JP2005038952A - Slimming manufacturing method and slimming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the variations of the line width over the entire surface of a wafer with respect to a slimming manufacturing method and a slimming method for slimming the line width formed on the wafer. <P>SOLUTION: The method has a first exposure step of repeating exposure of the entire part or one part of a region of a pattern to be slimmed on a resist-applied wafer, a first ion slimming step of performing ion slimming after development, a second exposure step of repeating exposure of the entire part or only one part of the region of the pattern of a predetermined shot after removing the resist and applying resist on the entire surface of the wafer, a second ion slimming step of performing ion slimming on the entire surface of the wafer after development, and a step of removing the resist. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slimming manufacturing method and a slimming system for slimming a line width formed on a wafer.
[0002]
[Prior art]
Conventionally, in order to form, for example, a write core having a predetermined width of a magnetic head on a wafer, a resist pattern is formed on the wafer and a write core having a slightly wider width is formed by electrodeposition or the like. After applying resist and exposing and developing the pattern of the area subject to ion slimming and performing ion slimming on the entire surface (processing to irradiate ions diagonally to reduce the pattern line width), the resist is removed and a predetermined pattern is formed on the wafer. The pattern line width is formed. At this time, for example, the entire surface is ion slimmed so that the width of the light core or the like on the wafer falls within the allowable range, and the width of the entire light core or the like is slightly narrowed and adjusted so as to be within the allowable range. It was.
[0003]
In addition, a large number of large monitor patterns having the same structure as the microcircuit to be ion milled are formed on the wafer and stopped when a predetermined time elapses after the color of the large monitor pattern changes during ion milling. There is a technique for adjusting the amount of ion milling in a minute region (Patent Document 1).
[0004]
[Patent Document 1] [0006] of Japanese Patent Application Laid-Open No. 09-282615 and FIG.
[0005]
[Problems to be solved by the invention]
However, in both of the former and the latter described above, when the width of the light core or the like is narrowed and the allowable range is narrow, it becomes difficult to perform ion slimming on the entire surface of the wafer to fit the entire surface within the allowable range. There was a problem that a light core or the like that could not fit was generated.
[0006]
In order to solve these problems, the present invention divides the entire surface of the wafer into a plurality of shots, pattern exposes and develops the region to be ion slimmed, develops the entire surface of the wafer by ion slimming, and then regenerates only a predetermined shot. The purpose is to adjust the pattern width to a predetermined allowable range by ion slimming and to improve the line width variation over the entire wafer surface.
[0007]
[Means for Solving the Problems]
Means for solving the problem will be described with reference to FIG.
In FIG. 1, a coater 1 coats a resist on a wafer.
[0008]
The stepper 2 sequentially exposes each divided area (shot) on the resist-coated wafer or sequentially exposes (re-exposes) each wide area (shot).
[0009]
The developer 3 develops the resist exposed on the wafer.
Here, the ion mill 4 irradiates the entire surface of the wafer with ions from an oblique direction, and reduces the line width of the pattern to make it narrow (ion slimming).
[0010]
The cleaning machine 5 cleans (removes) the resist on the wafer.
The CD-SEM 6 measures the line width of the pattern on the wafer.
Next, a manufacturing procedure will be described.
[0011]
A coater 1 applies a resist to the entire surface of the wafer, and a stepper 2 divides the resist into a plurality of shots, and repeats pattern exposure of an ion slimming target region, and a developer 3 develops the resist pattern to the wafer. The film is formed on the surface, and ion slimming is performed on the entire surface of the wafer by the ion mill 4 to reduce the line width. The cleaning machine 5 removes the resist on the wafer. Further, after the resist is applied on the wafer by the coater 1, the pattern exposure is repeated only on the area subject to ion slimming of a predetermined shot by the stepper 2, and the resist pattern is developed on the wafer by developing by the deburper 3. Ion slimming is performed on the entire surface of the wafer to reduce the line width, and the cleaning machine 5 removes the resist on the wafer.
[0012]
At this time, as a predetermined shot portion only, after the first ion slimming or after the first ion slimming measured in advance, the shot whose line width is wider than the predetermined value is the shot line width I am trying to make this part.
