JPH11204621A - Equipment and method for positioning semiconductor pattern, and equipment and method for inspecting semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To specify a proper position, even for a device pattern which is an isolated pattern by detecting whether reference patterns stored with respect to a specific pattern are properly formed on a specified pattern and determining the position of the specific pattern through the arrangements of the reference patterns. SOLUTION: Data on a first reference pattern 12 is read out. As the data is within field of vision, the pattern data on the reference pattern 12 is checked with pattern data on existing positions of reference patterns for a device pattern. As the reference pattern 12 exists properly, it is checked whether a next reference pattern needs to be detected and checked. Since this is a first reference pattern, the next reference pattern is detected. Then, data on the second reference pattern 13 is read. When it is within field of vision, the data is detected and compared similarly to the former one. Then, it is checked whether a next reference pattern is to be detected and checked. Since the two reference patterns have been detected so far, a next reference pattern is not detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for positioning a semiconductor pattern capable of accurately determining the position of a specific pattern in a predetermined device pattern on a semiconductor wafer, and the position thereof. The present invention relates to a semiconductor inspection apparatus and method capable of appropriately performing a desired inspection on a pattern.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor device, a measuring apparatus for inspecting whether or not a device pattern such as a resist pattern is appropriately formed in a desired shape, for example, by measuring the length of the pattern, and an inspection. In an apparatus, it is very important to detect the position of a device pattern to be inspected, and it is a difficult task that requires high accuracy.

In recent years, a method using pattern recognition has been used for detecting the inspection pattern. That is,
As shown in FIG. 4, a pattern having a characteristic such as a numeral or a character is registered as a reference pattern, the pattern is recognized by pattern matching, and the position of the pattern to be inspected is determined by relative coordinates based on the pattern. Is determined. However, when a characteristic pattern suitable for pattern recognition, such as a numeral or an alphabetic character, is not arranged near the pattern to be inspected for the device pattern, or when such a convenient pattern is In some cases, it is difficult to dispose it near the pattern. Therefore, in such a case, the device pattern itself is set as a recognition target, and the position is detected by pattern recognition.

[0004]

However, in the case of recognizing such a device pattern to be inspected, when the device pattern is a pattern having no feature, the recognition cannot be performed properly. There is a problem that the target pattern may not be properly extracted.

In particular, when there are only isolated patterns such as holes and dots as shown in FIG. 5, it is difficult to recognize a pattern to be inspected from these. For example, in FIG.
It is assumed that the pattern 91 is registered as a reference pattern in order to measure the length. However, since the pattern 92 is also the same pattern as the reference pattern 91, it cannot be determined which pattern is really the reference pattern.
As a result, the length measurement pattern 90 cannot be detected.

In the case of performing image recognition based on such a pattern, if the magnification is too small, the pattern to be recognized becomes too small, and the pattern can be properly recognized by either of the methods of contrast and edge detection. Often not. When the magnification is increased, the pattern is recognized as a pattern like the above-described reference pattern 91, but since only a few hole patterns are included in the recognition pattern, the characteristics of the pattern are difficult to appear, and the pattern with surrounding patterns is difficult to appear. There is also a problem that it cannot be distinguished.

Accordingly, an object of the present invention is to provide a semiconductor pattern positioning apparatus and a semiconductor pattern positioning apparatus capable of appropriately specifying a desired pattern position even in a device pattern formed by an isolated pattern having no features such as holes and dots. It is to provide a method. Further, another object of the present invention is that even in a device pattern formed by an isolated pattern having no features such as holes and dots, the position of a desired pattern can be appropriately specified and the device pattern can be inspected. An object of the present invention is to provide a semiconductor inspection device and a method thereof.

[0008]

In order to solve the above problems, a semiconductor pattern positioning apparatus according to the present invention stores a plurality of reference patterns corresponding to one specific pattern in a predetermined pattern of a semiconductor device. Means, reference pattern detecting means for detecting whether or not each of the plurality of stored reference patterns is appropriately arranged on a predetermined pattern of the semiconductor device, and a state of each arrangement of the reference pattern Specific pattern position determining means for determining the position of the specific pattern based on

Preferably, the specific pattern position determining means, when at least two or more of the plurality of reference patterns are properly detected on a predetermined pattern of the semiconductor device, the appropriately detected reference pattern Then, the position of the specific pattern is determined based on the relative positional relationship with.
Specifically, the predetermined pattern of the semiconductor device is a pattern constituted by a film formed on a semiconductor wafer.

In the method of positioning a semiconductor pattern according to the present invention, a plurality of reference patterns corresponding to one specific pattern in a predetermined pattern of a semiconductor device are stored in advance, and the stored plurality of reference patterns are stored. Detecting whether each of the patterns is appropriately arranged on a predetermined pattern of the semiconductor device, and determining a position of the specific pattern based on a state of each arrangement of the reference pattern; .

