JP3347800B2 - Reactive sputtering equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactive sputtering apparatus, and more particularly to an improvement of a reactive sputtering apparatus for forming a thin film on a substrate in a vacuum.

[0002]

2. Description of the Related Art In a sputtering apparatus for performing reactive sputtering, a discharge gas (Ar) and an active gas (for example, N ₂ ) are introduced into a film formation processing chamber in a vacuum state, and a plasma discharge is caused to occur. To form a metal compound thin film on the substrate. In a conventional reactive sputtering apparatus, for example, a nitride film (Ti
In the conventional process for forming N), a normal nitride film may not be formed due to the degree of nitriding of a Ti (titanium) target depending on the amount of N ₂ (nitrogen) gas to be introduced. Even in such a case, the configuration of the conventional sputtering apparatus cannot determine whether the nitride film to be formed is normal or abnormal during the film forming process. Therefore, in the conventional sputtering apparatus, after the lot processing in which the number of substrates is 50 to 100, for example, the normal or abnormal state of the film is determined based on the color of the manufactured substrate. For example, a normal film (TiN)
Has a brown to gold color and has an abnormal film (T
Since i) has a metallic color, it is possible to determine normal or abnormal.

[0003]

In the conventional reactive sputtering apparatus, the normality / abnormality of the produced film can be determined only after the completion of the film forming process, so that the determination is delayed and a huge loss is caused. There was a problem that it occurred.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to determine whether a film is normal or abnormal during execution of a film forming process, and to perform adjustment control when it is determined that the film is abnormal. It is an object of the present invention to provide a reactive sputtering apparatus that is returned to a normal state.

[0005]

The reactive sputtering apparatus according to the present invention is configured as follows.

In a reactive sputtering apparatus in which a discharge gas (Ar) and an active gas (N ₂ ) are introduced into a film formation processing chamber provided with a Ti target, detection is performed to detect electrical characteristics of plasma discharge during a film formation process. Device, data detected by the detector and abnormal Ti discharge characteristics prepared in advance.
Reference data and reference data on normal TiN discharge characteristics
And a control signal for controlling the amount of active gas introduced when the discharge is determined to be abnormal by the comparator and a comparator for determining whether the discharge is normal or abnormal. It is configured to include a control device for generating the flow rate and a flow rate regulator for adjusting the flow rate of the active gas in response to the control signal.

In the above configuration, preferably, at least one of a discharge voltage detector and a discharge current detector is used as the detector.

In the above structure, preferably, a light detecting means for detecting a light emission state of plasma discharge during the film forming process, and a discharge gas Ar obtained from an output signal of the light detecting means.
A specific wavelength and an active gas N determines the comparison determination unit ₂ based on the magnitude relation of the emission intensity signal of a specific wavelength according to the discharge to whether or abnormal is normal according to the discharge is abnormal in the comparative determination unit It is configured to include a control device that generates a control signal for controlling the amount of active gas introduced when it is determined to be present, and a flow controller that receives the control signal and adjusts the flow rate of the active gas.

In the above configuration, preferably, the light detecting means comprises a photoelectric converter and a filter for extracting only a signal component corresponding to the wavelength of the active gas.

In the above structure, preferably, the light detecting means includes a light separator for dividing the light emitted from the plasma discharge into two routes, and a light separator for extracting only a light component corresponding to the wavelength of the discharge gas in the first route. One optical filter and the first
A first photoelectric converter that converts the optical output of the optical filter into an electric signal, a second optical filter that extracts only a light component corresponding to the wavelength of the active gas through a second route, and an optical output of the second optical filter. A second photoelectric converter for converting the electric signal into an electric signal;
It is configured to determine whether the discharge is normal or abnormal based on the value of the ratio of each output signal of the photoelectric converter.

In the above configuration, preferably, the target is Ti and the active gas is N ₂ gas, and the normal discharge is a discharge that satisfies the condition of TiN discharge.

In the above-mentioned configuration, preferably, the abnormal discharge is caused by a shortage of N ₂ gas, which is an active gas, and the control signal generated by the control device when the abnormal discharge occurs is based on the N ₂ gas introduction amount. Is a control signal for increasing.

