JP2001232555A - Flattening method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently flattening a workpiece formed so as to allow a metallic film to be buried in only a groove on a surface of a substrate by a lift-off method and providing a metallic film formed face as a face to be machined. SOLUTION: A surface of a hard material layer accumulated on a soft material layer is used as a lap face, and mechanical lapping polishing a face to be machined of the workpiece is done on the lap face. Furthermore, buff polishing and MCP or CMP are done to flatten the face to be machined of the workpiece.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for flattening a work, and more particularly to a method for flattening a metal film forming surface of a work in which a metal film is buried only in a groove formed on the work surface by a lift-off method. On how to do it.

[0002]

2. Description of the Related Art In recent years, processing methods for flattening a processing surface of a processing object by polishing have been applied in various fields. Various flattening methods and flattening apparatuses have been proposed to improve the processing accuracy of flattening.

[0003] Work flattening can be carried out by various methods which differ in the type of abrasive grains used and the polishing mechanism. One example of the planarization method is mechanical wrapping. Mechanical lapping is a mechanical polishing method performed in a state where a slurry-like lapping agent containing abrasive grains is supplied between a work surface and a lap surface of a work and the abrasive grains are semi-fixed to a lapping machine. It is. Generally, a cast iron board or the like is used as a lapping machine, and one or more kinds of abrasive grains selected from diamond abrasive grains, alumina abrasive grains, SiC, zirconia, etc. are used as a lapping agent, in light oil, olive oil,
A mixture of oil or water, such as a seed oil or a wrapping-only liquid, is used. Planarization methods other than mechanical lapping include buffing, mechanochemical polishing using a solid-phase reaction between a workpiece and abrasive grains, and a chemical reaction between a workpiece and a solution in a slurry (eg, an alkaline solution). Chemical mechanical polishing (CMP) is well known. Work flattening depends on the type of work, especially the shape and material of the work surface,
One or more suitable methods are selected from the above-described planarization methods.

Now, as a work requiring flattening, a work is formed in which a metal film is buried by a lift-off method only in a groove formed on the surface of a substrate, and the surface on which the metal film is formed is used as a work surface. There is something. The reason why such a work should be flattened will be described below together with the outline of the lift-off method.

FIGS. 6A to 6F are schematic views showing the procedure of the lift-off method. First, the prepared substrate (10) (Fig. 6
(A)) is coated with a resist (FIG. 6 (b)), and the resist (14) is exposed and developed to form a predetermined resist pattern (FIG. 6 (c)). The resist pattern is determined according to the pattern of the groove formed on the substrate (10). Next, dry etching is performed to form a groove (16) in the exposed substrate portion (FIG. 6D), and after forming the groove, the metal is sputtered onto the surface of the resist (14) and the groove (16). And a metal film (12) is formed on the entire surface (FIG. 6E). The metal film (12) is deposited such that the surface of the metal film (12) embedded in the groove (16) is substantially flush with the surface of the substrate (10). After forming the metal film (12), the substrate (1
The resist (14) and the metal film (12) thereon are removed by immersing 0) or the like so that the metal film (12) remains only in the groove (FIG. 6 (f)).

As shown in FIG. 6E, the metal film (12)
When forming by sputtering, the metal is resist (1
It adheres and deposits on the side of 4). This part is resist (1
As shown in FIG. 6F, burrs (18) protruding from the surface of the substrate (10) are formed, and the flatness of the surface is remarkably reduced. Also, when metal is deposited by sputtering, the metal film (12) in the groove tends to have uneven thickness, and there is a portion where the surface of the metal film (12) and the surface of the substrate (10) are not on the same plane. In other words, a so-called recess (or recess) may be formed. This recess also reduces the flatness of the surface. As described above, it is difficult to make the surface of the substrate (10) including the metal film (12) a flat surface with high precision only by the lift-off method. Therefore, in order to obtain higher flatness on the substrate (10) on which the metal film (12) is formed by the lift-off method, a flattening process by polishing is required.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. For example, in a work in which a metal film is deposited in a groove on a substrate surface by a lift-off method, the surface on which the metal film is formed is formed. It is an object to provide a flattening method particularly suitable for flattening.