Further, the semiconductor inspection apparatus of the present invention comprises: means for storing a plurality of reference patterns corresponding to one specific pattern in a predetermined pattern of the semiconductor device; and each of the plurality of stored reference patterns. A reference pattern detecting means for detecting whether or not the reference pattern is appropriately arranged on a predetermined pattern of the semiconductor device, and a specification for determining a position of the specific pattern based on a state of each arrangement of the reference pattern. There is provided pattern position determining means, and inspection means for performing a predetermined inspection on the specific pattern whose position has been determined.

Preferably, when at least two or more of the plurality of reference patterns are properly detected on a predetermined pattern of the semiconductor device, the specific pattern position determination means preferably detects the appropriately detected reference pattern. Then, the position of the specific pattern is determined based on the relative positional relationship with.
Specifically, the predetermined pattern of the semiconductor device is a pattern composed of a film formed on a semiconductor wafer, and the inspection unit performs an inspection as to whether the thickness of the film is appropriate.

Further, the semiconductor inspection method of the present invention stores a plurality of reference patterns corresponding to one specific pattern in a predetermined pattern of the semiconductor device, and each of the stored plurality of reference patterns is Detecting whether the semiconductor device is appropriately arranged on a predetermined pattern, determining the position of the specific pattern based on the state of each arrangement of the reference pattern, the position is determined A predetermined inspection is performed for a specific pattern.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor inspection apparatus according to an embodiment of the present invention will be described with reference to FIGS. The semiconductor inspection apparatus according to the present embodiment has a length measuring SEM (Scan) having a function of specifying the position of a pattern to be measured by image recognition.
ning Electron Microscope). The function of positioning the pattern to be measured by image recognition according to the present invention is installed in the length measuring SEM device as a program executed by the controller. Therefore, in the present embodiment, the process of positioning the pattern to be measured will be described based on the flowchart shown in FIG.

FIG. 1 is a flowchart for explaining the processing in the length measuring SEM device. Hereinafter, the processing of the length measurement SEM will be described with reference to this flowchart. In this length measurement SEM, a plurality of reference patterns at different positions are prepared for one measurement pattern, and when a plurality of reference patterns are detected, the device pattern is positioned based on the position coordinates. Do
Detect the length measurement pattern.

First, when the processing is started, data relating to the first reference pattern is read (step S2). Next, based on the read data, it is checked whether or not the reference pattern to be detected exists in the current visual field (step S3). If the reference pattern is out of the field of view in step S3, the beam is deflected to read the image data at the position of the reference pattern (step S4). Then, the pattern data of the reference pattern is compared with the pattern data of the device pattern at the position where the reference pattern exists, and it is checked whether the reference pattern is appropriately present at the position (step S5). .

In step S5, if a reference pattern exists at that position, it is checked whether or not it is necessary to detect and collate the next reference pattern (step S5).
6) If necessary, return to step S2, read out the data of the next registered reference pattern, and execute step S2.
Repeat the processing of 3 and below.

If it is determined in step S6 that the detection and collation of the next reference pattern is no longer necessary, such as when a predetermined number of reference patterns are detected, the position coordinates of the reference pattern detected so far are determined. , The position of the length measurement pattern is detected (step S7). And
Whether or not a desired pattern is appropriately formed at the detected position is inspected by performing an arbitrary length measurement or the like (step S8).

If it is determined in step S5 that the pattern of the device pattern is different from the reference pattern, whether the inspection process should be terminated immediately based on the result or whether the matching process with the next reference pattern should be performed Is determined (step S9). If it is determined in step S9 that the process should be terminated immediately, the process proceeds to step S9.
At 10, a series of processing is abnormally terminated. For example, a serious problem occurs when a predetermined number or more of the reference patterns prepared cannot be detected or when a predetermined very important reference pattern cannot be detected from the device pattern. Thus, the inspection is immediately terminated.

In step S9, the fact that the recognition of the current reference pattern is abnormally terminated is temporarily stored, and if it is determined that comparison and comparison with the next reference pattern should be performed, the process returns to step S2. Then, the data of the next registered reference pattern is read out, and the processing from step S3 onward is repeated in the same manner as described above.

This will be described more specifically with reference to FIG. FIG. 2 is a flowchart for explaining a specific example of the processing shown in FIG. In this example, a plurality of reference patterns are prepared for the measurement pattern 11, and when two of the reference patterns are detected, the measurement pattern 11 is positioned based on the position coordinates, and the measurement pattern 11 is measured. Detect long patterns.

First, in step S2, data relating to the first reference pattern 12 is read. Since this first reference pattern 12 is within the field of view (step S
3) The pattern data of the reference pattern 12 is compared with the pattern data of the device pattern at the position where the reference pattern exists (step S5). As a result, since the reference pattern 12 is properly present, step S6
Then, it is checked whether the detection / collation of the next reference pattern is necessary. In this case, since the reference pattern is still the first reference pattern, it is determined that the next reference pattern is to be detected, and the process returns to step S2.

