CN114929926A - Object with metal film - Google Patents

Abstract

The object with a metal film of the present invention comprises: a substrate comprising a resin or glass; a metal film covering at least a portion of the substrate; a first layer which is located between the base material and the metal film and contains an oxide of a metal constituting the metal film as a main component; and a second layer which is located between the base material and the first layer, contains an oxide of the composition of the base material as a main component, and has an adhesion strength of 3[ N/cm ] or more to the second layer.

Description

object with metal film

technical field

The present invention relates to an object with a metal film.

Background technique

In order to form a conductive film on the surface of an insulator made of inorganic materials such as glass by metal plating, a thin conductive layer called a seed layer is formed on the surface of the insulator by electroless plating, and this crystal layer is used as an electrode Instead, electrolytic plating of metal is performed on the seed layer.

As a method of forming a seed layer on the surface of an insulator, there is known a method of forming fine irregularities on the surface of the insulator by etching, etc., adding a catalyst such as palladium, and then performing electroless plating (Patent Document 1).

[Prior Art Literature]

[Patent Literature]

Patent Document 1: Japanese Patent No. 5615881

SUMMARY OF THE INVENTION

[Problems to be Solved by Invention]

Conventional metal-coated objects are expected to be used in vehicle components such as mirror members, light members, door handle members, and antenna members, or in notebook personal computers. Note PC) and mobile phones (smartphone, smart phone) and other designed products, but there is a problem that the adhesion between the base material and the metal film is not sufficient, and peeling easily occurs. Furthermore, it is also expected to be employed in a circuit portion in which a current flows in an electronic circuit, but peeling becomes a problem.

[Technical means to solve the problem]

The object with the metal film in the first form includes: a base material including resin or glass; a metal film covering at least a part of the base material; and a first layer located between the base material and the metal film to constitute The metal oxide of the metal film is a main component; and the second layer is located between the substrate and the first layer, and the oxide of the composition of the substrate is a main component, and the first layer is located between the substrate and the first layer. The adhesion strength of one layer to the second layer is 3 [N/cm] or more.

[Effect of invention]

ADVANTAGE OF THE INVENTION According to this invention, the object with a metal film which has a metal film with high adhesiveness to base materials, such as resin and glass, can be realized.

Description of drawings

FIG. 1 is a diagram illustrating an object with a metal film according to an embodiment. FIG. 1( a ) is a perspective view of the object with a metal film, FIG. 1( b ) is a cross-sectional view of the object with a metal film, and FIG. 1( c ) is an enlarged cross-sectional view of the object with a metal film.

FIG. 2 is a cross-sectional view of the film forming apparatus.

3A and 3B are diagrams for explaining the change of the metal film before and after the heat treatment, FIG. 3( a ) is a diagram showing the state of the object to be processed and the metal film before the heat treatment, and FIG. 3( b ) is a diagram showing the object to be processed after the heat treatment and the state of the metal film.

FIG. 4 is a diagram showing an example of a film formation method.

FIG. 5 is a diagram showing a step of forming a plated layer.

Detailed ways

(Embodiment of Object with Metal Film)

Hereinafter, the object 61 with a metal film according to the embodiment will be described with reference to FIG. 1 . FIG. 1( a ) is a perspective view of an object 61 with a metal film. The object 61 with a metal film is, as an example, a print substrate including a plate-shaped substrate 50 including glass or resin. On a part of the surface 50d of the base material 50, a metal film 55 as a wiring member is formed.

(b) of FIG. 1 shows a cross-sectional view of the metal film-coated object 61 at a cross-section perpendicular to the surface 50d. In the substrate 50 , which is a flat plate, not only the metal film 55 is formed on the front surface 50d as described above, but also the metal film 55 is formed on at least a part of the back surface 50e. In addition, a through hole 50h penetrating from the front surface 50d to the back surface 50e is formed in a part of the surface 50d of the substrate 50, which is a flat plate, and a metal containing the same material as the metal film 55 is formed on the inner surface of at least a part of the through hole 50h 55h. The metal 55h may be filled in the entire inside of the through hole 50h.

FIG. 1( c ) is an enlarged cross-sectional view of the object 61 with a metal film, in the vicinity of the surface 50 d of the base material 50 , in the region 62 shown by the dashed quadrilateral in FIG. 1( b ). On the surface 50d of the base material 50 of the metal film-coated object 61 according to the embodiment, the base oxide film layer 52, the metal oxide layer 53, the seed crystal layer 51d, and the plating layer are formed in this order close to the surface 50d. 54d. The base oxide film layer 52 is a layer mainly composed of an oxide of a component contained in the base material 50, and the metal oxide layer 53 is a layer mainly composed of an oxide of a metal contained in the seed layer 51d.

The seed layer 51d is a conductive layer used when the plating layer 54d is formed by electrolytic plating, and a metal such as copper is formed on the surface 50d by a film-forming method such as sputtering.

The plating layer 54d is formed by using the seed layer 51d as an electrode to form a film of a metal such as copper by electrolytic plating or the like.

As an example, FIG. 1( c ) shows an enlarged cross-sectional view of the front surface 50 d of the base material 50 , but the structure of the back surface 50 e of the base material 50 is the same as that shown in FIG. 1 ( c ) except that the top and bottom are reversed. The structure is the same. The seed layer formed on the rear surface 50e is referred to as a seed layer 51e as described later, and the plating layer formed on the rear surface 50e is referred to as a plating layer 54e as described later.

In this specification, the seed crystal layer 51 d and the seed crystal layer 51 e are also collectively or individually called the seed crystal layer 51 . In addition, the plated layer 54d and the plated layer 54e are also collectively or individually called the plated layer 54 .

In this specification, the seed layer 51 and the plating layer 54 are also collectively or individually referred to as the metal film 55 . Furthermore, the metal film 55 is not limited to include the seed layer 51 and the plating layer 54 at the same time, and the plating layer 54 may be omitted.

In this specification, the metal oxide layer 53 formed between the base material 50 and the metal film 55 is also referred to as a first layer. In addition, the base oxide film layer 52 formed between the first layer and the base material 50 is also referred to as a second layer.

In addition, the seed layer 51 is also formed inside the through hole 50h, and the first layer and the second layer are also formed between the inner side surface of the through hole 50h of the base material 50 and the seed layer 51 .