[0008]

According to the present invention, there is provided a method for flattening a workpiece by mechanical lapping, wherein a surface of a hard material layer laminated on a soft material layer is used as a lap surface. A first object of the present invention is to provide a flattening method characterized in that a work surface of a work is polished on a surface.

Since mechanical lapping is suitable for polishing relatively large unevenness, mechanical lapping can efficiently remove burrs remaining on a work on which a metal film is formed by a lift-off method. The thickness unevenness of a certain metal film can be reduced to some extent.

The above flattening method is characterized in that mechanical lapping is performed using the surface of the hard material layer laminated on the soft material layer as a wrap surface. In the present specification, "soft" when referring to a soft material layer and a hard material layer
The terms "hard" and "hard" are used in a relative, not absolute, sense. Therefore,
If one layer is softer than the other in a combination of two layers, it can be said that the combination is a combination of a soft material layer and a hard material layer. Whether or not a material is “soft” is determined by whether or not the material easily conforms to the surface shape of an object in contact with the material. Therefore, the soft material layer tends to follow the surface shape of the object in contact with it, and the hard material layer does not easily follow the surface shape of the object in contact with it.
The indication of softness (hardness) includes, for example, Young's modulus.

[0011] The above feature is that, when "waving" or "warping" having a period of several centimeters and an amplitude of several micrometers on the surface to be processed of the work, the undulation caused by the undulation or warpage is maintained as it is. It is possible to flatten only the fine irregularities existing on the surface of the surface to be processed by polishing. That is, the soft material layer ensures that the lap surface follows large undulations or warpages present in the entire work, and the hard material layer does not substantially follow the surface shape of the object, thereby forming The protrusions of the fine unevenness existing on the surface are polished first to ensure that the surface to be processed is flattened.

[0012] The undulation and warpage are likely to occur in a work in which different materials having different linear expansion coefficients and the like are combined. A substrate in which a metal film is formed only in a groove by a lift-off method can be said to be a work in which different materials are combined, and undulation and warpage are likely to occur. In addition, when external force was applied during the manufacturing process and internal strain was generated, swelling and warping were likely to occur when the stress was released by forming a thin substrate, and undulation was generated in that way The flattening method by the mechanical lapping of the first aspect can be applied to the work.

The soft material layer is preferably made of, for example, rubber or sponge having a small Young's modulus. The hard material layer is preferably made of a material that is harder than the soft material layer and is not harder than the work, and specifically, is preferably made of a hard polyurethane foam.

It is preferable that the work in which the metal film is formed only in the groove on the substrate surface by the lift-off method be subjected to mechanical lapping a plurality of times by changing the size of the abrasive grains. By changing the dimensions of the abrasive grains, the surface to be processed of the work can be made a plane with higher precision. It is preferable that the mechanical lapping is started by using abrasive grains having a large size, and then sequentially performed by reducing the size of the abrasive grains.

According to the present invention, there is provided a method of flattening a work, wherein the work has a groove on a surface thereof, and a metal film is formed by a lift-off method so as to be embedded only in the groove. , The surface of the hard material layer laminated on the soft material layer as a wrap surface, and the work surface is formed on the lap surface. A planarization method for performing planarization by performing mechanical lapping for polishing a processed surface, performing buff polishing as a second step, and performing mechanochemical polishing and / or chemical mechanical polishing as a third step is a second step. Provided as a summary of.

This planarization method includes buffing and mechanochemical polishing (sometimes abbreviated as MCP) and / or chemical mechanical polishing (CMP).
) May be combined with mechanical wrapping. According to this flattening method, scratches generated by mechanical lapping can be removed in a later step, and a higher degree of flatness is imparted to the work surface of the work.

