JPH10321559A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the productivity of a semiconductor device by suppressing the occurrence of peeled foreign matters from the internal wall of an adhesion preventing jig provided in a film deposition device by simultaneously forming large irregularities having heights which fall within a specific range and small irregularities having specific heights on the internal surface of the adhesion preventing jig. SOLUTION: A semiconductor device is manufactured by forming a film while an aluminum adhesion preventing jig having both large irregularities having heights of several hundreds of μm to several tens of μm and small irregularities having heights of several tens of μm to several hundreds of nm formed by forming a porous film having irregularities of micro order by performing anodic oxidation after the surface of the film adhering section is roughened by sandblasting, etc., on the surface of the film adhering section of the jig is installed. Specifically, after the recessing and projecting shape having the maximum height of several hundreds of μm to several tens of μm is formed by sandblasting the surface of an aluminum base material 11 by using alumina particles 12, etc., the small irregularities are formed by performing liquid horning by jetting a fine abrasive 18a and a liquid 18b upon the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device in which dust generated during film formation in a sputtering film formation chamber is reduced.

[0002]

2. Description of the Related Art At present, in the management of a sputter deposition process in the production of semiconductor devices, the generation of particles (hereinafter referred to as foreign matters) is the most important problem. When foreign matter adheres to the wafer, film formation failure or disconnection of wiring may occur at the adhered portion, and the possibility of device failure increases as the size of the foreign matter increases. It is currently estimated that the defect caused by this foreign matter accounts for 50% or more of the device defect. For example, in a sputter deposition apparatus, high stress remains in a film that is unnecessarily adhered to a place other than the semiconductor substrate (wafer) in a film formation chamber, and the adhered film is eventually cracked or peeled off. It is believed that. With the diversification of materials used and the use of films having high residual stress in products, the number of foreign matter generation steps is on the increase. Therefore, from the viewpoint of stable production of devices, prevention of generation of foreign matter in the film formation chamber, that is, prevention of destruction of the adhered film in the film formation chamber is an essential issue.

[0003] This problem is not only related to the manufacture of semiconductor devices, but is also a problem common to magnetic disks, optical disks, thin-film magnetic heads, liquid crystal panels and the like manufactured by sputtering.

[0004] As the thickness of the sputtered film adhered to the inner wall of the film formation chamber increases, the shearing force generated at the interface of the adhered portion increases, and the sputtered film peels off from the inner wall. For this reason,
A so-called anti-adhesion jig is installed in the deposition chamber to prevent sputtered atoms from adhering to the inner wall of the film-forming chamber. To be exchanged.

[0005] However, the replacement of the deposition-preventing jig is performed by exposing the apparatus kept in vacuum to the atmosphere, so that the film is formed on the wafer until the inside of the film forming chamber is again in a vacuum state capable of forming a film. This has hindered the improvement of the number of processed wafers (throughput). Therefore, a film forming method capable of minimizing the replacement frequency is desired.

As a technique for preventing the separation of foreign matter for reducing the frequency of replacement, there are roughly two methods. One is a method to reduce the stress of the film to be attached,
Another method is to increase the adhesion strength of the film.

[0007] As a conventional technique aimed at improving the film adhesion strength, there is a method in which the film attachment portion of the anti-adhesion jig is subjected to thermal spraying such as sand blasting or aluminum to make the film attachment portion rough by surface anchoring. The adhesion was improved. These techniques are disclosed, for example, in JP-A-62-142758.

[0008]

However, in the prior art, there was a problem that the surface roughness had to be changed to an appropriate dimensional region each time according to the internal stress of the deposited film and its thickness.

For example, in the case where only large irregularities are formed, if the adhered film is thinner than the surface irregularities, it will adhere to a flat portion between the irregularities microscopically, and the adhesion strength of the film is not so high. It does not increase. In recent years, refractory metal films and the like which have been adopted as thin films for semiconductor devices have a very large internal stress of 1 GPa or more. Therefore, even if the film thickness is small, the film adhesion strength is exceeded and the film is peeled off. There is. Conversely, when only fine irregularities are formed, peeling of the film when the film thickness is small can be prevented,
When the film thickness increases, the anchor effect cannot be expected, and the film is easily peeled. Therefore, it is preferable that the shape is a combination of the rough unevenness and the fine unevenness. Specifically, it is desirable that a small unevenness of several μm or less is formed on a large unevenness of 100 μm or more.

