JP2004335850A - Aligner, exposing method, and manufacturing method and exposure program of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aligner, an exposing method, and a manufacturing method and an exposure program of a semiconductor device capable of properly taking into account the size at exposure this time in the case of determining the exposure amount in the succeeding exposure. <P>SOLUTION: An exposure amount calculation means 4 calculates an exposure amount of a lot this time on the basis of the size of a preceding lot when the size of the preceding lot entered from a size entry means 2 is within a specified range, and calculates the exposure amount this time on the basis of the size of a lot preceding to the preceding lot when the size of the preceding lot entered from the size entry means 2 is not within a specified range. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an exposure apparatus, an exposure method, a method of manufacturing a semiconductor device, and an exposure program, and is particularly suitable for being applied to a photolithography step in a semiconductor manufacturing process.
[0002]
[Prior art]
In a photolithography process in a conventional semiconductor manufacturing process, for example, as disclosed in Patent Literature 1, the post-processing dimension and the in-plane uniformity of the post-processing shape when processing using a photoresist film mask are improved. For this purpose, a set exposure condition is corrected based on data of a processed dimension and a processed shape of a pattern formed on a wafer.
[0003]
[Patent Document 1]
JP-A-10-256114
[Problems to be solved by the invention]
However, in the conventional method of correcting the set exposure condition, when determining the next exposure amount in consideration of the dimension value at the time of the current exposure, consideration is given to a case where an abnormal dimension value is detected at the time of the current exposure. Did not. For this reason, in the conventional method of correcting the set exposure condition, the next exposure amount may be determined based on the abnormal dimension value, and the correction of the exposure condition becomes excessive, and the dimension value is reduced at the next exposure. It could be out of standard.
[0005]
Therefore, an object of the present invention is to provide an exposure apparatus, an exposure method, a method of manufacturing a semiconductor device, and an exposure program that can appropriately consider a dimension value at the time of the current exposure when determining the next exposure amount. That is.
[0006]
[Means for Solving the Problems]
According to one embodiment of the present invention, there is provided an exposure apparatus, comprising: a dimension value input unit configured to input a dimension value of an exposed resist pattern; and a dimension value input by the dimension value input unit. Is a dimension value determining unit that determines whether or not is within a specified range, an exposure amount calculating unit that calculates an exposure amount based on the dimension value determined to be within the specified range by the dimension value determining unit, and the exposure amount calculating unit. And an exposure unit for performing exposure based on the calculated exposure amount.
[0007]
Accordingly, when determining the next exposure amount in consideration of the dimension value at the time of the current exposure, it is possible to exclude an abnormal dimension value at the time of the current exposure. For this reason, it becomes possible to prevent the exposure condition from being corrected excessively in the next exposure, and to reduce the number of times the dimension value becomes out of the standard.
Further, according to the exposure apparatus according to one aspect of the present invention, when the dimension value inputted this time by the dimension value inputting unit is within a specified range, the exposure amount calculating means may be based on the dimension value inputted this time. A next exposure amount is calculated, and when the dimension value currently input by the dimension value input means is out of the specified range, the next exposure amount is calculated based on the previously input dimension value.
[0008]
Thus, even if an abnormal dimension value is obtained during the current exposure, the next exposure amount can be optimized, and the dimension value can be easily set within the standard.
According to the exposure apparatus of one aspect of the present invention, the dimension input means for inputting the dimension value of the resist pattern of the current lot that has been exposed, and the dimension of the current lot input by the dimension value input means A dimension value determining unit that determines whether the value is within a specified range; an exposure amount calculating unit that calculates an exposure amount of a next lot based on the dimension value determined to be within the specified range by the size value determining unit; An exposure unit for exposing the next lot based on the exposure amount calculated by the exposure amount calculation unit.
[0009]
This makes it possible to exclude abnormal dimension values during the exposure of the current lot when determining the exposure amount of the next lot in consideration of the dimension values of the current lot during the exposure. For this reason, it is possible to prevent the exposure condition from being corrected excessively during the next lot exposure, and to reduce the number of times that the dimensional value of each lot becomes out of specification.
[0010]
According to the exposure apparatus of one embodiment of the present invention, if Δ exposure amount = (dimension specification value−dimension value of current lot) × coefficient value / 2, exposure amount of next lot = (Δ (Exposure amount + exposure amount of current lot).
As a result, it is possible to determine the exposure amount of the next lot in consideration of the dimension value at the time of exposure of the current lot, and it is possible to suppress the variation of the dimension value for each lot.
[0011]
Further, according to the exposure method according to one aspect of the present invention, a step of measuring the dimension of the exposed and developed resist pattern, and a step of determining whether the measured dimension value of the resist pattern is within a specified range. A step of calculating an exposure amount based on the dimension value determined to be within the specified range; and a step of performing exposure based on the calculated exposure amount.
[0012]
As a result, it is possible to prevent the next exposure amount from being determined based on the abnormal dimension value, and it is possible to reduce the possibility that the dimension value will be out of specification at the next exposure.
According to the exposure method of one aspect of the present invention, the step of measuring the size of the resist pattern of the current lot exposed and developed, and the step of measuring the dimension value of the measured resist pattern of the current lot Determining the exposure amount of the next lot based on the dimension value of the current lot determined to be within the specified range; and determining the next lot based on the calculated exposure amount. And performing a step of exposing.
[0013]
As a result, it is possible to prevent the exposure amount of the next lot from being determined based on the abnormal size lot, and it is possible to reduce the possibility that the dimension value becomes out of the standard when the next lot is exposed.
According to the method for manufacturing a semiconductor device of one embodiment of the present invention, a step of applying a first resist on a first semiconductor wafer of the current lot, and a step of applying the first resist on the first semiconductor wafer Exposing and developing; measuring the dimension of the exposed and developed first resist; determining whether the measured dimension value of the first resist is within a specified range; Calculating the exposure amount of the next lot based on the dimension value determined to be within the range; applying a second resist on the second semiconductor wafer of the next lot; and calculating the exposure amount of the next lot. A step of exposing a second resist applied on the second semiconductor wafer based on the amount of exposure, a step of developing the exposed second resist, and using the developed second resist as a mask Characterized in that it comprises a step for processing the serial second semiconductor wafer.
[0014]
As a result, it is possible to prevent the exposure amount of the next lot from being determined based on the abnormal-size lot, and it is possible to accurately process the semiconductor wafer.
According to the exposure program of one aspect of the present invention, a step of acquiring a dimension value of the exposed resist pattern; a step of determining whether the acquired dimension value of the resist pattern is within a specified range; The computer is configured to execute a step of calculating an exposure amount based on the dimension value determined to be within the specified range and a step of performing exposure based on the calculated exposure amount.
[0015]
As a result, by executing the exposure program, it is possible to determine the next exposure amount in consideration of the dimension value at the time of the current exposure while excluding abnormal dimension values, and hardware changes are required. Therefore, it is possible to set an appropriate exposure amount.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an exposure apparatus and an exposure method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of an exposure apparatus according to one embodiment of the present invention.
[0017]
In FIG. 1, the exposure apparatus 1 includes a dimension value input unit 2, a dimension value determination unit 3, an exposure amount calculation unit 4, an exposure amount storage unit 5, and an exposure unit 6. Here, the dimension value input means 2 inputs the dimension value of the resist pattern P exposed by the exposure device 1. The dimension value determining means 3 determines whether the dimension value input by the dimension value input means 2 is within a specified range. The exposure amount calculation means 4 calculates the exposure amount based on the dimension value determined by the dimension value determination means 3 to be within the specified range. The exposure amount storage unit 5 stores an exposure value before the exposure by the exposure unit 6. The exposure unit 6 performs exposure based on the exposure amount calculated by the exposure amount calculation unit 4.
[0018]
Next, the operation of the exposure apparatus 1 of FIG. 1 will be described.
A resist R is applied to the wafer W. When the exposure process is performed on the wafer W of the current lot by the exposure apparatus 1, for example, by using the scanning electron microscope 7, the resist pattern P of the previous lot that has been exposed by the exposure apparatus 1 is processed. Measure the dimensions. When the dimension of the resist pattern P of the previous lot is measured, the dimension value of the resist pattern P of the previous lot is input to the dimension value input means 2.
[0019]
When the dimension value of the resist pattern P of the previous lot is input to the dimension value input unit 2, the dimension value determining unit 3 determines whether the dimension value of the resist pattern P of the previous lot is within a specified range. . Then, when the dimension value of the previous lot input by the dimension value inputting means 2 is within the specified range, the exposure amount calculating means 4 calculates the exposure amount of the current lot based on the dimension value of the previous lot. On the other hand, when the dimension value of the previous lot input by the dimension value input means 2 is out of the specified range, the exposure amount calculating means 4 reads out the dimension value of the last two lots from the exposure amount storage means 5, and The present exposure amount is calculated based on the dimension value.
[0020]
Here, when calculating the exposure amount of the current lot based on the dimension value of the previous lot, the exposure amount calculating means 4 calculates Δexposure amount = (dimension specification value−dimension value of previous lot) × coefficient value / If it is 2, the following equation can be used.
Exposure amount of current lot = (Δ exposure amount + exposure amount of previous lot)
However, the dimensional specification value is a target dimensional value of the resist pattern P, and the coefficient value is a ratio between the exposure amount and the dimensional value, and can be determined from the relationship between the previously measured exposure amount and the dimensional value. Further, as the specified range for determining whether or not the dimension value of the resist pattern P is within the specified range, for example, a variation of 3σ (standard deviation) can be used.
[0021]
When the exposure amount of the current lot is calculated by the exposure amount calculating unit 4, the exposure unit 6 calculates the exposure amount of the current lot based on the exposure amount of the current lot calculated by the exposure amount calculating unit 4. An exposure process is performed on the wafer W. When adjusting the exposure amount, the exposure means 6 may control the exposure intensity or may control the exposure time.
[0022]
Accordingly, when determining the exposure amount of the current lot in consideration of the dimension value of the previous lot at the time of exposure, an abnormal dimension value of the previous lot at the time of exposure can be excluded. For this reason, it is possible to prevent the exposure condition from being corrected excessively during the exposure of the current lot, and it is possible to reduce the number of times that the dimension value of each lot is out of specification.
[0023]
FIG. 2 is a diagram illustrating an average value, a maximum value, and a minimum value of dimension values for each lot according to an embodiment of the present invention.
In FIG. 2, for example, it is assumed that the dimension specification value SCL is set to 0.35 μm. When the dimension value of the resist pattern P of the previous lot exceeds the upper limit UCL of the variation 3σ or falls below the lower limit LCL of the variation 3σ, the dimension value of the resist pattern P of the previous lot is excluded, The exposure amount of the current lot can be determined.
[0024]
For example, when determining the exposure amount of the lot of lot ID = 0135, the dimension value of the resist pattern P of the previous lot (lot of lot ID = 0137) is referred to. Since the dimension value of the resist pattern P of the previous lot falls within the range of the variation 3σ, the lot ID is taken into consideration in consideration of the dimension value of the resist pattern P of the last lot (lot ID = 0137). = 0135 can be determined.
[0025]
On the other hand, when determining the exposure amount of the lot of lot ID = 0144, the dimension value of the resist pattern P of the previous lot (lot of lot ID = 0145) is referred to. Here, the dimension value of the resist pattern P of the previous lot (lot ID = 0145) is smaller than the lower limit LCL of the variation 3σ, so that the resist pattern P of the previous lot (lot ID = 0145) is not changed. Ignore dimension values. The exposure amount of the lot with the lot ID = 0144 can be determined in consideration of the dimension value of the resist pattern P of the last lot (lot with the lot ID = 0142).
[0026]
FIG. 3 is a flowchart illustrating an exposure amount calculation method according to an embodiment of the present invention.
3, the exposure means 6 of FIG. 1 performs exposure of the resist R applied to the wafer W (step S1). Then, when the resist R applied to the wafer W is exposed, the resist R is developed to form a resist pattern P on the wafer W (Step S2). When the resist pattern P is formed on the wafer W, the dimensions of the resist pattern P are measured by the scanning electron microscope 7 (Step S3).
[0027]
Then, when the dimension of the resist pattern P is measured, the dimension value of the measured resist pattern P is input to the dimension value input means 2 (Step S4). Then, when the dimension value of the resist pattern P is input to the dimension value input unit 2, the dimension value determining unit 3 determines whether the dimension value of the resist pattern P is within a specified range (Step S5). When the dimensional value of the resist pattern P input by the dimensional value input means 2 is within the specified range, the exposure amount calculating means 4 calculates the next exposure amount based on the dimensional value of the resist pattern P measured this time. (Step S6). On the other hand, when the dimension value of the resist pattern P measured this time is out of the specified range, the exposure amount calculating means 4 calculates the next exposure amount based on the dimension value of the resist pattern P measured last time (step S7). . If the dimension value of the resist pattern P measured last time is also outside the specified range, the dimension value of the resist pattern P measured earlier can be used.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an exposure apparatus according to one embodiment.
FIG. 2 is a diagram showing dimension values for each lot.
FIG. 3 is a flowchart illustrating an exposure amount calculation method according to an embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Exposure apparatus, 2 dimension value input means, 3 dimension value determination means, 4 exposure amount calculation means, 5 exposure amount storage means, 6 exposure means, 7 scanning electron microscope, W wafer, R photoresist

Claims (8)

Dimension value input means for inputting the dimension value of the exposed resist pattern;
Dimension value determining means for determining whether the dimension value input by the dimension value input means is within a specified range,
An exposure amount calculating unit that calculates an exposure amount based on the dimensional value determined to be within the specified range by the dimensional value determining unit,
An exposure apparatus comprising: an exposure unit that performs exposure based on the exposure amount calculated by the exposure amount calculation unit. When the dimension value input this time by the dimension value input means is within a specified range, the exposure amount calculating means calculates a next exposure amount based on the dimension value input this time, and 2. The exposure apparatus according to claim 1, wherein when the input dimension value is out of the specified range, the next exposure amount is calculated based on the previously input dimension value. Dimension value input means for inputting the dimension value of the resist pattern of the current lot exposed,
Dimension value determining means for determining whether the dimension value of the current lot input by the dimension value input means is within a specified range,
Exposure amount calculation means for calculating the exposure amount of the next lot based on the size value determined to be within the specified range by the size value determination means,
An exposure apparatus comprising: an exposure unit configured to perform exposure of a next lot based on the exposure amount calculated by the exposure amount calculation unit. Δ exposure = (dimension specification value-current lot dimension value) x coefficient value / 2
4. The exposure apparatus according to claim 3, wherein the exposure amount of the next lot = (. DELTA. Exposure amount + the exposure amount of the current lot). Measuring the dimensions of the exposed and developed resist pattern;
Determining whether the measured dimension value of the resist pattern is within a specified range,
Calculating an exposure amount based on the dimension value determined to be within the specified range;
Performing an exposure based on the calculated exposure amount. Measuring the dimensions of the exposed and developed resist pattern of the current lot;
Determining whether the measured dimension value of the resist pattern of the current lot is within a specified range,
Calculating the exposure amount of the next lot based on the dimension value of the current lot determined to be within the specified range;
Exposing the next lot based on the calculated exposure amount. A step of applying a first resist on the first semiconductor wafer of the current lot;
Exposing and developing a first resist applied on the first semiconductor wafer;
Measuring the dimensions of the exposed and developed first resist;
Determining whether the measured dimension value of the first resist is within a specified range;
Calculating the exposure amount of the next lot based on the dimension value determined to be within the specified range,
A step of applying a second resist on a second semiconductor wafer of the next lot;
Exposing the second resist applied on the second semiconductor wafer based on the calculated exposure amount of the next lot;
Developing the exposed second resist;
Performing the processing of the second semiconductor wafer using the developed second resist as a mask. Obtaining a dimension value of the exposed resist pattern;
Determining whether the dimension value of the obtained resist pattern is within a specified range,
Calculating an exposure amount based on the dimension value determined to be within the specified range;
Causing the computer to execute the step of performing exposure based on the calculated exposure amount.

Images