[0013]

In the first reactive sputtering apparatus according to the present invention, the electrical characteristics in the discharge state are monitored during the formation of the thin film on the substrate due to the generation of the sputtering discharge, and the electrical characteristics in the discharge state are monitored based on the electrical characteristics. It is determined whether the discharge is a discharge or an abnormal discharge. The electrical characteristics are most preferably the relationship between the discharge voltage and the discharge current. For example, in the case of reactive sputtering film formation in which Ti is used as a target and N ₂ gas is introduced as an active gas to deposit a nitride film on a substrate, TiN discharge occurs during normal discharge, and TiN discharge occurs during abnormal discharge. Discharge close to discharge occurs. The TiN discharge has a unique discharge voltage / discharge current characteristic corresponding thereto, and the Ti discharge has a corresponding discharge voltage / discharge current characteristic corresponding thereto. Therefore, for example, by providing a discharge voltage detector and a discharge current detector, a set of a discharge voltage and a discharge current is detected as an electrical characteristic, and a comparison / determination unit examines the relationship between the discharge voltage value and the discharge current value. Or abnormal discharge can be determined. The cause of the abnormal discharge is that the introduction amount of the active gas (for example, N ₂ gas) is insufficient. Therefore, the control device generates a control signal for increasing the introduction amount of the reaction gas, and performs this control. The reaction gas flow controller is controlled by the signal to perform adjustment so as to increase the active gas. By applying the feedback control in this way, it is possible to monitor the discharge state during the film forming process and return to the normal state even if the discharge becomes abnormal.

Regarding the discharge voltage / discharge current characteristics,
Form a similar feedback control mechanism using the discharge voltage characteristics and discharge current characteristics independently to determine whether plasma discharge is normal or abnormal, and perform control to return to normal when abnormal. Can also.

In the second reactive sputtering apparatus according to the present invention, the luminous state of the plasma discharge is monitored during the formation of the thin film on the substrate due to the occurrence of the sputtering discharge, and the normal discharge is performed based on the luminous state. It is determined whether there is any abnormal discharge. In the light emission of the normal discharge, since the discharge gas and the active gas are supplied in appropriate amounts, the light emission intensity corresponding to each wavelength of the discharge gas and the active gas is obtained at a predetermined intensity on the emission spectrum. On the other hand, in the emission of the abnormal discharge, the supply amount of the active gas is insufficient, so that the emission intensity corresponding to the wavelength of the active gas decreases. Therefore, by taking out and examining the emission intensity corresponding to the wavelength of the active gas, or by detecting the emission intensity corresponding to the wavelength of the active gas and the emission intensity corresponding to the wavelength of the discharge gas and obtaining the ratio, the normal discharge is performed. Alternatively, abnormal discharge can be determined.

[0016]

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

FIG. 1 shows the configuration of a first embodiment of the reactive sputtering apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a processing chamber whose inside is maintained at a required vacuum level, and the processing chamber 1 forms a film forming processing chamber. Inside the processing chamber 1, a substrate 2 and a target (for example, Ti) 3 are installed at predetermined positions. The substrate 2 is arranged on a substrate support 4. The side of the substrate 2 is grounded via the substrate support 4, while a required negative voltage is applied to the side of the target 3 by the power supply 5. In the illustrated example, the power supply 5 is a DC power supply. An AC power supply can be used as the power supply 5.

The processing chamber 1 is provided with an exhaust device for keeping the inside of the processing chamber at a required vacuum level.
A substrate transfer device for loading or unloading the substrate. In FIG. 1, illustration of the exhaust device and the substrate transfer device is omitted for convenience of explanation.

Ar (argon) is used as a discharge gas in a space between the target 2 and the substrate 1 in the processing chamber 1.
Gas is introduced, and N ₂ (nitrogen) gas is introduced as an active gas. Ar gas is introduced from a gas source via the Ar gas flow controller 6, and N ₂ gas is supplied from the gas source to N ₂ gas.
It is introduced via a gas flow controller 7.

