JP2011058083A - Sputtering system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering system which can satisfactorily deposit a thin film on a substrate. <P>SOLUTION: A time check is started in such a manner that a normal discharge timing previously detected by either current detection part selected from the first current detection part 15 and the second current detection part 16 is used as a trigger. To a cathode in which the normal discharge timing has been detected by the other current detection part, a time difference between the normal discharge timing detected by either current detection part and the normal discharge timing detected by the other current detection part is obtained. Then, the voltage to be applied is set in such a manner that discharge is finished at the point of time in which the time obtained by adding the time difference to a prescribed time is measured. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sputtering apparatus for forming a thin film on a substrate.

  Conventionally, a sputtering apparatus is generally used to form an antireflection thin film on a substrate (for example, a lens). As a film forming method using this type of sputtering apparatus, a method of forming a thin film on both surfaces of a substrate by sputtering is known. In this method, cathodes with targets attached are arranged on both sides of a substrate, and a thin film is simultaneously formed on both sides of the substrate (see Patent Document 1). A plurality of cathodes are arranged on both sides of the substrate, and the input power can be controlled independently. Accordingly, it is possible to form a thin film having a composite composition by simultaneous sputtering in which materials for each target are made different, power is simultaneously applied to each cathode, and substances of each target are simultaneously deposited on the substrate.

Japanese Patent Laid-Open No. 2000-219964

  However, if film formation is performed simultaneously on the substrate in the same film formation chamber, plasma generated in the vicinity of each cathode may cause interference. More specifically, in order to generate a desired plasma state, it is necessary to control the gas flow rate so that the gas flows in the vicinity of the cathode. In particular, at the start of gas inflow from the vacuum state, the other cathode is arranged in the vicinity of one of the cathodes, so that the amount of gas of each other influences and the amount of gas around each cathode and the degree of vacuum are not constant. If plasma is simultaneously generated in this state, one of the cathodes on the side where the discharge conditions are aligned starts discharging first, which causes a time delay of discharge by the other cathode, and a desired discharge cannot be obtained. Interference may occur. This interference is more likely to occur when the cathodes are placed close together. When this interference occurs, only one of the cathodes starts to discharge, but there is a time difference before the normal cathode shifts to the other cathode. Therefore, if both surfaces of the substrate are formed in the same sequence, the amount of time delay due to interference is not formed, so that desired optical characteristics cannot be obtained on the substrate.

  In view of the above, an object of the present invention is to provide a sputtering apparatus that can satisfactorily form a thin film on a substrate.

  The present invention includes a first cathode and a second cathode disposed in a film formation chamber relative to a substrate, a first target and a second target mounted on each cathode, and a voltage across each cathode. In a sputtering apparatus comprising: a first power source and a second power source for applying a voltage; applying a voltage from each power source to each cathode; and depositing the target material on the substrate by sputtering; First detection means and second detection means for detecting the normal discharge timing at each cathode, respectively, and the first detection means and the second detection means. Time measuring means for starting time measurement with normal discharge timing as a trigger, and normal discharge timing detected by each detecting means, at each cathode Setting means for setting the applied voltage to each cathode so that the power obtained by the product of the electric current and the applied voltage to each cathode becomes a predetermined power value necessary for film formation, The means sets an applied voltage to the cathode, for which the normal discharge timing has been detected by the one detection means, so that the discharge ends when the time measuring means times a predetermined time, Of the detection means and the second detection means, the other detection means detects the normal discharge timing, the normal discharge timing detected by the one detection means, and the other detection means A time difference from the detected normal discharge timing is obtained, and the applied voltage is set so that the discharge ends when the time measuring means measures the time obtained by adding the time difference to the predetermined time. The one in which the features.

  The present invention also provides a first cathode and a second cathode that are disposed in the film formation chamber relative to the substrate, a first target and a second target mounted on each cathode, and each cathode. A sputtering apparatus comprising: a first power source and a second power source for applying a voltage to the substrate, and applying a voltage to each of the cathodes from each of the power sources, and depositing the target material on the substrate by sputtering The first detection means and the second detection means for detecting the normal discharge timing at each of the cathodes, respectively, and the detection means of any one of the first detection means and the second detection means. A timing means for starting timing with the normal discharge timing as a trigger, and a normal discharge timing detected by the one detection means, The voltage applied to each cathode is set so that the power obtained by the product of the discharge current and the voltage applied to each cathode becomes a predetermined power value required for film formation. Setting means for setting an applied voltage to each cathode so that the discharge is terminated when the time is measured, and the setting means detects the other of the first detection means and the second detection means. For the cathode whose normal discharge timing is detected by the means, the power obtained by the product of the discharge current at the cathode and the applied voltage to the cathode until the normal discharge timing is detected by the one detection means The applied voltage is set so that is smaller than the predetermined power value.