In addition, the metal oxide layer 53 is a weight ratio of the oxide of the metal which comprises the metal film 55, and contains 80% or more of metal oxide layers as an example.

When the base material 50 is glass, the seed layer 51 is copper with a thickness of 300 nm, and the thickness of the second layer (silicon oxide as the base oxide film layer 52 ) is 2.2 nm, the first layer (as the metal oxide layer 52 ) does not exist The actual measurement value of the adhesion strength in the case of copper oxide of the material layer 53) is 0.1 [N/cm] or less. On the other hand, it was found that the measured value of the adhesion strength increased to 3 [N/cm] when the first layer (copper oxide) and the second layer (silicon oxide) were formed between the substrate 50 and the seed layer 51 ]～5.5[N/cm].

That is, in the object 61 with the metal film of the embodiment, the first layer (metal oxide layer 53 ) and the second layer (the base oxide film layer 52 ) are formed between the base material 50 and the seed layer 51 . , and the adhesion strength between the substrate 50 and the seed layer 51 is increased to 3 [N/cm] or more. Therefore, the adhesion strength of the first layer 53 to the second layer 52 is also 3 [N/cm] or more.

Furthermore, since the adhesion strength is ensured as described above, the metal film 55 can be stably used as a conductive layer or a reflection film.

As an example, the thickness of the second layer (base oxide film layer 52 ) can be set to 2 nm or more and 5 nm or less. When the thickness of the second layer is 2 nm or more and 5 nm or less, the bonding force between the base material 50 and the metal film 55 via the first layer and the second layer can be further improved.

As an example, the thickness of the first layer (metal oxide layer 53 ) is 0.5 nm or more and 5 nm or less. When the thickness of the first layer is 0.5 nm or more and 5 nm or less, the bonding force between the base material 50 and the metal film 55 via the first layer and the second layer can be further improved.

In addition, the metal contained in the seed layer 51d, the seed layer 51e, the plating layer 54d, and the plating layer 54e is not limited to the above-mentioned copper, and may be an alloy containing copper, or nickel, aluminum, Other metals such as chromium and alloys containing these metals. The metal film 55 may be formed only on a part of the surface such as one side of the base material 50 , or may be formed over the front surface of the base material 50 . The through-hole 50h may not be formed in the base material 50 .

In addition, the object 61 with a metal film is not limited to the above-mentioned printed circuit board, for example, it may be an electronic part, an optical part, or a decoration formed on the surface wiring layer, and it may be any shape and arbitrary shape. object of use.

(film forming device)

Hereinafter, a film forming apparatus suitable for producing the object 61 with a metal film according to the embodiment will be described with reference to FIG. 2 . FIG. 2 is a cross-sectional view showing the film forming apparatus 100 .

The film-forming apparatus 100 includes a pressure-resistant chamber 1 of a pressure-resistant structure, and includes a plasma processing chamber 2, a film-forming processing chamber 3, and a heat treatment chamber partitioned by a partition wall 5a and a partition wall 5b inside the pressure-resistant chamber 1 4. The partition 5a is provided with an opening 6a connecting the plasma processing chamber 2 and the film formation processing chamber 3, and the opening 6a can be opened and closed by an opening and closing door 7a. The opening portion 6a and the opening/closing door 7a constitute an opening/closing mechanism for communicating and blocking the plasma processing chamber 2 and the film formation processing chamber 3 from each other. The partition wall 5b is provided with an opening 6b connecting the film formation processing chamber 3 and the thermal processing chamber 4, and the opening 6b can be opened and closed by an opening and closing door 7b. The opening portion 6b and the opening and closing door 7b constitute an opening and closing mechanism for communicating and blocking the film formation processing chamber 3 and the thermal processing chamber 4 from each other.

The film-forming apparatus 100 further includes a control device 8 .

Inside the plasma processing chamber 2, a plasma generating source 15 is included. As the plasma generation source 15, a general plasma generation source that generates high-density plasma can be used. The plasma generation source 15 is supplied with electric power from the plasma power supply 19 through the electric power supply line 20 , and is grounded through the ground wiring 21 . The plasma power supply 19 is, for example, a power supply that generates an AC or DC voltage (mainly a negative voltage) at a radio frequency (RF) frequency (eg, 13.56 MHz).

Hereinafter, the processing target (film forming target) of the film forming apparatus 100 is referred to as the processing target 50 . However, to avoid confusion, the object to be processed 50 is referred to as object to be processed 50 a when located in the plasma processing chamber 2 , the object to be processed 50 b when located in the film formation processing chamber 3 , and referred to as the object to be processed 50 b when located in the thermal processing chamber 3 . 4, the processing target object 50 is referred to as a processing target object 50c.

On the opposite side to the plasma generation source 15 in the plasma processing chamber 2, a first holding mechanism 23 for holding a processing object 50a for plasma processing is provided.

In addition, a first decompression pump 25a is connected to the plasma processing chamber 2 via the decompression piping 26, and the plasma processing chamber 2 can be decompressed by the first decompression pump 25a and the decompression piping 26 serving as a decompression mechanism. decompression inside.

The first decompression pump 25a is controlled by the control signal S3 from the control device 8 .

The plasma generating source 15 and the first holding mechanism 23 can also be understood as a plasma processing unit.

The film forming apparatus 100 further includes: a reaction gas supply pipe 16 connected to the closed space 22; a reaction gas supplier 17 connected to the reaction gas supply pipe 16 extending to the outside of the pressure-resistant chamber 1; and a control valve 18, The pressure in the closed space 22 is controlled by adjusting the flow rate of the reaction gas supplied from the reaction gas supplier 17 . The adjustment of the opening degree of the control valve 18 is controlled by the control signal S1 from the control device 8 . In the example of FIG. 2 , the control valve 18 is provided in the reaction gas supplier 17 . The reaction gas supply device 17 supplies the reaction gas through the factory piping 28, for example, but may also be supplied from a gas cylinder.

The film formation processing chamber 3 inside the pressure-resistant chamber 1 includes a second holding mechanism 35 b for holding the processing object 50 b , and a sputtering electrode 33 including an electrode portion 31 and a target material 32 . As an example, copper is used for the target material 32 . As the target material 32, aluminum or other metals or alloys containing said metals can also be used. The sputtering electrode 33 is connected to the power source 34 for sputtering.