The power supply line between the power source 5 and the target 3
The discharge current detector 8 and the discharge voltage detector 9 are connected. When a plasma discharge occurs between the target 3 and the substrate 2 on a power supply line that supplies a required voltage from the power supply 5 to the target 3, the discharge current detector 8 detects the value of the discharge current, and the discharge voltage detector 9 detects the value of the discharge current. The value of the discharge voltage is detected. The detection signal output from the discharge current detector 8 and the detection signal output from the discharge voltage detector 9 are input to the comparison / determination unit 10. A signal related to comparison / determination obtained by the comparison / determination unit 10 is input to the control device 11 as a difference signal.
The controller 11 determines N ₂ based on the given difference signal.
It generates a control signal for adjusting the amount of introduced gas, to adjust the control signal to an appropriate amount to the amount of introduced N ₂ gas flow rate controller 7 N ₂ gas is supplied to. The content of the operation related to comparison / determination in the comparison / determination device 10 and the content of the control of the N ₂ gas introduction amount by the control device 11 and the N ₂ gas flow rate controller 7 will be described later.

In FIG. 1, a magnetic field generator 12 is arranged on the back surface of the target 3 so as to generate a predetermined magnetic field near the substrate facing surface of the target 3.

The inside of the processing chamber 1 is set to a required level of vacuum by an exhaust device, and
The substrate 2 to be processed is carried into the inside of the substrate 2 by the substrate transfer device, so that the substrate 2 is set on the substrate support 4. Next, required amounts of Ar gas and N ₂ gas are introduced into the processing chamber 1. When power is supplied from the power supply 5 to the target 3, TiN discharge is generated based on the interaction between the magnetic field generated by the magnetic field generator 12 and the electric field generated by the applied voltage, and magnetron sputtering is performed on the target 3. Thereby, a thin film (nitride film) is formed on the substrate 2. In the film forming operation by the magnetron sputtering, it is important for the plasma discharge generated in the space between the substrate 2 and the target 3 whether or not the discharge is normally performed. In fact, according to the amount of N ₂ gas introduced, a TiN discharge occurs when the discharge is normal, and a discharge close to the Ti discharge occurs when the discharge is abnormal.

Therefore, in the sputtering apparatus having the above-described configuration, when the film forming process is being performed, the substrate 2
It is determined whether the discharge between the target and the target 3 is normal or abnormal. If it is determined that the discharge is abnormal, control is performed to return to a normal state by appropriately adjusting the amount of N ₂ gas introduced. In the case of the present embodiment, the detection and determination of the normal / abnormal state and the control for returning to the normal state in the case of an abnormal state are performed by the discharge current detector 8, the discharge voltage detector 9, the comparison determiner 10, the control unit 11, the N _This is executed by the _two- gas flow controller 7.

Here, the principle for determining whether the discharge is normal or abnormal, and the principle of control for returning the discharge to a normal state when the discharge is abnormal will be described. In order to normally deposit a nitride film (TiN) on the surface of the substrate 2, it is necessary to generate a TiN discharge which is a normal discharge. When the discharge between the substrate 2 and the target 3 was examined,
Phenomenonally, it has been found that the discharge impedance is increased in a normal TiN discharge, and the discharge impedance is reduced in an abnormal discharge, which is substantially close to a Ti discharge. The reason why the discharge impedance is increased in a normal TiN discharge is that the surface of the Ti target is nitrided and electron emission is not performed. Also, A
This is because the presence of the mixed gas of r and N ₂ lowers the ionization efficiency as compared with only Ar gas. On the other hand, in the abnormal discharge, the amount of the N ₂ gas introduced is insufficient, and it occurs in a state where the nitridation is insufficient, and has a characteristic that it is close to a Ti discharge.

In FIG. 2, reference numeral 13 denotes a discharge voltage / discharge current characteristic of a normal TiN discharge, and reference numeral 14 denotes T which is an abnormal discharge.
4 shows discharge voltage / discharge current characteristics of i-discharge. In the TiN discharge, for example, the supply power is 8 KW and the gas pressure is 6 mTorr
(Ar gas flow rate: N ₂ gas flow rate = 30%: 70%), the discharge voltage is about 520 V and the discharge current is about 14
It is about A (point P1). On the other hand, in the Ti discharge, which is an abnormal discharge, the discharge voltage is about 480 V and the discharge current is about 17 A under the same conditions as above (point P2). These values for normal discharge and abnormal discharge are experimentally confirmed. As described above, in the abnormal discharge as compared with the normal discharge, the discharge voltage decreases and the discharge current increases.
This is clear from the relationship between the characteristics 13 and 14 shown in FIG. Accordingly, when a TiN discharge which is a normal discharge is occurring, a discharge voltage value and a discharge current value satisfying the relationship on the discharge voltage / discharge current characteristic 13 or a relationship close to this characteristic are detected. Become. Conversely, the discharge voltage value detected by the discharge voltage detector 9 and the discharge current value detected by the discharge current detector 8 do not satisfy the relationship on the characteristic 13 or a relationship close thereto, and the characteristic 14 When the relationship close to the side is satisfied, it can be determined that the discharge is abnormal. Abnormal discharge is a when it is determined controls the flow rate of N ₂ gas with N ₂ gas flow rate controller 7 until it is determined that the normal discharge, it is necessary to increase the introduction amount of N ₂ gas.

An example of the configuration of the comparison and decision unit 10 will be described.
In the comparison / determination unit 10, voltage-current relation data relating to the discharge voltage-discharge current characteristic 13 representing a TiN discharge that is a normal discharge is prepared as reference data for comparison. The comparison / determination unit 10 receives the discharge voltage value and the discharge current value output from the discharge voltage detector 9 and the discharge current detector 8, respectively, and compares the detection data and the reference data related to the discharge voltage and the discharge current. If the relationship between the detected discharge voltage value and the detected discharge current value is different from the reference data indicating normal discharge, it is determined that abnormal discharge has occurred.

The comparison / determination unit 10 provides a signal corresponding to the difference between the detection data (data relating to the detected discharge voltage value and the discharge current value) and the reference data to the control device 11. The control device 11 inputs the difference signal and sets the difference signal to substantially zero, that is, the detection data substantially matches the reference data.
A control signal for increasing the amount of N ₂ gas introduced is generated. In other words, in the control device 11, the abnormal discharge
By increasing the introduction amount of N ₂ gas appropriately, for changing the TiN discharge is normal discharge, and generates a control signal for increasing the N ₂ gas introduction rate through the N ₂ gas flow rate controller 7. The specific relationship that associates the difference signal prepared by the control device 11 with the control signal is set based on, for example, an experiment, and has arbitrary characteristics.

As described above, the normal T in the processing chamber 1
When the iN discharge is occurring, the difference data is not output from the comparison / judgment unit 10 because the detection data and the reference data almost match. When an abnormal discharge (discharge close to Ti discharge) occurs during the film forming process in the processing chamber 1, it is determined that the discharge is abnormal based on the comparison operation of the comparison and determination unit 10, and a difference signal is output from the comparison and determination unit 10. Is output. When receiving the difference signal from the comparison / determination unit 10, the control device 11 generates a control signal corresponding to the difference signal,
This control signal is supplied to the N ₂ gas flow controller 7 to increase the amount of N ₂ gas introduced into the processing chamber 1. For example, when the Ar gas is 14 SCCM and the N ₂ gas is 40 SCCM, the N ₂ gas is increased by 10 SCCM and introduced at 50 SCCM. This feedback control is continued until the comparison and determination unit 10 determines that the discharge is normal.

In the above-described configuration, the comparison / judgment device 10 and the control device 11 are each realized as functional means using, for example, a microcomputer. The installation positions of the discharge current detector 8 and the discharge voltage detector 9 are not limited to the power supply line. As long as the discharge voltage and the discharge current can be detected, the discharge voltage and the discharge current can be arranged at an arbitrary position by an arbitrary detection method.

