KR20130104466A

KR20130104466A - Film forming method and sputtering apparatus

Info

Publication number: KR20130104466A
Application number: KR1020120025975A
Authority: KR
Inventors: 요시오 가와마타; 노부아키 우츠노미야; 아키히코 이토
Original assignee: 시바우라 메카트로닉스 가부시끼가이샤
Priority date: 2012-03-14
Filing date: 2012-03-14
Publication date: 2013-09-25

Abstract

PURPOSE: A film forming method and a sputtering apparatus are provided to easily form a discontinuous film by a sputtering method. CONSTITUTION: A film forming apparatus comprises a vacuum chamber(10), a support (20), and a counter electrode (30). An adhesion prevention plate (11) is attached to an inner wall of the vacuum chamber. The vacuum chamber is to maintain a decompressed state The support is installed on the bottom of the vacuum chamber, and the counter electrode is installed under an upper surface of the vacuum chamber. The support faces the counter electrode. The support maintains a substrate processed in the vacuum chamber. The counter electrode is a discharge electrode.

Description

Film deposition method and sputtering device {FILM FORMING METHOD AND SPUTTERING APPARATUS}

TECHNICAL FIELD This invention relates to the film-forming method. Specifically, It is related with the film-forming method and sputtering apparatus by a sputtering method.

As a film forming method for forming a thin film on a substrate, there are a vacuum deposition method and a sputtering method. In the vacuum deposition method, a raw material is supplied to a crucible, a deposition boat, or the like, and a thin film is formed on a substrate by evaporating the raw material in a vacuum. On the other hand, in the sputtering method, by sputtering a target, particles scattered from the target are deposited on the substrate to form a thin film on the substrate.

In these film-forming methods, even if a film component is the same, it is known that film quality differs. For example, about the metal thin film, it is said that the vacuum deposition method is easier to form a discontinuous film than the sputtering method (for example, refer patent document 1). For this reason, in order to intentionally form a discontinuous film, there exists a tendency to select vacuum deposition method rather than sputtering method generally.

Patent Document 1: Japanese Patent Application Laid-Open No. 2007-138270

However, in the vacuum evaporation method, delicate control of the film thickness is more difficult than the sputtering method. In addition, a vacuum deposition apparatus is a mainstream batch type | mold, and is not excellent in mass productivity.

An object of the present invention is to provide a film forming method and a sputtering apparatus for easily forming a discontinuous film by a sputtering method.

According to one aspect of the present invention, as a film forming method in which a substrate is opposed to a target in a vacuum chamber and formed on the substrate by a sputtering method, the surface temperature of the target is controlled to be a predetermined temperature higher than room temperature, Compared to the case where the surface temperature of the target is not set to the predetermined temperature, a film having a high resistance is formed on the substrate.

Moreover, according to one aspect of this invention, the sputtering apparatus which enables the said film-forming method is provided.

According to the present invention, a discontinuous coating is easily formed by the sputtering method.

1 is a sectional view of an essential part of a film forming apparatus.
2 is a block diagram of a film forming apparatus.
3 is a view illustrating a change in film quality.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings. First, before describing the film-forming method, the film-forming apparatus which concerns on this embodiment is demonstrated.

Example 1

1 is a sectional view of an essential part of a film forming apparatus. The entirety of the film-forming apparatus 1 is shown by FIG. 1A, and the enlarged view of the vicinity of the counter electrode 30 attached to the film-forming apparatus 1 is shown by FIG. First, the outline | summary of the film-forming apparatus 1 is demonstrated by FIG. 1 (a).

The film-forming apparatus 1 is provided with the vacuum chamber 10, the support stand 20, and the counter electrode 30 as a sputter apparatus. Moreover, on the inner wall of the vacuum chamber 10 except the support 20 and the counter electrode 30, the adhesion plate 11 is attached. In addition, the film forming apparatus 1 is provided with a supply pipe for supplying various gases into the vacuum chamber 10 and an exhaust pipe for exhausting the atmosphere in the vacuum chamber 10 (not shown). The shutter 60 is provided on the support 20.

The vacuum chamber 10 is what is called a vacuum container which maintains a reduced pressure state. The support base 20 is provided in the bottom surface of the vacuum chamber 10, and the counter electrode 30 is provided directly under the upper surface of the vacuum chamber 10. As shown in FIG.

The support 20 and the counter electrode 30 are disposed to face each other. The support 20 may hold the substrate 50 processed in the vacuum chamber 10. The counter electrode 30 is a discharge electrode.

The anti-glare plate 11 is, for example, a detachable replaceable part produced based on a flat plate, and can be attached to or taken out from the vacuum chamber 10. By attaching such an antifouling plate 11 to the inner wall of the vacuum chamber 10, sputter particle can be prevented from directly depositing on the inner wall of the vacuum chamber 10. FIG.

As the material of the vacuum chamber 10 and the adhesion plate 11, metal, such as iron, stainless steel, aluminum (Al), corresponds, for example. In addition, the vacuum chamber 10, the adhesion plate 11, and the support stand 20 are grounded.

Subsequently, the structure of the counter electrode 30 will be described with reference to FIG. 1B.

The counter electrode 30 includes, for example, a target 30t facing the support 20 side, a heating mechanism 30h for heating the target 30t, and a cooling mechanism 30c for cooling the target 30t. Have

In the heating mechanism 30h, for example, a heating wire and a temperature sensor are provided (not shown). In the cooling mechanism 30c, for example, a medium flow path 30ch is formed. The medium (eg, water, an organic solvent, organic matter-containing water, and a heat transfer gas) may flow from the arrow A, flow through the inside of the medium flow path 30ch, and be discharged from the medium flow path 30ch as shown by arrow B. FIG. Thereby, the amount of heat generated by the heating mechanism 30h and the heat radiation to the cooling mechanism 30c are adjusted to adjust the surface temperature of the target 30t.

The surface temperature of the target 30t may be controlled by spontaneous temperature rise during discharge and adjustment of the temperature of the medium without using the heating mechanism 30h. For example, the medium temperature can be set to a temperature lower than normal temperature by an external temperature controller. Moreover, even if the heating mechanism 30h is not used, the surface temperature of the target 30t can be set higher than normal temperature by setting the temperature of the medium higher than normal temperature (for example, 22 degreeC).

The heating mechanism 30h is covered with an insulating material. As a result, insulation between the heating mechanism 30h and the target 30t or insulation between the heating mechanism 30h and the cooling mechanism 30c is secured. In addition, a magnet may be provided on the back side of the counter electrode 30 in order to perform magnetron sputtering (not shown).

The power supply 32 is connected to the counter electrode 30 via the insulating member 31. The power supply 32 may be a direct current power supply or a high frequency power supply (RF power supply). Moreover, the sheath thickness is formed between the side surface of the counter electrode 30 and the adhesion plate 11 by the clearance gap between the side surface of the counter electrode 30 and the adhesion plate 11. Thereby, plasma generation in this gap is suppressed.

In addition, the place where a temperature sensor is provided is not limited to the inside of the heating mechanism 30h, but may be provided inside the cooling mechanism 30c. The surface temperature of the target 30t may be measured by a radiation thermometer.

In order to demonstrate the film-forming apparatus 1 which has the temperature adjustment mechanism of these target 30t in more detail, the block diagram of a film-forming apparatus is shown in FIG.

The film-forming apparatus 1 has the power supply 32 mentioned above, the cooling means 33 corresponding to the cooling mechanism 30c, and the heating means 34 corresponding to the heating mechanism 30h. In addition, the film forming apparatus 1 includes a gas supply source 36 and a flow rate regulator 35 for supplying gas into the vacuum chamber 10. A plurality of gas supply sources 36 may be provided.

These power sources 32, cooling means 33, heating means 34, and flow rate regulator 35 are controlled by a control unit (controller) 40 provided in the film forming apparatus 1.

For example, the measuring unit 40a may include the pressure in the vacuum chamber 10, the applied power (voltage, current, and application time), the surface temperature of the target 30t, the set temperature of the cooling means 33, and the heating means 34. The set temperature, gas flow rate and gas species are detected. In addition, the temperature control part 40b controls the cooling means 33 and the heating means 34. Thereby, the surface temperature of the target 30t is set to predetermined temperature. In addition, the discharge control unit 40c controls the power supply 32. In this way, the applied power (voltage, current, application time) is controlled. In addition, the gas control part 40d controls the pressure and gas flow volume in the vacuum chamber 10, for example by feedback control. In addition, when a plurality of gas species are provided, the gas species required is selected and controlled.

The surface temperature of the target 30t is controlled by adjusting the temperatures of the cooling means 33 and the heating means 34, and in addition to the gas pressure in the vacuum chamber 10, the gas species, the applied power to the target 30t, It is also adjusted by the film-forming conditions including the power application time to the target 30t. The correlation between the set temperatures of the cooling means and the heating means, the film formation conditions described above, and the surface temperature of the target 30t is determined in advance by experiment or the like. These correlations are stored in the storage unit 40e as a relationship table.

As described above, the film forming apparatus 1 according to the present embodiment includes the surface temperature of the target 30t, the set temperature of the cooling means or the heating means, the gas pressure in the vacuum chamber 10, the gas type, and the target 30t. The relationship between the deposition conditions including the applied power for the target and the power applied time to the target 30t, and the material and shape (diameter, thickness, aspect ratio) of the target 30t are obtained in advance. The surface temperature is controlled to be the desired temperature.

The correlation is also corrected according to the material and shape of the substrate 50. For example, a conversion table corresponding to the material (semiconductor, glass, resin, etc.) of the target 30t and the substrate 50 is stored in the storage unit 40e.

Moreover, data can be input from the input part 40f to the memory | storage part 40e as needed.

By the film-forming apparatus 1, the surface temperature of the target 30t is adjusted to a desired temperature regardless of during film-forming and non-film-forming.

In addition, the place where the support stand 20 and the counter electrode 30 are provided is not limited to the position shown to Fig.1 (a), Even if the support stand 20 and the counter electrode 30 are arrange | positioned upside down. good. Alternatively, the support 20 and the counter electrode 30 may be provided on the side of the vacuum chamber 10 so as to face each other.

The material of the target 30t is determined according to the components of the film formed on the substrate 50. For example, when the film formed on the substrate 50 is a film containing tin (Sn), indium (In), silver (Ag), an alloy or an oxide containing one or more of these, and the like, the target 30t Silver is comprised from the metal containing these metal components and alloy components.

Next, the film-forming method using the film-forming apparatus 1 is demonstrated.

First, preliminary operation of the film-forming apparatus 1 is performed before film-forming. In the preliminary operation, the shutter 60 is closed and the heating mechanism 30h is driven by flowing the medium through the cooling mechanism 30c in a state of covering the substrate. In addition, plasma discharge may be performed under predetermined conditions. At this time, the surface temperature of the target 30t is adjusted to the predetermined temperature by the feedback control mentioned above. This temperature is set in the range from normal temperature to melting | fusing point of the target 30t, for example.

When an adhesive member (for example, In (indium)) is provided at the interface between the target 30t and the heating mechanism 30h or at the interface between the heating mechanism 30h and the cooling mechanism 30c, the target 30t is used. May be set in the range from room temperature to the melting point of the adhesive member.

As long as sufficient heat quantity can be ensured by the heating mechanism 30h, preliminary operation may be abbreviate | omitted. In addition, even if the shutter 60 is not arranged, preliminary operation can be executed by using the dummy substrate. In addition, about the temperature setting, in the target 30t, the adhesive member, and other members, the melting point of the member having the lowest melting point may be the upper limit.

When the surface temperature of the target 30t is stabilized, the preliminary operation is finished, and the shutter 60 is opened. That is, it starts the tabernacle. When a film having a predetermined thickness is deposited on the substrate 50, the film formation is finished.

Thus, in this embodiment, electric power is supplied to the counter electrode 30 provided in the vacuum chamber 10, a plasma is generated in the vacuum chamber 10, and it is on the board | substrate 50 which opposes the counter electrode 30. As shown in FIG. The target component is deposited. And sputter film-forming can be performed, heating the surface of the target 30t to normal temperature or more.

Next, a description will be given of how the film quality changes when the surface of the target 30t is heated to or above normal temperature and sputtered, and when the surface of the target 30t is sputtered without heating to or above normal temperature. In the following description, the tin (Sn) film is described as an example. However, in this embodiment, it is not limited to the method of forming a tin film.

3 is a diagram illustrating a change in film quality.

First, the horizontal axis of FIG. 3 is the order (film number) of a film-forming process, and a vertical axis | shaft is sheet resistance ((ohm / square)) of a film. Film-forming conditions are as follows.

(Film forming condition)

Atmosphere gas: Argon (Ar)

Pressure: 0.5 Pa

Discharge time: 160 seconds

Target: Tin target, 3 inch diameter

Discharge power: about 300 W

Film thickness: 250 nm

Cooling medium temperature: 5 ° C, 22 ° C (room temperature), 50 ° C

In addition, a new substrate is prepared for each film forming process, and a film having a substantially same thickness is formed on the substrate. In addition, a 10 minute rest time is provided between each film-forming process.

First, the result at the time of starting a film-forming process without the above-mentioned preliminary operation called cold start is demonstrated.

First, when the surface of the target 30t is not heated above normal temperature (medium temperature: 22 ° C.), the sheet resistance of the tin (Sn) film is 1.0 × 10 (Ω) in the first to fourth film formation. / □) below. In the fifth film formation, the sheet resistance of the tin film is about 2.3 × 10 ² (Ω / □). Also in the sixth film formation, the sheet resistance of the tin film is about 1.6 × 10 ³ (Ω / □). Thus, when the surface of the target 30t is not heated above normal temperature, there exists a tendency for the sheet resistance of a tin film to be low.

In contrast, when the surface of the target 30t is heated (medium temperature: 50 ° C.), the sheet resistance of the tin film is already about 2.6 × 10 ⁶ (Ω / □) in the first film formation. In the second film formation, the sheet resistance of the tin film increases to about 2.5 x 10 ¹¹ (Ω / □).

Next, the result of starting the preliminary operation film-forming process called hot start is demonstrated. The preliminary operation is, for example, 30 minutes of continuous discharge under the film forming conditions described above. In addition, the target 30t is heated by the medium (medium temperature: 50 degreeC).

In the hot start, the first film is formed, and the sheet resistance of the tin film is already about 2.5 × 10 ¹¹ (Ω / □). When the second and third film formations are stopped and the fourth film formation is attempted, the sheet resistance of the tin film increases to about 5.0 × 10 ¹² (Ω / □). Here, in the "pause" at the hot start, discharge is not performed and circulation of the medium (50 degreeC) is performed. When the film formation from the fifth to the tenth is stopped and the eleventh film formation is attempted, the sheet resistance of the tin film is maintained at about 9.9 × 10 ¹⁰ (Ω / □).

In this manner, in either of the cold start and the hot start, it can be seen that the higher the surface temperature of the target 30t is, the higher the sheet resistance of the tin film is.

Moreover, it turned out that the resistivity of a tin (Sn) film becomes hard to be influenced by the rest time after preliminary operation, so that the surface temperature of the target 30t becomes high temperature.

For these reasons, the higher the surface temperature of the target 30t is, the higher the cohesiveness of the film deposited on the substrate 50 becomes, and the film is discontinuous (island shape in a direction substantially parallel to the main surface of the substrate 50). It is because it becomes easy to become). That is, according to this embodiment, a discontinuous film can be easily formed on the board | substrate 50 by sputtering method. In other words, the electrical characteristics (for example, sheet resistance, resistivity, etc.) of the film formed on the board | substrate 50 can be controlled according to the surface temperature of the target 30t.

In addition, the sputtering method is easier to control the film thickness than the vacuum vapor deposition method, and can form a more dense film. Moreover, a sputtering apparatus can be incorporated in an inline type apparatus, and is more excellent in mass productivity than the vacuum vapor deposition method.

In this way, by heating the target 30t, the resistance of the film formed on the substrate 50 increases as compared with the case where the target 30t is not heated. The target 30t is heated by raising the temperature of the medium flowing in the counter electrode 30. That is, the sputtering method can easily form a high-resistance, high-resistance, high-density coating film.

In addition, such a discontinuous coating is less likely to be metallic, and is close to insulation. As a result, the discontinuous coating easily passes radio waves (for example, several MHz to several GHz) and can be used for decorative coatings such as mobile phones and vehicle radars.

This effect is not only when tin is used as the material of the coating, but also, for example, an alloy containing at least one of indium (In), silver (Ag), tin, indium and silver, at least one of tin, indium and silver. The same can also be obtained when any one of oxides containing is used as the material of the film.

By the way, it is known that a discontinuous film is formed also by controlling (rising) a substrate temperature (for example, refer Unexamined-Japanese-Patent No. 2001-26071, Unexamined-Japanese-Patent No. 2003-289005). However, in such a method, the means for heating the substrate may be complicated.

For example, when using the small target 30t with respect to the diameter of the board | substrate 50, film-forming may be performed, rotating the support 20 in order to correct the nonuniformity of a film thickness. In such a case, the support 20 needs to include rotation means other than a heating means, and the mechanism becomes complicated. In addition, in order to form a discontinuous film uniformly on the substrate 50, temperature control in the substrate surface must also be performed, and the control means becomes complicated.

However, in this embodiment, only by adjusting the surface temperature of the target 30t, a discontinuous film can be formed on the board | substrate 50 easily.

As mentioned above, embodiment of this invention was described referring a specific example. However, the present embodiment is not limited to these specific examples. That is, the thing which a person skilled in the art added the design change suitably to the above specific example is contained in the scope of the present invention as long as it has the characteristics of this invention. For example, regarding the heating of the target 30t, the light generated from the heating lamp may be irradiated to the target 30t. In addition, each element with which each specific example mentioned above, its formation, material, conditions, a shape, a size, etc. are not limited to what was illustrated, and can be changed suitably.

In addition, each element with which each embodiment mentioned above can be compounded to the extent technically possible, The combination of these is also included in the scope of the present invention as long as it contains the characteristics of this invention.

In addition, in the scope of the idea of this invention, those skilled in the art include what can be imaged to various modifications and correction examples.

10: vacuum chamber 11: barrier plate
20: support 30: counter electrode
30ch: medium flow path 30c: cooling mechanism
30h: heating mechanism 30t: target
31: insulation member 32: power
33 cooling means 34 heating means
35 flow rate regulator 36 gas source
40: control unit 40a: measurement unit
40b: temperature controller 40c: discharge controller
40d: gas control section 40e: storage section
40f: input unit 50: substrate
60: shutter

Claims

As a film-forming method which opposes a board | substrate and a target in a vacuum chamber, and forms a film on the said board | substrate by sputtering method,
The surface temperature of the target is controlled to be a predetermined temperature higher than room temperature,
A film having a high resistance is formed on the substrate as compared with the case where the surface temperature of the target is not set to the predetermined temperature.

The film formation method according to claim 1, wherein the surface temperature of the target is adjusted to the predetermined temperature before the film is formed on the substrate.

The film forming method according to claim 1, wherein the film is a discontinuous film.

The film forming method according to claim 1, wherein the target is heated by means for raising the temperature of the medium flowing in the electrode including the target to be higher than room temperature, or by means of heating the target by a heating body.

The method of claim 4, wherein the surface temperature of the target,
The relationship between the set temperature of the medium or the heating body, the film forming conditions including the gas pressure in the vacuum chamber, the type of gas, the applied power to the target, and the time to apply the power to the target, and the material and shape of the target Finding,
And the surface temperature of the target is controlled to be the predetermined temperature from the relationship.

The film forming method according to claim 1, wherein the surface temperature of the target is adjusted at or above room temperature and below the melting point of the material of the target.

The film forming method of claim 1, wherein the coating film includes any one selected from the group consisting of tin (Sn), indium (In), silver (Ag), and an alloy or an oxide containing one or more thereof. Way.

The sputtering apparatus which enables the film-forming method in any one of Claims 1-7.