapor are not removed, the output signal 1 of the detector 13 is
1 is given by the following formula.

■, =αnIqvSG (2) On the other hand, a required voltage is applied to the removal electrode 6 and the ion particles originally supported by the metal vapor are removed by the removal electric field, and then an ionizing electron beam is applied in the ionization chamber 5. 20 to ionize neutral particles contained in the metal vapor 4, the output signal I of the detector 13 is given by the following equation.

■=α■e1w ((1-β)na0A) G ・(3
) Here, α is the transmittance of ion particles including the lens system 11, drift tube 12, and detector 13, and G is 2
The current amplification degree of the secondary electron multiplier 14, n and n are the densities of ion particles and neutral particles contained in the metal vapor 4, respectively, and q
is the charge of the ion particle, ■ is the velocity of the metal vapor in the passing direction,
S is the cross-sectional area of the metal vapor 4 in the ionization chamber 5, 1w
is the ionization distance of the metal vapor 4 by the electron beam 20, (■) is the electron current of the electron beam 20, and β is the decomposition probability of the particle of interest by the ionizing electron beam 20 (in the case of a single atom, β = 0)
, A is the rate at which the particle of interest is formed by decomposing a cluster composed of more atoms than the particle of interest.

In general, it is difficult to determine the above β and A, but if ionization is performed with an electron beam of energy smaller than the bonding energy between the atoms constituting the cluster, the decomposition term disappears, and the above equation (3) becomes Expressed as an expression.

■=α■, nσ1wG...(4) In the above equations (2) and (4), II and I are the third
It can be measured as the peak current value of the ion detection signal shown in (b) of the figure, and the electron current (8) can also be measured. Furthermore, the vapor cross-sectional area S and the ionization distance 1vr are
It is determined by the size of the vapor passage hole 8 formed in the ionization chamber 5, and the amplification degree G is determined by the secondary electron multiplier. As for the charge q of an ionic particle, in the case of a cluster, as mentioned above, it can be considered as q-e (single-valent ion),
In the case of a single atom, q can be determined from the flight time of the ion particle shown in FIG. Therefore, if the transmittance α, the ion particle velocity V, and the ionization cross section σ of the ion particles are determined in advance, the density n of the ion particles originally contained in the metal vapor 4 can be calculated from the equation (2), and the density n of the ion particles originally contained in the metal vapor 4 can be calculated from the equation (2). The density n of neutral particles can be determined from .

If the densities nl and n are determined in this way, their abundance ratio can also be determined.

Flight time t of ionic particles. - Metal vapor 4 based on t4
Calculate the size and single atoms of the clusters contained in the metal vapor 4, and calculate the density and abundance ratio of the neutral single atoms, clusters, and these ionic particles contained in the metal vapor 4 according to equations (2) and (4) above. What is done is to input the output signal of the amplifier 15, obtain the time data obtained from this input signal and the peak value data of the ion detection signal, and use the signal calculation processing device 22 which incorporates the above-mentioned analysis method as a program. executed. Further, constants for various conditions such as a reference time required for measuring flight time and other conditions required in the analysis may be prepared in advance in the storage section of the signal processing device 22, or may be input as necessary. It is configured to

The analysis method using the mass spectrometer described above may be applicable even when clusters are decomposed by the ionizing electron beam 20. That is, in the time-of-flight mass spectrometry method shown in FIG. The time required for this can be shortened to the order of 10-6 seconds by increasing the accelerating voltage, so if the cluster decomposition time is slower than the transit time through the lens system 11, the cluster will be decomposed into the detected mass spectrum. No effect appears. In such a case, the mass spectrometry method according to the present invention described above can be applied as is.

By the way, the decomposition of a cluster differs depending on the constituent atoms. For example, in clusters of aluminum, copper, lead, molybdenum, tungsten, etc., decomposition mainly occurs in which one atom is separated, and in carbon clusters, decomposition mainly occurs in which clusters of three atoms are separated. Therefore,
When determining β and A in the above equation (3), it is necessary to determine the cluster decomposition probability for each constituent atom in consideration of the above characteristics.

In the above embodiment, an example in which an electron beam is used as the ionization means has been described, but a laser beam may also be used.

Next, other embodiments will be described using FIG. 4.

In this embodiment, the device configuration is basically the same as that shown in FIG. 1, but the operation of the power supply 18 controlled by the controller 19 and the operation of the electron beam generator 9 are different, and the operation is controlled as follows be done. First, Figure 4(a)
As shown in , regarding the voltage applied to the removal electrode 6, the period T
In the first half up to T/2, no voltage is applied, and in the second half from T/2 to T, a square wave removal voltage 30 is applied. The ionizing electron beam 20 is generated in synchronization with the removal voltage, and is generated as an ionizing electron current 31 in synchronization with the start time of the latter half cycle, as shown in FIG. 4(b). According to this, when the removal voltage is not applied, the mass spectrum 32 of the ion particles contained in the metal vapor 4 can be obtained in the half cycle, and when the removal voltage 30 is applied, the mass spectrum 32 of the ion particles contained in the metal vapor 4 can be obtained in half the period. A mass spectrum 33 of neutral particles contained in the metal vapor 4 can be obtained periodically. T/2
The time is set to be sufficiently larger than the time width of the detected mass spectrum. As in this embodiment, by periodically switching the method of applying the removal voltage,
In addition to being able to measure at high speed, averaging processing can be performed by obtaining a large number of detection signals, and the reliability of measured values can be increased. In this embodiment as well, signal processing is performed in the signal arithmetic processing device 22. In this embodiment, the controller 19
and signal processing device i! Synchronization is achieved with 22.

FIG. 5 shows an embodiment of the evaporator according to the invention.

An evaporator 41 consisting of a crucible containing metal and an electron gun is installed in the vacuum container 40, and metal vapor 4 is generated from the evaporator 41. In this embodiment, it is assumed that mass spectrometry is performed on single atoms in the metal vapor 4.

Mass spectrometer 4 according to the present invention explained based on FIG.
2 is placed at a suitable position where the metal vapor 4 can be monitored. However, in this embodiment, the signal arithmetic processing device 22 is excluded. 43 is a power source, and this power source is the power source 1 mentioned above.
It also has the functions of ion source 7, lens system 11, and detector 1.
3 and amplifier 15, and provides a reference pulse for the flight time of the ion particles in the drift tube 12 to the time window 44. The output signal of the time window 44 is given to a peak detector 45, where the peak value of the ion detection signal is determined. 46 is a controller, and the detection signal of the peak detector 45 is input to this controller 46. Further, the controller 46 controls the output of a power source 47 that supplies power to an electron gun provided in the evaporator 41 based on the input signal.

It should be noted that the 48
is a product recovery device, and 49 generated during this is a laser beam for isotope separation.

In the evaporator 41 having the above control system, control is performed as follows. A predetermined power is supplied by a power source 47,
The electron gun irradiates the metal with an electron beam and metal vapor 4 is generated. When a removal voltage is applied to the removal electrode in the mass spectrometer 42, ion particles originally contained in the metal vapor 4 are removed.

As a result, as is clear from the above description of the mass spectrometry method, the signal output from the mass spectrometer 42 becomes a mass spectrum related to neutral particles contained in the metal vapor 4.

This signal is amplified by an amplifier 15 to a required level. The output signal of amplifier 15 is sent to time window 44 . The time window 44 is configured to pass only the ion detection signal that arrives at a time delayed by the flight time of the monatomic ion particle based on the reference pulse given from the power supply 43 out of the mass spectrum input from the amplifier 15. Set the delay time and time width.

The peak value of the detection signal related to the monatomic ion particle that has passed through the time window 44 is monitored by the peak detector 45, and the peak value signal thus obtained is sent to the controller 46. The controller 46 controls the electron gun power source 46 to cause the electron gun of the evaporator 41 to emit an electron beam when the detected signal of the monatomic atoms being monitored exceeds a preset tolerance range for a predetermined period of time or more. Control is performed by changing the position and output so that the peak value of the detection signal falls within an allowable range.

When the evaporator 41 is configured to evaporate metal with an electron beam, the evaporation surface of the metal is gradually dug, and the amount of evaporation often changes. It is extremely effective to keep the amount of evaporation constant by changing the position of the electron beam to even out the depth of the evaporation surface when performing evaporation for a long time.

Furthermore, the evaporator can be configured to determine the amount of neutral particles and ion particles by changing the control method of the mass spectrometer 41 and applying an appropriate removal voltage to the ion particle removal electrode. In this case, for example, the position and output of the electron beam may be adjusted based on the output signal of the mass spectrometer to reduce the proportion of neutral clusters contained in the metal vapor and the ion particles. It is possible.

〔Effect of the invention〕

As is clear from the above explanation, according to the metal vapor mass spectrometer according to the present invention, a removal electrode capable of removing ion particles in metal vapor as necessary is installed, and this removal electrode and a predetermined Since it is configured to include an ionization energy generating means that operates in a synchronous relationship, it is possible to distinguish between neutral particles and ionic particles contained in metal vapor and to identify the number of atoms that make up each particle. Therefore, the density and abundance ratio of neutral monatomic atoms, clusters, and these ions in metal vapor can be determined.

In addition, since the mass spectrometer according to the present invention can constantly monitor neutral particles in metal vapor, an evaporation device including an electron gun configured using this makes it possible to feed back the monitor signal to the electron gun. This allows stable and constant metal vapor to be generated.

Furthermore, according to the evaporation device using the mass spectrometer according to the present invention, it is possible to perform evaporation that reduces the abundance ratio of neutral clusters and ions in the metal vapor. By applying this method to body separation, steam utilization efficiency and concentration can be improved.

[Brief explanation of drawings]

Figure 1 is a configuration diagram showing a first embodiment of a metal vapor mass spectrometer according to the present invention, Figure 2 is a plan view of the main parts in Figure 1, and Figure 3 is the size of neutral particles and ionic particles. FIG. 4 is a diagram for explaining another embodiment of the metal vapor mass spectrometer according to the present invention, and FIG. 5 is a diagram for explaining an example of the evaporation device according to the present invention. FIG. 2 is a configuration diagram showing an example. [Explanation of symbols] 1--el crucible 2... Metal 3... Evaporation electron beam 4... Metal vapor 5... Ionization chamber 6...Ion particle removal electrode 9...Ionization electron beam generator 11...
・Lens system 12...Drift tube 13...Detector 19...φ...Controller 22...Signal processing unit 41...Evaporator 42... Mass spectrometer 45...Peak detector 46...Controller 11c Fig. 2t. 3 4 Figure □ Time

Claims (7)

[Claims] (1) In a mass spectrometer that analyzes the mass of metal vapor vaporized by being heated by an electron beam, an ionization chamber that takes in the metal vapor and a path of the metal vapor in front of the ionization chamber are provided, an ion particle removal electrode that generates an electric field for removing ion particles in the metal vapor; an energy generation means for supplying ionization energy to the ionization chamber; a removal electric field generation operation of the ion particle removal electrode; and the energy. A control means for controlling the ionization energy generation operation of the generation means, a lens system means for drawing out the ion particles present in the ionization chamber, a drift tube for making the drawn out ion particles fly a predetermined distance, and a detection of the drawn out ion particles. detection means for
signal calculation processing means that distinguishes between neutral particles and ionic particles contained in the metal vapor using the detection signal of the detection means, measures the differentiated neutral particles and ionic particles, and calculates the density and abundance ratio of each; A metal vapor mass spectrometer comprising: (2) In the metal vapor mass spectrometer according to claim 1, the control means does not operate the energy generation means when not generating a removal electric field at the ion particle removal electrode, and the control means does not operate the energy generation means to generate a removal electric field at the ion particle removal electrode. A metal vapor mass spectrometer, characterized in that when generating ionization energy, the energy generation means is controlled to generate ionization energy. (3) In the metal vapor mass spectrometer according to claim 2, a voltage that generates an electric field for removing ion particles in the metal vapor is periodically applied to the ion particle removal electrode to remove the ion particles from the metal vapor. A mass spectrometer for metal vapor, characterized in that it distinguishes between neutral particles and ionic particles contained in the vapor. (4) The metal vapor mass spectrometer according to claim 3, wherein the voltage applied to the ion particle removal electrode has a square wave shape. (5) In the metal vapor mass spectrometer according to any one of claims 1 to 4, the energy generating means generates energy smaller than the binding energy of a cluster consisting of two or more atoms contained in the metal vapor. 1. A mass spectrometer for metal vapor, characterized in that the ionization means generates ionization means, and neutral particles in the metal vapor are ionized by the ionization means. (6) In any one of claims 1 to 5, in an evaporation device that irradiates metal with an electron beam output from an electron gun to generate metal vapor, the amount of neutral particles contained in the metal vapor is detected. The described mass spectrometer and a control that compares the detection signal of this mass spectrometer with a set standard, and when the set standard is not met, adjusts the position and output of the electron beam so as to satisfy the set standard. An evaporation device comprising means. (7) An evaporation device that irradiates metal with an electron beam output from an electron gun to generate metal vapor, wherein the amount of neutral particles and ion particles contained in the metal vapor is detected. The mass spectrometer described in item 1 and the position and output of the electron beam are adjusted based on the detection signal of this mass spectrometer to reduce the abundance ratio of the neutral clusters and the ion particles contained in the metal vapor. 1. An evaporator comprising: control means for controlling the