As a modification of the first embodiment,
It is also possible to provide only one of the discharge current detector 8 and the discharge voltage detector 9 and use either the discharge current characteristic or the discharge voltage characteristic. That is, for example, only the discharge current detector 8 is provided, and the comparison / determination unit 10 is configured by a comparator including a reference current value setting unit. At the output of the comparator, it is determined whether the discharge is normal discharge or abnormal discharge based on the magnitude relationship between the reference current value and the detected current value. More specifically, for example, if the reference current value is 15 A and the detected current value is larger than this (for example, 17 A), an abnormal discharge output (comparator output “1”) is obtained, and the detected current value is smaller than this. In the state (for example, 14 A), the output is configured to be a normal discharge output (comparator output “0”). By using the comparator / discriminator 10 and the discharge current detector 8 having such a configuration, it is possible to determine whether the discharge is normal or abnormal. If the discharge is abnormal, the discharge can be made normal through the control function of the control device 11. .

Further, the comparison / judgment device 10 can be constituted by a differential amplifier having a reference current value setting device. In this case, since an output signal corresponding to the difference between the reference current value and the detected current value can be obtained, the feedback control is performed based on the difference signal.

In the same manner as described above, the discharge voltage detector 9 and the comparison / determination unit 10 are used to determine
The above-described operation of determining the normality / abnormality can be produced.

Next, a description will be given of a second embodiment of the reactive sputtering apparatus according to the present invention. In this embodiment, normal / abnormal discharge is determined by observing a plasma emission phenomenon occurring during a film forming process in the processing chamber 1.

The configuration of the apparatus will be described with reference to FIG. FIG.
In FIG. 7, the same reference numerals are given to substantially the same components as those shown in FIG. 21 is an optical detector, 22 is a filter (wavelength discriminator), and 23 is a comparison / determination device. The optical detector 21 detects the light emission state of the plasma discharge 24 generated during the film forming process by converting the light emission state into an electric signal, and uses a photodiode, a photomultiplier, or the like. The filter 22 extracts a signal related to the emission intensity corresponding to the wavelength of N ₂ from the electrical signal related to the emission detected by the optical detector 21.

Here, the principle of determining whether the discharge is normal or abnormal according to the present embodiment will be described. When the discharge is normal, that is, when a TiN discharge occurs, the emission intensity corresponding to each of Ar and N ₂ in the emission spectrum occurs in the state shown in FIG. Actually, there are a plurality of emission spectra of Ar and N ₂ , but only one representative emission spectrum is shown for convenience of explanation. This distribution related to the emission spectrum appears as a unique characteristic of a normal discharge. On the other hand, when the discharge is abnormal, that is, when a Ti discharge occurs, Ar has an emission spectrum with the same emission intensity, and the emission spectrum of N ₂ has an emission intensity of about 1/3.
become. Therefore, by monitoring the emission spectrum of N _{2 with} the plasma discharge 24 generated during the film forming process and examining the emission intensity, it is possible to determine whether the discharge is normal or abnormal. In FIG. 4, λ1 is 4198
Angstroms and λ2 are 1.45 μm.

Therefore, in the configuration of FIG.
The optical detector 21 detects light emitted from the plasma discharge 24 generated therein, and extracts an electric signal corresponding to the N ₂ emission spectrum of the wavelength λ2 from the output signal of the optical detector 21 by the filter 22. ing. The emission spectrum signal related to N ₂ is a voltage signal indicating the emission intensity. On the other hand, the comparison / determination unit 23 is a comparator in which a reference value is set, and the comparison / determination unit 23 compares the magnitude relationship between the reference value and the output signal of the filter 22.
Set reference value comparison determination unit 23 is the threshold for the emission intensity regarding N ₂ wavelengths λ2 shown in FIG. 4, it is determined whether the detected. That is, when the output signal of the filter 22 is larger than the reference value, it is determined that the emission intensity related to N ₂ shown in FIG. 4 has been detected, and the state of the plasma discharge 24 is determined to be normal. On the other hand, when the output signal of the filter 22 is smaller than the reference value, FIG.
Or absent emission intensity weakens about N ₂ shown in the state of the plasma discharge 24 is determined to be abnormal. When the output signal of the filter 22 is smaller than the reference value, the output signal of the filter 22 is supplied to the control device 11 as an abnormality detection signal. The control device 11 generates a control signal for optimally controlling the flow rate of the N ₂ gas based on the abnormality detection signal, and supplies the control signal to the N ₂ gas flow rate controller 7. The control of the flow rate of the N ₂ gas by the control device 11 is the same as in the above-described embodiment. The amount of N ₂ gas introduced is increased until the intensity of the emission spectrum for N ₂ becomes larger than the reference value and the emission intensity becomes normal. Note that a differential amplifier in which a reference value is set can also be used as the comparison / determination unit 23.