The mechanical lapping performed as the first step is performed to remove burrs of the metal film generated by the lift-off method and to reduce thickness unevenness of the metal film forming the recess in the groove. You. The mechanical lapping is performed in the same manner as in the planarization method according to the first aspect, and may be performed a plurality of times while changing the size of the abrasive grains.

The buff polishing performed as the second step is performed to remove scratches formed on the substrate surface (including the metal film surface) by mechanical lapping. The buff polishing can be performed by a conventional method, and can be performed using appropriate buffs and abrasive grains according to the type of the substrate surface and the metal film.

The buff used for buffing is a soft sheet having long bristle feet (for example, a suede-type foamed polyurethane). Therefore, when buffing is performed, the polishing of the metal film proceeds more, and the buffing proceeds. A step is formed between the surface of the substrate and the surface of the substrate, and a recess easily occurs on the surface to be processed. Therefore, MCP and / or CMP performed as a third step is performed to eliminate a recess caused by buffing. When the MCP and / or CMP is performed, the protruding substrate surface is polished preferentially, and the metal film surface is further polished, so that the finally-processed surface forms a highly accurate plane.

Further, according to the present invention, in the flattening method according to the second aspect, as a first step, instead of carrying out mechanical lapping, a portion having a clearance angle of 0 ° on a clearance surface side is cut in the cutting direction. Using a single crystal diamond tool that is provided so that the length of the groove is larger than the width of the groove formed in the work, the tool is moved to the work so as to cross the width direction of the groove formed in the work. The flattening method of performing cutting by relatively moving is the third method.
Provided as a summary of. This flattening method is characterized in that as a first step, cutting using a specific cutting tool is performed instead of mechanical lapping.

In the above-mentioned flattening method, a portion having a clearance angle of 0 ° is provided on the flank side, and the length of the portion in the cutting direction is larger than the groove width of the groove formed in the work. Use a single crystal diamond tool with dimensions. Since there is a part where the clearance angle is 0 ° in this cutting tool, the flank side of the cutting edge of the cutting tool is always in contact with the work, whereby the cutting edge is supported by the work and its position does not change. If it is used, stable cutting can be performed.

In the present invention, it is preferable to move the cutting tool relatively to the work so as to cross the width direction of the groove formed in the work. That is, it is preferable that the cutting direction, which is the relative moving direction of the cutting tool, be a direction orthogonal to the width of the groove. In order to move the cutting tool relative to the work, it is necessary to move the cutting tool itself or to move the work with the position of the cutting tool fixed. Alternatively, both may be moved.

When the cutting direction is as described above, the length of the portion where the clearance angle is 0 ° in the cutting direction is preferably larger than the width of the groove formed in the work. If the length in the cutting direction of the portion where the clearance angle is 0 ° is smaller than the width of the groove formed in the work, the entire portion where the clearance angle is 0 ° enters the groove, and as a result, the inside of the groove Excessive cutting or uneven cutting may occur on the metal surface to cause recess. More preferably, the portion where the clearance angle is 0 ° has a dimension in which the length in the cutting direction is about twice the width of the groove. The cutting is preferably performed under the condition that the cutting depth is 1 μm or less and the work does not break brittlely.

Although the flatness of the surface to be processed after cutting by the cutting tool is inferior to polishing, the processing efficiency is very high. Therefore, by combining cutting, which is excellent in efficiency, and polishing, which is excellent in accuracy, it is possible to efficiently obtain a highly accurate plane.

[0025]

Next, an embodiment of the present invention will be described. In order to implement the flattening method according to the first aspect of the present invention, it is necessary to stack a soft material layer and a hard material layer, and perform mechanical lapping with the surface of the hard material layer as a wrap surface.

The soft material layer is used for causing the lap surface to follow the undulation or warpage generated on the entire work surface of the work. The hard material layer is used to flatten fine irregularities existing on the surface to be processed of the work together with abrasive grains supplied between the surface and the work. Each of the soft material layer and the hard material layer can be formed by selecting an appropriate material according to the type of a workpiece to be planarized.

For example, based on the method described above with reference to FIG. 6, a groove having a width of 2 to 5 μm and a depth of 0.4 ± 0.1 μm is formed on the surface of the silicon substrate at a groove interval of 2 to 10 μm. In the case of mechanically wrapping a workpiece having a metal film such as aluminum, copper, cobalt, or nickel formed only in the groove by a lift-off method, the soft material layer is made of neoprene rubber having a Young's modulus of about 1 to 20 MPa. It is preferably a sponge sheet. Such a soft material sheet, for example, consists of polyurethane
Suba400 (trade name; manufactured by Rodale Nitta) or a rubber sheet can be used.

The hard material layer has a Young's modulus of 50 to 15
It is preferably a foamed polyurethane sheet of about 0 MPa. Such a hard material layer may be a polishing pad commonly employed in CMP or MCP, for example, IC1000 (trade name; manufactured by Rodale Nitta) made of polyurethane or L made of polyurethane.
A P series (manufactured by Kuju Denki) or the like can be used.

It is preferable that the soft material layer has a thickness sufficient to ensure the followability to the undulation or the like generated on the work surface of the workpiece. It is preferable that the layer is thin enough not to obstruct the undulation of the work and not thick enough to follow fine irregularities on the work surface of the work. For example, when flattening the work of the above-described embodiment, the thickness of the soft material layer exemplified above is preferably about 0.5 to 2 mm, and the thickness of the hard material layer is preferably about 0.1 to 2 mm.

It is preferable that the soft material layer and the hard material layer are incorporated in a lapping machine such that the surface of the hard material layer becomes a lap surface. For example, two layers are laminated on a lapping machine of a commonly used lapping machine so that a soft material layer is in contact with the lapping machine and a surface of the hard material layer is exposed as a lapping surface. It is good to attach to the board. Further, it is preferable to fix the gap between the soft material layer and the lapping machine and the gap between the soft material layer and the hard material layer with an adhesive or the like so as not to cause a shift or the like.

A laminate obtained by combining a soft material layer and a hard material layer is itself useful as a lapping tool constituting a lapping device. In addition, wrapping equipment incorporating this wrapping tool,
That is, a lapping apparatus having a surface of a hard material layer laminated on a soft material layer as a wrap surface is also useful as an apparatus capable of performing the mechanical lapping described below.

The mechanical lapping can be carried out under the conditions usually employed. For example, when the work is substantially circular, the shape of the lapping machine may be an annular body whose radial width is equal to or larger than the diameter of the work. Then, the work is rotated (rotated) about an axis passing through the center thereof and perpendicular to the surface to be processed, and the lapping machine is rotated (rotated) about an axis passing through the center and perpendicular to the lap surface. The mechanical lapping may be performed by supplying a lapping agent onto the lapping surface. The rotation speed of the work and the lapping machine differs depending on the work,
Generally, the rotation speed of the work may be about 10 to 100 rpm, and the rotation speed of the lapping machine may be about 10 to 100 rpm. The lapping agent comprises, for example, abrasive grains such as diamond abrasive grains, alumina abrasive grains or SiC, and oil or water such as light oil, olive oil or seed oil. The abrasive grains and oil may be supplied separately, or may be supplied as a slurry in which the abrasive grains are dispersed in oil or the like.

During the lapping, the work may be pressed against the lap surface by using a suitable load mechanism, for example, so that a predetermined pressure is generated between the work and the surface to be processed. The higher the pressure, the higher the lapping speed (ie, the processing rate).

FIGS. 1 and 2 schematically show mechanical lapping performed in the planarization method of the present invention. FIG. 1 is a perspective view showing a state in which a disk-shaped workpiece (1) is mechanically wrapped. In the embodiment shown, a single-sided lapping machine is used, the lapping machine (104) being a conventionally employed annular body, the radial width of which is approximately equal to the diameter of the workpiece (1). A sheet (100) made of a soft material and a sheet (102) made of a hard material are laminated and attached in this order to the lapping machine (104), and the surface of the hard material sheet (102) is replaced by the lapping machine (104). A wrap surface (105) is formed. The work (1) held by a holder (not shown) rotates around a vertical axis h passing through the center thereof. The lapping machine (104) also rotates about a vertical axis k passing through the center thereof. Work (1) and lapping machine (10
The rotation direction of 4) is as shown by the arrow in the figure. In the illustrated embodiment, the abrasive grains (106
a) and the oil (106b) separately from the nebulizer (108a)
(108b) is sprayed on the wrap surface.

FIG. 2 is a cross-sectional view in the thickness direction of the work (1) showing the state near the work surface and the lap surface (105) of the work (1) during lapping as shown in FIG. It is represented by In the illustrated embodiment, the work (1) is formed such that the metal film (12) is buried only in the groove (16) on the surface of the substrate (10) by a lift-off method. The formation surface is a work surface. The work surface of the work (1) is in contact with the lap surface (the surface of the hard material layer) (105) via a lapping agent (106) containing abrasive grains and oil. The work (1) is held by a holder (not shown). The work surface of the work (1) is finely cut by the lapping agent (106).

When the work is formed by a lift-off method so that the metal film is buried only in the groove on the surface of the substrate, first, mechanical lapping is performed with abrasive grains having a large size to remove burrs of the metal film. Then, in order to eliminate scratches formed by the use of large abrasive grains and obtain a more accurate flat surface, it is preferable to perform mechanical lapping with abrasive grains having small dimensions. In order to obtain a more accurate plane, mechanical lapping may be performed with abrasive grains having smaller dimensions. That is, in the flattening method according to the first aspect of the present invention,
By sequentially changing (preferably reducing) the size of the abrasive grains
A plurality of times of mechanical wrapping may be performed.

Next, an embodiment of a flattening method according to the second aspect of the present invention will be described. The flattening method is a work having a groove on a substrate surface and a metal film formed by a lift-off method so that the metal film is embedded only in the groove, and a work having a surface on which the metal film is formed as a work surface. Will be implemented. The method for forming such a work is as described above with reference to FIG. 6, and a detailed description thereof will be omitted. The work in which the metal film is formed only in the groove by the lift-off method can be used, for example, for manufacturing a semiconductor device, or is a master used when manufacturing a magnetic recording medium, and has a predetermined shape on a substrate for a magnetic recording medium. It can be used to manufacture a magnetic transfer master disk or the like in which the magnetic portion is formed so that the magnetic information can be provided by transfer.

The flattening method according to the second aspect of the present invention comprises:
The flattening method according to the first aspect of the present invention is performed as a first step, buff polishing is performed as a second step, and MCP or CMP is performed as a third step, thereby flattening a workpiece. is there. The first step is a step for removing burrs generated on the work on which the metal film has been formed by the lift-off method and for reducing the thickness unevenness of the metal film in the groove. Since the mechanical wrapping performed in the first step is as described above, a detailed description thereof will be omitted here. In the first step, the mechanical lapping may be performed plural times. However, since high flatness can be obtained by the second and third steps, it is not particularly necessary to perform high-precision flattening processing in the first step.

In the second step, buffing is performed to remove scratches generated on the surface to be processed in the first step. The buff and abrasive used in the buff polishing may be selected from commonly used ones according to the material of the work and the like. The buff is preferably made of, for example, a suede-type foamed polyurethane having a long hairy foot. As the abrasive grains, for example, one or more kinds of abrasive grains selected from alumina abrasive grains, diamond, SiC and the like can be used.

The buffing is continued until the scratch generated in the first step disappears. During buffing, the processing rate in the metal film is higher than that in the substrate,
The longer the buffing time, the greater the step created between the surface of the metal film in the groove and the surface of the substrate. When the step is increased, the time required for flattening the work in the third step to be performed becomes longer, and the processing efficiency may be deteriorated.
Therefore, it is preferable to finish the buff polishing immediately when the scratch on the work surface disappears.

In the third step, MCP or CMP is performed. The third step is a step for eliminating a step between the surface of the metal film in the groove and the surface of the substrate, ie, a recess, generated in the second step, and obtaining a highly accurate flat surface. Therefore,
MCP or CMP is performed so that the protruding substrate is selectively polished. MCP or CMP can be performed by a conventional method. Specifically, an abrasive or slurry selected so that a predetermined reaction occurs is supplied between a work surface of a work and a polishing surface of a polishing pad. By moving the polishing pad relative to the polishing pad.

When the MCP is performed in the third step,
When the work is a silicon substrate on which a metal film (for example, cobalt) is formed, for example, barium carbonate may be used as abrasive grains. When CMP is performed on a similar work, for example, colloidal silica is used as abrasive grains, and the slurry is preferably prepared by dispersing the same in an alkaline solution (eg, an aqueous potassium hydroxide solution).

The polishing pad used in MCP or CMP can be arbitrarily selected from those conventionally used according to the type of work. It is preferable that the polishing pad is formed by bonding a soft material layer and a hard material layer, and uses a surface of the hard material layer as a polishing surface. The operation and effect of using such a polishing pad are the same as the operation and effect of forming the lap surface with the hard material layer laminated on the soft material layer in the flattening method according to the first aspect. That is, in such a polishing pad, the soft material layer ensures that the polishing surface follows the large undulation or warpage existing in the entire work, and the hard material layer that does not easily follow the surface shape of the object is processed. It is ensured that fine irregularities existing on the surface of the surface are polished preferentially from the convex portions. Therefore, if such a polishing pad is used, the period to be processed is several cm, and the amplitude is several μm.If `` undulation '' or `` warpage '' occurs, the undulation due to undulation or warpage is left as it is. In addition, it is possible to flatten only the minute uneven portions existing on the surface of the processing surface by MCP or CMP.

When the polishing pad is formed by laminating a soft material layer and a hard material layer, the soft material layer is made of a material having a small Young's modulus so as to follow the undulation or warpage existing on the work surface of the work. Preferably, it is made of rubber, sponge or non-woven fabric. The hard material layer is preferably made of a material having a higher Young's modulus than the soft material layer, and specifically, is preferably a polyurethane foam.

In the MCP or CMP, operations not specifically mentioned above, such as an operation of moving a polishing pad relative to a work and an operation of supplying a slurry, can be performed by conventional means and methods. .

FIG. 3 schematically shows the first to third steps of the flattening method according to the second aspect of the present invention, together with the state of the processed surface of the work after each step. As a first step, mechanical lapping is performed by a method similar to the method described with reference to FIGS. Mechanical lapping is performed using the surface of the hard material layer (102) laminated on the lapping machine (104) via the soft material layer (100) as the wrap surface (105). After the first step, the burrs (18) of the metal film (12) are removed and the metal film (12) in the groove (16) is removed.
Becomes uniform, and the surface to be processed of the work (1) becomes almost flat, but a large number of scratches (20) are formed.

As a second step, buff polishing is performed. In the illustrated embodiment, buffing is performed by attaching a buff (200) to a lapping machine (204) similar to the lapping machine used in the first step, and both the work (1) and the lapping machine (204) are rotated. Let me do. Since the abrasive particles (202) supplied to the buff (200) are in a state of being attached to the hairs of the buff (200) during polishing, the holding rigidity of the abrasive particles is small. And
If the workpiece and the abrasive grains interfere with each other in this state, the workpiece is polished without generating scratches on the workpiece. Although the scratch (20) generated in the first step is eliminated by the buff polishing, since the processing rate of the metal film (12) is higher than that of the substrate, the surface to be processed includes the surface of the substrate (10) and the metal. A step is formed between the film and the surface of the film to form a recess.

As a third step, MCP is performed. In the illustrated embodiment, the MCP is a polishing pad (3) formed by laminating a soft material layer (300b) and a hard material layer (300a).
00), and the surface of the hard material layer (300a) is a polished surface (3
05) using a polishing pad (300). An abrasive (302) containing abrasive particles that reacts with the work is supplied between the work surface of the work (1) and the polishing pad (300). The polishing pad (300) is attached to a lapping machine (304) similar to the lapping machine used in the first step,
Work (1) and lapping machine (30
4) is rotated to move the polishing pad (300) relatively to the work (1). By the third step, the work surface of the work (1) has a high flatness without recess. Note that the third step may be CMP.

The flattening method according to the third aspect of the present invention comprises:
In the first step of the planarization method according to the second aspect of the present invention, instead of performing mechanical lapping,
This is a method for performing cutting using a diamond tool. The diamond cutting tool used in the present invention is a single crystal cutting tool provided with a portion having a clearance angle of 0 ° on the flank surface side.

As shown in FIG. 4, the portion provided on the flank so that the flank angle is 0 ° means the work surface (1a) of the work (1) after cutting with the cutting tool and the cutting tool (400). ) And the flank (400a). The portion where the clearance angle is 0 ° refers to a portion where θ is 0 ° and the flank is in contact with the processed surface after cutting.

In the present invention, it is preferable to move the cutting tool relatively to the work so as to cross the width direction of the groove formed in the work. In that case, it is preferable that the length in the cutting direction of a portion provided on the flank such that the clearance angle is 0 ° is larger than the width of the groove.

For example, as shown in FIG. 5, when the disk-shaped work (1) has grooves (16) formed radially on its surface, the work (400) can be When the work (1) attached to the chuck (500) of the precision lathe is rotated (rotated) about an axis j passing through the center of the work (1) and perpendicular to the surface to be machined, the cutting tool (400) becomes a groove. It moves relatively to the work (1) across the width of (16). And the byte (40
If the position of 0) is sequentially shifted from the outer periphery toward the center (in the direction of arrow x in FIG. 5) in the radial direction of the work surface of the work (1), the entire work surface of the work is cut. Can be. In the illustrated embodiment, a portion provided on the flank side of the cutting tool and having a clearance angle of 0 ° (402)
The length in the cutting direction is about twice the width of the groove (16). During the cutting, a coolant (not shown) is supplied to the work surface of the work in order to prevent abrasion of the diamond cutting tool.

After the cutting, buffing and MCP or CMP are performed in the same manner as in the flattening method according to the second aspect to improve the flatness of the work surface of the work. Buffing, MCP, and CMP can be performed in the same manner as the method described above, and therefore, detailed description thereof is omitted here.

The flattening method described above can also be said to be a method of obtaining a work having at least a part, for example, one surface flattened. Therefore, the present invention also provides a method of manufacturing a workpiece that is at least partially flattened, including the above-described flattening method. The workpiece provided by the manufacturing method of the present invention may be, for example, the workpiece formed by the lift-off method described above so that the metal film is embedded only in the groove on the substrate surface. The work manufactured by the present invention specifically constitutes, for example, a master disk for magnetic transfer for manufacturing a semiconductor device or a magnetic recording medium.

[0055]

According to the flattening method of the present invention, large undulations and warpages present on the work surface of the workpiece are eliminated by mechanical lapping in which the surface of the hard material layer laminated on the soft material layer is used as a wrap surface. As it is, only a relatively rough uneven portion existing on the work surface of the work can be efficiently flattened. Therefore, the flattening method of the present invention is advantageous for removing burrs of the metal film present on the work on which the metal film has been formed by the lift-off method. Further, the mechanical lapping may be performed by a conventional well-known buffing and MCP or CCP.
By combining with MP, a plane with higher accuracy can be given to the work surface of the work.