[0013]
Further, the line width of a predetermined representative pattern in a shot is set as the pattern line width subjected to ion slimming for each shot.
Further, the second and subsequent exposure steps and the second and subsequent ion slimming are performed in a plurality of stages.
[0014]
Therefore, the entire wafer surface is divided into a plurality of shots, and pattern exposure is performed on the area to be ion-slimmed and developed, and the entire wafer surface is ion-slimmed and developed. By adjusting to, it becomes possible to improve the line width variation over the entire wafer surface.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments and operations of the present invention will be sequentially described in detail with reference to FIGS.
[0016]
FIG. 1 is an explanatory diagram of the present invention.
In FIG. 1, a coater 1 is a thin and uniform coating of resist on a wafer. For example, a small amount of liquid resist is dropped by rotating the wafer at a high speed in the horizontal direction and centrifugal force is applied from the inner periphery to the outer periphery. A uniform resist film is formed by spreading toward the surface.
[0017]
The stepper 2 divides the wafer into predetermined regions (shots) and sequentially exposes the pattern. Here, the stepper 2 is composed of a division trim means 21 and the like.
[0018]
The division trim means 21 determines a divided area (shot) on the wafer, and for example, determines an area (shot) to be exposed on the wafer as shown in FIG.
[0019]
The developer 3 develops the resist-exposed wafer (develops in a solution or the like) and removes unnecessary resist (for example, removes the exposed portion) to form a resist pattern.
[0020]
The ion mill 4 performs ion etching by irradiating ions, and is constituted by a division trim unit 41 and the like. Here, a pattern is formed by irradiating ions obliquely to a pattern already formed on a wafer. The line width is reduced by narrowing (referred to as ion slimming). When ion irradiation is performed substantially vertically from above the wafer, the entire surface is ion etched, and if there is a resist, the hole portion of the resist can be ion etched.
[0021]
The division trim means 41 determines the amount of cutting, and determines the amount of cutting to perform ion slimming by irradiating ions from a diagonal of a wiring pattern previously formed on the wafer (so that the line width of the optimum pattern is obtained). The ion acceleration voltage, ion current density, ion irradiation time, ion irradiation direction, etc. are determined.
[0022]
The cleaning machine 5 cleans (removes) the resist on the wafer.
A CD-SEM (line width measuring device) 6 measures the line width of a pattern on a wafer.
[0023]
Next, in the configuration of FIG. 1, according to the order of the flowchart of FIG. 2, the line width of the pattern formed on the wafer is adjusted for each region (shot) by adjusting the ion slimming amount in multiple stages. The procedure for keeping the pattern line width within the predetermined range will be described in detail.
[0024]
FIG. 2 shows a procedure flowchart of the present invention.
In FIG. 2, resist coating is performed in S11. In this process, a resist is applied (coated) on a slightly wide wiring pattern (for example, a width of a write core constituting a write head of a magnetic disk) formed on the wafer in the previous process. The wiring pattern to be formed in the previous step is to form a resist pattern on the wafer and form a predetermined material in the hole portion of the resist pattern by electrodeposition (electroplating), and then remove the resist to form the resist pattern on the wafer. A wiring pattern is formed.
[0025]
In S12, exposure (entire surface) is performed. In this process, the entire surface of the wafer is repeatedly exposed on the wafer subjected to resist coating in S11 for every shot (all or part of the wiring pattern) subjected to ion slimming.
[0026]
In step S13, development is performed. In this process, the wafer exposed in S12 is developed to form a resist film having a hole in an ion slimming target region.
S14 performs ion milling (slimming the entire width). This is because development is carried out in S13 and there is a hole in the region subject to ion slimming (there is no resist film), so that ions are irradiated from an oblique direction of the wafer to reduce the line width of the wiring pattern (narrowing). To do). For example, as shown in FIG. 3A described later, the wiring pattern is irradiated with ions from an oblique direction, and the line width of the wiring pattern is reduced and narrowed (ion slimming).
[0027]
S15 removes. Since the first ion slimming is completed in S14, the resist film on the wafer is removed (for example, removed by immersion in a solvent).
In S16, measurement is performed (representative points for each necessary shot are measured). This measures the line width of the wiring pattern of the representative point for each shot on the wafer after removing the resist in S15.
[0028]
S17 determines. For this, it is determined whether the result measured in S16 (the line width of the wiring pattern of the representative point for each shot) is OK within the allowable value range for each shot, or is NG if greater than the allowable value.
[0029]
In step S18, resist coating is performed. In this process, a resist is coated (applied) on the entire surface of the wafer by the coater 1 shown in FIG.
In S19, exposure (only large shots are exposed). This is because only the shot in which the line width of the representative point for each shot is NG due to the determination in S17 is NG (the trimming means 21 of the stepper 2 sets only the NG shot as the target of the ion slimming. Determine and expose).
[0030]
In step S20, development is performed. The developer 3 in FIG. 1 develops the image after completing exposure (re-exposure) of the shot (region) in which the line width of the representative point of the shot is larger than the allowable value and becomes NG in S19. Then, a resist pattern is formed (see, for example, FIG. 3B described later).
[0031]
S21 performs ion milling (slimming a wide area). This is performed by ion slimming on the entire surface of the wafer by the ion mill 4 of FIG. As a result, the line width of the representative point of the shot is larger than the allowable value on the wafer, and only the NG shot is re-ion slimmed. For example, as shown in FIG. The narrow shot portion is coated with a resist, while the shot portion with a wide line width has no resist, and the line width is reduced by ion slimming to be within an allowable value. Here, when the line width of the representative point of the shot is still larger than the allowable value and NG, S18 and subsequent steps are repeated again, and re-ion slimming is performed only for the shot with the wide line width of the representative point of the shot.
[0032]
S22 removes. This removes the resist on the wafer. Then, the process proceeds to the next step.
As described above, the resist pattern is coated on the wiring pattern (for example, the write core of the magnetic disk) formed in the previous process on the wafer, and only the portion to be subjected to ion slimming necessary for each shot is exposed and developed to form a resist film. For a shot larger than the allowable value by drilling a hole (see FIG. 3A), thinning the line width by ion slimming, removing the resist and measuring the line width of the representative point for each shot, It is possible to adjust the line width of the representative point of the shot within an allowable value by resist coating on the wafer again, exposing it to make a hole, and performing re-ion slimming.
[0033]
FIG. 3 is an explanatory diagram of multi-stage division slimming according to the present invention.
FIG. 3A schematically shows a cross-sectional view of a wiring pattern (for example, a write core of a magnetic disk) formed on a wafer after the first ion slimming and removing the resist. Here, the arrows indicate a state in which ions are irradiated from an oblique direction of the wiring pattern to reduce the line width of the wiring pattern (referred to as ion slimming). Here, it is determined that two of them are narrowly cut and the line width is within the allowable range (OK in S17 in FIG. 2). Two wide (large) line widths on both sides are larger than the allowable value, and it is determined as NG (NG in S17 in FIG. 2).
[0034]
In FIG. 3B, two wiring patterns whose line width is within an allowable value are resist-coated, and two wiring patterns on both sides whose line width is larger than the allowable value are exposed to remove the resist. A sectional view of is schematically shown. Here, the two wiring patterns on both sides are narrowly cut to be the wiring patterns shown on both sides after removing the resist of FIG. 3C, and can be adjusted within an allowable value.
[0035]
FIG. 3C schematically shows a cross-sectional view after the resist is removed by performing ion slimming in the state of FIG. 3B to reduce the line width of the wiring patterns on both sides. Here, the line widths of all the wiring patterns can be adjusted within the allowable value. Even in the case of re-ion slimming, if the line width is larger than the allowable value, only the ion slimming target area of the shot having a wide line width is exposed and developed again as shown in FIG. A hole in the film is made and re-ion slimming is performed, and the line width of the wiring pattern is narrowed so as to be within an allowable value.
[0036]
As described above, the line width of the wiring pattern of the representative point is measured for each shot, and re-ion slimming is repeated only for the shot portion larger than the allowable value (re-ion slimming is repeated for each shot in multiple stages). Thus, the line widths of the wiring patterns in all shots can be adjusted within an allowable value.
[0037]
FIG. 4 shows an example of the divided region of the present invention. This shows an example of a region (shot) where exposure is repeated with a stepper on a wafer. The shot is rectangular and can be set to any size. On the wafer, for the first time, the areas subject to ion slimming of all shots are exposed and developed, holes are formed in the resist film, ion slimming is performed, the line width is narrowed, and the resist film is removed. Then, the line width of the representative point is measured for each shot (or measured in advance by experiment) and only a shot having a line width larger than the allowable value is re-exposed to open a hole in the resist (with a line width within the allowable value). The shot does not make a hole), and re-ion slimming is performed so that the line width is narrowed and adjusted so that it falls within the allowable value (when one time is insufficient, it can be repeated several times).
[0038]
FIG. 5 shows an example of the light core width distribution of the present invention. The lower horizontal axis indicates the outer periphery, the center, and the right outer periphery on the left side of the wafer, and the vertical axis indicates the deviation of the core width from the allowable value. Here, the allowable range is within the range of 0.02 μm. For the outer peripheral shot larger than the permissible value (here, 0.02 μm), the exposure and development of FIG. 3B described above are performed, the resist is removed, and reion slimming is performed to reduce the line width. As shown in the hatched area, each is adjusted within the allowable range (± 0.02 μm). Thus, in the experiment, the variation in R (core width μm) was improved from 0.06 μm to 0.03 μm or less by performing the divided slimming for each shot.
[0039]
【The invention's effect】
As described above, according to the present invention, the entire surface of the wafer is divided into a plurality of shots, and pattern exposure is performed on the region to be ion-slimmed and developed. Since a configuration is adopted in which the pattern width is adjusted to a predetermined allowable range by performing ion slimming, it is possible to improve the line width variation over the entire wafer surface.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of the present invention.
FIG. 2 is a procedure flowchart of the present invention.
FIG. 3 is an explanatory diagram of multi-stage split slimming according to the present invention.
FIG. 4 is an example of divided regions according to the present invention.
FIG. 5 is an example of a light core line width distribution according to the present invention.
[Explanation of symbols]
1: Coater 2: Stepper 21: Divided trim means 3: Developer 4: Ion mill 41: Divided trim means 5: Cleaning device 6: CD-SEM (line width measuring device)

Claims (5)

In a slimming manufacturing method for slimming a line width formed on a wafer,
A first exposure step of repeating exposure of all or a part of the pattern to be slimmed into a plurality of shots on a wafer on which a pattern has been formed and resist-coated,
After completing the first exposure step and developing, a first ion slimming step of ion slimming over the entire wafer surface;
After the first ion slimming is completed, the resist is removed, and after the resist is applied to the entire surface of the wafer, the exposure of only the whole or a part of the pattern of the ion slimming target of a predetermined shot is repeated. An exposure step;
A second ion slimming step for performing ion slimming on the entire surface of the wafer after the second exposure step is completed and developed;
And a step of removing the resist after finishing the second ion slimming. The pattern line width obtained by performing ion slimming for each shot of the first ion slimming after the first ion slimming or the previously measured first ion slimming as a whole or a part of the predetermined shot pattern is more than a predetermined value. The slimming manufacturing method according to claim 1, wherein only a portion having a wider line width is used. The slimming manufacturing method according to claim 2, wherein the pattern line width subjected to ion slimming for each shot is a line width of a predetermined representative pattern in the shot. The slimming manufacturing method according to any one of claims 1 to 3, wherein the second exposure step and the second ion slimming are performed in a plurality of stages. In a slimming system for slimming a line width formed on a wafer,
A first exposure unit that repeats exposure of all or part of the pattern to be slimmed in a plurality of shots on a wafer on which a pattern has been formed and resist-coated,
First ion slimming means for performing ion slimming on the entire surface of the wafer after completing the first exposure step and developing;
After the first ion slimming is completed, the resist is removed, and after the resist is applied to the entire surface of the wafer, the exposure of only the whole or a part of the pattern of the ion slimming target of a predetermined shot is repeated. Exposure means;
A second ion slimming means for performing ion slimming on the entire surface of the wafer after completing the second exposure step and developing;
And a means for removing the resist after finishing the second ion slimming.

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