WO2020105367A1

WO2020105367A1 - Metallic compound film deposition method and reactive sputtering device

Info

Publication number: WO2020105367A1
Application number: PCT/JP2019/041940
Authority: WO
Inventors: 慎一郎税所; 田中　康仁
Original assignee: 株式会社シンクロン
Priority date: 2018-11-20
Filing date: 2019-10-25
Publication date: 2020-05-28
Also published as: TW202022141A; JP6778439B2; JP2020084240A; TWI721619B

Abstract

This method is for depositing a metallic compound film, the method comprising: a first step for attaching, to a sputter electrode, at least two targets having different maximal values for the absolute value of the change rate of deposition speed with respect to a reactive gas flow rate, supplying a first sputtering intended electric power that is set in accordance with a pulse control signal pattern, to the sputter electrode having a first target attached thereto in a state where an electric discharge gas is introduced in a deposition chamber, and forming a metallic super-thin film of the first target on a substrate by stopping the introduction of the reactive gas into the deposition chamber from a reactive gas introducer only at an intended introduction timing set from the pulse control signal pattern; and a second step for supplying a second sputtering intended electric power that is set in accordance with the pulse control signal pattern, to the sputter electrode having a second target attached thereto in a state where the electric discharge gas is introduced in the deposition chamber, and forming a metallic super-thin film of the second target on the substrate by introducing the reactive gas into the deposition chamber from the reactive gas introducer only at the intended introduction timing set from the pulse control signal pattern.

Description

Metal compound film forming method and reactive sputtering apparatus

The present invention relates to a method for forming a metal compound film and a reactive sputtering apparatus.

When a thin film of a metal oxide is formed by the reactive sputtering method, if the flow rate of oxygen molecules introduced into the sputtering atmosphere is large, the film formation rate will be significantly lower than when a thin metal film is formed. Therefore, a radical electrode is provided in the film forming chamber in addition to the sputtering electrode on which the target is mounted, and oxygen radicals, that is, oxygen atoms, are supplied to the gap between the surface of the substrate and the surface of the target. A metal oxide film forming apparatus is known (Patent Document 1).

JP, 2007-204819, A

However, in the above-mentioned conventional technique, since a radical electrode is required in addition to the sputtering electrode, the cost of the high-frequency power source and other devices increases, and the film forming apparatus is increased in size by the volume occupied by the radical electrode in the film forming chamber. There is.

The problem to be solved by the present invention is to provide a metal compound film forming method and a reactive sputtering apparatus capable of forming a metal compound film with a simple structure.

According to the present invention, a pulse wave conversion switch for converting a DC voltage into a pulse wave voltage is provided between a DC power supply and at least two sputter electrodes in correspondence with at least two sputter electrodes. By controlling the introduction controller and the time required for the reaction with a programmable oscillator that generates a programmed pulse control signal pattern, the target power supplied to each sputter electrode and the target reaction gas introduction timing are set appropriately. By doing so, the above problem is solved.

In particular, under a predetermined reactive sputtering condition, at least two first targets each having a relatively large maximum absolute value of the rate of change of the film formation rate with respect to the flow rate of the reaction gas and at least two second targets are relatively small. After attaching to each of the sputter electrodes,
While the discharge gas is introduced into the film forming chamber, the first sputtering target power set by the pulse control signal pattern is supplied to the sputtering electrode on which the first target is mounted, and the sputtering target electrode is set by the pulse control signal pattern. A first step of stopping the introduction of the reaction gas from the reaction gas introduction device to the film formation chamber only at the specified target introduction timing, and forming the ultrathin metal film of the first target on the substrate;
While the discharge gas is introduced into the film forming chamber, the second sputtering target power set by the pulse control signal pattern is supplied to the sputtering electrode on which the second target is mounted, and the second target is supplied by the pulse control signal pattern. A second step of introducing a reaction gas from the reaction gas introduction device to the film forming chamber at a set target introduction timing to form an ultrathin metal film of the second target on the substrate. The above-mentioned problems are solved by the film forming method.

Moreover, after mounting the first target and the second target on each of the at least two sputter electrodes,
While the discharge gas is being introduced into the film forming chamber, the first sputtering target electric power set by the pulse control signal pattern is supplied to the sputtering electrode on which the first target is attached, and the sputtering control electrode pattern is used by the pulse control signal pattern. A first step of forming a metal ultrathin film of the first target on the substrate without introducing a reaction gas from the reaction gas introduction machine to the film formation chamber only at a set target introduction timing;
While the discharge gas is introduced into the film forming chamber, the second sputtering target power set by the pulse control signal pattern is supplied to the sputtering electrode on which the second target is mounted, and the second target is supplied by the pulse control signal pattern. A second step of forming an ultrathin metal film of the second target on the substrate without introducing a reaction gas from the reaction gas introduction machine to the film forming chamber at a set target introduction timing;
While the discharge gas is being introduced into the film forming chamber, the first sputtering target electric power set by the pulse control signal pattern is supplied to the sputtering electrode on which the first target is attached, and the sputtering control electrode pattern is used by the pulse control signal pattern. A third step of introducing a reaction gas from the reaction gas introduction machine to the film forming chamber only at a set target introduction timing to form an ultrathin metal film of the first target on the substrate;
While the discharge gas is introduced into the film forming chamber, the second sputtering target power set by the pulse control signal pattern is supplied to the sputtering electrode on which the second target is mounted, and the second target is supplied by the pulse control signal pattern. A fourth step of introducing a reaction gas from the reaction gas introduction machine to the film forming chamber at a set target introduction timing to form an ultrathin metal film of the second target on the substrate. The above-mentioned problems are solved by the film forming method.

In addition, a film forming chamber into which a substrate to be formed is placed,
A decompressor for decompressing the film forming chamber to a predetermined pressure,
A discharge gas introducing machine for introducing a discharge gas into the film forming chamber,
A plurality of sputtering electrodes, each of which includes a target serving as a film-forming material, and which faces one of the substrates,
A reaction gas introducing device for introducing a reaction gas into the film forming chamber,
A direct current power supply for supplying power to the plurality of sputter electrodes,
A plurality of pulse wave conversion switches connected between the DC power supply and the plurality of sputtering electrodes, for converting a DC voltage applied to each sputtering electrode into a pulse wave voltage,
A reaction gas introduction controller for controlling the introduction of the reaction gas from the reaction gas introduction machine to the film forming chamber,
A pulse control signal pattern according to each sputter target power supplied to the plurality of sputter electrodes and a target introduction timing of the reaction gas is programmable, and the plurality of pulses are controlled according to the programmed pulse control signal pattern. Each of the wave conversion switches, and a programmable oscillator for controlling the gas introduction controller,
The reaction gas introduction machine,
A reaction gas supply source,
A flow rate controller for adjusting the flow rate of the reaction gas supplied from the reaction gas supply source,
A first gas flow path branched from the flow rate controller to guide a reaction gas to the film forming chamber;
A second gas flow path branched from the flow rate controller to guide the reaction gas to the exhaust system of the pressure reducer;
A first opening / closing valve for opening / closing the first gas flow path;
A second on-off valve for opening and closing the second gas flow path,
The reactive gas introduction controller may also achieve the above object by a reactive sputtering device that exclusively controls the opening / closing of the first opening / closing valve and the second opening / closing valve based on a pulse control signal pattern from the programmable oscillator. Solve.

According to the present invention, it is possible to provide a film forming method and a reactive sputtering apparatus capable of forming a metal compound film with a simple structure.

It is a block diagram showing one embodiment of a reactive sputtering device concerning the present invention. It is a block diagram which shows the detail of the reaction gas introduction machine of FIG. 1A. It is a principal part block diagram which shows other embodiment of the reactive sputtering apparatus which concerns on this invention. It is a block diagram which shows the electric system of the reactive sputtering apparatus of FIG. 1C. It is a figure which shows an example of the voltage pulse wave (mask pulse) produced | generated by the programmable oscillator 24 of FIG. 1A, the 1st pulse wave conversion switch 22, or the 2nd pulse wave conversion switch 23. The figure which shows the other example of the voltage pulse wave (mask pulse) produced | generated by the programmable oscillator 24, the 1st pulse wave conversion switch 22 and the 2nd pulse wave conversion switch 23 of FIG. 1A when the bias DC power supply 21 is provided. Is. It is a figure which shows the base pulse and mask pulse set to the programmable oscillator of FIG. 1A, and the sputter mask pulse generated by these. It is a principal part block diagram which shows the electric system of other embodiment of the reactive sputtering apparatus which concerns on this invention. It is a principal part block diagram which shows the electric system of other embodiment of the reactive sputtering apparatus which concerns on this invention. 3 is a time chart showing a first example of a film forming method using the reactive sputtering apparatus according to the present invention. 6 is a time chart showing a second example of a film forming method using the reactive sputtering apparatus according to the present invention. It is a time chart which shows the 3rd example of the film-forming method using the reactive sputtering apparatus which concerns on this invention. 9 is a time chart showing a fourth example of a film forming method using the reactive sputtering apparatus according to the present invention. It is a time chart which shows the 5th example of the film-forming method using the reactive sputtering apparatus which concerns on this invention. 9 is a time chart showing a sixth example of a film forming method using the reactive sputtering apparatus according to the present invention. It is a time chart which shows the 7th example of the film-forming method using the reactive sputtering apparatus which concerns on this invention. 6 is a graph showing a characteristic profile of a film forming rate with respect to reaction gas flow rates of different targets under a predetermined reactive sputtering condition. 4B is a graph showing an example of the material flying amount of the first target when processed by the film forming method shown in FIG. 4A.

<Reactive sputtering equipment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a block diagram showing an embodiment of the reactive sputtering apparatus of the present invention, and FIG. 1B is a block diagram showing details of the reaction gas introducing device 16 of FIG. 1A. The reactive sputtering apparatus 1 according to the present embodiment includes a film forming chamber 11 that substantially forms a closed space, and a substrate holder 12 that holds a substrate S on which a film is formed and a film forming material in the film forming chamber 11. Targets (first target T1 and second target T2 in this example) respectively, and a plurality of sputter electrodes (first sputter electrode 18 and second sputter electrode 19 in this example) facing one substrate S are provided. ) And are provided. The film forming chamber 11 also serves as a decompressor 13 that decompresses the film forming chamber 11 to a predetermined pressure and a partition valve (main valve) that controls the pressure of the film forming chamber 11 that is decompressed by the decompressor 13. A conductance valve 14, a discharge gas introduction device 15 for introducing a discharge gas into the film forming chamber 11, a reaction gas introduction device 16 for introducing a reaction gas into the film forming chamber 11, and a reaction gas amount by the reaction gas introduction device 16. And a reaction gas introduction controller 17 for controlling. In addition, a conductance valve and a partition valve (main valve) other than the conductance valve may be provided in the pipe between the film forming chamber 11 and the pressure reducer 13 in this order from the film forming chamber 11 side.

The reactive sputtering apparatus 1 according to the present embodiment includes one DC power supply 20 that supplies electric power to the first sputtering electrode 18 and the second sputtering electrode 19. Further, the reactive sputtering apparatus 1 of the present embodiment is connected in parallel between the DC power supply 20 and the first sputtering electrode 18 and the second sputtering electrode 19, and the first sputtering electrode 18 and the second sputtering electrode 19 are connected. And a plurality of pulse wave conversion switches (first pulse wave conversion switch 22 and second pulse wave conversion switch 23 in this example) for converting the DC voltage applied to the pulse wave voltage to the pulse wave voltage. Further, the reactive sputtering apparatus 1 of the present embodiment has a program of a pulse control signal pattern corresponding to the respective target sputtering powers supplied to the first sputtering electrode 18 and the second sputtering electrode 19 and the target introduction timing of the reaction gas. A programmable oscillator 24 that controls each of the first pulse wave conversion switch 22 and the second pulse wave conversion switch 23 according to the pulse control signal pattern, and that controls the reaction gas introduction controller 17; The apparatus controller 25 that controls the machine 13, the conductance valve 14, the discharge gas introduction machine 15, and the reactive gas introduction machine 16 and the film formation controller 26 that controls the entire control of the reactive sputtering apparatus 1. Hereinafter, each component will be described.

The substrate holder 12 is formed, for example, in a flat plate shape, is provided in the film forming chamber 11, and the substrate S to be film-formed is placed on the upper surface thereof. Further, a heater for heating the substrate S may be provided in the substrate holder 12 in response to the case where the substrate S needs to be heated at the time of film formation. Although not shown in FIG. 1A, a load lock chamber is continuously provided on one sidewall of the film forming chamber 11 via a gate valve, and the substrate S is opened from the load lock chamber by a load mechanism or the like. It is put in and placed on the upper surface of the substrate holder 12. Further, the substrate S for which film formation has been completed is carried out from the substrate holder 12 to the load lock chamber by using the loading mechanism. The reactive sputtering apparatus 1 according to the present embodiment is a so-called single-wafer reactive sputtering apparatus that performs sputter film formation on one substrate S. However, the reactive sputtering apparatus 1 of the present invention is not limited to the single-wafer type, and may be one in which a plurality of substrates S are put into the film forming chamber 11 for processing. In addition, the substrate holder 12 of the present example is used when the substrate S is taken in and out of the rotation mechanism and the vertical mechanism for improving the uniformity of film formation quality (film thickness and composition ratio) with respect to the substrate S. An elevating mechanism for improving workability may be provided.

The first sputtering electrode 18 is provided with a first target T1 serving as a film forming material held on the tip surface thereof, and the surface of the first target T1 faces the substrate S mounted on the substrate holder 12. .. Similarly, the second sputtering electrode 19 is provided such that the second target T2 serving as a film-forming material is held on the tip surface thereof, and the surface of the second target T2 faces the substrate S mounted on the substrate holder 12. Has been. In the reactive sputtering apparatus 1 of this embodiment, two sputtering

electrodes

18 and 19 are provided on one surface of the substrate S, but the reactive sputtering apparatus of the present invention uses two

sputtering electrodes

18 and 19. However, the present invention is not limited to this, and three or more sputter electrodes may be provided on one surface of the substrate S.

Further, when a plurality of sputter electrodes are provided facing the substrate S, the surfaces of all targets and the surface of the substrate S are not parallel, but in consideration of the ease of film formation control, each sputter electrode is It is preferable to provide them so as to be equidistant or symmetrical with respect to the surface of S. In the two first sputter electrodes 18 and the second sputter electrodes 19 shown in FIG. 1A, the central axis C1 of the first sputter electrode 18 and the central axis C2 of the second sputter electrode 19 face the center O of the substrate S, respectively. The angles θ1 and θ2 formed by are equal to each other.

The decompressor 13 includes an exhaust port, an exhaust pipe, and an exhaust pump (vacuum pump) for adjusting the film forming chamber 11 to a pressure at which sputtering can be performed during the sputtering process. In order to remove the residual gas in the film forming chamber 11, the film forming chamber 11 is evacuated to a predetermined high vacuum pressure, and then the sputtering process is performed. In the sputtering process, the discharge gas is introduced from the discharge gas introducing device 15 into the film forming chamber 11, and the conductance valve 14 also serving as a partition valve is operated so that a reduced pressure (vacuum) atmosphere of, for example, several Pa to several tens Pa is obtained. The film forming chamber 11 is set to a predetermined pressure. The partition valve (main valve) is a valve that performs an opening or closing operation, and the conductance valve is a valve whose opening is variable in order to adjust the exhaust speed. Further, when the film formation is completed, the conductance valve 14 also serving as a valve valve is closed, and a leak valve (not shown) provided in the film formation chamber 11 is opened to return the film formation chamber 11 to the normal pressure. .. It is desirable that the film formation chamber 11 be opened to the atmosphere by a leak valve provided in the film formation chamber 11, and that the depressurizer 13 continues to operate except when the entire film formation apparatus 1 is stopped. If the decompressor 13 is stopped and opened to the atmosphere, the decompressor 13 may be contaminated by water and dust contained in the atmosphere, and it takes a long time to restart the decompressor 13 after stopping the decompressor 13. Because.

The discharge gas introducing device 15 supplies a discharge gas (a gas that forms a plasma state in the sputtering process and generates ions that collide with a target) to the film forming chamber 11, a gas cylinder, a regulator, a partition valve, an introducing pipe, It includes a flow control valve and a pump if necessary. The discharge gas is not particularly limited, but an inert gas such as argon gas is used.

The reaction gas introducing device 16 is used when performing the reactive sputtering process, and as shown in FIG. 1B, the reaction gas cylinder 161 that stores the compressed reaction gas, and the supply from the reaction gas cylinder 161 through the gas flow path 165. Flow rate controller 162 for setting the gas flow rate to be controlled, first

gas flow paths

166a and 166b branched from the flow rate controller 162 to guide the reaction gas to the film forming chamber 11, and branched from the flow rate controller 162.

Second gas passages

167a and 167b for guiding the reaction gas to the exhaust system of the pressure reducer 13, a first opening / closing valve 163 for opening / closing the first gas passage 166, and a second opening / closing valve for opening / closing the second gas passage 167. 164 and. Since the pressure of the reaction gas cylinder 161 is compressed to the primary pressure (for example, 100 MPa) when the cylinder is full, a regulator is provided in the reaction gas cylinder 161 to set the secondary pressure (for example, 50 to 300 KPa) to adjust the flow rate. The pressure is reduced to the operating pressure of the vessel 162 and is introduced into the gas passage 165. A needle valve may be provided in the second gas passage 167b to adjust the flow rate of the reaction gas exhausted to the decompressor 13.

Then, the reaction gas introduction controller 17 inputs the pulse control signal pattern generated by the programmable oscillator 24 described later, boosts this to a predetermined voltage that can be controlled by the reaction gas introduction device 16, and then performs the reaction. By outputting to the gas introduction device 16, the first opening / closing valve 163 and the second opening / closing valve 164 of the reaction gas introduction device 16 are exclusively opened / closed. As a result, the introduction timing and the introduction amount of the reaction gas introduced into the film forming chamber 11 are controlled with high accuracy. Strictly speaking, assuming that the amount of the reaction gas introduced into the film forming chamber 11 is the reaction gas flow rate × introduction time, the flow rate control of the reaction gas is controlled by the flow rate controller 162, and the introduction time is the programmable oscillator 24. Controlled by. Here, "exclusively controls opening / closing" means control to close one of the first opening / closing valve 163 and the second opening / closing valve 164 and to open the other when closing one. Say. As in this example, in the state where a certain amount of the reaction gas is supplied from the reaction gas cylinder 161 by the flow rate controller 162, at the timing of introducing the reaction gas into the film forming chamber 11, the first opening / closing valve 163 is opened and the second opening / closing valve 163 is opened. While closing the valve 164, at the timing of stopping the supply of the reaction gas to the film forming chamber 11, the first opening / closing valve 163 is closed and the second opening / closing valve 164 is opened to guide the reaction gas to the exhaust system of the pressure reducer 13. By doing so, it is possible to stably control the pulse-like introduction / non-introduction of the reaction gas into the film forming chamber 11 at a highly accurate timing of 100 msec or less.

Particularly, the pipe 166b between the first opening / closing valve 163 and the film forming chamber 11 is always in a reduced pressure atmosphere during film formation. On the other hand, if the second on-off valve 164 is not provided, the pipe 166a between the flow rate controller 162 and the first on-off valve 163 has a reaction gas cylinder when the first on-off valve 163 is "closed". The secondary pressure of 161 is returned, and when the reaction gas is introduced, the reaction gas rushes into the film forming chamber 11 due to the pressure difference between the pipe 166a and the film forming chamber 11. Therefore, by providing the second opening / closing valve 164 as in the present example, even when the first opening / closing valve 163 is “closed”, the second opening / closing valve 164 is “open”, so that the flow rate controller 162 is The depressurized state of the pipe 166a between the first on-off valve 163 and the first on-off valve 163 is maintained, and as a result, generation of rush gas into the film forming chamber 11 can be suppressed.

When sputtering a metal oxide film or a metal nitride film as a film forming material, oxygen gas or nitrogen gas is introduced into the film forming chamber 11 from the reaction gas introducing device 16. If necessary, the reaction gas introduction system may be separated for oxygen gas and nitrogen gas. When reactive sputtering is not performed, the reaction gas introduction controller 17 is controlled to control the reaction gas introduction device 16. It is sufficient to stop the introduction of the reaction gas by.

Only one DC power supply 20 is provided in the reactive sputtering apparatus 1 of this embodiment. The direct-current power supply 20 applies a direct-current voltage of 1 kV or less to the target to cause discharge, and as a result, a part of the argon gas (discharge gas) that has emitted electrons to be positively ionized collides with the target and the target is discharged. The atoms are knocked out and deposited on the substrate S in the direction of the target stretching. It is desirable that the DC power supply 20 of the present embodiment is a power supply capable of automatically switching control of power control (CP), voltage control (CV), and current (CC).

In particular, the power supply line between the DC power supply 20 and the first sputtering electrode 18 of the present embodiment is provided with a first pulse wave conversion switch 22 to supply power between the DC power supply 20 and the second sputtering electrode 19. A second pulse wave conversion switch 23 is provided on the line. Since the first pulse wave conversion switch 22 and the second pulse wave conversion switch 23 are connected in parallel to the DC power supply 20, the same voltage as that of the DC power supply 20 is applied. However, when the DC power supply 20 is power-controlled, the applied voltage may differ depending on the type of target. The first pulse wave conversion switch 22 and the second pulse wave conversion switch 23 are composed of switching elements that convert a DC voltage from the DC power supply 20 into a pulse wave voltage, and a switching element that can withstand a high voltage of several kV, such as a MOSFET. , IGBT, SiC and other power transistors can be used.

The first pulse wave conversion switch 22 and the second pulse wave conversion switch 23 are independently controlled by the programmable oscillator 24 while maintaining synchronization. That is, the programmable oscillator 24 outputs the pattern of the pulse control signal corresponding to the respective target sputtering power values supplied to the first sputter electrode 18 and the second sputter electrode 19 to the first pulse wave conversion switch 22 and the second pulse wave. It outputs to each of the conversion switches 23 to control ON / OFF.

FIG. 2C is a diagram showing a method for generating a sputter mask pulse in the programmable oscillator 24. As shown in the figure, the sputter mask pulse (pattern of pulse control signal) output to each of the first pulse wave conversion switch 22 and the second pulse wave conversion switch 23 is a base pulse representing a pulse sputter frequency and a sputter mask pulse. It is set as defined by the sputter mask pulse (AND condition of base pulse and mask pulse, output pulse) with the mask pulse representing the time frequency. At this time, the frequency, the duty ratio, and the phase angle of each of the base pulse and the mask pulse can be individually set, and the base pulse and the mask pulse are synchronized by using the same clock. When the same target material is used for the two targets, a dual cathode is obtained by advancing the phase angle of the base mask of one target by 180 °. Further, the sputter timing in one cycle is performed by changing the phase angle of the mask pulse. The base pulse shown in the figure is set, for example, at a frequency of 1 kHz to 500 kHz, a duty ratio of 50%, and a phase angle of 0 °, and the mask pulse has a frequency of 0.5 Hz to 1.0 Hz, a duty ratio of 50%, and a phase angle of 0 °. The set example is shown. The number of channels of the programmable oscillator 24 is equal to or more than the total number of the pulse wave conversion switches that are the output destinations and the number of the output destination devices that are included in the reaction gas introduction controller 17. .. Further, the programmable oscillator 24 can also set the number of repetitions of one cycle and the time from the start to the end. Further, the pulse signal output to the first opening / closing valve 163 and the second opening / closing valve 164 of the reactive gas introducing device 16 described later is composed of only mask pulses.

FIG. 2A is a diagram showing an example of a voltage pulse wave (mask pulse) generated by the programmable oscillator 24, the first pulse wave conversion switch 22 or the second pulse wave conversion switch 23 of FIG. 1A. For example, as shown in FIG. 2A, the programmable oscillator 24 includes a control including a frequency 1 / T and a duty ratio τ / T that turn on / off the first pulse wave conversion switch 22 and the second pulse wave conversion switch 23, respectively. The signal pattern is arbitrarily programmable. Further, since it is possible to create a waveform on the time axis without depending on the repetitive waveform, it is possible to program in a single-shot phenomenon. Further, the programmable oscillator 24 has a function of adjusting the start timing of the internal cycle of the unit, and has a control signal pattern output to the first pulse wave conversion switch 22 and a control signal pattern output to the second pulse wave conversion switch 23. And are generated from the same clock, so that highly accurate synchronism is maintained.

Further, as shown in FIG. 1A, in the circuit on the first sputter electrode 18 side of the first pulse wave conversion switch 22 and the circuit on the second sputter electrode 19 side of the second pulse wave conversion switch 23, about +50 V (at +100 V or less A bias DC power supply 21 (preferably present) may be connected. When the bias DC power supply 21 is connected and the sputtering voltage is not output, the bias voltage is applied to the target. FIG. 2B shows other voltage pulse waves (mask pulses) generated by the programmable oscillator 24, the first pulse wave conversion switch 22 and the second pulse wave conversion switch 23 of FIG. 1A when the bias DC power supply 21 is provided. It is a figure which shows an example. By providing the positive bias DC power supply 21, as shown in FIG. 2B, when the first pulse wave conversion switch 22 and the second pulse wave conversion switch 23 are OFF, the first and

second sputter electrodes

18 and 19 are inverted. A voltage (+ DC voltage) will be applied. In the sputtering process, the + potential is locally charged to the inclusions inside the target or the impurities adhering to the surface, and an arc may occur between the target and the sputtering electrode applied to the − potential. Therefore, as shown in FIG. 2B, when the first pulse wave conversion switch 22 and the second pulse wave conversion switch 23 are turned off, an inversion voltage pulse wave is generated to actively remove such + potential charging (medium). And the generation of arc can be suppressed.

Returning to FIG. 1A, the device controller 25 controls the decompressor 13, the conductance valve 14, the discharge gas introduction device 15, and the reaction gas introduction device 16 based on the control signal from the film formation controller 26. Together with the control of the reaction gas introduction controller 17 by the programmable oscillator 24, the exhaust of the film forming chamber 11 and the timing of introducing the discharge gas and the reaction gas into the film forming chamber 11 are controlled. Although a specific usage example will be described later, as an example, while supplying power to the first sputtering electrode 18 and / or the second sputtering electrode 19, argon gas or the like from the discharge gas introduction device 15 to the film forming chamber 11 is supplied. While controlling the discharge gas introduction device 15 so that the inert gas is introduced, while the electric power is being supplied to either the first sputtering electrode 18 or the second sputtering electrode 19, the reaction gas introduction controller The reaction gas introduction device 16 is controlled so that the reaction gas is introduced from 17 to the film forming chamber 11.

In the embodiment shown in FIG. 1A, the two

sputter electrodes

18 and 19 are provided only on one surface of the substrate S. However, as shown in FIG. 1C, film formation on both front and back surfaces of the substrate S is performed on the substrate holder 12. The substrate S is held so that a part thereof is exposed, and the third sputter electrode 27 having the third target T3 serving as a film forming material held on the tip surface is also formed below the substrate holder 12, and the film is formed on the tip surface. The fourth sputtering electrode 28 holding the fourth target T4 as a material is arranged so that the respective surfaces of the third target T3 and the fourth target T4 face the back surface of the substrate S held by the substrate holder 12. It may be provided. In this case, although not particularly limited, as shown in FIG. 1D, the first pulse wave conversion switch 22 is provided on the power supply line between the first DC power source 201 and the first sputter electrode 18 and the second sputter electrode 19. The second pulse wave conversion switch 23 is provided on the power supply line between the second DC power source 202 and the third sputtering electrode 27 and the fourth sputtering electrode 28. Then, the programmable oscillator 24 outputs to the first pulse wave conversion switch 22 a pattern of a pulse control signal according to the sputtering target power value supplied to the first sputtering electrode 18 and the second sputtering electrode 19, and the third sputtering device. A pattern of a pulse control signal according to the target sputtering power value supplied to the electrode 27 and the fourth sputtering electrode 28 may be output to the second pulse wave conversion switch 23 to control ON / OFF.

In each of the above-described embodiments, the targets (first target T1, second target T2, third target T3, and fourth target T4) provided on the respective sputter electrodes are different film forming materials. The film forming materials may be partially different, or all of the film forming materials may be the same. Even if the targets are the same film forming material, the introduction pattern of the reaction gas may be changed.

Further, the reactive sputtering apparatus 1 according to the present invention is not limited to the single DC power source 20 shown in FIG. 1A, and a plurality of DC power sources 20 may be provided. FIG. 3A is a block diagram of an essential part showing an electric system of still another embodiment of the reactive sputtering apparatus according to the present invention, and FIG. 3B is an electric system of yet another embodiment of the reactive sputtering apparatus according to the present invention. It is a principal part block diagram which shows a system. In the embodiment shown in FIG. 3A, a first DC power supply 201 and a second DC power supply 202 are provided for each of the two sputter electrodes (the first sputter electrode 18 and the second sputter electrode 19), and two pulse wave conversions are performed. This is an example in which a first bias DC power supply 211 and a second bias DC power supply 212 are provided for each of the switches (first pulse wave conversion switch 22 and second pulse wave conversion switch 23). In the embodiment shown in FIG. 3B, the first DC power source 201 and the second DC power source 202 are provided for each of the two sputtering electrodes (the first sputtering electrode 18 and the second sputtering electrode 19), while two pulses are provided. This is an example in which one bias DC power supply 21 is provided for the wave conversion switch (first pulse wave conversion switch 22 and second pulse wave conversion switch 23).

<< Film forming method using reactive sputtering apparatus >>
By using the reactive sputtering apparatus 1 according to the present embodiment as described above, it is possible to perform sputtering processing in various film formation forms. In particular, when forming a composite metal compound film such as a metal oxide film or a metal nitride film, a mixed film or a multilayer film targeting a plurality of different metals, there is a method capable of forming a film while suppressing a decrease in film formation rate as much as possible. It will be possible. The composite metal compound film and the mixed film are collectively referred to as a metal compound film.

FIG. 5 is a graph showing a characteristic profile of the film formation rate with respect to the flow rate of a reaction gas of a predetermined type under a predetermined reactive sputtering condition, the first target T1 is shown by a solid line, and the second target of a material different from this is shown. The characteristic of T2 is shown by a dotted line. A range in which the flow rate of the reaction gas is relatively small is called a metal mode, and a range in which the flow rate of the reaction gas is relatively large is an oxidation mode (in which oxygen is used as a reaction gas. Hereinafter, also referred to as a reaction mode. There is a region called the transition mode between them. The film formation rate with respect to the reaction gas flow rate of the first target T1 gradually decreases as the reaction gas flow rate increases from 0, then rapidly decreases in the range R (near the transition mode range), and then gradually decreases again. To do. The absolute value of the rate of change of the film forming rate (the slope of the profile) with respect to the reaction gas flow rate of the first target T1 gradually increases as the reaction gas flow rate increases from 0, gradually reaches a maximum value in the range R, and then gradually increases. Becomes smaller.

On the other hand, the film formation rate with respect to the reaction gas flow rate of the second target T2 gradually decreases as the reaction gas flow rate increases from 0, and then decreases abruptly in the range R (near the transition mode range). After that, it gradually decreases again. The absolute value of the rate of change of the film forming rate (the slope of the profile) with respect to the reaction gas flow rate of the second target T2 gradually increases as the reaction gas flow rate increases from 0, reaches a maximum value in the range R, and then gradually increases. Becomes smaller. However, the maximum value in the range R of the second target T2 is smaller than the maximum value of the first target T1. That is, the degree of influence of the film formation rate on the reaction gas flow rate of the second target T2 is relatively smaller than the degree of influence of the film formation rate on the reaction gas flow rate of the first target T1.

Therefore, the present inventors applied a voltage to the second sputtering electrode 19 for the second target T2 in which the degree of influence of the film formation rate on the flow rate of the reaction gas is relatively small (in other words, insensitive). If the step of introducing the reactive gas into the film forming chamber 11 and radicalizing the reactive gas by the sputtering power at the same time as performing the sputtering treatment of the two targets T2, the decrease in the film forming rate can be suppressed to the minimum and at the same time, Attention was paid to the fact that the reaction gas introduced into the film forming chamber 11 could be radicalized by the second sputtering electrode 19. That is, even if a radical electrode for a reaction gas is not separately provided, the second sputtering electrode 19 is also used as a radical electrode to convert the reaction gas into a radical, and the film deposition rate has a relatively large influence on the reaction gas flow rate (in other words, With respect to the first target T1 (which is sensitive), the reaction process can be performed by the reaction gas radicals remaining in the film forming chamber 11. Hereinafter, a target having a relatively large maximum absolute value of the rate of change of the film formation rate with respect to the reaction gas flow rate is referred to as a first target T1, and a target having a relatively small absolute value is referred to as a second target T2. Will be explained. Examples of the first target T1 include metals such as zirconium Zr, titanium Ti, aluminum Al, niobium Nb, and tantalum Ta, and examples of the second target T2 include metals such as yttrium Y, erbium Er / yttrium Y, and silicon Si. Can be illustrated.

4A to 4C are time charts showing an example of a film forming method using the reactive sputtering apparatus 1 according to the present invention, showing one cycle (one cycle) as a unit of the film forming process. This figure shows a pulse control signal pattern programmed in the programmable oscillator 24 (the vertical axis represents ON / OFF, the horizontal axis represents time), and is applied to the first sputter electrode 18 in order from the above figure. Pulse (ON / OFF), application pulse (ON / OFF) to the second sputtering electrode 19, application pulse (ON / OFF) to the reactive gas introduction controller 17, application pulse (ON / OFF) to the discharge gas introduction device 15. ) Respectively. Each of the film forming methods is an example of forming a metal compound film such as a metal oxide film or a metal nitride film by introducing a desired reaction gas from the reaction gas introducing device 16 into the film forming chamber 11. Hereinafter, the applied pulse applied to the sputter electrode in the pulse control signal pattern is also referred to as a sputter mask pulse.

Film forming method illustrated in FIGS. 4A ~ FIG. 4G, such as zirconium Zr as the first target T1, yttrium Y as the second target T2, oxygen respectively selected as the reaction gas, yttria stabilized zirconia YSZ _(ZrO 2 · _Y 2 O ₃ ) In the case of forming a metal compound film (first to third examples shown below), silicon Si is selected as the first target T1, yttrium Y is selected as the second target T2, and oxygen is selected as the reaction gas, and yttrium silicate is selected. When forming a metal compound film of (Y ₂ O ₃ .SiO ₂ ) (fourth to seventh examples shown below), silicon Si is used as the first target T1, erbium Er / yttrium Y is used as the second target T2, and a reaction is performed. This can be applied to the case where oxygen is selected as a gas and a metal compound film of erbium yttrium silicate (Er _x Y _{2 -x} SiO ₂ ) is formed (fourth to seventh examples below).

<< First example >>
In the film forming method shown in FIG. 4A, in a state where a discharge gas such as an inert gas is introduced into the film forming chamber 11, the first target T1 (for example, zirconia Zr) is attached to the first sputter electrode 18 for a predetermined time. A sputtering mask pulse having a width Pt1 is applied to form an ultrathin film by the first target T1. Next, a sputter mask pulse having a predetermined time width Pt2 is applied to the second sputter electrode 19 to form an ultrathin film of the second target T2 (eg, yttrium Y), and at the same time, a reaction gas (eg, oxygen O ₂ ) is formed. Introduce into chamber 11. That is, the reaction gas is not introduced into the film forming chamber 11 at the timing of sputtering the first target T1 in which the degree of influence of the film forming rate on the reaction gas flow rate is relatively sensitive, and the reaction rate of the film forming rate on the reaction gas flow rate is not introduced. The reaction gas is introduced into the film forming chamber 11 at the timing of performing the sputtering process of the second target T2, which is relatively insensitive to the influence and obtains the film forming speed.

As a result, the reaction gas introduced into the film forming chamber 11 is radicalized by the electric field of the second sputtering electrode 19, and the ultra thin film of the first target T1 and the ultra thin film of the second target T2 formed on the substrate S are simultaneously formed. React with reactive gas. Then, this cycle is repeated until the target film thickness is obtained. In this case, the power supplied to the first sputter electrode 18 and the power supplied to the second sputter electrode 19 may be set to the same value, or the power supplied to the first sputter electrode 18 and the second sputter electrode 19 may be set to the same value. It may be set to a different value.

FIG. 6 is a graph showing an example of the material flying amount of the first target T1 when processed by the film forming method shown in FIG. 4A. Time t1 to time t3 in FIG. 6 corresponds to the application time of the predetermined time width Pt1 in FIG. 4A, and time t3 to time t5 in FIG. 6 corresponds to the application time of the predetermined time width Pt2 in FIG. 4A. As shown in FIG. 6, during the initial time t1 to t2 when the voltage is applied to the first target T1, the mode transits to the metal mode and the flying amount of the material of the first target T1 increases, and at the time t2 to t3. The flying amount of the material of the first target T1 is maximized. When the application of the reaction gas is stopped while the application of the voltage to the first target T1 is stopped at the time t3, the reaction with the reaction gas occurs on the surface of the first target T1 during the time t3 to t4, and the reaction mode is transited. As a result, the flying amount of the material of the first target T1 sharply decreases. Since the voltage is applied to the second target T2 during this time t4 to t5, the introduced reaction gas is radicalized, and the reaction between the incomplete metal ultra-thin film deposited on the substrate S and the reaction gas radical occurs.

As a result, when forming a film of the content ratio (yttria-stabilized zirconia YSZ (ZrO ₂ · Y ₂ O ₃ ), the first target T1 having a high zirconia Zr: yttrium Y = 9: 1 has a high film formation rate by the metal mode. While maintaining the above, the incomplete metal ultra-thin film of the first target T1 can be reacted with the reactive gas radical having high reactivity at the same time as the film formation of the second target T2. Thereby, reactive sputtering can be performed at a high film formation rate. In addition, since the radical electrode for the reaction gas is also used as the second sputtering electrode 19, the time required for the reaction can be reduced, and it is not necessary to provide a separate radical electrode, which suppresses an increase in the device cost and an increase in the size of the device. can do.

The application time of the predetermined time width Pt2 to the second sputtering electrode 19 in FIG. 4A and the application time to the reactive gas introduction controller 17 are preferably the same time, but at least the overlapping time is sufficient. ..

<< Second example >>
In the film forming method shown in FIG. 4B, in a state where a discharge gas such as an inert gas is introduced into the film forming chamber 11, a sputtering mask pulse having a predetermined time width Pt2 is applied to the second sputtering electrode 19 to generate a second target. At the same time as forming an ultrathin film of T2 (eg, yttrium Y), a reaction gas (eg, oxygen O ₂ ) is introduced into the film forming chamber 11. Then, a sputter mask pulse having a predetermined time width Pt1 is applied to the first sputter electrode 18 on which the first target T1 (for example, zirconia Zr) is mounted to form an ultrathin film by the first target T1. That is, also in this film forming method, the reaction gas is not introduced into the film forming chamber 11 at the timing of sputtering the first target T1 in which the degree of influence of the film forming rate on the reaction gas flow rate is relatively sensitive. The reaction gas is introduced into the film forming chamber 11 at the timing of performing the sputtering process on the second target T2 in which the influence of the film forming rate on the gas flow rate is relatively insensitive.

As a result, the reaction gas introduced into the film forming chamber 11 is radicalized by the electric field of the second sputtering electrode 19, and the ultrathin films of the first target T1 and the second target T2 formed on the substrate S are reacted with the reaction gas. .. Then, this cycle is repeated until the target film thickness is obtained. In this case, the power supplied to the first sputter electrode 18 and the power supplied to the second sputter electrode 19 may be set to the same value, or the power supplied to the first sputter electrode 18 and the second sputter electrode 19 may be set to the same value. It may be set to a different value. Further, the application time of the predetermined time width Pt2 to the second sputtering electrode 19 of FIG. 4B and the application time to the reactive gas introduction controller 17 are preferably the same time, but at least the overlapping time is sufficient. ..

<< Third example >>
In the film forming method shown in FIG. 4C, in a state where a discharge gas such as an inert gas is introduced into the film forming chamber 11, the first target T1 (for example, zirconia Zr) is attached to the first sputtering electrode 18 for a predetermined time. A sputtering mask pulse having a width Pt1 is applied to form an ultrathin film by the first target T1. Next, a sputter mask pulse having a predetermined time width Pt2 is applied to the second sputter electrode 19 to form an ultrathin film of the second target T2 (eg, yttrium Y). While the pulse having the predetermined time widths Pt1 and Pt2 is applied, the reactive gas is not introduced into the film forming chamber 11, and the sputtering process is performed in the metal mode. Next, a pulse having a predetermined time width Pt3 is applied to the first sputter electrode 18 on which the first target T1 is mounted to form an ultrathin film by the first target T1. Next, a pulse having a predetermined time width Pt4 is applied to the second sputtering electrode 19 to form an ultrathin film by the second target T2, and at the same time, a reaction gas (eg oxygen O ₂ ) is introduced into the film forming chamber 11. That is, also in this film forming method, the reactive gas is not introduced into the film forming chamber 11 at least at the timing of performing the sputtering process on the first target T1 in which the influence of the film forming rate on the reaction gas flow rate is relatively sensitive.

As a result, the reaction gas introduced into the film forming chamber 11 at the same time when a pulse having a predetermined time width Pt4 is applied to the second sputtering electrode 19 is radicalized by the electric field of the second sputtering electrode 19 and is formed on the substrate S. The ultrathin films of the first target T1 and the second target T2 are reacted with the reaction gas. Then, this cycle is repeated until the target film thickness is obtained. In this case, the power supplied to the first sputter electrode 18 and the power supplied to the second sputter electrode 19 may be set to the same value, or the power supplied to the first sputter electrode 18 and the second sputter electrode 19 may be set to the same value. It may be set to a different value. Further, the application time of the predetermined time width Pt4 to the second sputtering electrode 19 of FIG. 4C and the application time to the reactive gas introduction controller 17 are preferably the same time, but at least the overlapping time is sufficient. ..

As described above, according to the reactive sputtering apparatus 1 of the present embodiment, the reactive gas is formed into a film at the timing of performing the sputtering process on the first target T1 in which the degree of influence of the film forming rate on the reaction gas flow rate is relatively sensitive. The reaction gas is introduced into the film formation chamber 11 at the timing when the second target T2 is not introduced into the chamber 11 and the influence of the film formation rate on the reaction gas flow rate is relatively insensitive. This makes it possible to cause the ultra-thin film of the first target T1 to react with the reaction gas during the film formation of the second target T2 while maintaining the film formation speed of the first target T1 at a high speed in the metal mode. Further, since the radical electrode for the reaction gas is also used as the second sputtering electrode 19, it is not necessary to provide a separate radical electrode, and it is possible to suppress an increase in device cost and an increase in size of the device.

As described above, when a metal target such as zirconium Zr, titanium Ti, aluminum Al, niobium NB, or tantalum Ta, which is relatively sensitive to the reaction gas flow rate, is used as one target, Although it is desirable to form a film as in the first to third examples, metal targets such as yttrium Y, erbium Er / yttrium Y, or silicon Si in which the influence of the film formation rate on the reaction gas flow rate is relatively insensitive. When the film is formed using, the following method may be used. For example, when silicon Si is selected as the first target T1, yttrium Y is selected as the second target T2, and oxygen is selected as the reaction gas, a metal compound film of yttrium silicate (Y ₂ O ₃ .SiO ₂ ) is formed, or For example, when silicon Si is used as the target T1, erbium Er / yttrium Y is used as the second target T2, and oxygen is used as the reaction gas to form a metal compound film of erbium yttrium silicate (Er _x Y _2-x SiO ₂ ). ..

<< 4th example >>
In the film forming method shown in FIG. 4D, a discharge gas such as an inert gas is introduced into the film forming chamber 11 for a predetermined time with respect to the first sputtering electrode 18 on which the first target T1 (for example, silicon Si) is mounted. A sputtering mask pulse having a width Pt1 is applied to form an ultrathin film by the first target T1. Next, a sputtering mask pulse having a width Pt2 for a predetermined time is applied to the second sputtering electrode 19 to form an ultrathin film of the second target T2 (eg, yttrium Y or erbium Er / yttrium Y). While the pulse having the predetermined time widths Pt1 and Pt2 is applied, the reactive gas is not introduced into the film forming chamber 11, and the sputtering process is performed in the metal mode. By performing the sputtering process without introducing the reaction gas, a time period for once removing the oxide on the target surface by sputtering is provided, and a regeneration for recovering the metal surface on the target surface is performed. By repeating this cycle, it is possible to recover the high film formation rate in the metal mode. Next, a pulse having a predetermined time width Pt3 is applied to the first sputter electrode 18 on which the first target T1 is mounted to form an ultrathin film by the first target T1. Next, similarly, in the state where the reaction gas (for example, oxygen O ₂ ) is introduced into the film forming chamber 11, a pulse having a predetermined time width Pt4 is applied to the second sputtering electrode 19 to form an ultrathin film by the second target T2. ..

That is, in this film forming method, although the degree of influence of the film forming rate on the reaction gas flow rate is relatively insensitive to both the first target T1 and the second target T2, as shown by the dotted line in FIG. Comparing the metal mode and the oxidation mode, the film formation rate in the oxidation mode becomes relatively slow. Therefore, at the timing of the sputtering process of the first target T1 and the second target T2 in the first half of one cycle of film formation, the reaction gas is not introduced into the film formation chamber 11 and the sputtering process is performed in the metal mode. To secure the film formation rate. On the other hand, at the timing of the sputtering process of the first target T1 and the second target T2 in the latter half of one cycle of film formation, the reaction gas is introduced into the film formation chamber 11 and the sputtering process is performed in the oxidation mode. The reaction gas introduced into the film forming chamber 11 is radicalized by the electric fields of the first sputtering electrode 18 and the second sputtering electrode 19, and the ultrathin film of the first target T1 and the second target T2 formed on the substrate S The thin film and the reaction gas are simultaneously reacted. Then, this cycle is repeated until the target film thickness is obtained. In this case, the power supplied to the first sputter electrode 18 and the power supplied to the second sputter electrode 19 may be set to the same value, or the power supplied to the first sputter electrode 18 and the second sputter electrode 19 may be set to the same value. It may be set to a different value.

<< 5th example >>
The film forming method shown in FIG. 4E is a modification of the film forming method shown in FIG. 4D. That is, in the film forming method shown in FIG. 4E, with the discharge gas such as an inert gas being introduced into the film forming chamber 11, the first target T1 (for example, silicon Si) is attached to the first sputter electrode 18. A sputter mask pulse having a predetermined time width Pt1 is applied to form an ultrathin film by the first target T1. Next, a sputtering mask pulse having a width Pt2 for a predetermined time is applied to the second sputtering electrode 19 to form an ultrathin film of the second target T2 (eg, yttrium Y or erbium Er / yttrium Y). While applying the pulses having the predetermined time widths Pt1 and Pt2, the reaction gas is introduced into the film forming chamber 11 to perform the sputtering process in the oxidation mode. Then, the introduction of the reaction gas into the film forming chamber 11 is stopped, and a pulse having a predetermined time width Pt3 is applied to the first sputtering electrode 18 on which the first target T1 is mounted to form an ultrathin film by the first target T1. Form. Next, similarly, in a state in which the reaction gas (eg, oxygen O ₂ ) is not introduced into the film forming chamber 11, a pulse having a predetermined time width Pt4 is applied to the second sputtering electrode 19 to form an ultrathin film by the second target T2. .. This film forming method also has the same effects as the film forming method shown in FIG. 4D.

<< 6th example >>
The film forming method shown in FIG. 4F is a modification of the film forming method shown in FIG. 4D. That is, in the film forming method shown in FIG. 4F, with the discharge gas such as an inert gas introduced into the film forming chamber 11, the first target T1 (for example, silicon Si) is attached to the first sputter electrode 18. A sputter mask pulse having a predetermined time width Pt1 is applied to form an ultrathin film by the first target T1. While the pulse having the predetermined time width Pt1 is applied, the reactive gas is not introduced into the film forming chamber 11, and the sputtering process is performed in the metal mode. Next, a sputtering mask pulse having a width Pt2 for a predetermined time is applied to the second sputtering electrode 19 to form an ultrathin film of the second target T2 (eg, yttrium Y or erbium Er / yttrium Y). While the pulse having the predetermined time width Pt2 is applied, the reactive gas is introduced into the film forming chamber 11 to perform the sputtering process in the oxidation mode. Then, the introduction of the reaction gas into the film forming chamber 11 is continued, a pulse of a predetermined time width Pt3 is applied to the first sputtering electrode 18 on which the first target T1 is mounted, and the first target T1 is placed in the oxidation mode. To form an ultra thin film. Then, a pulse having a predetermined time width Pt4 is applied to the second sputtering electrode 19 without introducing a reaction gas (for example, oxygen O ₂ ) into the film forming chamber 11, and the ultrathin film by the second target T2 in the metal mode is applied. To form. This film forming method also has the same effects as the film forming method shown in FIG. 4D.

<< 7th example >>
The film forming method shown in FIG. 4G is a modification of the film forming method shown in FIG. 4D. That is, in the film forming method shown in FIG. 4G, with the discharge gas such as an inert gas introduced into the film forming chamber 11, the first target T1 (for example, silicon Si) is attached to the first sputter electrode 18. A sputter mask pulse having a predetermined time width Pt1 is applied to form an ultrathin film by the first target T1. While the pulse having the predetermined time width Pt1 is applied, the reaction gas is introduced into the film forming chamber 11 to perform the sputtering process in the oxidation mode. Next, a sputtering mask pulse having a width Pt2 for a predetermined time is applied to the second sputtering electrode 19 to form an ultrathin film of the second target T2 (eg, yttrium Y or erbium Er / yttrium Y). While the pulse having the predetermined time width Pt2 is applied, the reactive gas is not introduced into the film forming chamber 11, and the sputtering process in the metal mode is performed. Next, without introducing the reaction gas into the film forming chamber 11, a pulse having a predetermined time width Pt3 is applied to the first sputtering electrode 18 on which the first target T1 is mounted, and the pulse is generated by the first target T1 in the metal mode. Form a thin film. Then, a reaction gas (eg, oxygen O ₂ ) is introduced into the film forming chamber 11, a pulse having a predetermined time width Pt4 is applied to the second sputtering electrode 19, and an ultrathin film is formed by the second target T2 in the oxidation mode. To do. This film forming method also has the same effects as the film forming method shown in FIG. 4D.

DESCRIPTION OF SYMBOLS 1 ... Reactive sputtering apparatus 11 ... Film-forming chamber 12 ... Substrate holder 13 ... Decompressor 14 ... Conductance valve 15 ... Discharge gas introduction machine 16 ... Reaction gas introduction machine 161 ... Reaction gas cylinder 162 ... Flow controller 163 ... First opening / closing valve 164 ... 2nd on-off valve 165 ... Gas channel 166 ... 1st gas channel 167 ... 2nd gas channel 17 ... Reactive gas introduction controller 18 ... 1st sputter electrode 19 ... 2nd sputter electrode 20 ... DC power supply 201 ... 1st DC power supply 202 ... 2nd DC power supply 21 ... Bias DC power supply 211 ... 1st bias DC power supply 212 ... 2nd bias DC power supply 22 ... 1st pulse wave conversion switch 23 ... 2nd pulse wave conversion switch 24 ... Programmable oscillator 25 ... Device controller 26 ... Film formation controller 27 ... Third sputter electrode 28 ... Fourth sputter electrode T1 ... First target T2 ... Second target T3 ... Third target T4 ... Fourth target S ... Substrate

Claims

A deposition chamber into which a substrate to be deposited is loaded,
A decompressor for decompressing the film forming chamber to a predetermined pressure,
A discharge gas introducing machine for introducing a discharge gas into the film forming chamber,
At least two sputter electrodes, each of which is provided with a target serving as a film forming material and faces one of the substrates;
A reaction gas introducing device for introducing a reaction gas into the film forming chamber,
A DC power supply for supplying power to each of the at least two sputter electrodes,
A pulse wave conversion switch, which is connected between the DC power supply and the at least two sputter electrodes and converts a DC voltage applied to each sputter electrode into a pulse wave voltage;
A reaction gas introduction controller for controlling the introduction of the reaction gas from the reaction gas introduction machine to the film forming chamber,
A pulse control signal pattern according to each target sputtering power supplied to the at least two sputtering electrodes and a target introduction timing of the reaction gas is programmable, and the at least two pulse control signal patterns are programmed according to the programmed pulse control signal pattern. A method for depositing a metal compound film, wherein a reactive sputtering apparatus comprising a pulse wave conversion switch and a programmable oscillator that controls the reactive gas introduction controller is used to perform a deposition process on the substrate. hand,
Under a predetermined reactive sputtering condition, a first target having a relatively large maximum absolute value of a change rate of a film forming rate with respect to a flow rate of the reaction gas and a second target having a relatively small absolute value are used as the at least two targets. After attaching to each of the sputter electrodes,
While the discharge gas is being introduced into the film forming chamber, the first sputtering target electric power set by the pulse control signal pattern is supplied to the sputtering electrode on which the first target is attached, and the sputtering control electrode pattern is used by the pulse control signal pattern. A first step of forming a metal ultrathin film of the first target on the substrate without introducing a reaction gas from the reaction gas introduction machine to the film formation chamber only at a set target introduction timing;
While the discharge gas is introduced into the film forming chamber, the second sputtering target power set by the pulse control signal pattern is supplied to the sputtering electrode on which the second target is mounted, and the second target is supplied by the pulse control signal pattern. A second step of introducing a reaction gas from the reaction gas introduction device to the film forming chamber at a set target introduction timing to form an ultrathin metal film of the second target on the substrate. Film forming method.
In one cycle of the film forming process after mounting the first target and the second target on each of the at least two sputtering electrodes,
Performing the second step after performing the first step, or
The method for forming a metal compound film according to claim 1, wherein the first step is performed after performing the second step.
In one cycle of the film forming process,
When carrying out the second step after carrying out the first step, before carrying out the first step or after carrying out the second step,
When carrying out the first step after carrying out the second step, before carrying out the second step or after carrying out the first step,
While the discharge gas is being introduced into the film forming chamber, the first sputtering target electric power set by the pulse control signal pattern is supplied to the sputtering electrode on which the first target is attached, and the sputtering control electrode pattern is used by the pulse control signal pattern. A third step of forming an ultrathin metal film of the first target on the substrate without introducing a reaction gas from the reaction gas introduction machine to the film forming chamber at a set target introduction timing;
While the discharge gas is introduced into the film forming chamber, the second sputtering target power set by the pulse control signal pattern is supplied to the sputtering electrode on which the second target is mounted, and the second target is supplied by the pulse control signal pattern. The fourth step of forming the ultra-thin metal film of the second target on the substrate without introducing the reaction gas from the reaction gas introduction device to the film forming chamber at the set target introduction timing. A method for forming a metal compound film according to item 1.
The method for forming a metal compound film according to any one of claims 1 to 3, wherein the first target is Zr, Ti, Al and the second target is Y, Er / Y or Si.
A deposition chamber into which a substrate to be deposited is loaded,
A decompressor for decompressing the film forming chamber to a predetermined pressure,
A discharge gas introducing machine for introducing a discharge gas into the film forming chamber,
At least two sputter electrodes, each of which is provided with a target serving as a film forming material and faces one of the substrates;
A reaction gas introducing device for introducing a reaction gas into the film forming chamber,
A DC power supply for supplying power to each of the at least two sputter electrodes,
A pulse wave conversion switch, which is connected between the DC power supply and the at least two sputter electrodes and converts a DC voltage applied to each sputter electrode into a pulse wave voltage;
A reaction gas introduction controller for controlling the introduction of the reaction gas from the reaction gas introduction machine to the film forming chamber,
A pulse control signal pattern according to each target sputtering power supplied to the at least two sputtering electrodes and a target introduction timing of the reaction gas is programmable, and the at least two pulse control signal patterns are programmed according to the programmed pulse control signal pattern. A method for depositing a metal compound film, wherein a reactive sputtering apparatus comprising a pulse wave conversion switch and a programmable oscillator that controls the reactive gas introduction controller is used to perform a deposition process on the substrate. hand,
After mounting a first target and a second target on each of the at least two sputter electrodes,
While the discharge gas is being introduced into the film forming chamber, the first sputtering target electric power set by the pulse control signal pattern is supplied to the sputtering electrode on which the first target is attached, and the sputtering control electrode pattern is used by the pulse control signal pattern. A first step of forming a metal ultrathin film of the first target on the substrate without introducing a reaction gas from the reaction gas introduction machine to the film formation chamber only at a set target introduction timing;
While the discharge gas is introduced into the film forming chamber, the second sputtering target power set by the pulse control signal pattern is supplied to the sputtering electrode on which the second target is mounted, and the second target is supplied by the pulse control signal pattern. A second step of forming an ultrathin metal film of the second target on the substrate without introducing a reaction gas from the reaction gas introduction machine to the film forming chamber at a set target introduction timing;
While the discharge gas is being introduced into the film forming chamber, the first sputtering target electric power set by the pulse control signal pattern is supplied to the sputtering electrode on which the first target is attached, and the sputtering control electrode pattern is used by the pulse control signal pattern. A third step of introducing a reaction gas from the reaction gas introduction machine to the film forming chamber only at a set target introduction timing to form an ultrathin metal film of the first target on the substrate;
While the discharge gas is introduced into the film forming chamber, the second sputtering target power set by the pulse control signal pattern is supplied to the sputtering electrode on which the second target is mounted, and the second target is supplied by the pulse control signal pattern. A fourth step of introducing a reaction gas from the reaction gas introduction device into the film forming chamber at a set target introduction timing to form an ultrathin metal film of the second target on the substrate. Film forming method.
The method for forming a metal compound film according to claim 5, wherein the first step, the second step, the third step, and the fourth step are performed in this order.
The method for forming a metal compound film according to claim 5, wherein the third step, the fourth step, the first step and the second step are performed in this order.
The method for forming a metal compound film according to claim 5, wherein the first step, the fourth step, the third step, and the second step are performed in this order.
The method for forming a metal compound film according to claim 5, wherein the third step, the second step, the first step and the fourth step are performed in this order.
The method for forming a metal compound film according to any one of claims 5 to 9, wherein the first target and the second target are any of Y, Er / Y, and Si.
A deposition chamber into which a substrate to be deposited is loaded,
A decompressor for decompressing the film forming chamber to a predetermined pressure,
A discharge gas introducing machine for introducing a discharge gas into the film forming chamber,
A plurality of sputtering electrodes, each of which includes a target serving as a film-forming material, and which faces one of the substrates,
A reaction gas introducing device for introducing a reaction gas into the film forming chamber,
A direct current power supply for supplying power to the plurality of sputter electrodes,
A plurality of pulse wave conversion switches connected between the DC power supply and the plurality of sputtering electrodes, for converting a DC voltage applied to each sputtering electrode into a pulse wave voltage,
A reaction gas introduction controller for controlling the introduction of the reaction gas from the reaction gas introduction machine to the film forming chamber,
A pulse control signal pattern according to each sputter target power supplied to the plurality of sputter electrodes and a target introduction timing of the reaction gas is programmable, and the plurality of pulses are controlled according to the programmed pulse control signal pattern. A programmable oscillator that controls each of the wave conversion switches and the reaction gas introduction controller,
The reaction gas introduction machine,
A reaction gas supply source,
A flow rate controller for adjusting the flow rate of the reaction gas supplied from the reaction gas supply source,
A first gas flow path branched from the flow rate controller to guide a reaction gas to the film forming chamber;
A second gas flow path branched from the flow rate controller to guide the reaction gas to the exhaust system of the pressure reducer;
A first on-off valve for opening and closing the first gas flow path;
A second on-off valve for opening and closing the second gas flow path,
The reactive sputtering apparatus, wherein the reaction gas introduction controller exclusively controls opening / closing of the first opening / closing valve and the second opening / closing valve based on a pulse control signal pattern from the programmable transmitter.