The power supply 34 for sputtering can input power of 10 kW or more, more preferably 30 kW or more, to the sputtering electrode 33 . The power supply 34 for sputtering is controlled by the control signal S5 from the control device 8 .

The sputtering electrode 33 and the second holding mechanism 35b can also be understood as a film forming portion.

The sputtering electrode 33 or its electrode portion 31 can also be understood as a film-forming source that supplies a material for a film to be formed on the object to be processed 50b.

A second decompression pump 25b is connected to the film formation processing chamber 3 via a decompression pipe 37, and the inside of the film formation processing chamber 3 is accessible through the second decompression pump 25b and the decompression pipe 37 as a decompression mechanism. Decompression. The second decompression pump 25b is controlled by the control signal S4 from the control device 8 .

The film formation apparatus 100 further includes: an inert gas supply pipe 41 for supplying an inert gas such as argon into the film formation processing chamber 3; an inert gas supplier 38 connected to the inert gas supply pipe 41; and a control valve 39 for regulating the supply of the inert gas The pressure in the film formation processing chamber 3 is controlled by the flow rate of the inert gas supplied from the device 38 . In the example of FIG. 2 , the control valve 39 is provided in the inert gas supplier 38 . The adjustment of the opening degree of the control valve 39 is controlled by the control signal S6 from the control device 8 . The inert gas supply device 38 supplies the inert gas through the factory piping 40, for example, but may also supply the inert gas from a gas cylinder.

The heat treatment chamber 4 inside the pressure-resistant chamber 1 includes a third holding mechanism 35c for holding the object to be processed 50c, and a heater 42 for heating the object to be processed 50c held by the third holding mechanism 35c to heat the object to be processed 50c. heat treatment. As the heater 42, a lamp, a sheath heater, or the like used in so-called annealing treatment can be used.

Electric power is supplied to the heater 42 from a heater power supply 43 arranged outside the pressure-resistant chamber 1 . The heater power supply 43 is controlled by the control signal S8 from the control device 8 .

A third decompression pump 25c is connected to the heat treatment chamber 4 via a decompression pipe 44, and the inside of the heat treatment chamber 4 is decompressed by the third decompression pump 25c and the decompression pipe 44 serving as a decompression mechanism. . The third decompression pump 25c is controlled by the control signal S7 from the control device 8 .

The heater 42 and the third holding mechanism 35c can also be understood as a heat treatment part.

The film forming apparatus 100 includes a first conveyance mechanism 30a that conveys the object to be processed 50a after the plasma processing has been completed from the first holding mechanism 23 in the plasma processing chamber 2 to the plasma processing chamber 2 without being exposed to the atmosphere. The second holding mechanism 35b in the film processing chamber 3 .

In addition, the film formation apparatus 100 includes a second conveyance mechanism 30b that conveys the object to be processed 50b that has completed the film formation treatment from the second holding mechanism 35b in the film formation treatment chamber 3 without being exposed to the atmosphere to the third holding mechanism 35c in the heat treatment chamber 4 .

In the film-forming apparatus 100 , when the film-forming process is performed, the object to be processed 50 a to be film-formed is carried into the plasma processing chamber 2 by a carrying mechanism not shown, and is held by the first holding mechanism 23 . It is preferable that the carrying-in mechanism (not shown) has a load lock chamber. When the processing object 50a is carried in, the opening and closing door 7a between the plasma processing chamber 2 and the film formation processing chamber 3 is closed.

The control device 8 sends the control signal S3 to the first decompression pump 25a to decompress the plasma processing chamber 2, and the control device 8 sends the control signal S1 to the control valve 18 to decompress the plasma generation source 15. A reaction gas of a predetermined pressure is supplied. Then, when the control device 8 transmits the control signal S2 to the plasma power supply 19 , the plasma power supply 19 applies an AC or DC voltage of the RF frequency (for example, 13.56 MHz) to the plasma generation source 15 via the power supply line 20 . (mainly negative voltage). Thereby, a discharge is generated in the plasma generating source 15, and the electrons generated by the discharge convert the reaction gas into plasma.

In the plasma processing chamber 2, the plasma generated by the plasma generation source 15 drifts from the right to the left by the distance d in FIG. 2, and reaches the processing target 50a.

In the stage of being discharged from the plasma generation source 15, the plasma is high temperature, but in the process of drifting in the plasma processing chamber 2, heat energy is lost due to collision with the reaction gas existing in the plasma processing chamber 2, etc., so the heat energy is lost. When reaching the processing object 50a, the temperature of the plasma has already dropped.

Therefore, in the film formation apparatus 100, the temperature increase of the process target object 50a during plasma processing can be suppressed.

Then, a part of the plasma changes from the plasma (charged state) to the activated state (radical state) due to collision with the reaction gas or the like. Thereby, the object to be processed 50a is also exposed to the reactive gas in the activated state (free state), not only the plasma of the reactive gas. In this specification, the reactive gas in a plasma state and the reactive gas in an activated state (free state) are referred to as a highly reactive reactive gas. Furthermore, the activation of the surface of the object to be processed 50a by the reactive gas in a plasma state and the reactive gas in a free state is referred to as plasma treatment.

By the plasma treatment, the surface of the object to be treated 50a is activated, and the bonding property with the metal atoms is improved.

The object to be processed 50 a after the plasma processing has been completed is transported to the film formation processing chamber from the first holding mechanism 23 in the plasma processing chamber 2 by the first transport mechanism 30 a provided in the plasma processing chamber 2 without being exposed to the atmosphere 3 in the second holding mechanism 35b.

When the object to be processed 50b is held by the second holding mechanism 35b in the film formation processing chamber 3 , the control device 8 transmits a control signal S5 to the power source 34 for sputtering, and a large power is supplied to the sputtering electrode 33 . The inert gas in the vicinity of the sputtering electrode 33 in the film formation processing chamber 3 is ionized by the electric power, accelerated by the electric field of the sputtering electrode 33 , and collides with the target material 32 , and the copper or other metal constituting the target material 32 is The atoms are released into the film formation processing chamber 3 and deposited on the processing object 50b.