As a method for roughening, sand blasting, thermal spraying, or the like is performed, and by these methods, it is possible to roughen the surface with irregularities having a maximum height of several tens to several hundreds of μm. However, when spraying fine aluminum powder of several μm or less into thermal spray particles, the thermal spray particles dissolve due to heat such as arc or plasma and the thermal spray particle supply nozzle is clogged. difficult. Since the range of usable particle size of the blasting sand and the sprayed powder is limited as described above, it is difficult to form small irregularities of several μm or less on the surface using very small particles. Therefore, good adhesion strength could not be maintained at all film thicknesses.

An object of the present invention is to form a large uneven shape having a height of several hundred μm to several tens μm and a small uneven shape having a height of several μm or less simultaneously on the inner wall of a deposition preventing jig in a film forming apparatus. It is another object of the present invention to provide a manufacturing method which suppresses the generation of foreign particles coming off from the inner wall of the deposition preventing jig and improves the productivity of the semiconductor device.

[0012]

SUMMARY OF THE INVENTION In a method of manufacturing a semiconductor device in which dust generation in a film forming chamber is reduced, a highly reliable semiconductor in which generation of peeling foreign matters from an inner wall of a deposition preventing jig in a sputter film forming apparatus is suppressed. In order to provide a method of manufacturing a device, the present invention has the following features.

(1) The method of manufacturing a semiconductor device according to the present invention
A method of forming a film that prevents peeling of a film adhered to an anti-adhesion jig installed in a sputtering film forming chamber and suppresses generation of foreign substances during film formation. After performing a roughening treatment such as sand blasting, anodizing is performed to form a porous film having irregularities on the order of microns, and a large surface having a height of several hundred μm to several tens μm A semiconductor device is manufactured by forming a film in a state where an anti-adhesion jig in which unevenness and small unevenness having a height of several tens μm to several hundreds of nm are simultaneously formed is installed.

(2) The film forming method of the present invention is a method of forming a film by preventing peeling of a film adhered to an anti-adhesion jig installed in a sputter film forming chamber and suppressing generation of foreign substances during film formation. Then, at least a part of the inner wall surface of the anti-adhesion jig is roughened by sandblasting or the like, the blasted surface is coated with an aluminum film, and the aluminum film surface is anodized to form a porous oxide film. Then, a film is formed in a state where an anti-adhesion jig is formed on the inner wall surface, in which large irregularities of several hundreds μm to several tens μm and small irregularities of several tens μm to several hundreds nm are formed at the same time. It is characterized by manufacturing the device.

The base material of the deposition jig of the deposition jig of the present invention described in (1) is not limited to aluminum, but may be any other material which is anodically oxidized to form a porous film, for example, Alternatively, the material may be one selected from aluminum alloy, titanium, titanium alloy, copper, and copper alloy. In addition, by performing a treatment such as liquid honing after performing a surface roughening treatment such as sand blasting on the surface of the anti-adhesion jig, a height of several hundred μm to It is also possible to form fine irregularities with a fine height of several tens of μm to several μm on the large irregularities of μm, and finally perform anodic oxidation.

The base material of the anti-adhesion jig according to the present invention described in (2) is preferably a material having good degassing properties because it is used in a vacuum vessel.
It is preferable that the material be one selected from aluminum, an aluminum alloy, zirconium, a zirconium alloy, stainless steel, silicon carbide, aluminum oxide, and silicon oxide.

The material for coating the base material of the present invention described in (2) is not limited to aluminum, but may be any other material which is anodically oxidized to form a porous film, for example, , Aluminum alloy, titanium, titanium alloy, copper, copper alloy. As a coating method, it is preferable to perform coating by a thin film manufacturing method such as thermal spraying, melt coating, vapor deposition, and sputtering. Further, by performing a treatment such as liquid honing on the surface of the coating film on the anti-adhesion jig before the anodizing, a finer height of 10 μm to 0.1 μm is formed on the coating film.
It is also possible to form small irregularities.

In the present invention described in (1) and (2), it is not necessary that all surfaces of the deposition preventing jig in the film forming apparatus have the features, and only the portion where the film is liable to adhere is provided. It is also effective to manufacture a semiconductor device by applying the present invention.

[0019]

According to the present invention, a roughening treatment such as sandblasting is performed on the inner wall of an anti-adhesion jig in a film forming apparatus, and then the surface is anodized to form a porous film. By forming, a height of several hundred μm
Simultaneously forming large irregularities of up to several tens μm and small irregularities of several tens μm to several hundred nm in height, and forming a film with this anti-adhesion jig installed, the inner wall of the anti-adhesion jig during film formation It is possible to form a film while suppressing the generation of foreign matter coming off the substrate. This leads to stable operation of the device, improvement in device manufacturing yield, and improvement in device quality, and makes it possible to manufacture a highly reliable semiconductor device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) An embodiment of a film forming method according to the present invention will be described with reference to a case where a semiconductor device is manufactured by forming a film using a sputtering apparatus.

FIG. 1 shows an apparatus configuration for performing a method of manufacturing a semiconductor device according to an embodiment of the present invention.

A target 1 is placed in a vacuum chamber 3 for a film forming chamber of a sputtering apparatus via an electrode insulator 2. In the case of sputtering, the semiconductor substrate 6 is set on the wafer stage 5 facing the target 1, a gas for plasma generation is introduced into the vacuum chamber 3 from the introduction port 7, and after reaching a predetermined gas pressure. Target 1
A plasma is generated by applying DC or AC power from a power supply 10 via a wiring 9 between the semiconductor substrate 6 and the semiconductor substrate 6, and a thin film of a target material is formed on the semiconductor substrate 6. The introduced gas is exhausted by a vacuum pump through the exhaust port 8.

As a gas to be introduced, an argon gas, a krypton gas, or a xenon gas is used, but a nitrogen gas or the like may be mixed for performing reactive sputtering.

When the sputtering is performed, the film adheres to places other than the semiconductor substrate. When the film thickness is large, the film self-collapses due to the internal stress of the film, and becomes a foreign substance.
The deposition preventing jig 4 is provided to prevent the sputtered film from directly adhering to the inner wall of the vacuum chamber 1 and to easily remove the deposited film by replacing the deposition preventing jig 4.

According to the present invention, the surface of the anti-adhesion jig is subjected to a treatment for preventing the adhesion film from peeling off to prevent the adhesion film from becoming thicker until the adhesion film becomes thicker, so that a stable film can be formed on the wafer. To provide a method of manufacturing a semiconductor device with high cost. Hereinafter, a method of surface treatment of an adhesion jig when aluminum is used as a base material of the adhesion jig will be described with reference to FIGS. 2 (1) to 2 (3).

(1) First, the surface of the aluminum base material 11 is sandblasted using alumina particles 12 of blast powder, and the surface roughness is reduced, for example, to a maximum height of several hundred μm.
The thickness is set to about several tens μm.

(2) The aluminum base material 11 is immersed in an acidic solution 9c such as sulfuric acid, phosphoric acid, oxalic acid, or chromic acid, and is acidified between the cathode 9b and the aluminum base material 11 using the power supply 10a via the wiring 9a. The surface of the aluminum base material 11 is anodized by applying a voltage to the solution 9c.
For example, a sulfuric acid solution 9c of 10 to 20 wt.
When used at 30 ° C., DC current density is 0.5 to 2 A / c
By performing the treatment at m ² and a voltage of 10 to 30 V, a porous film is formed on the surface of the aluminum base material 11. Also,
When a 2-4 wt.% Sulfuric acid solution is used at a temperature of 20-30 ° C., a DC current density of 0.5-1 A / cm ² and a voltage of 20
By performing the treatment at ３０30 V, a porous film is formed on the surface of the aluminum base material 11.

(3) Finally, it is possible to obtain a base material surface having small irregularities on the order of microns or less on the porous film.

By applying a surface treatment to the anodic oxide film described with reference to FIG. 2, the generation of foreign substances can be further suppressed. Addition of surface treatment to anodic oxide film Figure 3 (1), (2)
This will be described with reference to FIG. As an additional surface treatment, it is conceivable to control the crystallinity such as the orientation and the particle size of the deposited film by changing the base material of the film deposited portion. As a method of changing the base material, the inner surface of the hole 13 of the aluminum base material 11 and the porous film 15 as shown in FIG. There are methods of reducing the inner diameter and changing the surface base material. As a coating method, it is desirable to perform coating by melt coating, sputtering, chemical vapor deposition, or the like. Further, as shown in (2), the surface 16a of the porous film 15 can be chemically dissolved to form a new surface 16b, and the inner surface of the hole 13 can be expanded.