Next, a modified embodiment of the second embodiment will be described with reference to FIG. In this embodiment, an optical detection unit 25 is provided as means for detecting the light emission state of the plasma discharge 24 generated in the processing chamber 1. The optical detection unit 25 includes a prism 26 that separates the light from the plasma discharge 24 into two routes, and an optical filter (spectroscope or monochromator) that extracts light having a wavelength λ1 (Ar) in each of the separated lights. 27 and wavelength λ2
It comprises an optical filter (spectroscope or monochromator) 29 for extracting (N ₂ ) light, and optical detectors 28 and 30 provided corresponding to the optical filters 27 and 29, respectively. Therefore, the output signal A of the optical detector 28 is an electrical signal corresponding to the emission intensity of Ar, the output signal B of the optical detector 30 is an electrical signal corresponding to the luminous intensity of N _2. Each output signal from the optical detectors 28 and 30 is input to a comparison / determination unit 31.

The normal / abnormal discharge judgment in the above embodiment is performed as follows. When the ratio between the emission intensities of Ar and N _{2 in} a normal discharge was obtained, as shown in FIG.
1.5. On the other hand, when the ratio between the emission intensities of Ar and N _{2 in} the abnormal discharge is calculated, as shown in FIG.
5 Therefore, a signal corresponding to the emission intensity of Ar and N ₂ is obtained, and the ratio is calculated, whereby the processing chamber 1 is obtained.
It is possible to determine whether the plasma discharge generated in the step is normal or abnormal.

The comparison / determination unit 31 includes optical detectors 28 and 3
Output signals A and B of 0 are input, and their ratio A: B is obtained. When A: B is 1: 1.5, it is determined that there is normal discharge, and A: B is 1: 0.5. Sometimes it is determined that there is abnormal discharge. When it is determined that the discharge is abnormal, a signal is sent to the next control device 11 (not shown in FIG. 5), and the control device 11 transmits the N ₂ gas until the ratio A: B becomes, for example, 1: 1. A control signal for increasing the introduction amount of is generated.

In each of the above embodiments, the target 3 is made of Ti
Although an example in which a TiN discharge is generated and a nitride film is deposited on the substrate surface using N2 gas as an active gas has been described, the present invention is not limited to these. Further, when abnormal discharge occurs, the introduction amount of the active gas is configured to be controlled in a direction to increase the introduction amount. However, the control method can be appropriately changed according to the purpose and the case. It is not limited to control.

[0041]

As apparent from the above description, according to the present invention, in the film formation by reactive sputtering, the electrical characteristics of the plasma discharge or the light emission state accompanying the plasma discharge are monitored during the film formation process, and the plasma is formed. Normal / abnormal discharge is determined, and when abnormal discharge occurs, the amount of active gas introduced is adjusted appropriately to return to normal discharge.Thus, normal / abnormal discharge can be determined during the film formation process. When abnormal discharge occurs, normal discharge can be quickly returned to, and damage caused by abnormal discharge can be eliminated.

[Brief description of the drawings]

FIG. 1 shows a first example of a reactive sputtering apparatus according to the present invention.
It is a block diagram which shows an Example.