That is, on the surface of the object to be processed 50b activated by the plasma treatment, metal atoms are formed in a state in which the activated portion is not deactivated by water vapor, oxygen, etc. in the atmosphere, and therefore, It is possible to form a metal film having high bonding property with the object to be processed 50b, that is, high adhesiveness.

In the conventional sputtering process, in order to improve the purity of the formed film, the pressure in the sputtering apparatus is generally reduced to about 0.1 Pa, and the film is formed. The reason for this is that when the pressure in the sputtering apparatus is higher than this, it becomes difficult to remove impurities such as water remaining in the sputtering apparatus or released from the object to be processed, and as a result, impurities are mixed into the film and the film becomes difficult to remove. Quality declines.

However, especially when the object to be processed 50b is resin, the amount of impurities released from the object to be processed 50b is large, and the release of impurities continues for a long time, so it is difficult to reduce the pressure to 0.1 as in the conventional sputtering apparatus. The film is formed at about Pa.

Therefore, in order to realize the formation of a high-performance film even if the amount of impurities released from the object to be processed 50b is large, the film forming apparatus 100 is provided with a device capable of inputting 10 kW or more, and more preferably 30 kW or more, into the sputtering electrode 33 . The power source of electric power is used as the power source 34 for sputtering.

When the electric power supplied to the sputtering electrode 33 is a large electric power, the amount of metal atoms such as copper released from the target material 32 increases compared with the case where the ordinary electric power is less than 10 kW, and the amount of metal atoms held by the metal atoms increases. Kinetic energy will also increase. As a result, in the film formation apparatus 100, the purity of the film formed on the object to be processed 50b is improved by reducing the concentration of impurities in the film formation processing chamber 3 relative to the concentration of metal atoms. Furthermore, since the kinetic energy of the metal atoms colliding with the object to be processed 50b is large, the molecules constituting the object to be processed 50b and the metal atoms are stably bonded, so that a film with higher adhesion to the object to be processed 50b can be formed.

The metal atoms released from the target material 32 go straight into the film formation processing chamber 3 , but are diffused (scattered) in the advancing direction by colliding with the inert gas in the film formation processing chamber 3 . However, in the conventional sputtering apparatus, since the kinetic energy of metal atoms is low, the metal atoms that collide with the inert gas and scatter and lose kinetic energy cannot adhere to the object to be processed with sufficient strength. Therefore, if the object to be processed has a concavo-convex shape, only metal atoms scattered and lose kinetic energy are irradiated on the side surface of the concavo-convex shape, making it difficult to form a uniform film on the object having the concavo-convex shape.

However, in the film formation apparatus 100 , the kinetic energy of the metal atoms when released from the target material 32 is large, and thus the metal atoms have sufficient kinetic energy even after scattering by the inert gas. Therefore, by irradiating the object 50b with metal atoms having various traveling directions and high kinetic energy due to scattering, a uniform film can be formed even on the object 50b having a concavo-convex shape.

In order to form a uniform film even on the object to be processed having a concavo-convex shape, the pressure in the film-forming processing chamber 3 is desirably about 0.5 Pa to 5 Pa. If the pressure is 0.5 Pa or less, it is difficult to sufficiently scatter the metal atoms at the time of release from the target material 32 , and if it is about 5 Pa or more, the concentration of impurities in the film formation processing chamber 3 may increase and the quality of the film may deteriorate. .

In addition, when the object to be processed 50b with few surface irregularities is the object to be processed, the pressure in the film formation processing chamber 3 may be set to less than 0.5 Pa, and the power supplied to the sputtering electrode 33 may be set to less than 0.5 Pa. Full 10kW.

In addition, the film formation source is not limited to the sputtering electrode 33 described above, and may also be an evaporation device or a chemical vapor deposition (chemical vapor deposition, CVD) device.

The object to be processed 50b in the film formation processing chamber 3 that has completed the film formation processing is not exposed to the atmosphere from the second holding mechanism 35b in the film formation processing chamber 3 through the second conveyance mechanism 30b provided in the film formation processing chamber 3 It is transferred to the third holding mechanism 35c in the heat treatment chamber 4 . Before the transfer, the inside of the heat treatment chamber 4 is decompressed by sending the control signal S7 to the third decompression pump 25c from the control device 8 .

When the object to be processed 50c is held by the third holding mechanism 35c in the heat treatment chamber 4, the control device 8 transmits a control signal S8 to the heater power supply 43, and power is supplied to the heater 42 to heat the object to be processed 50c. That is, so-called annealing is performed on the object to be processed 50c.

The heater 42 heats the temperature of the object to be processed 50c to a temperature of 100°C or higher, more preferably about 300°C to 550°C. Of these, the control device 8 and the heater power source 43 are preferably heated so that the temperature of the object to be processed 50c does not exceed the lowest temperature among its melting point, glass transition, or softening point.

In the film formation apparatus 100 , the object to be processed 50 b formed into the film in the film formation processing chamber 3 can be transferred to the heat treatment chamber 4 without being exposed to the atmosphere, and the heat treatment (annealing) can be performed in the heat treatment chamber 4 under reduced pressure. . Therefore, the thin film of copper or other metals formed in the film formation processing chamber 3 can be annealed while preventing the surface of the thin film from being oxidized by oxygen in the atmosphere. Thereby, the adhesiveness of the film formed in the film formation processing chamber 3 and the processing target object 50c can be improved further.

The object to be processed 50c that has completed the heat treatment is carried out from the heat treatment chamber 4 (and the pressure-resistant chamber 1 ) by a carry-out mechanism not shown. It is preferable that the unillustrated carry-out mechanism has a load-lock chamber.

Furthermore, in the film formation apparatus 100, the plasma processing chamber 2, the film formation processing chamber 3, and the heat treatment chamber 4 are provided in the pressure-resistant chamber 1, but the structure of the pressure-resistant chamber 1 is not the same. It is not limited to this.

For example, the partition wall 5a and the partition wall 5b which divide the plasma processing chamber 2, the film formation processing chamber 3, and the thermal processing chamber 4, respectively, may be eliminated. In this case, what does not change is that the plasma generation source 15 , the first holding mechanism 23 , the sputtering electrode 33 , the second holding mechanism 35 b , the heater 42 , the third holding mechanism 35 c and the like are arranged in the pressure-resistant chamber 1 . Inside.

Alternatively, the plasma processing chamber 2 , the film formation processing chamber 3 , and the heat treatment chamber 4 may be formed in different pressure-resistant chambers. Among them, in this case, it is desirable to provide between the plasma processing chamber 2 and the film formation processing chamber 3 and between the film formation processing chamber 3 and the thermal processing chamber 4, an inert gas that can be decompressed or can be heated The conveyance path for performing gas replacement. In this case, the processing objects 50a and 50b processed in the previous processing chamber can be transferred to the next processing chamber without being exposed to the atmosphere. Furthermore, the different pressure-resistant chambers and the conveyance path connecting these chambers that can be decompressed or replaced with gas can be understood as one pressure-resistant chamber as a whole.

When the plasma processing chamber 2, the film formation processing chamber 3, and the thermal processing chamber 4 are different processing chambers via the partition wall 5a, the partition wall 5b, or the conveyance path, each processing chamber can be independently controlled The pressure aspect is preferred. As a result, the plasma processing in the plasma processing chamber 2 , the film forming processing in the film forming processing chamber 3 , and the thermal processing in the thermal processing chamber 4 can be performed in parallel, and the processing of the film forming apparatus 100 can be further improved. ability. Furthermore, since the mutual contamination (contamination) between the plasma processing chamber 2, the film-forming processing chamber 3, and the thermal processing chamber 4 can be minimized, the quality of the formed film can be further improved.

In addition, at least one of the first holding mechanism 23 for holding the object to be processed 50a in the plasma processing chamber 2 and the second holding mechanism 35b for holding the object to be processed 50b in the film formation processing chamber 3 may have a rotation mechanism, The rotation mechanism rotates the processing objects 50a and 50b during processing, so that the processing of the processing objects 50a and 50b becomes uniform.

In addition, the first holding mechanism 23 may be provided on the side surface 29 of the plasma processing chamber 2 on the opposite side to the plasma generation source 15 .

In addition, the mechanism for reducing the pressure in the pressure-resistant chamber 1 is not limited to the first pressure reducing pump 25a to the third pressure reducing pump 25c described above. Low pressure factory piping such as vacuum is connected to the decompression piping 26 and the decompression piping 37 . In this case, the control device 8 controls the pressures in the plasma processing chamber 2 , the film formation processing chamber 3 , and the thermal processing chamber 4 by giving an opening and closing command to the pressure regulating valve.

(film formation method)

Hereinafter, an example of a film-forming method (hereinafter, referred to as a "first film-forming method") suitable for producing the metal film-coated object 61 according to the embodiment will be described with reference to FIG. 2 .

The first film formation method is performed using the film formation apparatus 100 and includes at least a part of the following steps.

(Importation of handling object)

The object to be processed 50 a is arranged at a position separated by a predetermined distance from the plasma generation source 15 provided in the plasma processing chamber 2 in the pressure-resistant chamber 1 . At this time, the distance from the plasma generation source 15 to the processing object 50a is set as the distance d.

When the processing object 50a is carried into the plasma processing chamber 2, the opening/closing door 7a between the plasma processing chamber 2 and the film formation processing chamber 3 is closed.

(Decompression in the plasma processing chamber)

The inside of the plasma processing chamber 2 is decompressed by the first decompression pump 25a and the decompression piping 26 serving as decompression means. At this time, the first decompression pump 25a is controlled by the control signal S3 from the control device 8 .

Furthermore, when the plasma processing chamber 2 is provided with a load-lock chamber and a loading mechanism (not shown) as described above, the pressure reduction in the plasma processing chamber 2 is prior to the arrangement of the processing object. and proceed.

(plasma treatment)

The reaction gas is supplied into the plasma generation source 15 from the reaction gas supplier 17 via the reaction gas supply pipe 16 , and electric power is applied to the plasma generation source 15 from the plasma power supply 19 . Thereby, the reactive gas in the plasma state and the reactive gas in the activated state (free state) are generated from the plasma generating source 15 . The plasma treatment of the object to be processed 50a is performed by exposing the object to be processed 50a to the reaction gas.

After a predetermined time has elapsed, the control device 8 stops the supply of the reactive gas to the plasma generation source 15 or reduces the supply amount, and at the same time terminates the application of electric power to the plasma generation source 15, thereby ending the plasma processing.

In the first film forming method, as an example, the reactive gas used in the plasma treatment may be oxygen.

As described above, the plasma processing method in the first film forming method has the feature of using not only the reactive gas in the plasma state but also the reactive gas in the activated state (free state) to process the object to be processed 50a plasma treatment. Therefore, by using oxygen, which has strong reactivity in a free state, as a reactive gas in the plasma treatment method in the first film formation method, the efficiency of the plasma treatment can be further improved.

In addition, the reaction gas may be nitrogen.

As an example, an object to be processed containing a resin as a main component can be used as the object to be processed 50a.

In general, resins have low heat resistance, and thus it is difficult to perform conventional plasma processing that raises the temperature of the object to be processed. However, since the first film forming method can prevent the high temperature of the object to be processed 50a by using the film forming apparatus 100, it is preferably used for the object to be processed 50a mainly composed of resin.

As an example, the object to be processed 50a mainly composed of glass can be used.

In general, glass is not resistant to rapid temperature changes, and conventional plasma treatment is difficult. However, the first film-forming method can prevent the temperature increase of the object to be processed 50a by using the film-forming apparatus 100, and is preferably used for the object to be processed 50a mainly composed of glass.

(Conveyance of the object to be processed)

The plasma-treated object 50a is transported from the plasma processing chamber 2 to the film formation processing chamber 3 by the first transport mechanism 30a. Before the transfer, the opening and closing door 7a between the plasma processing chamber 2 and the film formation processing chamber 3 is opened, and after the transfer, the opening and closing door 7a is closed.

The object to be processed 50 a is held by the second holding mechanism 35 b in the film formation processing chamber 3 . The object to be processed 50a conveyed and held by the second holding mechanism 35b in the film formation processing chamber 3 is referred to as an object to be processed 50b.

(film formation treatment)

By supplying an inert gas from the inert gas supply 38 to the film formation processing chamber 3 through the inert gas supply pipe 41 and supplying electric power to the sputtering electrode 33 from the sputtering power supply 34 , the film formation on the object to be processed 50 b is performed ( sputtering, sputtering).

At the time of sputtering, it is preferable to supply power of 10 kW or more, more preferably 30 kW or more, from the power supply 34 for sputtering to the sputtering electrode 33 . Thereby, the amount of metal atoms such as copper released from the target material 32 can be increased, and the kinetic energy possessed by the metal atoms can be increased, compared with the case where the electric power of a normal level (several kW) is input. As a result, as described above, a film having high purity and high adhesion to the object to be processed 50b can be formed.

Furthermore, it is preferable to set the pressure in the film formation processing chamber 3 at the time of film formation (sputtering) processing to about 0.5 Pa to 5 Pa. In the conventional sputtering process, if a film is formed in such a low vacuum, impurities may be mixed into the film and the quality of the film may be degraded. In addition, when the object to be processed 50b is resin, it is difficult to reduce the pressure during film formation to about 0.5 Pa by the outside air from the object to be processed 50b.

However, since impurities are prevented from being mixed into the film as described above by inputting a large electric power of 10 kW or more to the sputtering electrode 33, even under a pressure of about 0.5 Pa to 5 Pa, it is possible to form a high-purity and process object. A film with high adhesion to the object 50b.

Furthermore, by setting the pressure in the film formation processing chamber 3 during the film formation (sputtering) process to about 0.5 Pa to 5 Pa, a uniform film can be formed also on the object to be processed 50b having the uneven shape as described above.

Furthermore, when the surface of the object to be processed 50b has few irregularities, sputtering can be performed by setting the pressure in the film formation processing chamber 3 to be less than 0.5 Pa and the electric power supplied to the sputtering electrode 33 to be less than 10 kW.

In addition, the film formation is not limited to sputtering, and may be performed by vapor deposition, chemical vapor deposition (CVD), or the like. However, compared with other film forming methods, sputtering is preferable in that atoms constituting the film collide with the object to be processed 50b with higher energy, so that a film with better adhesion can be formed.

(Conveyance of the object to be processed)

The object to be processed 50b formed into a film in the film formation processing chamber 3 is conveyed from the film formation processing chamber 3 to the heat treatment chamber 4 by the second conveyance mechanism 30b. Before the transfer, the opening and closing door 7b between the film formation processing chamber 3 and the heat treatment chamber 4 is opened, and after the transfer, the opening and closing door 7b is closed.

The object to be processed 50b is held by the third holding mechanism 35c in the heat treatment chamber 4 . The object to be processed 50b conveyed and held by the third holding mechanism 35c in the heat treatment chamber 4 is referred to as an object to be processed 50c.

(heat treatment)

When the object to be processed 50c is held by the third holding mechanism 35c in the heat treatment chamber 4, the control device 8 transmits a control signal S8 to the heater power supply 43, and power is supplied to the heater 42 to heat the object to be processed 50c. That is, so-called annealing is performed by subjecting the object to be processed 50c to heat treatment.

As for the heating of the object to be processed 50c, it is preferable to heat the temperature of the object to be processed 50c to 100°C or higher, more preferably about 300°C to 550°C. Among these, it is preferable to heat so that the temperature of the object to be processed 50c does not exceed the lowest temperature among its melting point, glass transition, or softening point.

If the heating temperature is lower than 100° C., a sufficient annealing effect cannot be obtained, and if the temperature exceeds the lowest temperature among the melting point, glass transition, or softening point of the object to be processed 50 c , the object to be processed 50 c may be deformed.

The heating time of the object to be processed 50c is 1 minute or more, more preferably 3 minutes or more, and may be 1 hour or less, more preferably 20 minutes or less, in order to shorten the processing time (improvement of productivity).

When the heating time is less than 1 minute, a sufficient annealing effect cannot be obtained, and when the heating time exceeds 1 hour, there is a fear that productivity will decrease.

FIG. 3 is a diagram illustrating the change of the metal film 55 formed in the film forming step before and after the heat treatment, and FIG. 3( a ) shows the metal film 55 formed on the surface 50d of the object 50 before the heat treatment A partially enlarged view of the state, and FIG. 3( b ) is a partially enlarged view showing the state after the heat treatment.

Before the heat treatment shown in FIG. 3( a ), between the object to be processed 50 and the metal film 55 , a base oxide film layer 52 a is formed through which the composition containing the object to be processed 50 passes through. A deformed product that has undergone modification such as oxidation by the above-mentioned plasma treatment. The deformed product that has undergone oxidation or the like by plasma treatment is, for example, an oxide of the composition of the object to be treated 50 in the case of the treatment with oxygen plasma, and is the oxide of the composition of the object to be treated 50 in the case of treatment with nitrogen plasma, for example The nitride of the composition of the object 50 to be processed. Moreover, a part (for example, functional group) of the molecular structure of the composition which comprises the process target object 50 which is partially cut|disconnected by plasma processing is also included.

When the object to be processed 50 on which the metal film 55 is formed is heat-treated (annealed) from this state, oxygen or nitrogen contained in the base oxide film layer 52a reacts with the metal atoms in the metal film 55 by heat. . As a result, a metal oxide layer (or metal nitride layer) 53 mainly composed of the metal oxide or nitride constituting the metal film 55 is formed between the base oxide film layer 52 a and the metal film 55 .

In the first film formation method, the object to be processed 50b formed into the film in the film formation processing chamber 3 is transferred to the heat treatment chamber 4 without being exposed to the atmosphere, and heat treatment (annealing) is performed in the heat treatment chamber 4 under reduced pressure. Therefore, the thin film of copper or other metals formed in the film formation processing chamber 3 can be annealed while preventing the surface of the thin film from being oxidized by oxygen in the atmosphere. Thereby, the adhesiveness of the film formed in the film formation processing chamber 3 and the processing target object 50c can be improved further.

The thickness T53 of the metal oxide layer 53 (first layer) varies depending on the temperature or time of the heat treatment (annealing). Therefore, the temperature and time of the heat treatment (annealing) can be set so that the thickness of the first layer becomes an appropriate thickness.

When the thickness T52 of the base oxide film layer 52 (the second layer) is 2 nm or more and 5 nm or less, as described in the above-mentioned embodiment of the object with a metal film, it is possible to further increase the thickness T52 of the base oxide film layer 52 (the second layer) through the first layer (metal The oxide layer 53) and the bonding force between the base material 50 of the second layer and the metal film 55. Further, when the thickness T53 of the metal oxide layer 53 (first layer) is 0.5 nm or more and 5 nm or less, the bonding force between the base material 50 and the metal film 55 via the first layer and the second layer can be further improved.

Furthermore, a part of oxygen or nitrogen contained in the base oxide film layer 52a is lost from the base oxide film layer 52a by reacting with the metal atoms in the metal film 55, so the thickness of the base oxide film layer 52 after heat treatment is T52 is smaller than the thickness of the base oxide film layer 52a before the heat treatment.

The object to be processed 50c that has completed the heat treatment is carried out from the heat treatment chamber 4 (and the pressure-resistant chamber 1 ) by a carry-out mechanism not shown. When the object to be processed 50c is carried out, the opening and closing door 7b between the film formation processing chamber 3 and the heat treatment chamber 4 is closed.

In the above-described embodiment, in the plasma processing chamber 2, the film formation processing chamber 3, and the thermal processing chamber 4, which are simultaneously separated by the partition wall 5a and the partition wall 5b in the pressure-resistant chamber 1, the plasma processing, Film formation treatment and heat treatment, but the place where each treatment is performed is not limited to this.

For example, the plasma treatment, the film formation treatment, and the heat treatment may be performed in the pressure-resistant chamber 1 without the partition wall 5a and the partition wall 5b.

Alternatively, each process may be performed in separate pressure-resistant chambers. However, in this case, it is desirable to pass a gas capable of decompression or use of an inert gas between the plasma processing chamber 2 and the film formation processing chamber 3 and between the film formation processing chamber 3 and the thermal processing chamber 4 It is transported by replacing the transport path. In this case, the processing object 50a and the processing object 50b processed in the previous processing chamber may be transferred to the next processing chamber without being exposed to the atmosphere.

In addition, the first holding mechanism 23, the second holding mechanism 35b, and the third holding mechanism 35c that hold the processing objects 50a to 50c can have a rotation function for rotating the processing objects 50a to 50c. During the process, the processing objects 50a to 50b are rotated so that the processing of the processing objects 50a to 50c is uniform.

The above processing procedure can be performed by executing a program stored in the control device 8 in advance. Alternatively, the control device 8 may be mounted with a sequencing circuit.

(Another film-forming method)

Hereinafter, another example (hereinafter, referred to as a "second film-forming method") of a film-forming method suitable for producing the metal film-coated object 61 according to the embodiment will be described with reference to FIGS. 2 to 5 . However, most of the second film formation method is common to the first film formation method, and therefore, only the differences from the film formation method of the embodiment will be described below.

In the second film forming method, as an example, the object to be processed 50 is a substrate made of a material containing resin or glass, and a plurality of through holes 50h connecting the front surface 50d and the back surface 50e are formed.

FIG. 4( a ) shows a state in which, in the second film forming method, the plasma treatment described in the first film forming method is performed on the surface 50 d of the object to be processed 50 . The plasma treatment using oxygen radicals O* is performed in the plasma treatment chamber 2 of the film formation apparatus 100 shown in FIG. 2 .

Next, the object to be processed 50 is reversed, and as shown in FIG. 4( b ), plasma processing is performed on the back surface 50e. The oxygen radical O* is irradiated not only to the front surface 50d and the back surface 50e of the object to be processed 50 but also to the inner surface of the through hole 50h to activate these parts.

After that, the object to be processed 50 is moved from the plasma processing chamber 2 of the film forming apparatus 100 shown in FIG. 2 to the film forming processing chamber 3 , and as shown in FIG. 4( c ), the surface 50 d is subjected to sputtering On the other hand, a metal such as copper (Cu) is formed into a film. In the sputtering of the above-described embodiment, since copper atoms having various traveling directions and high kinetic energy due to scattering are irradiated to the object 50 to be processed, the inner surface of the through-hole 50h can also have high adhesion, and the metal film.

Next, the object to be processed 50 is reversed, and as shown in FIG. 4( d ), a metal film is formed on the back surface 50e and the inner surface of the through hole 50h.

In the plasma treatment and the film formation treatment, the processing order of the front surface 50d and the back surface 50e may be reversed from the order described above, respectively.

Through the above steps, as shown in FIG. 4( e ), a seed layer 51d and a seed layer 51e that are metal films are formed on the front surface 50d, the back surface 50e, and the inner surface of the through hole 50h of the object 50 to be processed. The object to be processed 50 on which the seed layer 51 d and the seed layer 51 e shown in FIG. 4( e ) are formed is referred to as the object to be processed 60 with the seed layer.

The thickness of the seed layer 51 is, for example, about 100 nm to 500 nm. In addition, the diameter of the through hole 50h is set to 20 μm to 50 μm in the front surface 50d and the back surface 50e, and 15 μm to 20 μm in the middle part of the front surface 50d and the back surface 50e. That is, the inner diameter may be large in the vicinity of the front surface 50d and the back surface 50e, and the inner diameter may be relatively small inside.

Thereafter, the object to be processed 50 (the object to be processed 60 with the seed crystal layer shown in FIG. 4( e )) is not exposed to the atmosphere from the film formation processing chamber 3 of the film formation apparatus 100 shown in FIG. 2 . It is moved to the heat treatment chamber 4, and heat treatment (annealing) is performed under reduced pressure. The heat treatment is performed under the conditions (temperature, time) shown in the first film-forming method.

The seed layer 51 having a predetermined pattern shape can be formed by selectively removing the seed layer 51 formed on the front surface 50d and the back surface 50e of the object 50 in the above steps by photolithography.

Alternatively, by masking a part of the surface (front surface 50d, back surface 50e) of the object to be processed 50 before the plasma treatment, the seed layer 51 may not be formed on the masked part, but may be formed on other surfaces Seed layer 51 .

In addition, the material of the seed layer 51d and the seed layer 51e to be formed is not limited to copper, and may be an alloy containing copper, or other metals such as aluminum, chromium, and nickel, and alloys containing these metals.

Electrolytic plating is performed on the object 60 with the seed crystal layer after the above-described heat treatment, using the seed crystal layer 51 as an electrode, and the plating layer 54 is formed on the seed crystal layer 51 .

FIG. 5 is a diagram showing the steps of the electrolytic plating. The object to be treated 60 with the seed layer is immersed in the electrolytic solution 46 of the electrolytic plating apparatus 45 , and the surface of the seed layer 51 is connected to a lead wire 49 a connected to a power source 47 . . The electrolyte solution 46 is provided with a counter electrode 48 , and a lead wire 49 b connected to the power source 47 is connected to the counter electrode 48 .

As an example, the electrolytic solution 46 contains copper ions, and by applying a potential lower than a predetermined potential difference to the lead wire 49b to the lead wire 49a, copper is deposited on the surface of the seed crystal layer 51 of the object to be processed with the seed crystal layer 60, and electrolysis is performed. plating. As the counter electrode 48, a copper plate is used as an example. The electrolyte 46 also penetrates into the inside of the through hole 50h, and since the seed layer 51 is also formed on the inner surface of the through hole 50h, copper is also plated inside the through hole 50h.

In addition, in the step of electrolytic plating, the surface of the seed layer 51 may be partially plated by shielding a part of the surface of the seed layer 51 in advance.

By finishing the step of electrolytic plating, the printed circuit board shown in FIG. 1 is completed as an example of the object 61 with a metal film.

In addition, the plating step is not limited to the electrolytic plating, and may be performed by electroless plating, or may be performed by combining electrolytic plating and electroless plating.

In addition, in the case where a sufficiently low resistance value can be obtained only by the seed layer 51, the plating step may be omitted.

Alternatively, the plating step in the second film formation method may be applied to the first film formation method. That is, in the first film forming method, a plating step may be performed on the object to be processed 50 after the heat treatment.

In the above content, various embodiments and modified examples have been described, but the present invention is not limited to these content. In addition, each of the embodiments and modified examples may be applied independently, or may be used in combination. Other forms that can be considered within the scope of the technical idea of the present invention are also included in the scope of the present invention.

(form)

It is understood by those skilled in the art that the plurality of exemplary embodiments described above are specific examples of the following forms.

(Item 1) An object with a metal film in one aspect includes: a base material including resin or glass; a metal film covering at least a part of the base material; and a first layer located between the base material and the metal film The second layer is located between the base material and the first layer and has the oxide of the composition of the base material as the main component. , the adhesion strength of the first layer to the second layer is 3 [N/cm] or more.

According to this structure, the adhesion force of the metal film 55 to the base material (object to be processed) 50 is improved, and the tough metal film 55 that is not easily peeled off can be realized.

(Item 2) The object with a metal film according to Item 1, wherein in the object with a metal film according to another aspect, the thickness of the second layer is 2 nm or more and 5 nm or less. Thereby, the adhesion force to the base material 50 via the metal films 55 of the first layer and the second layer can be further improved.

(Item 3) The object with a metal film according to Item 1, wherein in the object with a metal film according to another aspect, the thickness of the first layer is 0.5 nm or more and 5 nm or less. Thereby, the adhesion force to the base material 50 via the metal films 55 of the first layer and the second layer can be further improved.

(Item 4) The object with a metal film according to Item 1, wherein in another aspect of the object with a metal film, the thickness of the second layer is 2 nm or more and 5 nm or less, and the thickness of the first layer is 2 nm or more and 5 nm or less. The thickness is 0.5 nm or more and 5 nm or less. Thereby, the adhesion force to the base material 50 via the metal films 55 of the first layer and the second layer can be further improved.

(Item 5) The object with a metal film according to any one of Items 1 to 4, wherein in the object with a metal film according to another aspect, the substrate is a flat plate having through holes, and The metal film, the first layer, and the second layer are provided on at least a part of the inner surface of the through hole. Thereby, it is possible to realize an object with a metal film in which a wiring (metal 55h) made of a conductor and having high peel resistance is formed between the front surface 50d and the back surface 50e of a printed circuit board and a flat plate (substrate 50). 61.

(Item 6) The object with a metal film according to Item 5, wherein in the object with a metal film according to another aspect, the main component of the metal film is copper. As a result, an object with a metal film, which is a printed circuit board having a low resistance, can be realized.

(Item 7) The object with a metal film according to any one of Items 1 to 4, wherein in the object with a metal film according to another aspect, the adhesion strength of the metal film to the base material 3 [N/cm] or more. Therefore, an object with a metal film having a metal film with high peeling resistance can be realized.

[Explanation of symbols]

61: Object with metal film

50, 50a to 50d: Base material (object to be processed)

51, 51d, 51e: seed layer

52: Substrate oxide film layer (second layer)

53: Metal oxide layer (first layer)

54, 54d, 54e: Metal plating

55: Metal film

100: Film forming device

1: pressure chamber

2: Plasma processing chamber

3: Film formation processing room

4: Heat treatment room

8: Control device

15: Plasma generation source

16: Reaction gas supply pipe

17: Reactive gas feeder

18: Control valve

19: Power supply for plasma

23: First Holding Body

25a: The first pressure reducing pump

25b: Second pressure reducing pump

25c: Third pressure reducing pump

33: Sputtering electrodes

34: Power supply for sputtering

35b: Second retention mechanism

35c: Third retention mechanism.

Claims (7)

1. An object with a metal film, comprising: a substrate comprising resin or glass; a metal film covering at least a portion of the substrate; a first layer, located between the substrate and the metal film, mainly composed of an oxide of a metal constituting the metal film; and The second layer, located between the substrate and the first layer, is mainly composed of the oxide of the composition of the substrate, The adhesion strength of the first layer to the second layer is 3 [N/cm] or more. 2. The object with metal film according to claim 1, wherein The thickness of the second layer is 2 nm or more and 5 nm or less. 3. The object with metal film of claim 1, wherein The thickness of the first layer is 0.5 nm or more and 5 nm or less. 4. The metal filmed object of claim 1, wherein The thickness of the second layer is 2 nm or more and 5 nm or less, The thickness of the first layer is 0.5 nm or more and 5 nm or less. 5. The object with metal film according to any one of claims 1 to 4, wherein The base material is a flat plate with through holes, The metal film, the first layer, and the second layer are provided on at least a part of the inner surface of the through hole. 6. The object with metal film of claim 5, wherein The main component of the metal film is copper. 7. The object with metal film according to any one of claims 1 to 4, wherein The adhesion strength of the metal film to the base material is 3 [N/cm] or more.

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