JPH1090116A - Defocus detecting method in photolithographic process and reticle used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a defocus detecting method by which the defocus detecting rate can be improved when very small defocus occurs. SOLUTION: A resist coat on a semiconductor substrate is exposed by using a positive reticle provided with a plurality of slits 4 having widths narrower than the critical resolution of an exposing device in an unexposed area 3. When the exposed resist coat is developed, such a resist pattern that the areas containing the slits 4 are recessed from the other area is formed. The presence/ absence of defocus is discriminated by inspecting the resist pattern whether or not the recessed areas are formed with a microscope or oblique ray.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting defocus in a photolithography step of a semiconductor manufacturing process and a reticle used therefor. It relates to a method that can be easily detected.

[0002]

2. Description of the Related Art Line width measurement, alignment measurement, surface inspection, oblique light inspection, and the like are usually performed as inspections after a resist pattern is formed in a photolithography step of a semiconductor manufacturing process. The line width measurement is intended to inspect whether or not the formed resist pattern is within a desired control dimension width. In a photolithography process requiring dimension control, an optical line width measuring machine or an electron microscope is used. (SEM). The purpose of alignment measurement is to inspect whether the misalignment between the formed resist pattern and the lower layer pattern is within an allowable range, and, like the line width measurement, an optical line width measuring device or an electronic line width measurement device. This is performed using a microscope (SEM) or an alignment vernier baked on a wafer.

In the photolithography process, for example, foreign matter adheres to a wafer stage of an exposure apparatus, and foreign matter intervenes between the wafer and the wafer stage to locally generate a convex portion. (Displacement) The phenomenon may occur. Therefore, the surface inspection is aimed at inspecting an abnormality such as occurrence of defocus in addition to mist on the wafer surface, adhesion of foreign matter, unevenness of resist coating, and the like. In general, a microscope is often used. In the oblique light inspection, the presence or absence of defocus is inspected by obliquely irradiating the wafer with broadband visible light and observing an interference pattern generated on the wafer.

As another method of checking for the presence or absence of defocus, instead of checking a normal product wafer,
A method is adopted in which a resist pattern composed of lines and spaces (a pattern in which lines and spaces are alternately arranged) is printed on a wafer at regular intervals or at a constant number of processed sheets, and inspection is performed by a microscope or oblique light inspection. .

[0005]

However, in the conventional defocus inspection using a microscope, Japanese Unexamined Patent Publication No.
As shown in the exposure method described in Japanese Patent Application Laid-Open No. 415, the exposure of the same layer is performed a plurality of times, so that an extremely long time is required to inspect the entire surface of the wafer, resulting in a reduction in processing capability. Therefore, oblique light inspection has been frequently used as a method capable of inspecting a large number of wafers in a relatively short time.

For example, in the case of a wiring process or the like in which a resist pattern printed on a wafer mainly consists of lines and spaces, when a slight defocus phenomenon occurs, the line width of the resist pattern is not constant, and depending on the location, Will fluctuate. In addition, when the defocus phenomenon is severe, the resist pattern becomes thick and adjacent lines are connected to each other, or a large area is locally formed in an exposed region (in the case of using a positive resist) without forming a pattern. Of the resist remains. Therefore, when oblique light inspection is performed when such a defocus phenomenon occurs, an interference pattern due to visible light is remarkably observed, so that the occurrence of defocus can be detected relatively easily.

However, in some photolithography processes, it may be difficult to detect defocus depending on the process. For example, when a defocus phenomenon occurs during the formation of a resist pattern having a very small exposed area, as in the step of forming a contact hole using a positive resist, the resist remaining area occupies most of the area, so that the resist area is extremely severe. Unless the contact hole is not opened due to the defocus, the defocus cannot be detected. If the defocus cannot be detected by the microscope inspection or the oblique light inspection of the own process and the oversight is found, it leads to a large number of defects particularly in the production line. Also, if the contact hole diameter becomes smaller than the specified size due to the defocus phenomenon and is not detected as a defect in the wafer test process,
There was a problem that the reliability of this product might be reduced.