FIG. 2 is a graph showing a discharge voltage-discharge current characteristic of a TiN discharge that is a normal discharge and a discharge voltage-discharge current characteristic of a Ti discharge that is an abnormal discharge.

FIG. 3 shows a second embodiment of the reactive sputtering apparatus according to the present invention.
It is a block diagram which shows an Example.

FIG. 4 is a diagram showing an emission spectrum in the case of normal discharge.

FIG. 5 is a configuration diagram showing a modified embodiment of the second embodiment.

FIG. 6 is a diagram showing an emission spectrum in the case of abnormal discharge.

[Explanation of symbols]

1 ... processing chamber 2 ... substrate 3 ... Target 4 ... substrate support 5 ... Power 6 ... for Ar gas flow rate controller 7 ... N ₂ gas flow rate controller 8 ... discharge current detector 9 ... discharge voltage detector 10, 23 , 31 ... Comparison / determination unit 11 ... Control unit 12 ... Magnetic field generator 13 ... Discharge voltage / discharge current characteristic of TiN discharge 14 ... Discharge voltage / discharge current characteristic of Ti discharge 21 ... Optical detector 22 ... Filter 24 ... Plasma discharge 25 optical detection unit 26 prism 27, 29 optical filter 28, 30 optical detector

Continuation of the front page (56) References JP-A-4-280970 (JP, A) JP-A-62-111378 (JP, A) JP-A-3-2366 (JP, A) JP-A-2-290966 (JP) JP-A-2-306429 (JP, A) JP-A-63-250459 (JP, A) JP-A-63-34931 (JP, A) JP-A-63-60277 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 14/00-14/58

Claims (5)

(57) [Claims] In a reactive sputtering apparatus in which a discharge gas (Ar) and an active gas (N ₂ ) are introduced into a film formation processing chamber provided with a Ti target, electrical characteristics of discharge during a film formation process are detected. A detector, and data detected by the detector and a base for abnormal Ti discharge characteristics prepared in advance.
Reference data and reference data on normal TiN discharge characteristics
Preparative a comparison determination means for determining whether the discharge is or abnormal is normal by comparing the control for controlling the introduction amount of the active gas when the discharge is determined to be abnormal in the comparative determination means A reactive sputtering apparatus, comprising: a control unit for generating a signal; and a flow controller for adjusting a flow rate of the active gas in response to the control signal. 2. The reactive sputtering apparatus according to claim 1, wherein at least one of a discharge voltage detector and a discharge current detector is used as said detector. 3. A light detection device for detecting light emitted by a discharge during a film formation process in a reactive sputtering apparatus in which a discharge gas (Ar) and an active gas (N ₂ ) are introduced into a film formation processing chamber having a target. Means, a specific wavelength and an active gas related to a discharge gas Ar obtained from an output signal of the light detection means.
Comparison determination means for determining the or discharge is or abnormal is normal based on the magnitude relation of the emission intensity signal of a specific wavelength according to the N _2, is the discharge in this comparative determining means is determined to be abnormal A reactive sputtering apparatus comprising: control means for generating a control signal for controlling the introduction amount of the active gas; and a flow controller for receiving the control signal and adjusting a flow rate of the active gas. 4. The reactive sputtering apparatus according to claim 3, wherein said light detecting means includes a light separator for dividing said light into two routes, and a light component corresponding to a wavelength of a discharge gas in said first route. A first optical filter for extracting only the light component, a first photoelectric converter for converting an optical output of the first optical filter into an electric signal, and a second optical component for extracting only a light component corresponding to the wavelength of the active gas in the second route. An optical filter; and a second photoelectric converter for converting an optical output of the second optical filter into an electric signal, wherein the comparing and judging means outputs each output signal of the first photoelectric converter and the second photoelectric converter. A determination as to whether the discharge is normal or abnormal based on a value of the ratio. 5. The reactive sputtering apparatus according to claim 1 , wherein the abnormal discharge is generated due to a shortage of N ₂ gas, and the control signal generated by the control unit when the abnormal discharge occurs. Is a control signal for increasing the amount of N ₂ gas introduced, the reactive sputtering apparatus being characterized in that: