KR20230056593A - Sputtering film formation device and sputtering film formation method - Google Patents

Abstract

Provided is a sputtering film formation device that sputters a target efficiently. The sputtering film formation device includes: a processing container having a mounting table for mounting a substrate; a metal window facing the mounting table, having a first surface constituting a ceiling surface of the processing container, and made of a non-magnetic metal; an inductively coupled antenna disposed away from a second surface of the metal window opposite to the first surface of the metal window and generating plasma within the processing container; a high-frequency power source connected to the inductively coupled antenna; any one of a direct current power source, a direct current pulse power source, or an alternating current power source connected to the metal window; and a gas supply part that supplies the processing gas for generating the plasma in the processing container.

Description

Sputtering film formation device and sputtering film formation method {SPUTTERING FILM FORMATION DEVICE AND SPUTTERING FILM FORMATION METHOD}

The present disclosure relates to a sputtering film formation apparatus and a sputtering film formation method.

For example, the magnetron sputtering film formation apparatus of Patent Document 1 sputters the target material by forming a high-density plasma using a DC electric field based on a DC voltage applied to the target material and a magnetic field from a magnet on the back surface of the target material. do

For example, the sputtering film-forming apparatus of Patent Document 2 sputters a target material using an inductively coupled plasma to form a film. This sputtering film formation apparatus has an induction coil provided corresponding to a dielectric plate, and has a magnet on the back surface of the target material. When high-frequency power is introduced to the induction coil, an induction electric field is formed in the processing space through the dielectric plate.

[Patent Document 1] International Publication No. 2009/116430 [Patent Document 2] Japanese Unexamined Patent Publication No. 2012-209483

The present disclosure provides a technique capable of efficiently sputtering a target material.

According to one aspect of the present disclosure, a processing container having a mounting table on which a substrate is mounted, a metal window facing the mounting table, having a first surface constituting a ceiling surface of the processing container, and made of a non-magnetic metal; an inductive coupling antenna disposed spaced apart from a second surface of the metal window opposite to the first surface of the metal window and generating plasma in the processing container; a high-frequency power source connected to the inductive coupling antenna; A sputtering film forming apparatus is provided, which includes a DC power supply, a DC pulse power supply, or an AC power supply connected thereto, and a gas supply unit that supplies a processing gas for generating the plasma into the processing container.

According to one aspect, a target material can be efficiently sputtered.

1 is a cross-sectional view showing a sputtering film forming apparatus according to an embodiment.
Figure 2 is a view for explaining the generation of inductively coupled plasma using a metal window.
3 is a plan view of a metal window and an inductively coupled antenna according to an embodiment;
4 is a plan view of a metal window and an inductively coupled antenna according to an embodiment;
5 is a diagram showing an example of a longitudinal winding rectangular coil antenna according to an embodiment;
Fig. 6 is a diagram showing experimental results of source power dependence in sputtering film formation according to the embodiment;
7 is a diagram for explaining sputtering of a target material according to an embodiment.
Fig. 8 is a diagram showing experimental results of DC voltage dependence and plasma electron density in sputtering film formation according to the embodiment.
9 is a diagram for explaining a parallel magnetic field and sputtering by a sputtering film forming apparatus according to an embodiment.
10 is a flowchart showing a sputtering film formation process according to an embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this indication is demonstrated with reference to drawings. In each drawing, the same code|symbol is attached|subjected to the same component part, and overlapping description may be abbreviate|omitted.

[Sputtering Film Formation Equipment]

First, a sputtering film forming apparatus 10 according to an embodiment will be described. 1 is a cross-sectional view showing a sputtering film forming apparatus 10 according to an embodiment. The sputtering film formation apparatus 10 shown in FIG. 1 is a rectangular substrate, for example, a glass substrate for FPD (hereinafter referred to as substrate G) using plasma to form an aluminum oxide (AlO) film or an oxide semiconductor (IGZO). It can be used when performing the deposition of the . Here, as an FPD, a liquid crystal display (LCD), an electro luminescence (EL) display, a plasma display panel (PDP), etc. are illustrated. However, the substrate is not limited to a glass substrate for FPD.

The sputtering film forming apparatus 10 has an airtight container 1 in the shape of a rectangular cylinder made of a conductive material, for example, aluminum whose inner wall surface is anodized. This body container 1 is assembled so that it can be disassembled, and is electrically grounded by the ground wire 1a.

The main body container 1 is partitioned vertically into an antenna chamber 3 and a processing container 4 by rectangular metal windows 2 formed insulated from the main body container 1 . The metal window 2 constitutes a ceiling wall of the processing container 4 . The metal window 2 is made of, for example, a non-magnetic and conductive metal, for example, aluminum or an alloy containing aluminum.

Between the side wall 3a of the antenna chamber 3 and the side wall 4a of the processing container 4, a support shelf 5 protruding inwardly of the body container 1 is provided. The support shelf 5 is made of a conductive material, preferably a metal such as aluminum.

The metal window 2 is composed of a plurality of partition windows 2a to 2d electrically insulated from each other with an insulating member 7 interposed therebetween. The split windows 2a to 2d are supported by the support shelf 5 with the insulating member 7 interposed therebetween. It is a structure in which the metal window 2 is suspended from the ceiling of the body container 1 by a plurality of suspenders (not shown). 1 schematically shows the division form of the metal window 2, and does not show the actual division form. Various division forms of the metal window 2 will be described later.

A plurality of gas supply holes 21a are formed in the support shelf 5 . The gas supply unit 20 is connected to a plurality of gas supply holes 21a through a gas supply pipe 21 . The gas supply unit 20 supplies a process gas containing source gas for plasma generation. The processing gas is introduced into the processing container 4 through the gas supply pipe 21 and through the plurality of gas supply holes 21a. Alternatively, a gas space (not shown) may be provided inside the metal window 2 to be connected to the gas supply pipe 21 to supply gas.

Inside the antenna chamber 3 on the metal window 2, there is an antenna unit 40 having an inductively coupled antenna 13 disposed facing the metal window 2 and circling around to form a ring shape. As will be described later, the inductively coupled antenna 13 is made of a conductive material such as copper and is spaced apart from the metal window 2 by a spacer (not shown) made of an insulating member.

A first high frequency power supply 18 is connected to the inductive coupling antenna 13 of the antenna unit 40 via a power supply line 16 and a matching device 17 . Then, during the plasma processing (sputtering film formation process), the inductively coupled antenna 13 is supplied with, for example, 13.56 MHz high frequency power (hereinafter referred to as source power) via the power supply line 16 extending from the first high frequency power supply 18. ) is supplied. Then, a loop current is induced in the split windows 2a to 2d of the metal window 2 by the induced electric field formed by the inductive coupling antenna 13 . As a result, an induced electric field is formed in the processing container 4 through the loop current generated in the split windows 2a to 2d of the metal window 2 . By this induction electric field, in the plasma generating space S directly under the metal window 2 in the processing chamber 4, the processing gas supplied from the gas supply hole 21a is converted into plasma, and inductively coupled plasma is generated.

The metal window 2 has a first surface and a second surface. The lower surface 22a of the metal window 2 is taken as a first surface, and the upper surface 22b of the metal window 2, which is opposite to the first surface, is taken as a second surface. The first surface constitutes a ceiling surface of the processing container 4 . On the side of the second surface, an inductively coupled antenna 13 is disposed spaced apart from the metal window 2 and generates plasma in the processing container 4 . A target material T is fixed to the lower surface 22a of the metal window 2 while maintaining electrical conduction with the metal window 2 by bonding with indium brazing or screwing. Since the target material T is a consumable item, it is replaced when it is consumed to a thickness below a certain threshold value, and a new target material T is bonded to the lower surface 22a of the metal window 2 by brazing or fixed by screwing or the like. The target material T is composed of a material corresponding to the film to be formed. In the case of forming an AlO film or an AlN film, the target material T may be made of aluminum. In the case of forming the SiO ₂ film and the SiN film, the target material T may be made of silicon. When forming an IGZO film, target material T may be comprised by indium (In), gallium (Ga), zinc (Zn), and oxygen (O).

At the bottom of the processing container 4, a mounting table 23 facing the first surface is fixed with an insulating member 24 interposed therebetween. The mounting table 23 is made of a conductive material, for example, aluminum having an anodized surface, and a substrate G is placed on the mounting surface of the mounting table 23 . The mounted substrate G is adsorbed and held by an electrostatic chuck (not shown) provided on the mounting surface.

An insulating shield ring 25a is provided on the upper periphery of the mount table 23, and an insulating ring 25b is provided on the peripheral surface of the mount table 23. A lifter pin 26 used for loading and unloading of the substrate G is inserted through the bottom wall of the body container 1 and the insulating member 24 in the mounting table 23 . The lifter pins 26 are lifted and driven by a lift mechanism (not shown) provided outside the body container 1 to transport the substrate G when the substrate G is loaded and unloaded.

Further, in the mounting table 23, a temperature control mechanism including heating means such as a heater and a refrigerant passage, and a temperature sensor are provided to control the temperature of the substrate G (both not shown). Piping and wiring for these mechanisms and members are all led out of the body container 1 through the opening 1b provided in the bottom surface of the body container 1 and the insulating member 24 .

The sidewall 4a of the processing container 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. In addition, an exhaust device 30 including a vacuum pump or the like is connected to the bottom of the processing container 4 via an exhaust pipe 31 . The inside of the processing container 4 is exhausted by this exhaust device 30, and a predetermined vacuum atmosphere (for example, 10 mTorr (1.33 Pa)) inside the processing container 4 is set and maintained during the plasma processing.

A fine gap (not shown) serving as a cooling space is formed on the back side of the substrate G mounted on the mounting table 23, and a He gas flow path 32 for supplying He gas as a heat transfer gas at a constant pressure. is provided. By supplying the gas for heat transfer to the back side of the substrate G in this way, it is possible to suppress the temperature rise and temperature change of the substrate G due to the sputtering film forming process in a vacuum.

The sputtering film forming apparatus 10 further includes a control unit 100. The controller 100 is composed of a computer and includes a CPU for controlling each component of the plasma processing device, an input device, an output device, a display device, and a storage device. The storage device has a storage medium in which parameters of various processes executed by the plasma processing device and programs for controlling processes executed by the sputtering film forming apparatus 10, that is, process recipes, are stored. The CPU calls a predetermined processing recipe stored in the storage medium, and causes the plasma processing device to execute a predetermined processing operation based on the processing recipe.

[Metal Window]

Next, the metal window 2 will be described in detail. DC pulse power supplies 62a and 62b are connected to the metal window 2, and the DC pulse power supplies 62a and 62b (collectively referred to as the DC pulse power supply 62) are rectangular with a predetermined duty ratio. A wave (pulse wave) DC voltage (hereinafter, also referred to as a DC pulse voltage) is applied to the metal window 2 . The frequency of the DC pulse voltage may be 5 kHz to 150 kHz. The DC pulse voltage has binary values constituting a rectangular wave, and the binary values are controlled to 0 or negative DC voltage. A DC power supply or an AC power supply may be connected to the metal window 2 instead of the DC pulse power supply 62 . When a DC power source is connected to the metal window 2, a negative DC voltage is applied to the metal window 2. When an AC power supply is connected to the metal window 2, the AC power supply applies an AC voltage of a predetermined frequency (for example, 50 kHz) to the metal window 2. From the above, since any one of DC power, DC pulse power, and AC power is electrically connected to the metal window 2, the metal window 2 is made of a conductive material. Also, the metal window 2 is made of a non-magnetic metal. The non-magnetic metal is, for example, aluminum. In the following description, increasing (enlarging) the DC voltage (DC pulse voltage) applied to the metal window 2 means increasing (enlarging) the absolute value of the DC voltage (DC pulse voltage).

A low pass filter (LPF) 61 is provided between the metal window 2 and each of the DC pulse power supplies 62a and 62b, so that the high frequency power from the first high frequency power supply 18 passes through the DC pulse power supply 62a. , so as not to propagate through (62b). With this structure, high-density plasma is generated in the processing chamber 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 converted to metal. drawn into window 2, enabling reactive sputtering.

FIG. 2 is a diagram for explaining generation of inductively coupled plasma using a metal window 2 . As shown in FIG. 2 , an induced current is generated on the upper surface of the metal window 2 by the high-frequency current I _RF flowing through the inductively coupled antenna 13 . The induced current flows only on the surface portion of the metal window 2 due to the skin effect, but the metal window 2 is insulated from the support shelf 5 and the body container 1. For this reason, if the planar shape of the inductive coupling antenna 13 is straight, the induced current flowing on the upper surface of the metal window 2 flows on the side surface of the metal window 2, and then the induced current flowing on the side surface , flows to the lower surface of the metal window 2, and again returns to the upper surface of the metal window 2 via the side surface of the metal window 2 to generate an eddy current I _ED . In this way, the eddy current I _ED looping from the upper surface to the lower surface is generated in the metal window 2 . Among these looping eddy currents I _ED , the current flowing through the lower surface of the metal window 2 generates an induced electric field I _P in the processing chamber 4, and plasma of the processing gas is generated by the induced electric field I _P.

On the other hand, when the inductively coupled antenna 13 is provided to circumnavigate along the circumferential direction within the plane corresponding to the metal window 2, if a clean sheet is used as the metal window 2, the metal window 2 Eddy currents do not flow on the bottom side and no plasma is generated. That is, the eddy current I _ED generated on the upper surface of the metal window 2 by the inductive coupling antenna 13 only loops on the upper surface of the metal window 2, and the eddy current IED does not flow on the lower surface of the metal window 2 . Therefore, the metal window 2 is configured in various configurations 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.

[Composition of the metal window]

In the first aspect, the metal window 2 is divided into a plurality of divided regions and insulated from each other. This causes the eddy current I _ED to flow on the lower surface of the metal window 2 . That is, by dividing the metal window 2 into a plurality of parts in a state of being insulated from each other, an induced current flowing to the side surface flows through the upper surface of the divided metal window 2 (split window), flows from the side surface to the lower surface, and then flows again to the side surface. creates a loop-shaped eddy current I _ED that flows through and returns to the upper surface. For this reason, the metal window 2 is divided into a plurality of split windows. Some division examples of the metal window 2 and arrangement examples of the inductively coupled antenna 13 will be described below.

3 is a plan view of the metal window 2 and the inductively coupled antenna 13 according to the embodiment. The metal window 2 has a rectangular shape having a long side and a short side corresponding to the substrate G. In FIG. 3(a), in the inductively coupled antenna 13, a plurality of antenna segments 131, 132, and 133 each composed of an annular rectangular coil antenna are provided so as to face the metal window 2 and go around. there is. The ring-shaped rectangular coil antenna constituting the plurality of antenna segments 131, 132, and 133, respectively, may be formed in a frame shape by winding one antenna wire (not shown) in a spiral shape, or two Alternatively, the four antenna wires may be spirally wound symmetrically with each other to form a frame shape. Thus, in this example, in order to uniformly form an induced electric field along the lower surface 22a of the metal window 2, the rectangular metal window 2 is provided at each corner of the metal window 2. ) in a generally radial shape. Thereby, the metal window 2 is divided into four division windows 2a to 2d. The four split windows 2a to 2d are trapezoidal on the long side and triangular on the short side. These trapezoids and triangles are configured so that the height of the trapezoid with the long side as the base and the height of the triangle with the short side as the base become the same. The split windows 2a to 2d are insulated from each other with an insulating member 7 therebetween.

In this way, as an example of the inductively coupled antenna 13, a plurality of antenna segments composed of an annular rectangular coil antenna are arranged.

In Fig. 3(b), as shown in Fig. 1, two DC pulse power supplies 62a and 62b are provided. The DC pulse power source 62a is connected to the split windows 2a and 2b, and supplies DC pulse voltage to the split windows 2a and 2b. The DC pulse power supply 62b is connected to the split windows 2c and 2d, and supplies a DC pulse voltage to the split windows 2c and 2d. 3(b) and (c), illustration of the low-pass filter 61 is omitted.

In Fig. 3(c), a DC pulse power supply 62 is connected to the split windows 2a to 2d, and supplies a DC pulse voltage to the split windows 2a to 2d. For example, when the outside plasma is weak, the duty of the DC voltage applied to the split windows 2c and 2d is greater than the duty of the DC voltage applied to the split windows 2a and 2b (i.e., The uniformity of the in-plane distribution of the film formation can be achieved by lengthening the period during which the negative DC voltage is applied among the two values of the pulse voltage. For this reason, it is possible to change the in-plane distribution of ion entrainment in the plasma according to the area of the split window. In this case, it is sufficient to provide one DC pulse power supply 62, and the number of DC pulse power supplies can be reduced.

FIG. 4 is a planar view of the metal window 2 and the inductively coupled antenna 13 according to the embodiment, and is another example of FIG. 3 . In this example, the metal window 2 is divided into six rectangular windows 2e to 2j. The division windows 2e to 2j are connected via a low-pass filter 61 to any one of the DC pulse power supplies 62c, 62d, and 62e. The DC pulse power source 62c is connected to the split windows 2e and 2f, and supplies DC pulse voltage to the split windows 2e and 2f. The DC pulse power source 62d is connected to the split windows 2g and 2h, and supplies a DC pulse voltage to the split windows 2g and 2h. The DC pulse power supply 62e is connected to the split windows 2i and 2j, and supplies DC pulse voltage to the split windows 2i and 2j.

As shown in Fig. 4, the inductive coupling antenna 13 may be composed of only a parallel antenna. The parallel antenna generates an induced electric field that contributes to plasma generation, and has rectangular regions formed so as to face the metal window 2 and face the substrate G, and these rectangular regions are linear or lattice-shaped plasma control regions. divide by Then, the antenna segments 134 constituting a part of the rectangular area are arranged in each of the divided areas, and the antenna lines in the plurality of antenna segments 134 are all parallel, so that a multi-segmented parallel antenna is configured.

As shown in FIG. 5, the antenna segment 134 in FIG. 4 is a direction in which an antenna wire 135 made of a conductive material, for example copper, crosses the substrate G (metal window 2), for example It consists of a longitudinal rectangular coil antenna configured by winding in a spiral shape in an orthogonal direction, that is, in a vertical direction. The high frequency power is supplied from the first high frequency power supply 18 to each longitudinal winding rectangular coil antenna.

In Fig. 4, five antenna segments 134 spanning the two split windows 2e and 2f are arranged in the longitudinal direction of the split windows 2e and 2f. Similarly, five antenna segments 134 spanning the two split windows 2g and 2h and five antenna segments 134 spanning the two split windows 2i and 2j are arranged.

The vertical winding rectangular coil antenna is not limited to those in which the antenna segments 134 are linearly arranged in the longitudinal direction of each split window shown in Fig. 4, but may be arranged in a lattice shape. For example, the antenna segment 134 is divided into 4 divisions of 2 vertical and horizontal, 9 divisions of 3 vertical and horizontal, 25 divisions of 5 vertical and horizontal, or more, and a longitudinal rectangular coil antenna is installed in each division. You may arrange it in a lattice shape.

In this way, the antenna segments 134 composed of vertical winding rectangular coil antennas are arranged in a straight line or lattice shape so that the directions of the induced electric fields (high frequency currents) of the antenna segments 134 are all the same. As a result, there is no region where the induced electric field cancels out, as in the case of arranging annular rectangular coil antennas. For this reason, it is possible to increase the uniformity of the plasma while increasing the efficiency compared to the case where the annular rectangular coil antennas are arranged.

Further, in the area corresponding to the inductive coupling antenna 13 of the metal window 2, the relationship between the number of divisions of the metal window 2 and the number of divisions of the inductive coupling antenna 13 (the number of antenna segments) is arbitrary. am. 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.

With the sputtering film formation apparatus 10 described above, the metal window 2 mediates the induced electric field by the inductive coupling antenna 13 and functions to form plasma in the processing container 4 . In addition, the metal window 2 functions to attract ions to the target material T for performing the sputtering film forming process on the substrate G.

With this structure, a high-density plasma is generated in the processing chamber 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 are attracted and high-density plasma is generated. It enables reactive sputtering by plasma. By depositing the sputtered particles emitted from the target material T by sputtering on the substrate G, it is possible to form an AlO film, an AlN film, a SiO film, a SiN film, a TiN film, an IGZO film, or the like.

Plasma is formed by an electromagnetic field formed by supplying source power to the inductively coupled antenna 13 . Sputtering of the target is performed by attracting ions by applying a DC pulse voltage to the metal window 2 on which the target material T is attached. Therefore, according to the sputtering film formation apparatus 10 of the present disclosure, the formation of plasma and the attraction of ions can be independently controlled. In addition, high density plasma is achieved by the magnetic field and DC electric field formed by the inductive coupling antenna 13, but since the magnetic field formed by the inductive coupling antenna 13 is an alternating magnetic field, it is generated by a static magnetic field and a DC electric field. There is an advantage that the target material is uniformly sputtered without the deflection of the plasma as such.

Also, the metal window 2 itself may be used as a target material. Further, the DC voltage to be applied to the target material is described using a DC pulse voltage as an example in the present disclosure, but is not limited thereto, and may be a continuous DC voltage or an AC voltage. The inductive coupling antenna 13 may have a configuration in which a plurality of antenna segments composed of longitudinally wound rectangular coil antennas are arranged in a straight line or lattice shape. The inductively coupled antenna 13 may have a configuration in which a plurality of annular rectangular coil antennas are concentrically arranged, or a configuration in which a longitudinal winding rectangular coil antenna and an annular rectangular coil antenna are combined.

Hereinafter, four effects of the sputtering film forming apparatus 10 of the present disclosure will be described in order. The four effects are high film formation rate by high-density plasma (effect 1), independent control of source power and DC voltage (effect 2), film formation such as IGZO film with few defects (effect 3), sputtering effect by parallel magnetic field ( effect 4). The metal window 2 and the inductive coupling antenna 13 were evaluated according to the configuration shown in FIG. 3 .

[Effect 1: High film formation rate by 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 obtained by the high-density plasma generated by the DC electric field and the alternating magnetic field by the inductively coupled antenna 13 . An experiment was conducted using the sputtering processing apparatus 10 of FIG. 1 based on the following process conditions.

＜Process conditions＞

Gap from the metal window to the mounting table 50mm

pressure in the processing vessel 5mT (0.67Pa)

Gas Argon (Ar) gas, Oxygen (O ₂ ) gas 50/50 sccm

target material aluminum

DC pulse voltage -500V 50 kHz Duty=50%

source power variable

6 shows the result of forming a transparent AlO film by sputtering the target material with plasma using a mixed gas of argon and oxygen under the above conditions. 6 is a diagram showing experimental results of source power dependence in sputtering film formation according to the embodiment.

6, the horizontal axis represents the source power from the first high frequency power supply 18, the vertical axis (left) represents the AlO film formation rate (DR), and the vertical axis (right) represents the AlO film refractive index (RI). According to this, by supplying source power to the inductively coupled antenna 13 and applying a DC pulse voltage to the metal window 2, the plasma can be made high in density, thereby increasing the film formation rate.

In addition, by increasing the source power, a higher density plasma could be generated, and the film formation rate (DR) and refractive index (RI) of the AlO film could be further improved. Further, the ratio of the film thickness of the side part to the film thickness of the bottom part of the AlO film formed on the stepped part on the substrate G was 1.00, 1.00, and 0.95 when the source power was 1000 W, 3000 W, and 5000 W, respectively. That is, the coverage of the AlO film was good regardless of the magnitude of the source power. From the above, it has been found that according to the sputtering film formation apparatus 10 of the present disclosure, the film formation rate and the refractive index can be improved, and a dense AlO film with good coverage can be formed by sputtering.

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

In addition, oxidation and nitrification of the film are promoted by the high-density plasma generated by the supply of the source power, so that a dense AlO film can be formed. In the inductive coupling antenna 13 to which source power is supplied, a parallel magnetic field B is generated by the shapes of the antenna segments 131 to 134 shown in FIGS. 3 to 5 . As a result, Al ions (Al ⁺ ) are emitted at a high angle by receiving the Lorentz force (F=qv×B). Thereby, an AlO film with good coverage can be formed by sputtering.

[Effect 2: Independent control of source power and DC voltage]

In the sputtering film formation apparatus 10, the control of applying the DC pulse voltage to the metal window 2 and the control of supplying the plasma source to the inductively coupled antenna 13 can be independently performed. For this reason, a film with few defects can be formed. An experiment was conducted using the sputtering processing apparatus 10 of FIG. 1 based on the following process conditions.

＜Process conditions＞

Gap from the metal window to the mounting table 50mm

pressure in the processing vessel 5mT (0.67Pa)

Gas Argon (Ar) gas, Oxygen (O ₂ ) gas 50/50 sccm

target material aluminum

source power 3kW

DC pulse voltage Variable 50kHz Duty=50%

8 shows the results of forming an AlO film by sputtering the target material T with plasma using a mixed gas of argon and oxygen under the above conditions. 8 is a diagram showing experimental results of DC voltage dependence and plasma electron density in sputtering film formation according to the embodiment.

In Fig. 8(a), the horizontal axis represents the DC pulse voltage (DC), the vertical axis (left) represents the film formation rate (DR) of the AlO film, and the vertical axis (right) represents the refractive index (RI) of the AlO film. According to this, if the DC pulse voltage applied to the metal window 2 is increased, the probability that ions in the plasma, for example, argon ions collide with the target material T is increased, and the sputtering force can be increased, so that the film formation rate ( DR) could be increased. On the other hand, even if the DC pulse voltage was increased, the refractive index (RI) could be maintained.

In Fig. 8(b), the horizontal axis represents the source power, and the vertical axis represents the plasma electron density (Ne density [pcs/cm ³ ]). According to this, comparing the line A when the DC pulse voltage is 0 V and the line B when the DC pulse voltage is -300 V, the plasma electron density Ne is hardly affected by the value of the DC pulse voltage. That is, it was found that the plasma electron density Ne depends on the source power and does not depend on the DC pulse voltage.

From the above, by independently performing the control for applying the DC pulse voltage to the metal window 2 and the control for applying the plasma source to the inductively coupled antenna 13, an insulating film or an IGZO film with few defects can be formed while generating a high-density plasma. It has been proven that it is possible to form a tabernacle.

[Effect 3: Formation with fewer defects]

For example, if the DC voltage applied to the metal window 2 is increased, ions in the plasma can be strongly attracted to the target material T. For this reason, the amount of sputtered particles discharged from the target material T can be increased, and the film formation rate can be increased. On the other hand, if the direct current voltage applied to the metal window 2 is increased, the energy of the emitted sputtered particles also increases and they become strongly embedded in the film, which may cause film defects. In the sputtering film formation apparatus 10 of the present disclosure, the DC voltage and the source power can be independently controlled. For this reason, for example, in order to form an IGZO film with fewer defects, the DC voltage applied to the metal window 2 can be lowered and the source power can be increased to, for example, about 5000 W. IGZO film|membrane with few defects can be formed into a film by controlling DC voltage so that the attraction of the ion in plasma may be weakened, generating|generating high-density plasma and raising a film-forming rate by this.

[Effect 4: Sputtering effect by parallel magnetic field]

9 is a diagram for explaining sputtering and a parallel magnetic field formed below the metal window 2 of the sputtering film formation apparatus 10 according to the embodiment. Fig. 9(a) shows the parallel magnetic field B1 below the metal window 2 (target material T) at the time of sputtering by the sputtering film forming apparatus 10 according to the embodiment, and Fig. 9(b) shows a reference example. The magnetic field B2 below the metal window 2 (target material T) at the time of sputtering by the magnetron sputtering apparatus according to is shown.

In the magnetron sputtering film formation apparatus of the reference example shown in FIG. 9( b ), 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 the magnet 91 on the back surface of the target material T. is formed, the target material T is sputtered, and film formation is performed. In such sputtering film formation, a high-density plasma is generated by surrounding electrons in the plasma with the magnetic field B2, and the film formation rate (sputtering rate) is increased. However, the sputtering region of the target material T is biased by the magnetic field B2 between the magnets 91 of the N pole and the S pole, and the target material T between the magnets 91 is cut into an annular shape. Thereby, the consumption of the target material T between the magnets 91 becomes higher than the consumption of the target material T under the magnets 91. The replacement time is advanced due to uneven use of the target material T, and the utilization efficiency of the target material T is poor. In addition, a portion where the target material T is not shaved under the magnet 91 tends to accumulate reaction by-products and other substances, and may become a particle generation source.

In contrast, in the sputtering film formation apparatus 10 of the present disclosure, a plurality of antenna segments of the inductively coupled antenna 13 are used, and the antenna wire facing the metal window 2 is looped parallel to the metal window 2. It is arranged so as to form a shape, or all of the antenna wires facing the metal window 2 are arranged so that they are parallel.

Therefore, as shown in Fig.9 (a), parallel magnetic field B1 is formed widely in the horizontal direction from the lower part of target material T. Therefore, in the sputtering film formation apparatus 10, there is no location where the magnetic field becomes locally strong as in the reference example shown in FIG. 9(b). For this reason, the target material T is uniformly shaved by the DC electric field E due to the DC voltage applied to the metal window 2 and the parallel magnetic field B1 formed over a wide area below the target material T, enabling uniform film formation and coverage can form a good curtain. Since the target material T is cut uniformly, the utilization efficiency of the target material T is high, and the lifetime of the target material T can be lengthened.

[Method of film formation by sputtering]

Finally, a sputtering film formation method executed in the sputtering film formation apparatus 10 of the present disclosure will be described with reference to FIG. 10 . 10 is a flowchart showing a sputtering film formation process according to an embodiment. The sputtering film formation process is controlled by the control unit 100 and executed by the sputtering film formation apparatus 10 .

When this process starts, in step S1, the gate valve 27 is opened, the control unit 100 carries in the board|substrate G from the carrying-in/outlet 27a, and mounts it on the mounting table 23. In this way, preparation of the substrate G is completed.

Next, in step S3 , the control unit 100 supplies a processing gas from the gas supply unit 20 into the processing container 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 chamber 4.

Next, in step S7, the controller 100 applies a DC pulse voltage from the DC pulse power source 62 to the metal window 2 to attract ions to the metal window 2 side. Next, in step S9, the target material T is sputtered by ions, and the sputtered particles emitted from the target material T are deposited on the substrate G. Thereby, a desired film such as an AlO film is formed on the substrate.

According to the above sputtering film formation method, a high-density plasma can be generated using the sputtering film formation apparatus 10 of the present disclosure, and a desired film such as an AlO film can be formed by reactive sputtering. In addition, 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 to the metal window 2 from the DC pulse power supply 62, high travel A desired film such as an IGZO film having high reliability and reliability can be formed.

As described above, according to the sputtering film formation apparatus and sputtering film formation method of the present embodiment, it is possible to efficiently sputter the target material T and increase the film formation rate by forming a high-density plasma by applying a DC pulse voltage to the metal window. there is.

It should be considered that the sputtering film formation apparatus and sputtering film formation method according to the embodiment disclosed this time are examples and not restrictive in all respects. Embodiments can be modified and improved in various forms without departing from the scope of the appended claims and their main points. The matters described in the above plurality of embodiments can also take other configurations within a range that is not contradictory, and can be combined within a range that is not contradictory.

10 Sputtering film formation device
1 body container
2 metal window
2a, 2b, 2c, 2d panes
3 antenna room
4 processing vessel
13 inductively coupled antenna
18 1st high frequency power supply
20 gas supply
22a The lower surface of the metal window
22b top of metal window
23 mount
62 DC pulse power
T target material

Claims (9)

A processing container having a mounting table on which a substrate is mounted;
a metal window facing the mounting table, having a first surface constituting a ceiling surface of the processing container, and made of a non-magnetic metal;
an inductively coupled antenna disposed spaced apart from a second surface of the metal window opposite to the first surface of the metal window and generating plasma in the processing container;
a high-frequency power source connected to the inductively coupled antenna;
Any one of DC power, DC pulse power, and AC power connected to the metal window;
A gas supply unit supplying a processing gas for generating the plasma into the processing container.
A sputtering film formation apparatus having a. According to claim 1,
The metal window has a function of mediating an induced electric field by the inductive coupling antenna, forming the plasma in the processing container, and a function of a target material for performing a sputtering process on the substrate.
Sputtering film formation device. A processing container having a mounting table on which a substrate is mounted;
a metal window facing the mounting table, having a first surface constituting a ceiling surface of the processing container, and made of a non-magnetic metal;
an inductively coupled antenna disposed spaced apart from a second surface of the metal window opposite to the first surface of the metal window and generating plasma in the processing container;
A target material provided on the first surface;
a high-frequency power source connected to the inductively coupled antenna;
Any one of DC power, DC pulse power, and AC power connected to the metal window;
A gas supply unit supplying a processing gas for generating the plasma into the processing container.
A sputtering film formation apparatus having a. According to any one of claims 1 to 3,
The metal window is composed of a plurality of split windows electrically insulated from each other
Sputtering film formation device. According to any one of claims 1 to 4,
In the inductively coupled antenna, a plurality of antenna segments are disposed
Sputtering film formation device. According to claim 5,
In the inductively coupled antenna, a plurality of the antenna segments, which are ring-shaped rectangular coil antennas, are concentrically arranged.
Sputtering film formation device. According to claim 5,
In the inductive coupling antenna, a plurality of antenna segments, which are longitudinal rectangular coil antennas, are arranged in a lattice or linear shape, and antenna lines at the bottom of the longitudinal winding rectangular coil antenna constituting the plurality of antenna segments are parallel to each other. arranged so that
Sputtering film formation device. According to any one of claims 1 to 7,
The non-magnetic metal is aluminum
Sputtering film formation device. A sputtering film formation method executed in the sputtering film formation apparatus according to any one of claims 1 to 8,
A step of mounting a substrate on a mounting table;
supplying a processing gas from a gas supply unit into a processing container;
supplying high-frequency power from a high-frequency power source to an inductively coupled antenna and generating plasma in the processing chamber;
applying a DC voltage, a DC pulse voltage, or an AC voltage from any one of a DC power supply, a DC pulse power supply, and an AC power supply connected to the metal window, and attracting ions from the plasma to the metal window;
A step of depositing sputtered particles sputtered by the ions on the substrate
A sputtering film formation method having

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