Therefore, as described above, a line and space pattern is printed on a wafer at regular intervals or at a constant number of processed sheets, and inspection is performed by a microscope or oblique inspection. However, even in this method, in the case of minute defocus, the line width variation is minute, so that the defocus detection sensitivity is low, and when the defocus phenomenon occurs spontaneously, it is difficult to detect. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a defocus detection method capable of increasing the detection rate particularly when minute defocus occurs, and a reticle used therefor. The purpose is to do.

[0010]

According to a first aspect of the present invention, there is provided a method for detecting a defocus in a photolithography process, comprising a non-exposed area and an exposed area. An exposure step of exposing a resist coat on a semiconductor substrate using a positive-type resist product reticle having a plurality of slits disposed in close proximity as an exposure light transmitting area having a width equal to or less than the limit resolution of the exposure apparatus, By performing a development process on the subsequent resist coat, a development step of forming a resist pattern in which a region provided with a plurality of slits in an unexposed region becomes a recess recessed from other regions, and a microscopic inspection or oblique light inspection An inspection step of observing the surface of the resist pattern.

According to a second aspect of the present invention, there is provided a method for detecting defocus in a photolithography step, comprising a non-exposed area and an exposed area, wherein the exposed area is close to a light-shielding area having a width equal to or less than the limit resolution of the exposure apparatus. An exposure step of exposing a resist coat on a semiconductor substrate using a negative-type resist product reticle provided with a plurality of linear patterns, and a development treatment of the exposed resist coat allow a plurality of exposures in an exposed area. And a developing step of forming a resist pattern in which the area provided with the linear pattern is a concave portion depressed from other areas, and an inspection step of observing the surface of the resist pattern by microscopic inspection or oblique light inspection. Is what you do.

According to a third aspect of the present invention, there is provided a method of detecting defocus in a photolithography step, wherein a resist coat on a semiconductor substrate is exposed using a positive type resist product reticle having an unexposed area and an exposed area. A pattern exposure step, which is provided immediately before or immediately after the product pattern exposure step, is close to an area corresponding to an unexposed area of the positive resist product reticle as an exposure light transmitting area having a width equal to or less than the limit resolution of the exposure apparatus. Using a reticle dedicated to defocus detection with multiple slits,
A plurality of slits are formed in the unexposed area by performing a detection pattern exposure step of exposing the resist coat with an exposure energy equal to or greater than the minimum exposure amount at which the resist coat can be removed by exposure, and developing the resist coat after exposure. A developing step of forming a resist pattern in which the depressed region becomes a concave portion depressed from other regions, and an inspection step of observing the surface of the resist pattern by a microscope inspection or oblique light inspection.

According to a fourth aspect of the present invention, there is provided a method for detecting defocus in a photolithography step, wherein a resist coat on a semiconductor substrate is exposed using a positive type resist product reticle having an unexposed area and an exposed area. A pattern exposure step, which is provided immediately before or immediately after the product pattern exposure step, is close to an area corresponding to an unexposed area of the positive resist product reticle as an exposure light transmitting area having a width equal to or greater than the limit resolution of the exposure apparatus. Using a reticle dedicated to defocus detection with multiple slits,
A plurality of slits are provided in the unexposed area by performing a detection pattern exposure step of exposing the resist coat with an exposure energy less than the minimum exposure amount at which the resist coat can be removed by exposure, and developing the resist coat after exposure. A developing step of forming a resist pattern in which the depressed region becomes a concave portion depressed from other regions, and an inspection step of observing the surface of the resist pattern by a microscope inspection or oblique light inspection.

According to a fifth aspect of the present invention, there is provided a method for detecting defocus in a photolithography step, wherein a resist coat on a semiconductor substrate is exposed using a negative type resist product reticle having an unexposed area and an exposed area. A plurality of lines which are provided immediately before or immediately after the pattern exposure step and the product pattern exposure step, and are adjacent to each other as a light shielding area having a width equal to or less than the limit resolution of the exposure apparatus within an area corresponding to the exposure area of the negative resist product reticle. Using a reticle dedicated to defocus detection provided with a pattern, a detection pattern exposure step of exposing the resist coat with an exposure energy equal to or greater than the minimum exposure amount at which the resist coat can be removed by exposure, and a development process on the exposed resist coat By applying, the region where a plurality of linear patterns are provided in the exposure region A developing step of forming a resist pattern comprising the concave portion recessed from the band, is characterized in that it has an inspection process, observing the surface of the resist pattern by microscopic examination or oblique light inspection.

According to a sixth aspect of the present invention, there is provided a method for detecting defocus in a photolithography step, wherein a resist coat on a semiconductor substrate is exposed using a negative type resist product reticle having an unexposed area and an exposed area. A plurality of lines that are provided immediately before or immediately after the pattern exposure step and the product pattern exposure step, and are adjacent to each other as a light-shielding area having a width equal to or greater than the limit resolution of the exposure apparatus within an area corresponding to the exposure area of the negative resist product reticle. Using a reticle dedicated to defocus detection provided with a defocus pattern, a detection pattern exposure step of exposing the resist coat with an exposure energy less than the minimum exposure amount at which the resist coat can be removed by exposure, and a development process on the exposed resist coat By applying, the region where a plurality of linear patterns are provided in the exposure region A developing step of forming a resist pattern comprising the concave portion recessed from the band, is characterized in that it has an inspection process, observing the surface of the resist pattern by microscopic examination or oblique light inspection.

A reticle according to claim 7 is a reticle which is compatible with a positive resist and has a defocus detection function at the same time as forming a product pattern, and has a non-exposed area and an exposed area. A plurality of adjacent slits are provided as an exposure light transmitting region having a width equal to or less than a limit resolution of the exposure apparatus.

The reticle according to claim 8 is a reticle which is compatible with a negative resist and has a defocus detection function simultaneously with the formation of a product pattern. The reticle has an unexposed area and an exposed area. A plurality of adjacent linear patterns are provided as light-shielding regions having a width equal to or less than the limit resolution of the device.

The reticle according to the ninth aspect is a reticle dedicated to defocus detection corresponding to a positive type resist, and transmits exposure light to a position corresponding to an unexposed area of a product reticle for a positive type resist used in a set. A plurality of adjacent slits are provided as regions.

A reticle according to a tenth aspect is a reticle for defocus detection corresponding to a negative resist, which is close to a position corresponding to an exposure area of a negative reticle product reticle used as a set as a light shielding area. A plurality of linear patterns are provided.

In the defocus detection method of the present invention, when a positive resist or a negative resist is used, exposure is performed using the above-described defocus detection reticle, and a concave portion is formed in the remaining resist pattern. It is formed, and its concave portion is detected by microscopic inspection or oblique light inspection.

That is, when the reticle of the present invention is used,
For example, a normal exposure is performed at a place where a product pattern is to be formed, such as a contact hole, and a portion where the resist is removed by a subsequent development process completely reaches the semiconductor substrate surface. On the other hand, in an area provided with a plurality of slits or linear patterns having a width equal to or less than the limit resolution of the exposure apparatus, insufficient exposure such that the intensity of the exposure light takes an intermediate value of 0% to 100%. Therefore, the portion from which the resist is removed in the subsequent development processing is from the surface of the resist coat to halfway in the depth direction. That is, in the resist pattern, a region where a plurality of slits or linear patterns are provided becomes a concave portion which is more concave than other regions. However, the resolution is highest at the best focus point, and the resolution is reduced when defocus occurs. The depth of the concave portion is smaller than that of the region where no cracks are generated.

Therefore, while a depressed portion having a certain depth is formed in a region on the resist pattern where no defocus occurs, for example, when foreign matter is interposed between the wafer stage of the exposure apparatus and the wafer substrate, Defocus occurs in an area in the vicinity, and substantially no concave portion is formed. As a result, the presence or absence of defocus can be easily detected by a microscope inspection or oblique light inspection.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a method for using a reticle having a defocus detection function added to a product reticle for a contact hole forming step will be described as an example. Further, the method corresponds to a positive resist.

FIG. 1A is a plan view of a reticle used in the present embodiment, and FIG. 1B is a sectional view. As shown in these figures, the reticle 1 has an unexposed area 3 where a chrome pattern is provided on a glass substrate, and an exposed area 2 where no chrome pattern exists. When a positive resist is used, the unexposed region 3 is a region where the resist remains later, and the exposed region 2 is a region where the resist does not remain, that is, a region where a contact hole is to be formed. In the unexposed area 3, a plurality of slits 4 are provided close to each other as an exposure light transmitting area having a width equal to or less than the limit resolution of the exposure apparatus to be used. For example, exposure wavelength λ = 436n
m, numerical aperture NA = 0.55, critical resolution = 0.65 .mu.m
Is used, the width of the slit 4 is 0.3 μm
Set to about. However, this dimension is not limited to this value, and it depends not only on the exposure apparatus used, but also on the exposure energy at the time of exposure, the desired depth of the concave portion to be formed later in the resist pattern, and the like. Can be set appropriately according to the conditions.

Next, exposure is performed on the resist coat on the silicon oxide film formed on the surface of the semiconductor substrate by using the reticle 1 having the above structure (exposure step). As the exposure condition at this time, the value of the exposure energy is set to be equal to or more than Eth (the minimum exposure amount at which the resist can be removed by exposure). Here, the state of exposure light in a photolithography process using the reticle will be described with reference to FIG. FIG. 2 shows the intensity distribution of the exposure light transmitted through the reticle. The vertical axis shows the intensity (Intensity: unit%) of the exposure light, and the horizontal axis shows the position on the reticle. Referring to this figure, light is completely transmitted in the exposure region 2 where the contact hole is to be formed.
The light intensity is 100%. On the other hand, in an area where a plurality of slits 4 are provided in the unexposed area 3, exposure is performed through slits 4 having a width equal to or less than the limit resolution, and light transmitted through each slit 4 is reduced by the light intensity to be resolved. However, a light intensity distribution of more than 0% and less than 100% is obtained, and in the case of the present embodiment, the light intensity is about 15%. In addition, even in the unexposed area 3, light is completely blocked in areas other than the slit 4, so that the light intensity is 0%.

Thereafter, a resist pattern is formed by subjecting the resist coat to a developing process, whereby a region in which the plurality of slits 4 are provided is a concave portion depressed from other regions (developing step). FIGS. 3A and 3B show the exposure state of the resist 7 on the surface of the silicon oxide film 8 and the state after development, respectively. As shown in this figure,
Since the light intensity is 100% at the portion 5 of the resist 7 corresponding to the exposed region 2 where the contact hole is to be formed,
When the developing process is performed, the resist 7 is completely removed, and the surface of the silicon oxide film 8 is exposed. On the other hand, since the portion 6 corresponding to the region where the plurality of slits 4 are provided is a portion where the light intensity is only about 15%, a large amount of the resist 7 remains after the development processing, and a slightly recessed concave portion 6a is formed. . In the case of the present embodiment, the above exposure apparatus and reticle, film thickness = 1.2 μm, Eth = 85 mj, Eopt (exposure amount where reticle dimension and finished resist dimension are the same) = 1
When a resist of 45 mj is used, the dimension of the concave portion 6a of the resist pattern 7a formed after development is such that the width W is 0.3
μm or less, and the depth D is about 0.2 μm.

However, the concave portion 6a as shown in FIG. 3B is formed when the focus state at the time of exposure is near the best focus. If defocusing occurs, the resolving power is lower than at the time of best focus, so that the light intensity further decreases from 15% in the region where the plurality of slits 4 are provided, and the depth of the recess 6a is accordingly reduced. Becomes extremely shallow. In other words, when a depressed portion 6a having a depth of about 0.2 μm is formed in a region where defocus does not occur on the resist pattern 7a, for example, when foreign matter is interposed between the wafer stage of the exposure apparatus and the wafer substrate, Is defocused in a region near the region, and the region is substantially flat. As a result, the light reflection state is different between the defocused portion and the non-defocused portion, so that the presence or absence of defocus can be easily detected by a microscopic inspection or oblique light inspection (inspection step).

Conventionally, it is impossible to detect the defocus in a step where the resist remaining area occupies most, such as the step of forming a contact hole, unless excessively large defocus occurs. Also, in a method in which a line and space pattern is printed on a wafer every fixed period or every fixed number of processed wafers, and inspection is performed by a microscope or oblique light inspection, in the case of minute defocus, the line width variation is minute, so There is a problem that the focus detection sensitivity is low. On the other hand, in the method of the present embodiment, the resist pattern 7
A concave portion 6a is provided in a, so that even a slight focus variation appears in the form of presence or absence of a concave portion on the resist pattern surface. As a result, in the defocus detection method of the present embodiment, the occurrence of minute defocus can be reliably detected by microscopic inspection, oblique light inspection, and the like, and the detection of defocus can be performed with high sensitivity, high accuracy,
And it can be made simple.

In this embodiment, the case where a positive resist is used has been described, but a negative resist may be used. In this case, the reticle in which the black and white pattern of this embodiment is reversed, that is, the area where the contact hole is to be formed is the unexposed area, the other area is the exposed area, and the limit of the exposure apparatus is within the exposed area. A reticle provided with a plurality of linear patterns having a width equal to or less than the resolution may be used.

Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. While the first embodiment is an example using a reticle having a defocus detection function added to an actual product reticle, the method of the present embodiment uses a normal product reticle as it is, This is an example in which a reticle dedicated to defocus detection is separately used. Also, the present embodiment will be described as an example corresponding to a positive resist.

As shown in FIG. 4A, the product reticle 11 has an unexposed area 3 in which a resist remains and an exposed area 2 in which a contact hole is to be formed. First, using the product reticle 11, exposure is performed on a resist coat on a silicon oxide film formed on the surface of a semiconductor substrate (product pattern exposure step). Exposure conditions at this time may be completely normal. In this step, as shown in FIG. 4 (b), light is completely transmitted in the exposed region 2 where the contact hole is to be formed, so that the light intensity is 100%. In this portion 5, the entire resist is exposed. State.

Next, as shown in FIG. 5A, the reticle 12 dedicated to defocus detection is a reticle 11 for the product.
A plurality of slits 4 having a width equal to or less than the limit resolving power of the exposure apparatus to be used are provided close to a position corresponding to the unexposed area 3. When using the same exposure apparatus as in the first embodiment, the dimensions of the slit 4 may be the same as those in the first embodiment. Then, the resist coat is exposed again using the reticle 12 dedicated to defocus detection (detection pattern exposure step). The exposure conditions at this time are as follows:
The value of the exposure energy is set to be equal to or larger than Eth. In this step, exposure is performed through slits 4 having a width equal to or less than the limit resolution, but the light transmitted through each slit 4 does not reach the light intensity to be resolved, and the light intensity is about 15%.
Therefore, as shown in FIG. 5B, only the portion 6 having a thickness of about 15% from the surface of the resist 7 is exposed.

After the two exposure steps with the reticle changed, the resist coat 7 is subjected to a developing process, whereby the region provided with the plurality of slits 4 becomes a concave portion depressed from other regions. A resist pattern similar to that of the embodiment is formed (development step). Hereafter, the first
As in the first embodiment, it is possible to easily detect the presence or absence of defocus through an inspection process using a microscope inspection or oblique light inspection.

In the detection pattern exposure step of the present embodiment, a slit 4 having a width smaller than the limit resolution is provided in the reticle 12 dedicated to defocus detection, and the exposure is performed with the exposure energy not less than Eth. Alternatively, the same resist pattern can be formed even when the width of the slit of the reticle dedicated to defocus detection is set to be equal to or more than the limit resolution and the exposure energy is set to be smaller than Eth. In the case of the method of the present embodiment, since the exposure conditions in the detection pattern exposure step do not affect the formation of the contact holes, such a method can be used.

In the present embodiment, the detection pattern exposure step is performed after the product pattern exposure step, but the same resist pattern can be obtained even if the order of these exposure steps is reversed. . Also, as in the first embodiment, the present method can be made compatible with a negative resist by using a reticle in which the pattern of the present embodiment is reversed in black and white. Further, the step of applying the present method is not limited to the contact hole forming step, but can be applied to various other steps. Specific numerical values such as slit dimensions, exposure conditions, resist characteristics, and the like used in the above embodiments can be appropriately changed.

[0036]

As described above in detail, according to the present invention, the occurrence of minute defocus can be reliably detected by a microscope inspection, oblique light inspection, etc., and the detection of the defocus in the photolithography process. Can be made highly sensitive, highly accurate and simple.

[Brief description of the drawings]

FIG. 1A is a plan view showing a reticle used in a first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA in FIG.

FIG. 2 is a graph showing a relationship between a position on a reticle and light intensity.

3A and 3B are diagrams respectively showing (a) an exposure state of a resist and (b) a cross-sectional shape of a developed resist pattern when exposure is performed using a reticle.

FIG. 4A is a plan view showing a product reticle used in a second embodiment of the present invention, FIG. 4B is a sectional view taken along line BB of FIG. It is.

5A is a plan view showing a reticle dedicated to defocus detection used in the embodiment, and FIG.
FIG. 3 is a diagram illustrating a cross-sectional view taken along line C and an exposure state of a resist.

[Explanation of symbols]

 Reference Signs List 1 reticle 2 exposed area 3 unexposed area 4 slit 5 part corresponding to exposed area of resist 6 part corresponding to area provided with slit 6a concave part 7 resist 7a resist pattern 8 silicon oxide film 11 product reticle 12 de Focus detection reticle

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/027 H01L 21/66 J 21/66 Y 21/30 502V

Claims (10)

[Claims] 1. A positive-type resist product reticle having an unexposed area and an exposed area, and a plurality of slits provided in the unexposed area as exposure light transmitting areas having a width equal to or less than a limit resolution of an exposure apparatus. By exposing the resist coat on the semiconductor substrate to light using an exposure process, and subjecting the exposed resist coat to a development process,
A developing step of forming a resist pattern in which the area provided with the plurality of slits in the unexposed area is a recess depressed from other areas; and an inspection step of observing the surface of the resist pattern by microscopic inspection or oblique light inspection And a defocus detection method in a photolithography step. 2. A negative-type resist product reticle having an unexposed area and an exposed area, wherein a plurality of linear patterns are provided in the exposed area as a light-shielding area having a width equal to or less than a critical resolution of an exposure apparatus. By exposing the resist coat on the semiconductor substrate to light and developing the resist coat after the exposure,
A developing step of forming a resist pattern in which a region where the plurality of linear patterns are provided in the exposure region is a concave portion depressed from other regions; and an inspection for observing the surface of the resist pattern by microscopic inspection or oblique light inspection A defocus detecting method in a photolithography step. 3. A product pattern exposure step of exposing a resist coat on a semiconductor substrate using a positive type resist product reticle having an unexposed area and an exposed area; And
Using a reticle dedicated to defocus detection provided with a plurality of slits close to each other as an exposure light transmitting area having a width equal to or less than the critical resolution of the exposure apparatus in an area corresponding to an unexposed area of the positive resist product reticle, A detection pattern exposure step of exposing the resist coat with an exposure energy not less than the minimum exposure amount through which the resist coat can be removed, and by performing a development process on the exposed resist coat,
A developing step of forming a resist pattern in which the area provided with the plurality of slits in the unexposed area is a recess depressed from other areas; and an inspection step of observing the surface of the resist pattern by microscopic inspection or oblique light inspection And a defocus detection method in a photolithography step. 4. A product pattern exposure step of exposing a resist coat on a semiconductor substrate using a positive type resist product reticle having an unexposed area and an exposure area, provided immediately before or immediately after the product pattern exposure step. And
Using a reticle dedicated for defocus detection provided with a plurality of slits close to each other as an exposure light transmission area having a width equal to or greater than the limit resolution of the exposure apparatus in an area corresponding to the unexposed area of the product reticle for the positive resist, A detection pattern exposure step of exposing the resist coat with an exposure energy less than the minimum exposure amount through which the resist coat can be removed, and by performing a development process on the exposed resist coat,
A developing step of forming a resist pattern in which the area provided with the plurality of slits in the unexposed area is a recess depressed from other areas; and an inspection step of observing the surface of the resist pattern by microscopic inspection or oblique light inspection And a defocus detection method in a photolithography step. 5. A product pattern exposing step of exposing a resist coat on a semiconductor substrate using a negative resist product reticle having an unexposed area and an exposed area; And
Using a reticle dedicated to defocus detection provided with a plurality of linear patterns close to each other as a light-shielding region having a width equal to or less than the limit resolution of the exposure device in an area corresponding to the exposure area of the negative-type resist product reticle, A detection pattern exposure step of exposing the resist coat with an exposure energy not less than the minimum exposure amount at which the resist coat can be removed, and by performing a development process on the exposed resist coat,
A developing step of forming a resist pattern in which a region where the plurality of linear patterns are provided in the exposure region is a concave portion depressed from other regions; and an inspection for observing the surface of the resist pattern by microscopic inspection or oblique light inspection A defocus detecting method in a photolithography step. 6. A product pattern exposing step of exposing a resist coat on a semiconductor substrate using a negative resist product reticle having an unexposed area and an exposed area, and a step provided immediately before or immediately after the product pattern exposing step. And
Using a reticle dedicated for defocus detection provided with a plurality of linear patterns close to each other as a light-shielding region having a width equal to or greater than the limit resolution of the exposure device in a region corresponding to the exposure region of the negative-type resist product reticle, A detection pattern exposure step of exposing the resist coat with an exposure energy less than the minimum exposure amount at which the resist coat can be removed, and by performing a development process on the exposed resist coat,
A developing step of forming a resist pattern in which a region where the plurality of linear patterns are provided in the exposure region is a concave portion depressed from other regions; and an inspection for observing the surface of the resist pattern by microscopic inspection or oblique light inspection A defocus detecting method in a photolithography step. 7. A reticle which is compatible with a positive resist and has a defocus detection function at the same time as a product pattern is formed. The reticle has an unexposed area and an exposed area. A reticle provided with a plurality of adjacent slits as an exposure light transmitting region having: 8. A reticle which is compatible with a negative resist and has a defocus detection function simultaneously with the formation of a product pattern. The reticle has an unexposed area and an exposed area, and has a width within the exposure area which is equal to or less than a limit resolution of an exposure apparatus. A reticle comprising a plurality of adjacent linear patterns provided as light shielding regions. 9. A reticle corresponding to a positive resist and dedicated to defocus detection, wherein a plurality of slits are provided as exposure light transmitting regions at positions corresponding to unexposed regions of a positive reticle product reticle used as a set. A reticle characterized by being obtained. 10. A reticle corresponding to a negative resist and dedicated to defocus detection, wherein a plurality of linear patterns close to each other as light-shielding regions are provided at positions corresponding to exposure regions of a negative reticle product reticle used as a set. A reticle characterized in that: