JP2007314841A - Mask for use in forming film by sputtering, and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mask for use in forming a film, which gives an adequate edge shape to a thin-film pattern when the pattern is formed on a substrate with a sputtering technique. <P>SOLUTION: The mask which is used when the thin film pattern is formed on the substrate with the sputtering technique has an opening pattern corresponding to the thin film pattern. A portion of forming the opening pattern of the mask has a cross-section which forms such a taper shape that the taper angle can be 30 degrees to 60 degrees with respect to the surface placed in a substrate side when the film is formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a sputtering film forming mask and a method for manufacturing the same.

  Thin film technology is the most important technology that supports electronics in hardware. In recent years, the minimum dimensions of devices that make up electronics have shifted to the nanometer range. In order to realize such a device, the material inevitably becomes a thin film, and the fabrication of the material requires a controllability of nanometers to angstroms. On the other hand, industrially, materials and devices must be advanced without impairing productivity, and a technology having atomic level controllability and sufficient thin film formation speed is required. Furthermore, as the functions of devices are diversifying, the thin film forming materials to be controlled are becoming widespread such as semiconductors, magnetic materials, insulators, oxides, dielectrics, metals, and superdielectrics.

  The thin film thus laminated is, for example, for an electrode of a display device such as a liquid crystal display device or an electroluminescence display device, a functional thin film, a wiring of a printed wiring board, or a passive element formed on a printed wiring board. Examples thereof include a resistance film, a high dielectric film, and a film for controlling optical characteristics and molecular transmission.

  Thin film formation methods used in this way are mainly vapor deposition methods that have been used in the past, as well as plasma and ion beam assisted vapor deposition methods, ion plating methods, and ion beam sputtering methods that have been used in recent years for optical communications. In other cases, wet methods such as a sol / gel method and a spray method may be used. On the other hand, there is a sputtering method as a method used in mass production apparatuses in thin film manufacturing processes such as semiconductors, flat panel displays, and electronic components.

The sputtering method is a glow discharge between a substrate and a sputter target mainly made of metal or metal oxide while introducing an inert gas (mainly Ar gas) in a vacuum of 1.0 × 10 ⁻² Pa or less. In this technique, a high voltage is applied to cause ionized Ar to collide with a sputter target, and the sputtered material that has been blown off is deposited on the substrate. In the sputtering method, a direct current voltage (DC) is applied to the cathode (sputter target) when the sputter target is a conductive material such as metal, and a high frequency voltage is applied when the sputter target is an insulator such as ceramic or glass. It can be roughly divided into two methods of applying (RF). Among them, there are magnetron sputtering (FIG. 1), ECR sputtering, counter target sputtering, etc., depending on the sputtering method. The sputtering method is widely used as a method suitable for mass production because the film formation rate and film composition are stable and uniform film formation on a large area substrate is possible.

  However, when a thin film pattern is formed on a substrate using a metal mask by sputtering, the mask is thermally deformed due to thermal radiation generated on the target surface by plasma confinement, and recoil Ar ions and secondary electrons that are plasma charged particles. There is a concern that the pattern on the substrate will be blurred.

  In order to prevent this, a sputtering method using a non-conductive material with little thermal deformation as a mask material has been proposed (see, for example, Patent Document 1). In addition, a photosensitive resin material is provided on the ceramic substrate, a predetermined masking pattern is formed on the ceramic substrate by photolithography, and a blasting means is applied to the surface of the ceramic substrate having the photosensitive resin pattern. A ceramic mask having a desired opening pattern by forming a through-hole having an opening shape has been proposed (see, for example, Patent Document 2).

JP 11-36070 A JP 2003-170352 A

  However, the shape of the edge of the thin film pattern patterned on the substrate using the mask is determined by the directivity of the thin film material and the taper angle of the cross section of the opening of the mask pattern. In the forming method, there is a problem that precise taper angle cannot be controlled. Further, in the method of forming a masking pattern using a photoresist method, there is a problem that it takes time and cost by performing long and complicated processes such as resist coating, pre-baking, exposure, development, and post-baking.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a sputtering film forming mask in which the edge shape of a thin film pattern is good when a pattern is formed on a substrate using a sputtering method. And It is another object of the present invention to provide a method for manufacturing a sputtering film forming mask capable of easily and accurately controlling the taper angle of the opening cross section of the mask pattern.

  A first invention made to solve the problems of the present invention is a sputtering film forming mask having an opening pattern corresponding to a thin film pattern used when forming a thin film pattern on a substrate by a sputtering method. The cross-sectional shape of the portion where the opening pattern is formed is tapered with respect to the surface on the substrate side during film formation, and the taper angle of the cross-sectional tapered shape of the portion where the opening pattern of the mask is formed is 30 ° or more and 60. A sputtering film forming mask characterized by having a temperature of ≦ °.

  The second aspect of the present invention made to solve the problems of the present invention is characterized in that the maximum film thickness in a portion within 1 mm from the opening pattern of the mask is 20 μm or more and 200 μm or less. This is a film mask.

  According to a third aspect of the present invention, there is provided a thick film portion having a thickness of 1 mm or more and 5 mm or less in a portion exceeding 1 mm from the opening pattern of the mask. A sputtering film forming mask according to claim 1.

  4th invention made | formed in order to solve the subject of this invention, The said mask formation material consists of Pyrolytic Boron Nitride (pyrolytic boron nitride), Sputtering in any one of Claim 1 thru | or 3 characterized by the above-mentioned. This is a film forming mask.

  A fifth invention made in order to solve the problems of the present invention is a method of manufacturing a sputtering film forming mask according to any one of claims 1 to 5, wherein the plate has a convex portion corresponding to the opening pattern. A method of manufacturing a mask for sputtering film formation, comprising at least a step of depositing a mask forming material by a CVD method and a step of peeling the obtained mask from a plate.

  A sixth invention made to solve the problems of the present invention is characterized in that an angle formed between a side surface of the plate-like convex portion and the plate is 60 ° or more and 90 ° or less. It is a manufacturing method of the sputtering film-forming mask of description.

  The cross-sectional shape of the portion where the mask opening pattern is formed is tapered with respect to the surface on the substrate side during film formation, and the taper angle of the cross-sectional taper shape of the portion where the mask opening pattern is formed is 30 ° or more. By forming a thin film pattern on the substrate by sputtering using the sputtering mask of the present invention of 60 ° or less, the edge shape rises and the edge shape is uniform and the edge shape is not blurred. An excellent thin film pattern could be obtained on the substrate.

  By forming a thin film pattern on the substrate by sputtering using the sputtering mask of the present invention having a maximum film thickness of 20 μm or more and 200 μm or less in a portion within 1 mm from the opening pattern of the mask, the film thickness is uniform. A thin film pattern with excellent edge shape was obtained on the substrate.

  In addition, by increasing the film thickness at locations other than the periphery of the opening of the mask pattern, the impact resistance of the mask was improved, and the heat capacity increased due to the increase in volume, thereby suppressing thermal deformation of the mask. .

  In addition, by using Pyrolytic Boron Nitride (pyrolytic boron nitride) as a mask forming material, when a thin film is formed on a substrate in the sputtering method, the target surface radiant heat due to plasma confinement, and further, the edge loss of plasma causes Thermal deformation due to incident secondary electrons (accelerated electrons accompanying sequential ionization process) could be suppressed.

  Furthermore, the impact resistance of the mask could be improved by laminating the ceramic thin films by the CVD method. In addition, by forming a mask pattern opening by laminating a ceramic thin film on the surface of a plate having a mask pattern-shaped projection on the surface by CVD, the opening pattern of the sputtering mask can be easily formed. It was.

  Furthermore, by controlling the taper angle of the side surface of the convex part on the plate, the taper angle of the cross section of the opening of the mask pattern can be easily and accurately controlled, and a sputtering film forming mask having a desired taper angle can be manufactured. It has become possible.

  Hereinafter, an example of a sputtering film forming mask according to an embodiment of the present invention will be described in detail with reference to the drawings. As the sputtering method of the present invention, an ion beam sputtering method, a direct current sputtering method, a high frequency sputtering method, a magnetron sputtering method, or the like can be used. FIG. 1 shows a conceptual diagram of a magnetron sputtering apparatus when a magnetron sputtering method is used as a sputtering method in the present invention.

  In FIG. 1, a sputtering film formation mask 2 according to the present invention is disposed immediately below a substrate 1 and is used when target particles 6 a scattered from a sputtering target 6 are deposited in a desired pattern on the surface of the substrate 1. Here, in the magnetron sputtering apparatus, the magnet 9 is disposed on the back surface of the target 6 and the plasma 4 is generated by applying a magnetic field. Ar ions 5 in the plasma are accelerated by the voltage drop of the target 9 and are incident on the target 9, causing the target particles 6 a to jump out and adhere to the opposing substrate 1. Further, when Ar ions are incident on the target, secondary electrons 10 and the like are emitted in addition to the target particles 6a. The secondary electrons 10 and the expanded Ar ions are incident on the substrate 1 and the sputtering deposition mask 2.

  Next, the sputtering film forming mask of the present invention will be described. FIG. 2 is a cross-sectional view of the sputtering film forming mask of the present invention. In the sputtering film forming mask 2 of the present invention, the cross-sectional shape of the portion where the opening pattern 13 of the mask is formed is tapered with respect to the substrate side surface during film formation, and the opening pattern of the mask is formed. The taper angle θ1 in the taper shape of the cross section of the portion is 30 ° or more and 60 ° or less.

  FIG. 3 is an explanatory sectional view showing the relationship between the taper angle θ1 of the sputtering film forming mask and the sectional shape of the thin film pattern 15 obtained on the substrate 1. In the present invention, the taper angle θ1 of the cross section of the mask pattern opening is 30 ° or more and 60 ° or less. When the taper angle θ1 exceeds 60 °, the sputtered particles wrap around between the substrate and the mask, causing the thin film pattern 15 formed on the substrate to blur and adhere to the adjacent pattern (FIG. 3). (A)). On the other hand, if the taper angle θ1 is less than 30 °, the edge of the thin film pattern 15 formed on the substrate rises, the film thickness at the edge of the pattern increases, and the film thickness uniformity is lost. (FIG. 3B). Therefore, the taper angle of the mask is preferably set to 30 ° or more and 60 ° or less.

  In the sputtering mask of the present invention, the maximum film thickness in a portion within 1 mm from the opening pattern of the mask is preferably 20 μm or more and 200 μm or less. Moreover, it is preferable to have a thick film part with a thickness of 1 mm or more and 5 mm or less in a part exceeding 1 mm from the opening pattern of the sputtering mask.

  FIG. 4 shows a cross-sectional view of the sputtering mask of the present invention. 2 and 4, a portion within 1 mm of the opening pattern 13 is a thin film portion 11 having a maximum film thickness of 20 μm or more and 200 μm or less. In addition, in a portion exceeding 1 mm from the opening pattern of the sputtering mask, a thick film portion 12 having a thickness of 1 mm or more and 5 mm or less is provided.

  It is preferable that the maximum film thickness of the thin film portion 11 where the film thickness of the mask is thin is 20 μm or more and 200 μm or less. When the maximum film thickness of the thin film portion is less than 20 μm, it is difficult to maintain the hometown as a mask. In addition, when the maximum film thickness of the thin film portion exceeds 200 μm, the film thickness of the edge portion of the pattern becomes large.

  The thin film portion 11 is preferably at least 10 mm or more from the mask pattern opening. Thus, when the mask opening is separated from the step between the thin part and the thick part by 10 mm or more, the sputtered particles incident on the mask opening are blocked by the step between the thin part and the thick part. Can be prevented.

  Further, the film thickness of the thick film portion 12 which is a thick film portion of the mask is desirably 1 mm or more and 5 mm or less. When the thickness is within this range, sufficient impact resistance can be ensured, and the production cost is also preferable.

  In the sputtering film forming mask 2 of the present invention, a range 11 in which the thickness of the mask is reduced is provided around the opening pattern 13, and the thickness 12 of the mask other than the range in which the thickness of the mask is reduced is sufficient for impact. By making the film thickness strong, it is possible to prevent the mask from being broken by an impact when handling the mask.

  The sputtering film forming mask 2 in the present invention is preferably a ceramic having a smaller thermal deformation than a metal as a material constituting the mask body. This is because it is possible to suppress thermal deformation of the mask due to thermal radiation generated on the target surface by the plasma confinement 4 and further, recoil Ar ions and secondary electron incidence 10 (FIG. 1) which are plasma charged particles. . Known ceramics can be used, but Pyrolytic Boron Nitride (PBN, pyrolytic boron nitride) is preferable as a mask material because of its impact resistance. Here, PBN is a thin film formed by stacking parallel thin films having a hexagonal crystal structure composed of atoms of boron and nitrogen, and is formed by stacking BN (Boron Nitride) by a CVD method.

  Note that the sputtering film forming mask of the present invention may be a mask made of a plurality of materials. For example, the material for forming the opening pattern and the thick film portion may be different.

  Next, a method for producing the sputtering film forming mask of the present invention will be described. FIG. 5 is an explanatory view of a method for manufacturing the mask of the present invention.

First, the thin film 20 made of a mask forming material is laminated on the surface of the plate 16 having the mask pattern-shaped convex portions 17 on the surface (FIG. 5A). A CVD method is used as a lamination method. In the CVD method, the vaporized compound (source gas) containing the elements of the crucible inner wall surface forming material is directly or mixed with a carrier gas such as hydrogen or nitrogen to cause chemical reactions such as decomposition, reduction, oxidation, and substitution. This is a method of laminating ceramic thin films with a thickness of about several nm. The plate 16 and the convex portion 17 are fixed by a detachable method. As a detachable fixing method, for example, a fixing method using screws can be used.

The mask forming material constituting the thin film 20 made of the mask forming material is preferably BN (Boron Nitride). When BN is used as a mask forming material, source gases used in the CVD method are boron trichloride (BCl ₃ ) and ammonia (NH ₃ ). Further, as activation energy, heat (1800 to 2000 ° C.), plasma, near ultraviolet to vacuum ultraviolet / laser light is used.

  At this time, it is preferable that an angle θ2 formed by the side surface of the plate-like convex portion 17 and the plate is 60 ° or more and 90 ° or less. This is because when the angle is within this range, the taper angle of the cross section of the mask pattern opening formed on the surface of the plate 16 can be controlled to 30 degrees or more and 60 degrees or less.

By removing the projections 17 having the mask pattern shape from the thin film 20 made of the mask forming material formed on the surface of the plate 16 in this way, it is possible to form a through portion having a mask pattern opening shape in the ceramic layer.

Further, a thick film forming material is laminated using a mask 21 having an opening 23 in a range at least 10 mm away from the opening 13 of the mask pattern formed on the surface of the plate 16 (FIG. 5B). By doing so, it is possible to form the thick film portion 12 in which the mask becomes thick (FIG. 5C). The sputtering film formation mask 2 of the present invention is obtained by peeling the thin film having the opening pattern and the thick film portion laminated on the surface of the plate 16 through the above steps from the plate 16 (FIG. 5D).

  Examples will be described below.

<Manufacture of sputtering film forming mask>
Stainless steel was used as the plate, and a convex portion with an angle of 60 ° formed on the plate was provided on the plate. At this time, the convex part was fixed on the plate by a detachable method using screws. On this, pyrolytic boron nitride was laminated | stacked using CVD method so that a film thickness might be set to 50 micrometers. At this time, a cold-wall system of direct substrate heating was used as the CVD apparatus, boron trichloride (BCl ₃ ) was used as the source gas, and nitrogen and hydrogen were used as the carrier gas. The deposition temperature was 1300 ° C. and the total gas pressure was 10 Torr.

  By removing the convex portion from the pyrolytic boron nitride thin film, a through portion having an opening shape of the mask pattern was formed. The taper angle of the cross section of the mask pattern opening at this time was 45 °.

Next, using a mask, pyrolytic boron nitride was laminated using a CVD method so that the film thickness in a range 10 mm away from the opening of the mask pattern was 2 mm. Finally, the thin film was peeled from the plate to obtain the sputtering film forming mask of the present invention.

<Formation of thin film pattern>
Using the obtained mask, an electrode pattern having a thickness of 2 mm was formed on a glass substrate by sputtering. Here, direct-current voltage (DC) type magnetron sputtering was used as the sputtering apparatus. Moreover, ITO (Indium-Tin-Oxide) was used as a target, and Ar was used as an inert gas. Here, the film formation conditions were a discharge power of 600 W, a gas introduction pressure of 0.5 Pa, an Ar flow rate of 150 sccm, and an O ₂ flow rate of 1.5 sccm. The electrode pattern obtained on the substrate had a good edge shape and was an electrode pattern with a uniform film thickness. Further, the mask was not thermally deformed during the sputtering film formation, and the obtained electrode pattern had good positional accuracy.

FIG. 1 is a conceptual diagram of a magnetron sputtering apparatus. FIG. 2 is a cross-sectional view of the sputtering film forming mask of the present invention. FIG. 6 is an explanatory cross-sectional view regarding the relationship between the taper angle θ1 of the mask and the cross-sectional shape of the thin film pattern obtained on the substrate 1 FIG. 4 is a cross-sectional view of the sputtering mask of the present invention. FIG. 5 is an explanatory diagram of the mask manufacturing method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Sputtering deposition mask 3 Substrate rack 4 Ar plasma 5 Ar ion 6 Target 6a Target particle 7 Backing plate 8 Cooling water 9 Cathode magnet 10 Secondary electron 11 Thin film portion 12 Thick film portion 13 Opening pattern 15 Thin film pattern 16 Plate 17 Convex part 18 Screw part 20 Thin film 20 made of mask forming material
21 Mask 22 Masking part 23 Opening part

Claims (6)

In a sputtering film forming mask having an opening pattern corresponding to a thin film pattern used when forming a thin film pattern on a substrate by a sputtering method,
The cross-sectional shape of the portion where the opening pattern of the mask is formed is tapered with respect to the surface on the substrate side during film formation, and the taper angle of the tapered shape of the cross-section of the portion where the opening pattern of the mask is formed is 30 °. A mask for sputtering film formation, wherein the mask is 60 ° or more and 60 ° or less.   2. The sputtering film forming mask according to claim 1, wherein the maximum film thickness in a portion within 1 mm from the opening pattern of the mask is 20 μm or more and 200 μm or less.   3. The sputtering film forming mask according to claim 1, wherein the mask has a thick film portion having a thickness of 1 mm or more and 5 mm or less in a portion exceeding 1 mm from the opening pattern of the mask.   The mask for sputtering film formation according to any one of claims 1 to 3, wherein the mask forming material is made of pyrolytic boron nitride (pyrolytic boron nitride). It is a manufacturing method of the mask for sputtering film-formation in any one of Claim 1 thru | or 5, Comprising:
Manufacturing of a mask for sputtering film formation comprising at least a step of forming a mask forming material on a plate having a convex portion corresponding to the opening pattern by a CVD method and a step of peeling the obtained mask from the plate Method. 6. The method of manufacturing a mask for sputtering film formation according to claim 5, wherein an angle formed between a side surface of the plate-like convex portion and the plate is 60 ° or more and 90 ° or less.

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