  The present invention also provides a first cathode and a second cathode that are disposed in the film formation chamber relative to the substrate, a first target and a second target mounted on each cathode, and each cathode. A sputtering apparatus comprising: a first power source and a second power source for applying a voltage to the substrate, and applying a voltage to each of the cathodes from each of the power sources, and depositing the target material on the substrate by sputtering The first detection means and the second detection means for detecting the normal discharge timing at each of the cathodes respectively, and the first detection means and the second detection means are first detected by the detection means. Time measuring means for starting time measurement using the normal discharge timing as a trigger, and for each of the cathodes, when the time measuring means times a predetermined time, the discharge occurs. Setting means for setting the applied voltage so as to end, the setting means, for the cathode for which the normal discharge timing is detected by the one detection means, to the discharge current in the cathode and to the cathode The applied voltage is set so that the power obtained by the product of the applied voltage and the applied voltage becomes a predetermined power value necessary for film formation, and the other detecting means is normal among the first detecting means and the second detecting means. For the cathode in which the discharge timing is detected, a time difference between the normal discharge timing detected by the one detection means and the normal discharge timing detected by the other detection means is obtained, and the discharge current in the cathode And the applied voltage to the cathode, the applied voltage is set so that the power obtained by adding the power value corresponding to the time difference to the predetermined power value is obtained. A constant, it is characterized in.

  The present invention also provides a first cathode and a second cathode that are disposed in the film formation chamber relative to the substrate, a first target and a second target mounted on each cathode, and each cathode. A sputtering apparatus comprising: a first power source and a second power source for applying a voltage to the substrate, and applying a voltage to each of the cathodes from each of the power sources, and depositing the target material on the substrate by sputtering The first detection means and the second detection means for detecting the normal discharge timing at each of the cathodes, respectively, and the detection means of any one of the first detection means and the second detection means. Timing means for starting timing with the normal discharge timing as a trigger, and the normal discharge timing detected by each of the detection means at each cathode. The voltage applied to each cathode is set so that the power obtained by the product of the discharge current and the voltage applied to each cathode becomes a predetermined power value necessary for film formation, and the time measuring means sets a predetermined time. Setting means for setting an applied voltage to each cathode so that the discharge is finished at the time of counting, and a shielding position for shielding the substrate and the shielding, which are disposed between the substrate and each target so as to be able to advance and retreat. A first shielding plate and a second shielding plate which are movable to a retracted position retracted from a position, and a moving means for moving each of the shielding plates from the shield position to the retracted position at a timing timed by the time measuring means. It is characterized by comprising.

  According to the present invention, even when the normal discharge timing at each cathode is shifted due to plasma interference, the film can be formed on the substrate with the power and time required for film formation, and the quality of the film formed on the substrate Will improve.

It is a schematic block diagram of the sputtering device which concerns on 1st Embodiment of this invention, (a) is the figure which showed the structure in a vacuum chamber, (b) is the figure which showed the structure of the power supply. It is the film-forming sequence figure of a sputtering device, (a) is a figure which shows the case where correction | amendment is not performed, (b) is a figure when correction | amendment is performed. It is the film-forming sequence diagram of the sputtering device which concerns on 2nd Embodiment of this invention. It is the film-forming sequence diagram of the sputtering device which concerns on 3rd Embodiment of this invention. It is a schematic block diagram of the sputtering device which concerns on 4th Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
A sputtering apparatus 100 shown in FIG. 1A forms an antireflection thin film on a substrate 8 such as a lens by a magnetron sputtering method. The sputtering apparatus 100 includes a vacuum chamber 1 serving as a film forming chamber in which the substrate 8 is disposed, and a first cathode 2 and a second cathode disposed in the vacuum chamber 1 (film forming chamber) relative to the substrate 8. 3 is provided. In addition, the sputtering apparatus 100 includes a first target 4 and a second target 5 mounted on the cathodes 2 and 3, and a first power source 6 that is electrically connected to the cathodes 2 and 3 and applies a voltage. And a second power source 7.

  The cathodes 2 and 3 are disposed on both sides of the substrate 8. Therefore, the first target 4 is opposed to one surface of the substrate 8, and the second target 5 is opposed to the other surface of the substrate 8. The cathodes 2 and 3 are connected to the power sources 6 and 7 disposed outside the vacuum chamber 1 and applied with negative voltages, respectively. Although illustration is omitted, gas is introduced between the first target 4 and the substrate 8 and between the second target 5 and the substrate 8. More specifically, an inert gas is introduced near the targets 4 and 5, and a reactive gas is introduced near the substrate 8. As the inert gas used for sputtering, for example, Ar, Kr, Xe, etc. are used, and Ar is usually used. As the reactive gas, oxygen is usually used. As the material of the targets 4 and 5, Nb, Ti, Al, Si or the like is used.

