Sputtering film formation apparatus and sputtering film formation method

Abstract

To efficiently sputter a target.SOLUTION: A sputtering film deposition apparatus includes: a treatment vessel including a mounting table for mounting a substrate; a metal window facing the mounting table, having a first surface constituting the ceiling surface of the treatment vessel and consisting of non-magnetic metal; an inductive coupling antenna arranged to be separated from a second surface of the metal window on the side opposite to the first surface of the metal window and for forming plasma in the treatment vessel; a RF power supply connected to the inductive coupling antenna; one of a DC power supply, DC pulse power supply or AC power supply connected to the metal window; and a gas supply part for supplying raw gas for forming the plasma in the treatment vessel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a sputtering film formation apparatus and a sputtering film formation method. [Background technology]

[0002] For example, the magnetron sputtering film formation apparatus of Patent Document 1 forms high-density plasma by using a DC electric field generated by a DC voltage applied to a target material and a magnetic field from a magnet behind the target material, thereby sputtering the target material and forming a film.

[0003] For example, the sputtering deposition apparatus in Patent Document 2 uses inductively coupled plasma to sputter a target material and deposit a film. This sputtering deposition apparatus has an induction coil provided in correspondence with a dielectric plate, and also has a magnet on the backside of the target material, and when high frequency power is introduced into the induction coil, an induction electric field is formed in the processing space via the dielectric plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2009 / 116430 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-209483 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a technique that allows for efficient sputtering of target material. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a processing vessel having a mounting table for mounting a substrate thereon; a metal window made of a non-magnetic metal facing the mounting table and having a first surface constituting a ceiling surface of the processing vessel; an inductively coupled antenna disposed apart from a second surface of the metal window opposite the first surface of the metal window and configured to generate plasma in the processing vessel; a high-frequency power supply connected to the inductively coupled antenna; a DC power supply, a DC pulse power supply, or an AC power supply connected to the metal window; and a gas supply unit configured to supply a processing gas for generating the plasma into the processing vessel. The metal window functions as a target material for sputtering the substrate. A sputtering deposition apparatus is provided. [Effects of the Invention]

[0007] According to one aspect, the target material can be efficiently sputtered. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a sputtering film formation apparatus according to an embodiment. [Figure 2] FIG. 1 is a diagram for explaining generation of inductively coupled plasma using a metal window. [Figure 3] FIG. 2 is a plan view of a metal window and an inductively coupled antenna according to the embodiment. [Figure 4] FIG. 2 is a plan view of a metal window and an inductively coupled antenna according to the embodiment. [Figure 5] 1A and 1B are diagrams showing an example of a vertically wound rectangular coil antenna according to an embodiment. [Figure 6] FIG. 10 is a diagram showing experimental results of source power dependency in sputtering film formation according to the embodiment. [Figure 7] 3A and 3B are diagrams for explaining sputtering of a target material according to an embodiment. [Figure 8] 10A and 10B are diagrams showing experimental results of DC voltage dependency and plasma electron density in sputtering film formation according to an embodiment. [Figure 9] 3A and 3B are diagrams for explaining a parallel magnetic field and sputtering by the sputtering film formation apparatus according to the embodiment. [Figure 10]1 is a flowchart showing a sputtering film formation process according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0010] [Sputtering deposition equipment] First, a sputtering film formation apparatus 10 according to one embodiment will be described. FIG. 1 is a cross-sectional view showing the sputtering film formation apparatus 10 according to the embodiment. The sputtering film formation apparatus 10 shown in FIG. 1 can be used to form an aluminum oxide (AlO) film, an oxide semiconductor (IGZO), or the like on a rectangular substrate, for example, a glass substrate for an FPD (hereinafter referred to as substrate G), using plasma. Examples of FPDs include liquid crystal displays (LCDs), electroluminescence (EL) displays, and plasma display panels (PDPs). However, the substrate is not limited to a glass substrate for an FPD.

[0011] The sputtering deposition apparatus 10 has a rectangular, airtight main body container 1 made of a conductive material, for example, aluminum whose inner wall surface has been anodized. The main body container 1 is assembled so that it can be disassembled, and is electrically grounded by a grounding wire 1a.

[0012] Main vessel 1 is vertically divided into antenna chamber 3 and processing vessel 4 by rectangular metal window 2 formed and insulated from main vessel 1. Metal window 2 forms the ceiling wall of processing vessel 4. Metal window 2 is made of, for example, a non-magnetic, conductive metal, such as aluminum or an alloy containing aluminum.

[0013] A support shelf 5 protruding into the inside of main vessel 1 is provided between side wall 3a of antenna chamber 3 and side wall 4a of processing vessel 4. Support shelf 5 is made of a conductive material, preferably a metal such as aluminum.

[0014] The metal window 2 is composed of a plurality of divided windows 2a to 2d that are electrically insulated from one another via insulating members 7. The divided windows 2a to 2d are supported on a support shelf 5 via the insulating members 7. The metal window 2 is suspended from the ceiling of the main container 1 by a plurality of suspenders (not shown). Note that FIG. 1 shows a schematic representation of the divided form of the metal window 2, and does not show the actual divided form. Various divided forms of the metal window 2 will be described later.

[0015] A plurality of gas supply holes 21a are formed in the support shelf 5. The gas supply unit 20 is connected to the plurality of gas supply holes 21a via a gas supply pipe 21. The gas supply unit 20 supplies a processing gas including a raw material gas for plasma generation. The processing gas is introduced into the processing chamber 4 from the plurality of gas supply holes 21a via the gas supply pipe 21. Note that a gas space (not shown) may be provided inside the metal window 2 and connected to the gas supply pipe 21 to supply gas.

[0016] An antenna unit 40 having an inductively coupled antenna 13 arranged in a ring shape around the metal window 2 is provided in the antenna chamber 3 above the metal window 2. As will be described later, the inductively coupled antenna 13 is made of a conductive material such as copper, and is arranged at a distance from the metal window 2 by a spacer (not shown) made of an insulating material.

[0017] A first high-frequency power supply 18 is connected to the inductively coupled antenna 13 of the antenna unit 40 via a power supply line 16 and a matching box 17. During plasma processing (sputtering film formation processing), high-frequency power (hereinafter also referred to as source power) of, for example, 13.56 MHz is supplied to the inductively coupled antenna 13 via the power supply line 16 extending from the first high-frequency power supply 18. The inductive electric field formed by the inductively coupled antenna 13 induces a loop current in the partitioned windows 2a to 2d of the metal window 2. As a result, an inductive electric field is formed in the processing chamber 4 via the loop current induced in the partitioned windows 2a to 2d of the metal window 2. This inductive electric field converts the processing gas supplied from the gas supply hole 21a into plasma in the plasma generation space S directly below the metal window 2 in the processing chamber 4, thereby generating inductively coupled plasma.

[0018] The metal window 2 has a first surface and a second surface. The lower surface 22a of the metal window 2 is the first surface, and the upper surface 22b of the metal window 2, which is the opposite surface to the first surface, is the second surface. The first surface constitutes the ceiling surface of the processing chamber 4. An inductively coupled antenna 13 is disposed on the second surface side, spaced apart from the metal window 2, and generates plasma within the processing chamber 4. A target material T is fixed to the lower surface 22a of the metal window 2 by indium brazing or by screwing, while maintaining electrical continuity with the metal window 2. The target material T is a consumable item and is replaced when it is worn down to a thickness below a certain threshold, and a new target material T is fixed to the lower surface 22a of the metal window 2 by brazing or by screwing. The target material T is made of a material appropriate for the film to be formed. When forming an AlO film or an AlN film, the target material T may be made of aluminum. When forming an SiO2 film or a SiN film, the target material T may be made of silicon. When forming an IGZO film, the target material T may be composed of indium (In), gallium (Ga), zinc (Zn), and oxygen (O).

[0019] A mounting table 23 facing the first surface is fixed to the bottom of the processing vessel 4 via an insulating member 24. The mounting table 23 is made of a conductive material, for example, aluminum whose surface is anodized, and the substrate G is placed on the mounting surface of the mounting table 23. The placed substrate G is attracted and held by an electrostatic chuck (not shown) provided on the mounting surface.

[0020] An insulating shield ring 25a is provided on the upper periphery of the mounting table 23, and an insulating ring 25b is provided on the circumferential surface of the mounting table 23. Lifter pins 26 used when loading and unloading the substrate G are inserted into the mounting table 23 via the bottom wall of the main container 1 and insulating member 24. The lifter pins 26 are driven to move up and down by a lifting mechanism (not shown) provided outside the main container 1, so as to transfer the substrate G when loading and unloading the substrate G.

[0021] Furthermore, a temperature control mechanism including a heating means such as a heater and a coolant flow path, and a temperature sensor (none of which are shown) are provided within mounting table 23 to control the temperature of substrate G. Piping and wiring for these mechanisms and members are all led out to the outside of main container 1 through opening 1b provided in the bottom surface of main container 1 and insulating member 24.

[0022] A sidewall 4a of the processing vessel 4 is provided with a loading / unloading port 27a for loading / unloading the substrate G and a gate valve 27 for opening / closing the loading / unloading port 27a. An exhaust device 30 including a vacuum pump and the like is connected to the bottom of the processing vessel 4 via an exhaust pipe 31. The exhaust device 30 exhausts the inside of the processing vessel 4, and a predetermined vacuum atmosphere (e.g., 10 mTorr (1.33 Pa)) is set and maintained inside the processing vessel 4 during plasma processing.

[0023] A fine gap (not shown) that functions as a cooling space is formed on the backside of the substrate G placed on the mounting table 23, and a He gas flow path 32 is provided for supplying He gas as a heat transfer gas at a constant pressure. By supplying the heat transfer gas to the backside of the substrate G in this manner, it is possible to suppress temperature increases and temperature changes caused by the sputtering film formation process of the substrate G under vacuum.

[0024] The sputtering deposition apparatus 10 further includes a control unit 100. The control unit 100 is made up of a computer and includes a CPU that controls each component of the plasma processing apparatus, an input device, an output device, a display device, and a storage device. The storage device includes a storage medium that stores parameters for various processes performed in the plasma processing apparatus and programs for controlling the processes performed in the sputtering deposition apparatus 10, i.e., process recipes. The CPU retrieves a predetermined process recipe stored in the storage medium and causes the plasma processing apparatus to perform a predetermined process operation based on the process recipe.

[0025] [Metal window] Next, the metallic window 2 will be described in detail. DC pulse power supplies 62a and 62b are connected to the metallic window 2, and the DC pulse power supplies 62a and 62b (collectively referred to as DC pulse power supplies 62) apply a square-wave (pulse wave) DC voltage (hereinafter also referred to as DC pulse voltage) with a predetermined duty ratio to the metallic window 2. The frequency of the DC pulse voltage may be 5 kHz to 150 kHz. The DC pulse voltage has two values ​​that form a square wave, and the two values ​​are controlled to be 0 or a negative DC voltage. Instead of the DC pulse power supply 62, a DC power supply or an AC power supply may be connected to the metallic window 2. When a DC power supply is connected to the metallic window 2, a negative DC voltage is applied to the metallic window 2. When an AC power supply is connected to the metallic window 2, the AC power supply applies an AC voltage of a predetermined frequency (for example, 50 kHz) to the metallic window 2. As described above, the metal window 2 is electrically connected to either a DC power supply, a DC pulse power supply, or an AC power supply, and therefore is made of a conductive material. The metal window 2 is also made of a non-magnetic metal. An example of the non-magnetic metal is aluminum. In the following explanation, increasing (increasing) the DC voltage (DC pulse voltage) applied to the metal window 2 means increasing (increasing) the absolute value of the DC voltage (DC pulse voltage).

[0026] Low-pass filters (LPFs) 61 are provided between the metal window 2 and each of the DC pulse power supplies 62a and 62b to prevent the radio frequency power from the first radio frequency power supply 18 from propagating to the DC pulse power supplies 62a and 62b. With this structure, high-density plasma is generated in the processing vessel 4 using the inductively coupled antenna 13 and the metal window 2, and by applying a DC pulse voltage to the metal window 2, ions in the high-density plasma are attracted to the metal window 2, enabling reactive sputtering.

[0027] 2 is a diagram for explaining generation of inductively coupled plasma using a metal window 2. As shown in FIG. 2, a high-frequency current I RF As a result, an induced current is generated on the upper surface of the metal window 2. The induced current flows only on the surface of the metal window 2 due to the skin effect, but the metal window 2 is insulated from the support shelf 5 and the main container 1. For this reason, if the planar shape of the inductively coupled antenna 13 is linear, the induced current that flows on the upper surface of the metal window 2 flows to the side of the metal window 2, then the induced current that flows on the side flows to the lower surface of the metal window 2, and further returns to the upper surface of the metal window 2 via the side of the metal window 2, generating an eddy current I ED In this way, an eddy current I that loops from the upper surface to the lower surface flows through the metal window 2. ED is generated. This looping eddy current I ED The current flowing through the lower surface of the metal window 2 generates an induced electric field I P This induces an electric field I P A plasma of the process gas is generated by this.

[0028] On the other hand, when the inductive coupling antenna 13 is provided so as to go around in the circumferential direction within the plane corresponding to the metal window 2, if a solid single plate is used as the metal window 2, no eddy current flows on the lower surface of the metal window 2 and no plasma is generated. In other words, the eddy current I generated on the upper surface of the metal window 2 by the inductive coupling antenna 13 ED The eddy current I ED does not flow on the lower surface of the metal window 2. Therefore, the metal window 2 can be configured in various ways as described below so that eddy currents flow on the lower surface of the metal window 2 and a desired induced electric field is generated.

[0029] [Metal window configuration] In the first embodiment, the metal window 2 is divided into a plurality of divided regions which are insulated from each other. ED flows on the underside of the metal window 2. In other words, by dividing the metal window 2 into multiple parts while insulating them from each other, an induced current flows on the top surface of the divided metal window 2 (divided window) that reaches the side, flows from the side to the bottom, and then flows again on the side and returns to the top, forming a loop eddy current I ED For this purpose, the metal window 2 is divided into a plurality of divided windows. Below, several examples of dividing the metal window 2 and examples of arranging the inductive coupling antenna 13 will be described.

[0030] FIG. 3 is a plan view of the metal window 2 and the inductive coupling antenna 13 according to the embodiment. The metal window 2 has a rectangular shape with long and short sides corresponding to the substrate G. In FIG. 3(a), the inductive coupling antenna 13 includes multiple antenna segments 131, 132, and 133, each of which is an annular rectangular coil antenna, and which are arranged around the metal window 2. The annular rectangular coil antennas constituting each of the multiple antenna segments 131, 132, and 133 may be formed into a frame shape by spirally winding a single antenna wire (not shown), or may be formed into a frame shape by spirally winding two or four antenna wires symmetrically. In this example, in order to generate a uniform induction electric field along the lower surface 22a of the metal window 2, the rectangular metal window 2 is divided approximately radially toward each corner of the metal window 2. This divides the metal window 2 into four divided windows 2a to 2d. The four divided windows 2a to 2d are trapezoidal on the long sides and triangular on the short sides. These trapezoids and triangles are configured so that the height of the trapezoids with their long sides as their bases is the same as the height of the triangles with their short sides as their bases. The divided windows 2a to 2d are insulated from one another via insulating members 7.

[0031] As such, one example of the inductively coupled antenna 13 is an arrangement of a plurality of antenna segments each made of a circular rectangular coil antenna.

[0032] In Figure 3(b), as shown in Figure 1, two DC pulse power supplies 62a and 62b are provided. The DC pulse power supply 62a is connected to the partition windows 2a and 2b and supplies a DC pulse voltage to the partition windows 2a and 2b. The DC pulse power supply 62b is connected to the partition windows 2c and 2d and supplies a DC pulse voltage to the partition windows 2c and 2d. Note that the low-pass filter 61 is not shown in Figures 3(b) and 3(c).

[0033] In FIG. 3(c), a DC pulse power supply 62 is connected to the partition windows 2a to 2d and supplies a DC pulse voltage to the partition windows 2a to 2d. For example, when the plasma outside is weak, the duty cycle of the DC voltage applied to the partition windows 2c and 2d can be made greater than the duty cycle of the DC voltage applied to the partition windows 2a and 2b (i.e., the time during which the negative DC voltage is applied is lengthened). This allows the in-plane distribution of ion attraction in the plasma to be changed depending on the area of ​​the partition windows. In this case, only one DC pulse power supply 62 is required, reducing the number of DC pulse power supplies.

[0034] FIG. 4 is a plan view of the metal window 2 and the inductive coupling antenna 13 according to the embodiment, which is another example of FIG. 3. In this example, the metal window 2 is divided into six rectangular partition windows 2e to 2j. The partition windows 2e to 2j are connected to one of DC pulse power supplies 62c, 62d, and 62e via a low-pass filter 61. The DC pulse power supply 62c is connected to the partition windows 2e and 2f and supplies a DC pulse voltage to the partition windows 2e and 2f. The DC pulse power supply 62d is connected to the partition windows 2g and 2h and supplies a DC pulse voltage to the partition windows 2g and 2h. The DC pulse power supply 62e is connected to the partition windows 2i and 2j and supplies a DC pulse voltage to the partition windows 2i and 2j.

[0035] The inductive coupling antenna 13 may be composed of only a parallel antenna, as shown in Fig. 4. The parallel antenna generates an inductive electric field that contributes to plasma generation and has a rectangular region formed facing the metal window 2 and facing the substrate G, and this rectangular region is divided into linear or lattice-shaped plasma control regions. Then, antenna segments 134 that form part of the rectangular region are arranged in each of the divided regions, and the antenna wires of the multiple antenna segments 134 are all parallel to each other, forming a multi-divided parallel antenna.

[0036] 5, the antenna segment 134 in Fig. 4 is composed of a vertically wound rectangular coil antenna formed by spirally winding an antenna wire 135 made of a conductive material, such as copper, in a direction intersecting, for example, a direction perpendicular to, the substrate G (metal window 2), i.e., in the vertical direction. High-frequency power is supplied to each vertically wound rectangular coil antenna from a first high-frequency power supply 18.

[0037] 4, five antenna segments 134 are arranged across the two divided windows 2e and 2f in the longitudinal direction of the divided windows 2e and 2f. Similarly, five antenna segments 134 are arranged across the two divided windows 2g and 2h, and five antenna segments 134 are arranged across the two divided windows 2i and 2j.

[0038] The vertically wound rectangular coil antenna is not limited to the antenna segments 134 arranged linearly in the longitudinal direction of each partition window as shown in Fig. 4, but may also be arranged in a lattice pattern. For example, the antenna segments 134 may be divided into four segments (two segments vertically and two segments horizontally), nine segments (three segments vertically and three segments horizontally), twenty-five segments (five segments vertically and five segments horizontally), or more, and a vertically wound rectangular coil antenna may be arranged in a lattice pattern in each partition window.

[0039] In this way, the antenna segments 134, each consisting of a vertically wound rectangular coil antenna, are arranged in a line or a grid, so that the direction of the induced electric field (high frequency current) of each antenna segment 134 is the same. This eliminates the need for areas where the induced electric fields cancel each other out, as occurs when annular rectangular coil antennas are arranged. This results in higher efficiency and improved plasma uniformity compared to when annular rectangular coil antennas are arranged.

[0040] In the region of the metal window 2 corresponding to the inductive coupling antenna 13, the relationship between the number of divisions of the metal window 2 and the number of divisions (number of antenna segments) of the inductive coupling antenna 13 is arbitrary. However, when a bipolar DC pulse power supply is used as the DC pulse power supply, the number of divisions of the metal window must be an even number.

[0041] In the sputtering deposition apparatus 10 described above, the metal window 2 functions to mediate the induced electric field generated by the inductively coupled antenna 13 and to generate plasma in the processing chamber 4. In addition, the metal window 2 functions to attract ions to the target material T for performing sputtering deposition processing on the substrate G.

[0042] With this structure, high-density plasma is generated in the processing vessel 4 using the inductively coupled antenna 13 and the metal window 2, and ions are attracted by applying a DC pulse voltage to the metal window 2, enabling reactive sputtering using the high-density plasma. By depositing sputter particles emitted from the target material T by sputtering onto the substrate G, it is possible to form films such as AlO films, AlN films, SiO films, SiN films, TiN films, and IGZO films.

[0043] The plasma is generated by an electromagnetic field generated by supplying source power to the inductively coupled antenna 13. The target is sputtered by applying a DC pulse voltage to the metal window 2 to which the target material T is attached, thereby attracting ions. Therefore, the sputtering deposition apparatus 10 of the present disclosure makes it possible to independently control the generation of plasma and the attraction of ions. Furthermore, the magnetic field and DC electric field generated by the inductively coupled antenna 13 increase the density of the plasma. However, because the magnetic field generated by the inductively coupled antenna 13 is an alternating magnetic field, there is no bias in the plasma, which would occur with a static magnetic field and a DC electric field, and this has the advantage of allowing the target material to be sputtered uniformly.

[0044] The metal window 2 itself may be used as the target material. Although the DC voltage applied to the target material is described in this disclosure as a DC pulse voltage, the present invention is not limited to this and may be a continuous DC voltage or an AC voltage. The inductively coupled antenna 13 may be configured with multiple antenna segments each consisting of a vertically wound rectangular coil antenna arranged in a linear or lattice pattern. The inductively coupled antenna 13 may be configured with multiple annular rectangular coil antennas arranged concentrically, or may be configured by combining a vertically wound rectangular coil antenna and an annular rectangular coil antenna.

[0045] Four effects of the sputtering deposition apparatus 10 of the present disclosure are described below in order. The four effects are a high deposition rate due to high-density plasma (Effect 1), independent control of source power and DC voltage (Effect 2), deposition of IGZO films and the like with few defects (Effect 3), and sputtering effect due to a parallel magnetic field (Effect 4). The metal window 2 and the inductively coupled antenna 13 were evaluated using the configuration shown in FIG. 3.

[0046] [Effect 1: High deposition rate due to high density plasma] By applying a DC pulse voltage to the metal window 2 to generate a DC electric field, a high film formation rate can be achieved by the plasma that is densified by the AC magnetic field and DC electric field generated by the inductively coupled antenna 13. Experiments were conducted under the following process conditions using the sputtering processing apparatus 10 shown in Figure 1.

[0047] <Process conditions> Gap from metal window to mounting table: 50mm Pressure inside the processing vessel: 5mT (0.67Pa) Gas: Argon (Ar) gas, oxygen (O2) gas 50 / 50sccm Target material: Aluminum DC pulse voltage -500V 50kHz Duty=50% Variable Source Power The target material was sputtered under the above conditions with plasma from a mixed gas of argon and oxygen to form a transparent AlO film, and the results are shown in Figure 6. Figure 6 is a diagram showing the experimental results of the source power dependency in sputtering film formation according to the embodiment.

[0048] 6, the horizontal axis represents the source power from the first high-frequency power supply 18, the vertical axis (left) represents the deposition rate (DR) of the AlO film, and the vertical axis (right) represents the refractive index (RI) of the AlO film. This shows that by supplying source power to the inductively coupled antenna 13 and applying a DC pulse voltage to the metal window 2, the plasma could be made denser, thereby increasing the deposition rate.

[0049] Furthermore, increasing the source power enabled the generation of a higher density plasma, further improving the deposition rate (DR) and refractive index (RI) of the AlO film. Furthermore, the ratio of the side film thickness to the bottom film thickness of the AlO film formed on the stepped portion of the substrate G was 1.00, 1.00, and 0.95 when the source power was 1000 W, 3000 W, and 5000 W, respectively. In other words, the coverage of the AlO film was good regardless of the magnitude of the source power. From the above, it was found that the sputtering deposition apparatus 10 of the present disclosure can improve the deposition rate and refractive index, and can deposit a dense AlO film with good coverage by sputtering.

[0050] The reason why a film with good coverage can be formed by sputtering will be described with reference to FIG. 7. FIG. 7 is a diagram for explaining sputtering of a target material T in a sputtering film formation apparatus 10 according to an embodiment. When a negative DC voltage is applied to the metal window 2, ions in plasma formed from argon gas, for example, argon ions (Ar + ) are drawn into the metal window 2 and collide with the target material T, and are released as sputter particles from the target material T made of aluminum by Al ions (Al + ) is emitted.

[0051] Furthermore, the high-density plasma generated by the supply of source power promotes oxidation and nitridation of the film, allowing the deposition of a dense AlO film. In the inductively coupled antenna 13 to which source power is supplied, a parallel magnetic field B is generated due to the shapes of the antenna segments 131 to 134 shown in FIGS. 3 to 5. This generates a Lorentz force (F=qv×B) that causes Al ions (Al + ) is emitted at a high angle. This allows AlO films with good coverage to be deposited by sputtering.

[0052] [Effect 2: Independent control of source power and DC voltage] In the sputtering deposition apparatus 10, it is possible to independently control the application of a DC pulse voltage to the metal window 2 and the supply of a plasma source to the inductively coupled antenna 13. This makes it possible to deposit a film with few defects. An experiment was conducted using the sputtering processing apparatus 10 shown in Figure 1 under the following process conditions.

[0053] <Process conditions> Gap from metal window to mounting table: 50mm Pressure inside the processing vessel: 5mT (0.67Pa) Gas: Argon (Ar) gas, oxygen (O2) gas 50 / 50sccm Target material: Aluminum Source power 3kW DC pulse voltage variable 50kHz Duty=50% The target material T was sputtered under the above conditions with plasma from a mixed gas of argon and oxygen to form an AlO film, and the results are shown in Figure 8. Figure 8 is a diagram showing experimental results of the DC voltage dependency and plasma electron density in sputtering film formation according to the embodiment.

[0054] The horizontal axis of Figure 8(a) represents the direct current pulse voltage (DC), the vertical axis (left) represents the deposition rate (DR) of the AlO film, and the vertical axis (right) represents the refractive index (RI) of the AlO film. This shows that increasing the DC pulse voltage applied to the metal window 2 increases the probability that ions in the plasma, such as argon ions, collide with the target material T, thereby increasing the sputtering force and thereby increasing the deposition rate (DR). Meanwhile, the refractive index (RI) could be maintained even when the DC pulse voltage was increased.

[0055] The horizontal axis of Fig. 8(b) represents the source power, and the vertical axis represents the plasma electron density (Ne density [particles / cm 3 ]) is shown. Comparing line A when the DC pulse voltage is 0 V with line B when the DC pulse voltage is -300 V, it is found that the plasma electron density Ne is hardly affected by the value of the DC pulse voltage. In other words, it was found that the plasma electron density Ne depends on the source power, but not on the DC pulse voltage.

[0056] From the above, it has been proven that by independently controlling the application of a DC pulse voltage to the metal window 2 and the application of a plasma source to the inductively coupled antenna 13, it is possible to form insulating films and IGZO films with few defects while generating high-density plasma.

[0057] [Effect 3: Film formation with fewer defects] For example, increasing the DC voltage applied to the metal window 2 can strongly attract ions in the plasma to the target material T. This increases the amount of sputtered particles emitted from the target material T, thereby increasing the deposition rate. On the other hand, increasing the DC voltage applied to the metal window 2 also increases the energy of the emitted sputtered particles, which can impact the film more strongly, potentially causing defects in the film. The sputtering deposition apparatus 10 of the present disclosure allows for independent control of the DC voltage and source power. Therefore, for example, to deposit an IGZO film with fewer defects, the DC voltage applied to the metal window 2 can be reduced and the source power can be increased to, for example, approximately 5000 W. This allows for the deposition rate to be increased by generating high-density plasma while controlling the DC voltage to weaken the attraction of ions in the plasma, thereby depositing an IGZO film with fewer defects.

[0058] [Effect 4: Sputtering effect due to parallel magnetic field] 9A and 9B are diagrams illustrating the parallel magnetic field formed below the metal window 2 of the sputtering deposition apparatus 10 according to the embodiment and sputtering. Fig. 9A shows the parallel magnetic field B1 below the metal window 2 (target material T) during sputtering by the sputtering deposition apparatus 10 according to the embodiment, and Fig. 9B shows the magnetic field B2 below the metal window 2 (target material T) during sputtering by the magnetron sputtering apparatus according to the reference example.

[0059] In the magnetron sputtering film formation apparatus of the reference example shown in FIG. 9(b), a high-density plasma is formed by a DC electric field E due to a DC voltage applied to the target material T and a magnetic field B2 formed by a magnet 91 behind the target material T, and the target material T is sputtered to form a film. In this sputtering film formation, the magnetic field B2 surrounds electrons in the plasma, generating a high-density plasma and increasing the film formation rate (sputtering rate). However, the magnetic field B2 between the N-pole and S-pole magnets 91 biases the sputtering region of the target material T, and the target material T between the magnets 91 circularAs a result, the consumption of the target material T between the magnets 91 is higher than the consumption of the target material T below the magnets 91. Uneven use of the target material T leads to earlier replacement times, and the utilization efficiency of the target material T is poor. Furthermore, reaction by-products and other substances tend to accumulate in the portions of the target material T below the magnets 91 where it cannot be cut, and this can become a source of particle generation.

[0060] In contrast, in the sputtering deposition apparatus 10 of the present disclosure, multiple antenna segments of the inductively coupled antenna 13 are used, and the antenna wires facing the metal window 2 are arranged so as to form a ring parallel to the metal window 2, or all of the antenna wires facing the metal window 2 are arranged so as to be parallel.

[0061] Therefore, as shown in FIG. 9(a), a wide parallel magnetic field B1 is formed in the horizontal direction below the target material T. Therefore, in the sputtering deposition apparatus 10, there are no locations where the magnetic field is locally strong, as in the reference example shown in FIG. 9(b). As a result, the target material T is uniformly scraped by the DC electric field E due to the DC voltage applied to the metal window 2 and the wide parallel magnetic field B1 formed below the target material T, enabling uniform deposition and deposition of a film with good coverage. Because the target material T is uniformly scraped, the utilization efficiency of the target material T is high, and the life of the target material T can be extended.

[0062] [Sputtering deposition method] Finally, a sputtering film formation method performed in the sputtering film formation apparatus 10 of the present disclosure will be described with reference to Fig. 10. Fig. 10 is a flowchart showing a sputtering film formation process according to the embodiment. The sputtering film formation process is controlled by the control unit 100 and performed by the sputtering film formation apparatus 10.

[0063] When this process starts, in step S1, the control unit 100 opens the gate valve 27, loads the substrate G through the load / unload port 27a, and places it on the mounting table 23. This completes the preparation of the substrate G.

[0064] Next, in step S3, the control unit 100 supplies a processing gas from the gas supply unit 20 into the processing vessel 4. Next, in step S5, the control unit 100 supplies high-frequency power from the first high-frequency power supply 18 to the inductively coupled antenna 13 to generate plasma in the processing vessel 4.

[0065] Next, in step S7, the control unit 100 applies a DC pulse voltage from the DC pulse power supply 62 to the metal window 2, thereby attracting ions toward the metal window 2. Next, in step S9, the target material T is sputtered by the ions, and the sputtered particles emitted from the target material T are deposited on the substrate G. As a result, a desired film such as an AlO film is formed on the substrate.

[0066] According to the above sputtering deposition method, a high-density plasma can be generated using the sputtering deposition apparatus 10 of the present disclosure, and a desired film such as an AlO film can be deposited by reactive sputtering. Furthermore, by independently controlling the source power supplied from the first high-frequency power supply 18 to the inductively coupled antenna 13 and the DC pulse voltage applied from the DC pulse power supply 62 to the metal window 2, a desired film such as an IGZO film having high mobility and high reliability can be deposited.

[0067] As described above, according to the sputtering deposition apparatus and sputtering deposition method of this embodiment, a high-density plasma is formed by applying a DC pulse voltage to the metal window, which allows the target material T to be sputtered efficiently and increases the deposition rate.

[0068] The sputtering deposition apparatus and sputtering deposition method according to the presently disclosed embodiments should be considered to be illustrative in all respects and not restrictive. The embodiments can be modified and improved in various ways without departing from the spirit and scope of the appended claims. The features described in the above embodiments can be configured in other ways as long as they are not inconsistent, and can be combined as long as they are not inconsistent. [Explanation of symbols]

[0069] 10 Sputtering deposition equipment 1 Main container 2 Metal windows 2a, 2b, 2c, 2d split window 3 Antenna Room 4 Processing container 13 Inductively Coupled Antenna 18 First high frequency power source 20 Gas supply unit 22a Underside of metal window 22b Top of metal window 23 Mounting table 62 DC pulse power supply T target material

Claims

1. a processing vessel having a stage on which a substrate is placed; a metal window made of a non-magnetic metal, the metal window having a first surface facing the mounting table and constituting a ceiling surface of the processing chamber; an inductively coupled antenna disposed apart from a second surface of the metal window opposite to the first surface of the metal window, the inductively coupled antenna generating plasma in the processing chamber; a high frequency power source connected to the inductively coupled antenna; any one of a DC power supply, a DC pulse power supply, and an AC power supply connected to the metal window; a gas supply unit that supplies a processing gas for generating the plasma into the processing chamber; and The metal window functions as a target material for performing sputtering processing on the substrate.

2. the metal window has a function of mediating an induced electric field generated by the inductively coupled antenna to generate the plasma in the processing chamber. The sputtering film forming apparatus according to claim 1 .

3. a processing vessel having a stage on which a substrate is placed; a metal window made of a non-magnetic metal, the metal window having a first surface facing the mounting table and constituting a ceiling surface of the processing chamber; an inductively coupled antenna disposed apart from a second surface of the metal window opposite to the first surface of the metal window, the inductively coupled antenna generating plasma in the processing chamber; a target material provided on the first surface; a high frequency power source connected to the inductively coupled antenna; any one of a DC power supply, a DC pulse power supply, and an AC power supply connected to the metal window; a gas supply unit that supplies a processing gas for generating the plasma into the processing chamber; A sputtering film forming apparatus having the same.

4. The metal window is composed of a plurality of divided windows that are electrically insulated from each other. The sputtering film forming apparatus according to any one of claims 1 to 3.

5. The inductively coupled antenna has a plurality of antenna segments arranged therein. The sputtering film forming apparatus according to any one of claims 1 to 4.

6. The inductively coupled antenna has a plurality of antenna segments, each of which is an annular rectangular coil antenna, arranged concentrically. The sputtering film forming apparatus according to claim 5 .

7. In the inductively coupled antenna, a plurality of the antenna segments, each of which is a vertically wound rectangular coil antenna, are arranged in a lattice or linear pattern, and antenna wires at the bottoms of the vertically wound rectangular coil antennas constituting the plurality of antenna segments are arranged in parallel to each other. The sputtering film forming apparatus according to claim 5 .

8. The non-magnetic metal is aluminum. The sputtering film forming apparatus according to any one of claims 1 to 7.

9. A sputtering deposition method performed in the sputtering deposition apparatus according to any one of claims 1 to 8, placing the substrate on the mounting table; supplying a processing gas into the processing vessel from the gas supply unit; supplying high frequency power from the high frequency power supply to the inductively coupled antenna to generate the plasma in the processing chamber; applying a DC voltage, a DC pulse voltage or an AC voltage from a DC power supply, a DC pulse power supply or an AC power supply connected to the metal window to attract ions from the plasma into the metal window; depositing sputter particles sputtered by the ions on the substrate; A sputtering film formation method comprising:

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