Patent Application
20170309459
The present invention relates to a method and a device for measuring particles (ion particles and neutral particles) discharged from a target by a method such as a sputtering method, an arc discharge method or a laser ablation method. The present invention specifically relates to a method and a device for instantly measuring the kind and intensity of sputtered particles discharged by a pulse sputtering method or specifically by a high power impulse magnetron sputtering method.
The high power impulse magnetron sputtering method (which will be abbreviated as “HIPIMS (High Power Impulse Magnetron Sputtering)” hereafter) is one of the methods for discharging particles from a target as described above. The HIPIMS is expected as a sputtering technology with high performance and high efficiency (see patent documents 1 and 2). A sputtering source of the HIPIMS applies pulses of a high voltage to a target such as a sputtering metal placed in an inert gas such as Ar (argon), thereby sputtering particles (ion particles and neutral particles), that is, causing impact detachment of the particles, from the target.
The HIPIMS can generate a high-temperature and high-density plasma and can provide a higher degree of ionization than the conventional RF method or the DC magnetron sputtering method. Therefore, it is expected that use of the HIPIMS results in film formation with higher quality than the conventional technologies. However, in terms of industry, the HIPIMS is on the way of development regarding its use, concrete use conditions and the like.
In the film formation using the HIPIMS, in order to form a vapor-deposited film with aimed specifications, it is desirable to clarify factors that affect the film formation and to control the factors with high accuracy. Usually, an oxide film and extraneous substances exist on a surface of a work, on which the vapor-deposited film is to be formed. Therefore, before performing the vapor deposition using the sputtering, the work surface may be etched to remove the oxide film and the extraneous substances therefrom, thereby improving the quality of adhesion of the vapor-deposited film to the work and improving the quality of the vapor-deposited film. When performing the sputtering etching using the HIPIMS, in order to perform the etching with aimed specifications, it is desirable to clarify factors that affect the etching and to control the factors with high accuracy.
It is therefore an object of the present invention to provide a method and a device capable of accurately measuring sputtered particles (ion particles and neutral particles) discharged by a sputtering method. Specifically, it is an object of the present invention to provide a method and a device capable of instantly measuring the kind and intensity of sputtered particles discharged by a pulse sputtering method or specifically by the HIPIMS. Thus, for instance, factors affecting film formation or etching using the sputtering method or specifically the HIPIMS can be grasped, and the film formation or the etching can be controlled with high accuracy and in real time based on the grasped factors. Moreover, advantages similar to the above-mentioned advantages can be obtained if the discharged particles (ion particles and neutral particles) can be measured with high accuracy not only in the case where the particles are discharged from the target by the sputtering method but also in the case where the particles are discharged from the target by a method such as an arc discharge method or a laser ablation method. Therefore, it is also an object of the present invention to provide a method and a device capable of measuring the particles discharged from the target by these methods with high accuracy and to provide a method and a device capable of instantly measuring the kind and intensity of the discharged particles.
To solve the above problems, the inventors of the present invention studied hard and reached following aspects. That is, a measuring device according to an aspect of the present invention has a measuring section for measuring a ratio between an equivalent value of the number of ion particles discharged from a target by sputtering caused by a pulsed electric discharge and an equivalent value of the number of neutral particles discharged from the target by the pulsed electric discharge.
The ratio between the number of the ion particles and the number of the neutral particles discharged (or sputtered) from the target by the sputtering is considered to be one of factors affecting not only the quality of the vapor-deposited film but also a film formation rate or an etching rate. Therefore, with the measuring device according to the above aspect, one of the factors affecting the film formation or the etching using the sputtering such as the HIPIMS can be grasped.
According to another aspect of the present invention, the measuring device further has an ionizing section for ionizing the neutral particles discharged from the target by the sputtering, and the measuring section measures the equivalent value of the number of the ion particles and the equivalent value of the number of the neutral particles by the time-of-flight mass spectrometry.
In the time-of-flight mass spectrometry using the TOFMS (Time-of-Flight mass spectrometer), ions as the analysis object are accelerated by a static electric field. At that time, the same energy is given to every ion. Accordingly, light ions have high speed, and heavy ions have low speed. By using this principle, the time (time of flight) since the acceleration is started until the ion reaches a detector after the ion flies through an inside of a flight tube is measured, thereby obtaining a mass spectrum.
With the configuration according to the above aspect, the ions discharged from the target are accelerated by the static electric field and the mass spectrum is obtained by the time-of-flight measurement. From the mass spectrum, the kind of the produced ion particles and the equivalent value of the number of the produced ion particles can be obtained. As for the neutral particles discharged from the target, the neutral particles may be ionized by the ionizing section and accelerated by the static electric field likewise, whereby the kind of the produced ion particles can be observed and the equivalent value of the number thereof can be measured.
A measuring device according to another aspect of the present invention has a discriminating section for discriminating the ion particles discharged from the target by the sputtering and the neutral particles discharged from the target by the sputtering based on the times of flight thereof, and the measuring section measures the equivalent values based on the result of the discrimination by the discriminating section.
It was found by the experiments conducted by the inventors of the present invention that, if the ion particles and the neutral particles produced by the same pulsed electric discharge are the detection objects of the TOFMS at the same time and potential fluctuation of an electron amplification detector anode is observed on an oscilloscope, a deviation occurs in positions of potential peaks, which indicate the times of arrival to the detection electrode, between the ion particles discharged from the target by the sputtering in the form of the ions from the beginning and the ion particles that originate from the neutral particles and that are discharged by the sputtering in the form of the neutral particles and that are ionized by the ionizing section. That is, the obtained result showed that the ion particles that are discharged in the form of the ions from the beginning have the shorter time of flight than the ion particles originating from the neutral particles. The cause thereof is thought to be that the ion particles discharged in the form of the ions from the beginning have higher speed than speed of the neutral particles in the acceleration area. Therefore, with the above scheme, the equivalent value of the number of the ion particles and the equivalent value of the number of the neutral particles discharged by the sputtering caused by the single pulsed electric discharge can be measured at the same time.
According to another aspect of the present invention, the measuring device further has a frequency divider for generating a frequency dividing signal based on a pulse signal synchronized with an occurrence of the pulsed electric discharge, the frequency dividing signal having a period that is integral multiple of a period of the pulse signal, and a driver for driving the ionizing section with the frequency dividing signal.
With such the construction, at respective timings when the sputtering is performed, both of timings for driving the ionizing section and timings not for driving the ionizing section can be defined. Through the measurement at the timing for driving the ionizing section, the sum total of the equivalent value of the number of the ion particles discharged in the form of the ions by the sputtering and the equivalent value of the number of the ion particles that are discharged in the form of the neutral particles and ionized by the ionizing section is measured. At the timing when the ionizing section is not driven, the neutral particles are not ionized, so only the equivalent value of the number of the ion particles discharged in the form of the ions by the sputtering is measured through the measurement at such timing. Thus, only with the two timings at the minimum, the equivalent values can be obtained for the respective kinds of the sputtered particles of the ion particles and the neutral particles (in this case, equivalent value of number of neutral particles can be obtained by subtraction). Thus, the measurement within the very short time can be realized under substantially the same conditions.
The measuring device according to another aspect of the present invention has a frequency divider for generating a frequency dividing signal based on a pulse signal synchronized with an occurrence of the pulsed electric discharge. The frequency dividing signal has a period that is integral multiple of a period of the pulse signal. The measuring device further has a section for allowing or prohibiting the ionization of the neutral particles by the ionizing section based on the frequency dividing signal. Also with such the construction, effects similar to those of the above aspects can be exerted.
According to another aspect of the present invention, the frequency dividing signal has a period that is integral multiple of the period of the pulse signal and that is two to ten times the period of the pulse signal. Experiments conducted by the inventors of the present invention showed that, by setting the period of the frequency dividing signal in the above range, significant values as the equivalent values of the number of the ion particles and the number of the neutral particles to be compared with each other can be obtained.
According to another aspect of the present invention, the pulsed electric discharge is constituted by a plurality of successive pulsed electric discharges. The measuring section measures the ratio based on the equivalent value or the equivalent values of either or both of the ion particles and the neutral particles discharged from the target by the sputtering caused by the pulsed electric discharge occurring at timing corresponding to timing when the frequency dividing signal is generated and based on the equivalent value or the equivalent values of either or both of the ion particles and the neutral particles discharged from the target by the sputtering caused by the pulsed electric discharge occurring at timing different from the timing when the frequency dividing signal is generated. With such the construction, the measurement of the ratio can be performed within a very short time under substantially the same conditions.
According to another aspect of the present invention, the measuring device further has an ion particle removing section for removing the ion particles discharged from the target by the sputtering. With such the construction, only the equivalent values of the numbers of the respective kinds of the neutral particles discharged from the target by the sputtering can be measured respectively while removing the ion particles.
According to another aspect of the present invention, the measuring device further has a section for synchronizing the drive of the ionizing section and the drive of the ion particle removing section. With such the construction, when the ionizing section is driven in the state where the ion particles are removed by the ion particle removing section, only the ion particles originating from the neutral particles can be used as the measurement object. Thus, the kind of the neutral particle can be observed with high precision and the equivalent value of the number of the neutral particles can be measured with high accuracy.
According to another aspect of the present invention, the pulsed electric discharge is constituted by a plurality of successive pulsed electric discharges. The measuring section measures the ratio based on the equivalent values of the ion particles and the neutral particles discharged from the target by the sputtering caused by one or a plurality of the pulsed electric discharges arbitrarily selected from the successive pulsed electric discharges. Further, according to another aspect of the present invention, the pulsed electric discharges selected by the measuring section are pulsed electric discharges that are timewise adjacent to each other. With such the construction, the measurement of the ratio can be performed within a very short time under substantially the same conditions.
A sputtering device according to another aspect of the present invention is a sputtering device using the HIPIMS. The sputtering device has the measuring device according to any one of the above aspects and a controller for controlling at least one of a current amount, a voltage or an electric energy for one time of the pulsed electric discharge of the HIPIMS and a bias potential applied to a work as a processing object of the sputtering device based on the ratio of the equivalent values measured by the measuring device.
There is a tendency that the ratio of the number of the ion particles discharged from the target to the number of the neutral particles discharged from the target increases as the current amount, the voltage value or the electric energy for the discharge during each pulsed electric discharge of the HIPMS increases. Therefore, feedback control of the ratio of the equivalent values can be performed by controlling the current amount, the voltage value or the electric energy for each pulsed electric discharge based on the ratio of the equivalent values measured with the measuring device.
In addition, there is a tendency that the etching of the work is promoted as the absolute value of the bias voltage (negative voltage) applied to the work increases. There is a tendency that the deposition on the work (i.e., film formation) is promoted as the absolute value of the bias voltage decreases. Therefore, by controlling the bias voltage applied to the work based on the ratio of the equivalent values measured with the measuring device, the film formation and the etching can be controlled with high accuracy.
By using either or both of such control schemes, the film formation and the etching can be controlled with high accuracy based on the actual state of the production of the ion particles and the neutral particles from the target.
A measuring device according to another aspect of the present invention has a measuring section for measuring a ratio between an equivalent value of the number of ion particles discharged from a target and an equivalent value of the number of neutral particles discharged from the target, an ion particle removing section for removing the ion particles discharged from the target in a stage prior to the measuring section, and an ion particle removal controlling section for allowing or prohibiting the removal of the ion particles by the ion particle removing section based on successive pulse signals.
With such the construction, the ratio between the equivalent value of the numbers of the ion particles actually discharged from the target and the equivalent value of the number of the neutral particles actually discharged from the target can be measured instantly by using any type of the system for discharging the particles form the target, the system not being limited to the system that discharges the particles from the target based on the pulsed electric discharge.
Hereafter, a first embodiment of the present invention will be explained.
If the argon gas is supplied into the chamber 11 and a pulsed electric power is supplied from the power supply 18 to the sputtering source 13 (that is, for instance, if high voltage of approximately 1 kV in the shape of pulse of 10 microseconds to 2000 microseconds is applied between target 12 and anode electrode 14), a pulsed glow discharge arises between the target 12 and the anode electrode 14, and a pulsed plasma originating from the argon is formed near the target 12. The HIPIMS section 10 according to the present embodiment can perform magnetron sputtering by forming a magnetic field near the surface of the target 12 using the magnet unit 15 and can generate a comparatively strong glow discharge. As a result, neutral particles and ions (monovalent ions and multivalent ions) of the material forming the target are discharged from the target 12.
The controller 30 has a trigger signal generating section 31 and a controlling section 32. Every time the high-voltage pulse is applied from the power supply 18 to the sputtering source 13, a pulse signal synchronized with that timing is outputted from the power supply 18 to the trigger signal generating section 31 of the controller 30. The trigger signal generating section 31 generates trigger signals synchronized with the pulse signal and outputs the trigger signals to an ion accelerator driver 35, a TOF (i.e., time of flight) specifying section 37 and a frequency divider 65 of the TOF mass spectrometry section 40.
The TOF mass spectrometry section 40 further has a casing 41, a gate 43 consisting of a metal plate, an ion accelerator 45, an ion detector 48 and a UV laser irradiator 61. The present embodiment uses a reflectron TOF mass spectrometry section 40 having a reflectron 47. An inside of the casing 41 is partitioned into a first chamber 40A and a second chamber 40B. The ion accelerator 45 is arranged in the first chamber 40A. The reflectron 47 and the ion detector 48 are arranged in the second chamber 40B. The casing 41 is fixed to the chamber 11 of the HIPIMS section 10. The casing 41 faces the sputtering source 13 of the HIPIMS section 10 and opens to the sputtering source 13 through an aperture 42. The aperture 42 is made by boring a hole having the diameter of, for instance, approximately 1 mm in the gate 43.
It is necessary to maintain the pressure inside the casing 41 of the TOF mass spectrometry section 40 to be lower than the pressure inside the chamber 11 of the HIPIMS section 10. Therefore, it is desirable to make the aperture 42, which serves as an interface therebetween, as small as possible. At the same time, it is necessary to stably introduce the ions and the neutral particles, which have been produced in the chamber 11, into the TOF mass spectrometry section 40. In order to do so, it is desirable to make the diameter of the aperture 42 large. It is desirable to set the diameter of the aperture 42, which has such a trade-off, in a range from 0.1 mm to 5 mm according to the study performed by the inventors of the present invention.
The gate 43 can be switched between a state where the gate 43 is earthed to the ground (Gnd) and a state where the gate 43 is at a predetermined potential by a potential changing circuit 44. In the TOF mass spectrometry section 40 used for grasping the state of the sputtering, the ions can be introduced into the casing 41 by setting the potential of the gate 43, which serves as an ion introduction hole to the TOF mass spectrometry section 40, to be equal to or lower than the ground potential.
The gate 43 can be made to function as a prevention electrode by maintaining the potential of the gate 43 to a plasma potential using the potential changing circuit 44. The plasma potential is a predetermined potential equal to or higher than a potential exceeding an energy, which the ion can have. For instance, the predetermined potential is a potential Vg higher than approximately 20V. Thus, the ions can be prevented from entering the casing 41 through the aperture 42. In this case, only the neutral particles can pass through the aperture 42 and enter the inside of the casing 41. Thus, the object of the analysis by the TOF mass spectrometry section 40 can be limited to the ion particles originating from the neutral particles.
The aperture 42 is deviated outward from the center of the target 12. In the present embodiment, the aperture 42 is decentered by 22.5 mm to sample a portion having the highest concentration of the sputtered particle ions. The clearance of 5 cm is provided between the aperture 42 and the target 12 in the present embodiment, but the clearance therebetween may be set arbitrarily. The ion accelerator 45 provided in the first chamber 40A consists of multiple metal plates having openings 46 on the same axis as the aperture 42. The ion accelerator 45 accelerates the ions that pass through the openings 46. Metal meshes may be attached to the openings 46 to rectify distortion of an electric field. A fixed high voltage Va (1.4 kV in this example) is applied from the ion accelerator driver 35 to the ion accelerator 45. The accelerated ion is reflected by the reflectron 47 and is detected with the ion detector 48 consisting of a MCP detector, for instance. A time since the occurrence of the trigger signal to the detection of the ion is specified as a time of flight (that is, TOF) with the TOF specifying section 37. A kinetic energy ½ mv2 given from the ion accelerator 45 is constant. Therefore, difference in the mass (m) of the ion is detected as the difference in the speed (v), or the time for the ion to reach the ion detector 48. The lighter the ion is, the higher the speed is. The heavier the ion is, the lower the speed is. The detection result is outputted from the TOF specifying section 37 to the controlling section 32 of the controller 30.
It is desirable to provide an evacuation device 51 also in the TOF mass spectrometry section 40 and to perform evacuation (differential evacuation) separately from the HIPIMS section 10, thereby discharging the argon gas from the inside of the TOF mass spectrometry section 40. In the present embodiment, the degree of vacuum in the TOF mass spectrometry section 40 is set at 1×10−4 Pa in the first chamber 40A and is set at 3×10−5 Pa in the second chamber 40B.
Next, a measuring method of the sputtered particles using the sputtered particle measuring device 1 according to the present embodiment will be explained as a working example. In the working example, it is aimed to discriminate the kinds of the ion particles and the neutral particles, which are sputtered particles sputtered from the target 12 by the pulsed electric discharge of the HIPIMS, to grasp both of an equivalent value of the number of the ion particles and an equivalent value of the number of the sputtered neutral particles in the sputtered particles using the TOF mass spectrometry technique regarding the respective kinds of the sputtered particles, and to grasp the actual state of the sputtering based on a ratio between the equivalent values. In the working example below, a target consisting of a single element metal is used as the target 12, but the present invention is not limited to this.
When the ion accelerator driver 35 receives the trigger signal from the trigger signal generating section 31, the ion accelerator driver 35 accelerates the ions by applying a predetermined high voltage Va to the ion acceleration electrodes 45. A time (TOF: Time of Flight) from timing when the acceleration is started to timing when the ion reaches the detector 48 by flying through a flight tube having a fixed distance is measured, and the mass spectrum is obtained. The trigger signal is applied also to the TOF specifying section 37 to determine the start timing of the flight of the ion. An equivalent value (M+) correlated with the number of the metal ion particles produced in the HIPIMS section 10 can be obtained from the obtained mass spectrum. The time from the ion acceleration start to the detection is very short time of tens to hundreds of microseconds.
The metal neutral particles discharged from the target 12 by the pulsed electric discharge in the HIPIMS section 10 enter the inside of the casing 41 through the aperture 42. The UV laser irradiator 61 irradiates the metal neutral particles in the casing 41 with a UV laser through a transmission window 63 provided in the casing 41 and ionizes the metal neutral particles. If the metal neutral particles are ionized, they are brought into the state where they can be accelerated by the ion accelerator 45. In this way, the metal neutral particles can also be made into the object of analysis by the TOF mass spectrometry section 40, and the equivalent value (M) correlated with the number of the metal neutral particles sputtered from the target 12 by the HIPIMS becomes measurable by the TOF mass spectrometry section 40. In this working example, a vacuum UV laser generator as the UV laser irradiator 61 uses the ninth-order harmonic (118 nm, 10.5 eV) of the fundamental wave (1064 nm) of the Nd:YAG laser. Not only the vacuum UV laser generator but also any other ionizing device such as a thermal electron pulse beam generator may be used. In the embodiment, the UV laser is emitted so that it passes through substantially the middle between the two metal plates of the ion acceleration electrode 45.
The frequency divider 65 generates a pulsed frequency dividing signal having a period, which is integral multiple of a period of the trigger signal, based on the trigger signal and outputs the frequency dividing signal to the UV laser irradiator 61. The UV laser irradiator 61 emits a UV laser by using the input of the frequency dividing signal as a trigger.
A TOF spectrum obtained with the device according to the above-mentioned embodiment (shown in
Target: Ti
Applied voltage: 600V
Voltage pulse width: 1500 microseconds
Trigger signal frequency: 50 Hz
Ar gas flow: 200 ccm
Laser frequency: 10 Hz
Detection intensity of the metal (Ti in this example) in this mass spectrum can be used as the equivalent value (M+) of the number of the metal ion particles and the equivalent value (M) of the number of the metal neutral particles, which are discharged from the target 12 by the HIPIMS. Detection intensity of Ar as the sputtering gas is also shown as reference.
The detection intensity shown in
In this way, by generating the frequency dividing signal at the same timing as a part of the trigger signals using the frequency divider 65, the TOF mass spectrometry in the case where both of the pulsed electric discharge of the HIPIMS and the ionization of the neutral metal particles are performed and the TOF mass spectrometry in the case where only the pulsed electric discharge of the HIPIMS is performed but the ionization is not performed can be performed within a very short time. For instance, when the frequency of the trigger signal is 50 Hz, the time length from the timing t1 to the timing t2 is 20 milliseconds, which is very short. The equivalent value of the number of the metal neutral particles and the number of the metal ion particles can be calculated respectively even from only the TOF mass spectrometry results at the time t1 and the time t2 within the very short interval. The output result of the TOF mass spectrometry section 40 can be obtained within hundreds of microseconds. Even if the time for obtaining the output result of the TOF mass spectrometry section 40 is taken into account, the measurement still completes within a short time. In this way, the equivalent values of the number of the metal neutral particles and the number of the metal ion particles can be measured within a very short time, so there is an advantage that both the equivalent values can be measured under substantially the same measurement conditions. According to the experiments conducted by the inventors of the present invention, it is desirable to set the frequency dividing ratio to an integer from two to ten in order to acquire significant values as the metal ion particle number equivalent value and the metal neutral particle number equivalent value, which are to be compared with each other.
The controlling section 32 receives the trigger signal from the trigger signal generating section 31 and the frequency dividing signal from the frequency divider 65 in addition to the detection result from the TOF specifying section 37. Based on the received trigger signal and frequency dividing signal, the controlling section 32 determines whether the measurement result sent from the TOF specifying section 37 is the measurement result in the case where the laser emission is performed or the measurement result in the case where the laser emission is not performed. When the measurement result of each timing is displayed on the display section 70 based on the determination result, the measurement result is displayed with the information that the measurement result indicates the equivalent value of only the number of the neutral particles, or indicates the equivalent value of only the number of the ion particles, or indicates the equivalent value of the sum total of the number of the neutral particles and the number of the ion particles. In addition, a computation result of M+/M is displayed in real time.
Next, an example of the concept of the method of controlling the film formation or the etching using the observation method of the sputtered particles according to the present invention when performing the film formation or the etching of the work by the sputtering using the HIPIMS section 10 of the sputtered particle measuring device 1 according to the present embodiment will be explained with reference to
It is thought that the metal ion particles and the metal neutral particles contribute to a metal deposition rate vd, i.e., a film forming rate vd, on the work, and it is thought that the metal ion particles and the sputtering gas ion contribute to an etching rate ve of the work. Next, a method for controlling the film forming and the etching based on the ratio (M+/M) (which will be hereinafter referred to as equivalent value ratio) of the equivalent value (M+) of the number of the metal ion particles produced by the pulsed electric discharge of the HIPIMS to the equivalent value (M) of the number of the metal neutral particles similarly produced by the pulsed electric discharge will be explained.
A straight line “a” and curve lines “b” and “c” in
According to
As control on the characteristic chart shown in
In the case of the control of the bias voltage Vbias, if the equivalent value ratio (M+/M) is set constant, the etching rate ve increases as the absolute value of the bias voltage (negative potential) is increased (as it goes rightward in
The control of the equivalent value ratio (M+/M) and the control of the bias voltage Vbias may be performed in combination.
In the above embodiment, the equivalent values of the number of the metal neutral particles and the number of the metal ion particles are grasped respectively by the switching on and off of the UV laser irradiation, but the present invention is not limited thereto. Alternatively, the equivalent values of both the number of the metal neutral particles and the number of the metal ion particles may be measured simultaneously using only the case where both the pulsed electric discharge and the irradiation of the UV laser are performed.
That is, the inventors of the present invention found that, when the TOF mass spectrometry is conducted by irradiating the metal neutral particles, which are discharged by the HIPIMS, with the UV laser, two peaks appear in the detection intensity of the metal as shown in
In the above-mentioned embodiment, the ratio (M+/M) of the equivalent value (M+) of the number of the metal ion particles discharged by the HIPIMS to the equivalent value (M) of the number of the metal neutral particles discharged in the same way is used as the equivalent value ratio. Alternatively, a ratio (M+/(M+M+)) of the equivalent value (M+) of the number of the metal ion particles to an equivalent value (M+M+) of the sum total of the number of the metal neutral particles and the number of the metal ion particles may be used as the equivalent value ratio.
The configuration of the control system including the controller 30 explained with reference to the above-mentioned embodiment is only an example. Any system configuration may be used as long as the configuration can perform control similar to each of the above-mentioned control.
Next, a second embodiment of the present invention will be described with reference to
In the present embodiment, as shown in
Next, a sputtered particle measuring device 200 according to a third embodiment of the present invention will be explained with reference to
As shown in
In the present embodiment, the trigger signal and the laser emission are synchronized with each other as shown in
The ratio between the frequency of the timings t1, t6 when the equivalent value (M+M+) of the sum total of the number of the neutral particles and the number of the ion particles is detected and the frequency of the timings t2-t5, t7-t8 when the equivalent value (M) of only the number of the neutral particles is detected can be freely set by the configuration of the frequency dividing ratio. There is a tendency that sensitivity of the detection of the neutral particles produced by each sputtering is lower than sensitivity of the detection of the ion particles produced by each sputtering. Therefore, in the present embodiment, the frequency of the timing when the equivalent value (M) of only the number of the neutral particles is detected is increased to improve the measurement accuracy of the number of the neutral particles.
Next, a sputtered particle measuring device 300 according to a fourth embodiment of the present invention will be explained with reference to
Next, a measurement example using the sputtered particle measuring device 300 according to the present embodiment will be explained. As shown in
With the control shown in
Next, a sputtered particle measuring method according to a fifth embodiment of the present invention will be explained with reference to
In the above explanation, it is assumed that the positive ions are the object of the detection by the ion detector 48. The present invention is not limited thereto. Alternatively, negative ions may be used as the object of the detection by the ion detector 48. In the measurement of the kind and the equivalent value (M−) of the negative ions in that case, the potentials applied to the gate 43 and the respective electrodes included in the TOF-mass analyzer 40 may be adjusted as appropriate.
That is, when the negative ions are used as the object of the detection, the gate can be switched between the state where the gate 43 is earthed to the ground (Gnd) and a state where the gate 43 is set to a certain potential by the potential changing circuit 44. In the state where the gate 43 is set to the certain potential, the gate 43 as the ion introduction hole of the TOF mass spectrometry section 40 is set to a potential equal to or higher than the earth, so the introduction of the negative ions to the inside of the casing 41 is facilitated. By maintaining the gate 43 to a plasma potential, i.e., a predetermined potential (e.g., potential lower than approximately −20 V) equal to or lower than a potential exceeding an energy, which the ion can have, the gate 43 can function as a prevention electrode. Thus, the entrance of the ions to the inside of the casing 41 through the aperture 42 can be prevented. Also, the polarity of the voltage applied to the ion acceleration electrodes 45 for accelerating the negative ions in the TOF mass spectrometry is inverted to the negative voltage.
In the above, as the system for discharging the particles from the target (which will be referred to as “system of evaporation source,” hereafter), the system for discharging the particles from the target using the pulsed electric discharge, or more specifically the system using the HIPIMS, is explained as an example. However, the present invention is not limited thereto. Alternatively, any other method such as the DC magnetron sputtering method, the high-frequency magnetron sputtering method, the arc discharge method or the laser ablation method can be used. When necessary, the system may have a device for generating a trigger signal independently (i.e., independently from operation of evaporation source), the trigger signal serving as the reference for the measurement of the particles. Thus, any kind of system can be employed as the system of the evaporation source to realize the measurement explained in the description of the above embodiments, the modification and the working example.
More specifically, for instance, a device for outputting the trigger signal shown in
The present invention is not limited to the embodiments of the invention and the explanation of the embodiments. Various modifications thereof, which do not depart from the scope of the claims and which can be easily thought of by a person skilled in the art, are included in the present invention. For instance, any feasible combinations of the embodiments, the modification and the working example mentioned above are included in the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-166410 | Aug 2014 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/072444 | 8/7/2015 | WO | 00 |