  As a sputtering operation, a gas is introduced in a state where the vacuum chamber 1 is decompressed, and a voltage is applied to each of the cathodes 2 and 3 to generate plasmas 20 and 21. Then, the positive ions in the generated plasmas 20 and 21 are struck against the targets 4 and 5 which are cathodes, so that the material of the targets 4 and 5 is sputtered on the substrate 8, and the substances of the targets 4 and 5 are formed on the substrate 8. Is deposited. The introduction of the gas starts just before the voltage is applied, and ends after the voltage application is completed.

  When a thin film is formed on the substrate 8 by the sputtering apparatus 100, variations in film thickness and uniformity of film distribution become problems. In the magnetron sputtering method, a magnet (not shown) disposed on the back surface of the targets 4 and 5 forms a portion where the plasma concentrates on the surface of the targets 4 and 5 (erosion portion) and the other portion (non-erosion portion). The

  As an optical thin film, it is common to form a film over several layers to obtain desired optical characteristics. When a difference occurs in the film thickness, a difference occurs in film characteristics such as reflectance and transmittance. In the present embodiment, although not shown, when a plurality of layers are formed, the layers 4 and 5 are formed by changing the materials of the targets 4 and 5 or moving the substrate 8.

  Further, the optical characteristics are required to have a uniform film thickness distribution on the substrate surface. If the film thickness distribution is non-uniform, the optical characteristics become uneven and the quality of the lens is degraded. Therefore, in this embodiment, although illustration is omitted, regarding the film thickness distribution, non-uniformity is improved by performing film formation while rotating the substrate 8 using a mechanism such as rotation or revolution.

  Next, the configuration of each power supply and control device will be described in detail. The first power supply 6 generates a pulse with the DC voltage as an input, and outputs a pulse to the first cathode 2 by converting the AC input into DC and changing the DC voltage. The first pulse generation unit 11 is provided. Similarly, the second power source 7 generates a pulse by using the DC voltage as an input, and a second AC / DC converter 10 that changes the DC voltage by converting the AC input into a DC voltage. And a second pulse generation unit 12 that outputs a pulse. Each AC / DC converter 9, 10 outputs a negative DC voltage. The pulse generators 11 and 12 apply a negative DC voltage pulse to the cathodes 2 and 3 with the vacuum chamber 1 set to zero potential.

  The control device 200 includes a first control unit 17 and a first control unit 17 that control applied voltages to the cathodes 2 and 3 by the power sources 6 and 7, that is, DC voltages that are output voltages of the AC / DC conversion units 9 and 10. Two control units 18 are provided. In addition, the control device 200 detects the applied voltage (discharge voltage) to the cathodes 2 and 3 by the power sources 6 and 7, that is, the DC voltage that is the output voltage of the AC / DC converters 9 and 10. The voltage detector 13 and the second voltage detector 14 are provided. In addition, the control device 200 includes a first current detection unit 15 and a second current detection unit 16 that detect a discharge current at each of the cathodes 2 and 3. Furthermore, the control device 200 includes a device control unit 27 that controls the entire device such as a pump and a power supply.

  Next, the first power supply 6 will be described as an example. The first control unit 17 outputs a control signal to the first AC / DC conversion unit 9 based on the detection values (voltage value and current value) of the first voltage detection unit 13 and the first current detection unit 15. And the voltage is controlled. The direct current output of the first AC / DC converter 9 is pulsed by the first pulse generator 11. By pulsing in this way, charging on the oxide film generated on the target surface can be reduced. The pulse output from the first pulse generator 11 is supplied to the first cathode 2 in the vacuum chamber 1. The pulse output is preferably generated at a frequency between 1 kHz and 1 MHz, and more preferably generated at 10 kHz to 100 kHz.

  Here, the pulse conditions up to the start of discharge and the pulse conditions at the time of film formation are set differently. The pulse conditions are frequency and duty. The pulse conditions until the start of discharge are the same for different target materials. As a result, the time taken from turning on the power to starting discharge is substantially the same. The first control unit 17 performs control to gradually increase the voltage by the control signal after setting the pulse conditions until the start of discharge. When the discharge in the first cathode 2 starts, the first control unit 17 changes the setting to the pulse condition (frequency and duty) when performing film formation, and sets the voltage, current, or power based on the detected value. Stable film formation is performed by controlling. As the conditions at the time of film formation, pulse conditions and film formation power for film formation with the target material are changed. The set value of the pulse condition for film formation is set to a value that does not cause local arc discharge. The arc discharge is a local discharge of charges accumulated on the target surface, and since it has an influence on film formation, it is necessary to suppress the generation. The set value of the pulse condition for film formation varies depending on the target material, but a maximum of about 60% may be set to a pulse condition of 0 V or a positive potential. As the detection value, the current detection by the current detection unit 15 and the voltage detection by the voltage detection unit 13 are simultaneously performed, and the control unit 17 calculates and performs control by power detection. It is generally known that the thickness of film formation is proportional to electric power, and more detailed film formation can be performed by setting the electric power to a set value (predetermined electric power value). The apparatus control unit 27 performs a plurality of film formation controls, that is, film formation sequences, in the same film formation chamber. The film formation sequence is a sequence in which a gas flow rate, a degree of vacuum, power, a film formation time, and the like are set in detail on a target substrate to form a plurality of layers.

  By the way, when film formation is performed in the same vacuum chamber 1, the plasmas 20 and 21 generated near the targets 4 and 5 may interfere with each other. In FIG. 2A, the discharge current I1 flows with the start of discharge with respect to the discharge voltage V1 of the first cathode 2. At this time, the impedance between the first cathode 2 and the ground (vacuum chamber 1) decreases. However, when plasma interference occurs, the discharge current I2 of the second cathode 3 rises later than the discharge current I1. This is because the plasma of the first cathode 2 exists in the vicinity even though the second cathode 3 side does not reach the conditions for starting the discharge such as the gas amount and the degree of vacuum. This is because the discharge current I2 leaks through the plasma. Thereafter, when the conditions for the gas amount and the degree of vacuum are met, normal discharge also starts on the second cathode 3 side. As an influence of interference as on the second cathode 3 side, a time delay may occur after the start of the discharge of the first cathode 2 to reach a normal discharge timing. The time delay due to this interference is not constant, and is indefinite because it changes due to environmental variations, device configurations, and power source variations. Note that the discharge voltage V1 in FIG. 2A is set so that the average voltage value until the start of discharge becomes larger when the average voltage under the pulse condition until the start of discharge and the pulse condition at the time of film formation are compared. The sequence when it was done is described. Further, the discharge voltage V2 is the maximum average voltage under the pulse conditions during film formation in a portion where there is a delay due to interference.

  Here, the time at which the discharge current I1 becomes a current value exceeding a predetermined threshold after the start of discharge in the first cathode 2 is defined as a normal discharge timing. Further, the time when the discharge current I2 becomes a current value exceeding a predetermined threshold after the start of discharge at the second cathode 3 is defined as a normal discharge timing. That is, in the first embodiment, the first current detection unit 15 is a first detection unit that detects the normal discharge timing in the first cathode 2, and the second current detection unit 16 is the second cathode 3. It is the 2nd detection means which detects the normal discharge timing in. In FIG. 2A, since the plasma of the first cathode 2 exists in the vicinity of the second cathode 3, the normal discharge timing is delayed with respect to the second cathode 3 due to plasma interference. There is. Before reaching the normal discharge, a leak current il flows as the discharge current I2, but the leak current il is lower than the threshold value, and the normal discharge timing is not detected.

  The film formation time required to form a thin film on a substrate is required to obtain desired antireflection optical characteristics on each substrate on which film formation is performed, and a film forming material that satisfies the optical characteristics and Time is determined from the thickness. In the case of no correction, if a time delay due to interference occurs, the film formation time is reduced accordingly. According to this study, although the time delay is within several seconds, a time delay occurs every time when film formation is started. Therefore, if film formation is performed over a plurality of layers, the time delay is accumulated and the degree of influence increases.

  Therefore, in the first embodiment, control is performed to correct the film formation end timing with respect to film thickness variations that occur when films are formed on the targets 4 and 5. Specifically, the device controller 27 first increases the applied voltages V1 and V2 little by little at the same time. Next, the device control unit 27 starts timing by using the normal discharge timing previously detected by any one of the first and second current detection units 15 and 16 as a trigger (time measurement unit). In FIG. 2B, the normal discharge timing t1 is first detected by the first current detector 15.

  Here, the apparatus control unit 27 requires the power P1 obtained by the product of the discharge current I1 at the cathode 2 and the applied voltage V1 to the cathode 2 at the normal discharge timing detected by the current detection unit 15 for film formation. The applied voltage V1 to the cathode 2 is set so as to have a predetermined power value p. Data of the set value of the applied voltage V1 to the cathode 2 is output to the control unit 17, and the control unit 17 outputs a control signal to the AC / DC conversion unit 9 so that the voltage becomes the set value. Similarly, the apparatus control unit 27 requires the power P2 obtained by the product of the discharge current I2 at the cathode 3 and the applied voltage V2 to the cathode 3 at the normal discharge timing detected by the current detection unit 16 for film formation. The applied voltage V2 to the cathode 3 is set so as to have a predetermined power value p. Data of the set value of the applied voltage V2 to the cathode 3 is output to the control unit 18, and the control unit 18 outputs a control signal to the AC / DC conversion unit 10 so that the voltage becomes the set value. Thus, in the first embodiment, the device control unit 27 functions as a setting unit.

  Then, the apparatus control unit 27 causes the discharge to end at the time when a predetermined time (necessary film formation time) T is measured for the cathode 2 in which the normal discharge timing t1 is detected by the one current detection unit 15. Is set to the applied voltage V1. Specifically, the applied voltage V1 is adjusted based on the discharge current I1 detected by the current detector 15, and the power P1 is adjusted to a predetermined power value p for performing a constant film formation.

  In contrast, the normal discharge timing t2 detected by the other current detection unit 16 is delayed from the normal discharge timing t1 detected by the one current detection unit 15. Accordingly, the device control unit 27 applies the normal discharge timing t1 detected by the current detection unit 15 and the normal discharge detected by the current detection unit 16 to the cathode 3 in which the normal discharge timing t2 is detected by the current detection unit 16. A time difference Δt (t2−t1) from the timing t2 is obtained. Next, the device control unit 27 sets the applied voltage V <b> 2 so that the discharge ends when the time obtained by adding the obtained time difference Δt to the predetermined time T is counted. At this time, the applied voltage V2 is adjusted based on the discharge current I2 detected by the current detector 16, and the power P2 is adjusted to a predetermined power value p for performing a constant film formation. Thereby, the shortage due to the time delay is corrected so that the timing of completion of the film formation of the discharge current I2 is lengthened. In other words, although the normal discharge timing (timing of starting film formation) is different, the film forming time by the first cathode 2 and the film forming time by the second cathode 3 are adjusted by correcting the timing of film forming end. It will be the same. In the first embodiment, the case where the first cathode 2 starts discharging first has been described. However, even if the second cathode 3 starts discharging first, similar detection and correction are performed. .

  Therefore, even if the normal discharge timings of the cathodes 2 and 3 are shifted due to plasma interference, the film can be formed on the substrate 8 with the power and time required for film formation. Quality is improved. Further, detailed correction can be performed by a simple means that only adds the time difference Δt, and stable film formation can be performed.

[Second Embodiment]
Next, the sputtering apparatus of 2nd Embodiment is demonstrated. In the second embodiment, since the apparatus configuration is the same as that of the first embodiment and the control operation of the control apparatus is different, the description of each part of the apparatus will be omitted with reference to FIG.

  As shown in FIG. 3, the device controller 27 increases the applied voltages V1 and V2 little by little at the same time. Any one of the first current detection unit 15 and the second current detection unit 16 detects the normal discharge timing first. Hereinafter, the case where the normal discharge timing t2 is detected by the second current detection unit 16 after the normal discharge timing t1 is detected by the first current detection unit 15 will be described.

  When the device control unit 27 detects the normal discharge timing t1 for the first cathode 2, the power P1 is smaller than the predetermined power value p, and the power value pm is low enough to maintain the discharge. The applied voltage V1 is set so as to be (setting means). With this low power control, no film is formed on the substrate 8 even if normal discharge is reached. This low power control is performed until the normal discharge timing t2 is detected by one of the current detectors 16.

  Next, the device control unit 27 performs normal discharge timing detected later by one of the first current detection unit 15 and the second current detection unit 16, that is, by the second current detection unit 16. Time measurement is started by using the detected normal discharge timing t2 as a trigger (time measuring means).

  Further, the apparatus control unit 27 applies the voltage applied to each cathode 2 and 3 so that the powers P1 and P2 become the predetermined power value p required for film formation at the normal discharge timing t2 detected by the one current detection unit 16. V1 and V2 are set. That is, when the normal discharge timing t2 is detected by one current detection unit 16, the predetermined power required for film formation is applied to the first cathode 2 in which the normal discharge timing t1 is detected by the other current detection unit 15. Control to return to the value p is performed. The apparatus control unit 27 then applies the applied voltages V1 and V2 to the cathodes 2 and 3 so that the discharges at the cathodes 2 and 3 are completed simultaneously when a predetermined time (necessary film formation time) T is measured. Set. Specifically, the apparatus control unit 27 ends the application of voltage by the power supplies 6 and 7 when measuring a predetermined time (necessary film formation time) T.

  Therefore, even if the normal discharge timings of the cathodes 2 and 3 are shifted due to plasma interference, the film can be formed on the substrate 8 with the power and time required for film formation. Quality is improved.

  In addition, when the normal discharge timing t2 after the normal discharge timing t1 is detected, the applied voltages V1 and V2 are set so that the power P becomes the predetermined power value p for each of the cathodes 2 and 3. The start timing of film formation is simultaneous. That is, the film formation start timing and the film formation end timing are the same, and the film formation time by the first cathode 2 and the film formation time by the second cathode 3 are the same. Therefore, a stable film formation time can be obtained by performing a control in which such a normal discharge timing t2 is regarded as a normal discharge start with the film formation time as a starting point. At the end of the discharge, the introduction of the gas is terminated almost in conjunction with the power sources 6 and 7. Therefore, since the film formation end timings at the cathodes 2 and 3 are the same, there is an advantage that the next film formation can be performed while the degree of vacuum and the gas pressure are stable.

[Third Embodiment]
Next, the sputtering apparatus of 3rd Embodiment is demonstrated. In the third embodiment, the apparatus configuration is the same as that of the first embodiment, and the control operation of the control apparatus is different. Therefore, the description of each part of the apparatus will be omitted with reference to FIG.

  As shown in FIG. 4, the device controller 27 increases the applied voltages V1 and V2 little by little at the same time. Any one of the first current detection unit 15 and the second current detection unit 16 detects the normal discharge timing first. Hereinafter, the case where the normal discharge timing t2 is detected by the second current detection unit 16 after the normal discharge timing t1 is detected by the first current detection unit 15 will be described.

  First, the device control unit 27 starts measuring time using a normal discharge timing previously detected by either one of the first and second current detection units 15 and 16 as a trigger (time measuring unit). In FIG. 4, the normal discharge timing t <b> 1 is detected first by one of the first and second current detection units 15 and 16.

  Next, at the normal discharge timing t1 detected by the current detection unit 15, the device control unit 27 requires the power P1 obtained by the product of the discharge current I1 at the cathode 2 and the applied voltage V1 to the cathode 2 for film formation. The applied voltage V1 to the cathode 2 is set so as to have a predetermined power value p. The device controller 27 then discharges the cathode 2 when the normal discharge timing t1 is detected by one of the current detectors 15 when a predetermined time (necessary film formation time) T is measured. The applied voltage V1 is set so as to end.

  In contrast, the normal discharge timing t2 detected by the other current detection unit 16 is delayed from the normal discharge timing t1 detected by the one current detection unit 15. Accordingly, the device control unit 27 applies the normal discharge timing t1 detected by the current detection unit 15 and the normal discharge detected by the current detection unit 16 to the cathode 3 in which the normal discharge timing t2 is detected by the current detection unit 16. A time difference Δt (t2−t1) from the timing t2 is obtained. Next, the device control unit 27 obtains a power value ΔP corresponding to the obtained time difference Δt. This power value ΔP is set so that the required film thickness can be obtained in the film formation time obtained by subtracting the time difference Δt from the predetermined time T. Then, the device control unit 27 sets the voltage applied to the cathode 3 so that the power P2 becomes a value obtained by adding the power value ΔP to the predetermined power value p (setting unit). Specifically, the power value ΔP is increased by increasing the discharge current I2 by increasing the applied voltage V2 by increasing the voltage value ΔV. In this way, the generated time difference Δt is converted into the power value ΔP, and the power value ΔP is added to the predetermined power value p, thereby correcting the film formation amount per unit time. As a result, the discharge end timing in each of the cathodes 2 and 3, that is, the film formation end timing is the same.

  Therefore, even if the normal discharge timings of the cathodes 2 and 3 are shifted due to plasma interference, the film can be formed on the substrate 8 with the power and time required for film formation. Quality is improved. Since the end timing of film formation is the same, the next film formation can be performed in a state where the degree of vacuum and the gas pressure are stable.

[Fourth Embodiment]
Next, the sputtering apparatus of 4th Embodiment is demonstrated. In FIG. 5, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 5, the sputtering apparatus 100 </ b> A includes a first shielding plate 31 movably disposed between the first target 4 and the substrate 8, and a second target 5 and the substrate 8. And a second shielding plate 32 arranged so as to be able to advance and retreat. Each of the shielding plates 31 and 32 is configured to be movable between a shielding position and a retracted position by moving or rotating in the vertical direction and the horizontal direction.

  The sputtering apparatus 100A serves as a moving unit that moves the first shielding plate 31 to a shielding position that shields the substrate 8 (solid line position in FIG. 5) and a retreat position (a broken line position in FIG. 5) that retreats from the shielding position. 1st drive part 33 is provided. Further, the sputtering apparatus 100 </ b> A includes a second driving unit 34 as a moving unit that moves the second shielding plate 32 to a shielding position that shields the substrate 8 and a retreat position that retreats from the shielding position. The first drive unit 33 and the second drive unit 34 are controlled by the device control unit 27. Here, the shielding positions of the shielding plates 31 and 32 are the positions between the targets 4 and 5 and the substrate 8, and the retracted positions of the shielding plates 31 and 32 are the targets 4 and 5. And a position deviated from between the substrate 8 and the substrate 8.

  The apparatus control unit 27 controls the film formation time by moving the shielding plates 31 and 32 to the shielding position and the retracted position. First, the device control unit 27 increases the applied voltage to the cathodes 2 and 3 little by little at the same time. One of the first current detector 15 (FIG. 1) and the second current detector 16 (FIG. 1) detects the normal discharge timing first.

  The device control unit 27 makes the power obtained by the product of the discharge current at each cathode 2 and 3 and the voltage applied to each cathode 2 and 3 become a predetermined power value necessary for film formation at each normal discharge timing. The voltage applied to each of the cathodes 2 and 3 is set (setting means).

  Here, the device control unit 27 starts timing with a normal discharge timing detected later by one of the first current detection unit 15 and the second current detection unit 16 (FIG. 1) as a trigger. (Time measuring means)

  Next, the device control unit 27 operates the driving units 33 and 34 so that the shielding plates 31 and 32 are moved from the shielding position to the retracted position at the timed timing. Thereby, even if each normal discharge timing differs, the start timing of each film-formation becomes simultaneous. Then, the device control unit 27 sets the applied voltage to each of the cathodes 2 and 3 so that the discharge ends when a predetermined time is measured.

  As described above, in the fifth embodiment, even when discharge is started at any one of the cathodes 2 and 3, the film is physically formed on the substrate 8 in a state where the shielding plates 31 and 32 are moved to the shielding position. Is not done. Accordingly, it is possible to eliminate the influence of unstable discharge until the normal discharge timing is reached in both the cathodes 2 and 3, and to perform more stable film formation. And since each shielding board 31 and 32 moves to a retracted position at the timing which started timing, ie, the normal discharge timing detected later by any one current detection part, the timing of the start of film formation becomes simultaneous, The end timing of film formation is also the same. Therefore, there is an advantage that the next film formation can be performed in a state where the degree of vacuum and the gas pressure are stable.

  In addition, although this invention was demonstrated based on the said embodiment, this invention is not limited to this. Although the case where the sputtering apparatus includes two cathodes has been described in the above embodiment, the present invention is applicable to a case where two or more cathodes are provided. That is, among the plurality of cathodes, the relationship between the first cathode and the second cathode operates as described above.

  Moreover, although the said embodiment demonstrated the case where the 1st cathode 2 and the 2nd cathode 3 were arrange | positioned on the both surfaces side of the board | substrate 8, it is not limited to this, and the 1st cathode 2 and the 2nd cathode 3 are arranged on one side of the board | substrate. The present invention is also applicable to the case where the cathode and the second cathode are arranged.

  Moreover, although the said embodiment demonstrated the case where the normal discharge timing was detected by the electric current detection parts 15 and 16, it is not limited to this. Each detection means is composed of each current detection unit 15, 16 and each voltage detection unit 13, 14, and the discharge current detected by each current detection unit 15, 16 and the application detected by each voltage detection unit 13, 14. You may make it detect the electric power obtained by the product with a voltage (discharge voltage). In this case, the same effect as the above embodiment can be obtained.

1 Vacuum chamber (deposition chamber)
2 1st cathode 3 2nd cathode 4 1st target 5 2nd target 6 1st power supply 7 2nd power supply 8 board | substrate 15 1st electric current detection part (1st detection means)
16 2nd electric current detection part (2nd detection means)
27 Device control unit (time measuring means, setting means)

Claims (6)