Also, by performing cutting using a cutting tool having a specific shape instead of mechanical lapping, it is possible to efficiently remove burrs of the metal film existing on the metal film formed by the lift-off method. Therefore,
By combining cutting and polishing, it is possible to impart a high degree of flatness to the work surface of the workpiece with high processing efficiency.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a state in which a flattening method according to a first aspect of the present invention is performed.

FIG. 2 is a cross-sectional view schematically showing a state in which a planarization method according to a first aspect of the present invention is performed.

FIG. 3 is a schematic view illustrating a planarization method according to a second aspect of the present invention.

FIG. 4 is a schematic view showing a clearance angle of a cutting tool.

FIG. 5 shows a first example of the planarization method according to the third aspect of the present invention.
It is a perspective view which shows a process typically.

FIGS. 6A to 6F are schematic views showing steps of a method of manufacturing a workpiece formed by embedding a metal film only in a groove on a substrate surface by a lift-off method.

[Explanation of symbols]

1 ... work, 1a ... work surface, 10 ... substrate, 12 ... metal film, 14 ... resist, 16 ... groove, 18 ... burr, 20 ... scratch , 22 ... recess, 100 ... soft material layer (soft material sheet), 102 ... hard material layer (hard material sheet), 104 ... lapping machine, 105 ... lap surface, 106 ... .Lapping agent, 106a ... Abrasive, 106b ... Oil, 108a, 108b ... Sprayer, 200 ...
Buff, 202 ... abrasive, 204 ... lapping machine, 300 ... polishing pad, 300a ... hard material layer, 300b ... soft material layer, 302 ...
Slurry, 304 ... lapping machine, 305 ... polishing surface, 400 ... bite, 400a ... flank surface, 402 ... portion where clearance angle is 0 °, 50
0 ... Chuck.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3C058 AA07 AA09 AC04 BA02 BA09 CA01 CB01 DA02 DA12 5F043 AA24 AA26 DD16 DD18 EE08 EE40 FF07 GG02 GG10

Claims (10)

[Claims] 1. A method for flattening a work by mechanical lapping, wherein a surface of a hard material layer laminated on a soft material layer is used as a lap surface, and the work surface of the work is polished on the lap surface. Flattening method. 2. The method according to claim 1, wherein the hard material layer is a polyurethane foam. 3. The workpiece according to claim 1, wherein the workpiece is formed by a lift-off method such that the metal film is buried only in the groove on the surface of the substrate, and the surface on which the metal film is formed is a workpiece. The flattening method according to claim 1 or 2. 4. The method according to claim 1, wherein the mechanical lapping is performed a plurality of times while changing the size of the abrasive grains.
The flattening method according to the paragraph. 5. A method of flattening a work, wherein the work has a groove on a surface thereof, and a metal film is formed by a lift-off method so as to be embedded only in the groove. The surface on which the film is to be formed is a surface to be processed. The work is a first step, and the surface of the hard material layer laminated on the soft material layer is a wrap surface.
A flattening method for performing flattening by performing mechanical lapping for polishing a work surface of a work, performing buff polishing as a second step, and performing mechanochemical polishing or chemical mechanical polishing as a third step. 6. The method according to claim 5, wherein the hard material layer is a polyurethane foam. 7. A method for flattening a work, wherein the work has a groove on a surface thereof, and a metal film is formed by a lift-off method so as to be embedded only in the groove. The surface on which the film is to be formed is the surface to be processed.
A single crystal diamond tool is used in which the length in the cutting direction is larger than the groove width of the groove formed in the work, so that the portion crosses the width direction of the groove formed in the work. The cutting is performed by moving the cutting tool relatively to the workpiece, the buffing is performed as the second step, and the mechanochemical polishing or the chemical mechanical polishing is performed as the third step, thereby flattening. Flattening method. 8. A method for manufacturing a workpiece that has been at least partially flattened, comprising the flattening method according to claim 1. Description: 9. A lapping tool in which a soft material layer and a hard material layer are laminated. 10. A lapping apparatus having a surface of a hard material layer laminated on a soft material layer as a wrap surface.