By using the method (1) or (2), the unevenness of the surface can be precisely controlled, and the peeling of the adhered film can be further suppressed.

A case where liquid honing is performed on the surface formed by the sandblasting process to form finer irregularities will be described with reference to FIGS. 4 (1) to 4 (4). Liquid honing is a method in which a mixture of water and a fine abrasive (abrasive size 50 μm or less) is sprayed to perform polishing. Fine particles are used as compared to ordinary sandblasting, so fine unevenness can be formed. It is.

First, as shown in FIG.
The surface of 1 is sandblasted using alumina particles 12 or the like to form an uneven surface having a maximum height of several hundreds to several tens of μm. Next, as shown in (2), the fine abrasive 18a and the liquid 1
Liquid honing is performed by injecting the mixture 8b in the direction 18c indicated by the arrow in the figure. At this time, fine irregularities 20 are formed. As shown in (3), the surface of the aluminum base material 11 is anodized to form irregularities 20 of several μm to several tens of nm to obtain a final shape as shown in FIG. When this processing method is used, irregularities on the surface having a maximum height of several hundreds to several tens of μm, irregularities of about several tens to
Asperities 20 of m to several tens of nm can be formed. If anodic oxidation is performed after this liquid honing, the shape becomes more complicated, so that the adhesion strength to the film can be further increased, and a more reliable semiconductor device can be manufactured by more stable film formation.

Next, the present invention in the case where sputtering is performed using a collimator will be described with reference to FIGS. 5 (a) and 5 (b). The collimator 30 has a honeycomb structure that faces the semiconductor substrate 6 from the target 1 and is provided between the target 1 and the wafer. It improves the rectilinearity of atoms to be sputtered in the direction of the wafer and enables film formation in a contact hole having a large aspect ratio. Conversely, sputtered atoms having poor directivity from the target 1 to the semiconductor substrate 6 adhere to the collimator holes 31. Therefore, the thickness of the deposited film is larger than that in the case of sputtering film formation without using a normal collimator.

The inner surface of the honeycomb structure of the collimator is usually subjected to a roughening treatment by blasting for the purpose of improving the adhesion strength of the adhered film. However, since it is not easy to apply a sand vertically and cut like a shield or the like, it is difficult to form a necessary surface unevenness only by blasting. For a part where physical surface roughening treatment is difficult such as blasting, in the case of anodic oxidation, unevenness is chemically formed, so that shape control can be easily performed.

A method of manufacturing a semiconductor device by the above-described sputtering film forming method will be described with reference to the cross sections of the semiconductor device shown in FIGS.

(A) is a cross section of the semiconductor device when the steps of forming the gate electrode 41, depositing the insulating film 42a, depositing the insulating film 42b, and forming the contact hole 44a are performed on the semiconductor substrate 6. For the manufacturing method up to this point, a conventionally known technique may be used.

(B) Next, a wiring 43a is formed by using the sputtering film forming method of the present invention. Since the generation of foreign matter is suppressed as much as possible, there is almost no place where the deposited thin film 43a is disconnected by the foreign matter or is not formed due to the foreign matter.

(C) Successively, Deposition of Insulating Film 42c, Thin Film 4
3b and an insulating film 42d are deposited. As for the film formation of the thin film 43b, the sputtering film formation method of the present invention is used as described in the above (b).

As described above, a stable film can be formed by using the present invention, and a highly reliable semiconductor device can be provided.

(Embodiment 2) In Embodiment 1, the invention in the case where anodically oxidizable metal such as aluminum was used as the base material of the anti-adhesion jig was described. However, depending on material properties such as heat conduction, jig strength, and surface shape, it may be structurally better to use a material different from the material described in the first embodiment. Here, a case where a film is coated on the surface of a base material using an arbitrary deposition-preventing jig base material and anodization is performed on the coating film will be described with reference to FIGS. 7 (1) to 7 (4). I do.

(1) First, an aluminum base material 11 is blasted with alumina particles 12 or the like. As the base material, stainless steel, titanium, or the like is preferable to increase the rigidity.

(2) Powder 20 of a material that can be anodized next
Is sprayed on the blasted surface and coated. Since the thermal spray powder is a powder having a diameter of about 10 to 100 μm, the thermal spray film 21a has irregularities of the same order as the thermal spray powder. As the thermal spraying material, pure aluminum, aluminum alloy, titanium, titanium alloy, copper, copper alloy and the like are desirable.

(3) Anodize the sprayed film 21a. A porous film 21b having many holes 13 on the film surface is formed. The anodic oxidation may be performed according to the procedure described in the first embodiment. The details are given to the first embodiment. For example, the wiring 9a is provided between the cathode 9b and the aluminum base material 11.
To a power supply 10a, and immersed in an acidic solution 9c such as sulfuric acid, phosphoric acid, oxalic acid, or chromic acid to apply a voltage,
Anodizing is performed on the surface of the aluminum base material 11.

(4) As a final shape, a surface of an anti-adhesion jig in which an irregular shape having a maximum roughness of several hundreds to several tens of μm and an irregular shape of several μm to several tens of nm are formed by blasting and thermal spraying. Shape can be obtained.

The method of spraying the aluminum base material 11 has been described as a method of coating. However, the method is not limited to the spraying, and the aluminum base material 11 may be coated by another method such as melt coating or sputtering. Furthermore, before coating or anodizing, liquid honing to the surface of the anti-adhesion jig base material or to the surface of the coating film for the purpose of forming fine irregularities having a finer height of 10 μm to 0.1 μm. Is also effective.

By using the present invention, the adhesion strength of the film adhering to the deposition preventing jig can be increased, and a more reliable semiconductor device can be manufactured by performing more stable film formation.

[0048]

As described above, the use of the deposition-inhibiting jig for the film-forming chamber of the film-forming apparatus according to the present invention can reduce the generation of foreign matters and can form a good film. By using this film forming method, a sputtering device can be operated stably, and a highly reliable semiconductor device can be manufactured by stable film formation.

[Brief description of the drawings]

FIG. 1 is an apparatus configuration diagram of a film forming apparatus when a method of manufacturing a semiconductor device according to a first embodiment of the present invention is performed.

FIG. 2 is an explanatory cross-sectional view of a method of manufacturing a deposition-preventing jig used when performing a method of manufacturing a semiconductor device according to a first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a surface treatment method for an anti-adhesion jig used when the method of manufacturing a semiconductor device according to the first embodiment of the present invention is performed.

FIG. 4 is an explanatory cross-sectional view of another method of manufacturing a deposition-preventing jig used when performing the method of manufacturing a semiconductor device according to the first embodiment of the present invention.

FIG. 5 is an apparatus configuration diagram of a film forming apparatus when a method of manufacturing a semiconductor device using the collimator according to the first embodiment of the present invention is performed.

FIG. 6 is an explanatory cross-sectional view of a method of manufacturing a deposition-preventing jig used when performing a method of manufacturing a semiconductor device according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a film forming method in a film forming chamber apparatus according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Target, 2 ... Target insulator, 3 ... Vacuum chamber, 4 ... Adhesion prevention jig, 5 ... Wafer stage, 6 ... Semiconductor substrate, 7 ... Inlet, 8 ... Exhaust, 9,9a ... Wiring, 9b
... Cathode, 9c ... Acid solution (sulfuric acid, phosphoric acid, oxalic acid, chromic acid, etc.) 10, 10a ... Power supply, 11 ... Aluminum base material, 12 ... Alumina particles, 13 ... Holes, 15 ... Porous film, 16a, 16b: Surface, 17: Film, 18a: Abrasive, 18b: Liquid, 18c: Direction of arrow, 19: Fine irregularities on the surface of the anti-adhesion jig base material formed by liquid honing,
Reference numeral 20: unevenness, 21a: sprayed film, 21b: sprayed film on which fine unevenness is formed by anodic oxidation, 30: collimator, 3
1: Collimator hole, 41: Gate electrode, 42a, 42
b, 42c, 42d ... insulating film, 43a, 43b ... thin film,
44a: contact hole; 44b: through hole.

Claims (1)

[Claims] In a method of manufacturing a semiconductor device in which a semiconductor substrate is transported into a sputtering device and a wiring or a capacitor made of a conductive thin film is formed by a sputtering method, a surface of a film forming chamber or a surface of the inner wall of the sputtering device is removed. A method of manufacturing a semiconductor device, wherein a surface of an anti-adhesion jig to be covered has irregularities with a maximum height of 10 to 500 microns, and irregularities of 10 nanometers to 5 microns are formed on each irregular surface. .