A first cathode and a second cathode disposed in the film formation chamber relative to the substrate, a first target and a second target mounted on each cathode, and a first voltage for applying a voltage to each cathode. A sputtering apparatus that includes a power source of 1 and a second power source, applies a voltage from each power source to each cathode, and deposits the target material on the substrate by sputtering.
First detection means and second detection means for detecting normal discharge timing at each of the cathodes;
Timing means for starting timing with a normal discharge timing detected previously by one of the first detection means and the second detection means as a trigger;
At each normal discharge timing detected by each detection means, the power obtained by the product of the discharge current at each cathode and the voltage applied to each cathode is a predetermined power value required for film formation. Setting means for setting the voltage applied to the cathode,
The setting means includes
For the cathode for which the normal discharge timing is detected by the one detection means, an applied voltage is set so that the discharge ends when the time measuring means times a predetermined time,
Of the first detection means and the second detection means, the normal detection timing detected by the one detection means and the other detection means for the cathode whose normal discharge timing is detected by the other detection means Obtaining a time difference from the normal discharge timing detected by the detecting means, and setting the applied voltage so that the discharge is terminated when the time measuring means measures the time obtained by adding the time difference to the predetermined time.
A sputtering apparatus characterized by that. A first cathode and a second cathode disposed in the film formation chamber relative to the substrate, a first target and a second target mounted on each cathode, and a first voltage for applying a voltage to each cathode. A sputtering apparatus that includes a power source of 1 and a second power source, applies a voltage from each power source to each cathode, and deposits the target material on the substrate by sputtering.
First detection means and second detection means for detecting normal discharge timing at each of the cathodes;
Timing means for starting timing with a normal discharge timing detected later by one of the first detection means and the second detection means as a trigger;
At each normal discharge timing detected by the one detection means, the power obtained by the product of the discharge current at each cathode and the applied voltage to each cathode is the predetermined power value required for film formation. Setting voltage applied to the cathode, and setting means for setting the voltage applied to each cathode so that the discharge ends when the time measuring means times a predetermined time, and
The setting means includes
For the cathode in which the normal discharge timing is detected by the other detection means of the first detection means and the second detection means, until the normal discharge timing is detected by the one detection means, Setting the applied voltage so that the power obtained by the product of the discharge current at the cathode and the applied voltage to the cathode is smaller than the predetermined power value;
A sputtering apparatus characterized by that. A first cathode and a second cathode disposed in the film formation chamber relative to the substrate, a first target and a second target mounted on each cathode, and a first voltage for applying a voltage to each cathode. A sputtering apparatus that includes a power source of 1 and a second power source, applies a voltage from each power source to each cathode, and deposits the target material on the substrate by sputtering.
First detection means and second detection means for detecting normal discharge timing at each of the cathodes;
Timing means for starting timing with a normal discharge timing detected previously by one of the first detection means and the second detection means as a trigger;
For each of the cathodes, setting means for setting an applied voltage so that the discharge ends when the time measuring means times a predetermined time, and
The setting means includes
For the cathode whose normal discharge timing is detected by the one detection means, the power obtained by the product of the discharge current at the cathode and the voltage applied to the cathode is the predetermined power value required for film formation. Set the applied voltage so that
Of the first detection means and the second detection means, the normal detection timing detected by the one detection means and the other detection means for the cathode whose normal discharge timing is detected by the other detection means The time difference from the normal discharge timing detected by the detection means is obtained, and the power obtained by the product of the discharge current at the cathode and the voltage applied to the cathode is the power value corresponding to the time difference in the predetermined power value. Set the applied voltage to be the added value,
A sputtering apparatus characterized by that. A first cathode and a second cathode disposed in the film formation chamber relative to the substrate, a first target and a second target mounted on each cathode, and a first voltage for applying a voltage to each cathode. A sputtering apparatus that includes a power source of 1 and a second power source, applies a voltage from each power source to each cathode, and deposits the target material on the substrate by sputtering.
First detection means and second detection means for detecting normal discharge timing at each of the cathodes;
Timing means for starting timing with a normal discharge timing detected later by one of the first detection means and the second detection means as a trigger;
At the normal discharge timing detected by each detection means, the power obtained by the product of the discharge current at each cathode and the applied voltage to each cathode becomes a predetermined power value required for film formation. Setting means for setting the applied voltage to each cathode so that the discharge ends when the time measuring means times a predetermined time,
A first shielding plate and a second shielding plate, which are arranged between the substrate and each target so as to be movable back and forth, and are movable between a shielding position for shielding the substrate and a retreating position for retreating from the shielding position;
A sputtering apparatus comprising: a moving unit that moves each of the shielding plates from the shielding position to the retracted position at a timing measured by the timing unit.   5. The sputtering apparatus according to claim 1, wherein each of the detection units detects a discharge current at each cathode. 6.   Each said detection means detects the electric power obtained by the product of the discharge current in each cathode, and the applied voltage to each said cathode, The sputtering device as described in any one of Claim 1 thru | or 4 characterized by the above-mentioned.

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