As for the first reference pattern 12, first, data on the second reference pattern 13 is read, and it is confirmed that the data is within the field of view (step S).
3) The pattern data of the reference pattern 13 is compared with the pattern data of the device pattern at the position where the reference pattern exists (step S5). As a result, since the reference pattern 13 is properly present, step S6
Then, it is checked whether the detection / collation of the next reference pattern is necessary. In this case, since two reference patterns have been detected, the detection of the next reference pattern is not performed. As a result, the position of the length measurement pattern is detected based on the detected position coordinates of the first reference pattern 12 (step S7), and whether or not a desired pattern is appropriately formed at the detected position is determined. Is inspected by performing an arbitrary length measurement or the like (step S8).

As described above, according to the processing of this embodiment, a reference pattern can be appropriately detected and positioned even for a device pattern formed of holes, dots, and the like. As a result, a desired pattern can be inspected appropriately. Further, as compared with a case where the recognition image is simply enlarged, only a necessary portion needs to be confirmed, so that an increase in image data is small. In addition, even when a pattern that is a key necessary for producing a feature is separated to some extent, a reference area can be easily set.

The present invention is not limited to the embodiment, and various modifications are possible.

For example, the present invention can be applied not only to the automatic length measuring SEM as described above, but also to various semiconductor inspection apparatuses. For example, the present invention can be applied to a length measurement SEM that performs alignment using an optical microscope image, a visual device that inspects a recognized image itself, and the like.

In such an apparatus, when recognizing an alignment pattern, a pattern registered in advance is searched for. However, due to problems of wafer loading and stage accuracy, as shown in FIG. There is a case where the target alignment pattern does not exist at the position brought first. Therefore, as shown in FIG. 3B, all the patterns that are four sides away from the desired alignment mark by the field of view are registered, and if any of them is detected, the alignment mark is removed from the pattern. You may make it detect. The processing in this case can be performed in the same manner as in the above-described embodiment. Then, the possibility that any of the target alignment mark and the registered pattern is detected in the field of view becomes very high.

In this case, the direction in which the pattern shifts in the wafer loader is often constant. In such a case, the same effect can be obtained even if only a pattern shifted in that direction is registered.

In the above-described method for detecting a length measurement pattern, the length measurement pattern is finally determined based on the position relative to the position of the reference pattern. At this stage, recognition of the length measurement pattern is further performed. It is also possible to determine the length measurement pattern at the stage when the matching is performed.

[0030]

As described above, according to the present invention,
It is possible to provide an apparatus and a method for positioning a semiconductor pattern capable of appropriately specifying the position of a desired pattern even in a device pattern formed by an isolated pattern having no features such as holes and dots. Also,
Provided is a semiconductor inspection apparatus and method that can appropriately specify the position of a desired pattern and inspect the device pattern even in a device pattern formed by an isolated pattern having no features such as holes and dots. be able to.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining processing in a length measuring SEM apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a specific example for specifically explaining the processing of FIG. 1;

FIG. 3 is a diagram for specifically explaining a modified example of the present invention.

FIG. 4 is a view for explaining processing in a conventional length measuring SEM apparatus.

FIG. 5 is a diagram for explaining a problem of processing in a conventional length measuring SEM device.

[Explanation of symbols]

11: length measurement pattern, 12: first reference pattern, 13
... second reference pattern, 90 ... length measurement pattern, 91 ... reference pattern, 92 ... similar pattern

Claims (11)

[Claims] 1. A semiconductor device according to claim 1, wherein:
Means for storing a plurality of reference patterns corresponding to the specific pattern, and detecting whether or not each of the plurality of stored reference patterns is appropriately arranged on a predetermined pattern of the semiconductor device. A semiconductor pattern positioning apparatus, comprising: a reference pattern detecting unit; and a specific pattern position determining unit that determines a position of the specific pattern based on a state of each arrangement of the reference pattern. 2. The semiconductor device according to claim 1, wherein said specific pattern position determining means is configured to, when at least two or more of said plurality of reference patterns are properly detected on a predetermined pattern of said semiconductor device, to determine whether said plurality of reference patterns are properly detected. 2. The semiconductor pattern positioning device according to claim 1, wherein the position of the specific pattern is determined based on a relative positional relationship. 3. The semiconductor pattern positioning apparatus according to claim 2, wherein the predetermined pattern of the semiconductor device is a pattern formed by a film formed on a semiconductor wafer. 4. A semiconductor device according to claim 1, wherein:
A plurality of reference patterns corresponding to the specific pattern are stored in advance, and it is detected whether or not each of the stored plurality of reference patterns is appropriately arranged on a predetermined pattern of the semiconductor device. And a semiconductor pattern positioning method for determining a position of the specific pattern based on a state of each arrangement of the reference pattern. 5. The method according to claim 5, wherein the position of the specific pattern is determined when at least two or more of the plurality of reference patterns are properly detected on a predetermined pattern of the semiconductor device. 5. The method for positioning a semiconductor pattern according to claim 4, wherein the method is performed based on the relative positional relationship of: 6. A semiconductor device according to claim 1, wherein:
Means for storing a plurality of reference patterns corresponding to the specific pattern, and detecting whether or not each of the plurality of stored reference patterns is appropriately arranged on a predetermined pattern of the semiconductor device. A reference pattern detection unit; a specific pattern position determination unit that determines a position of the specific pattern based on a state of each arrangement of the reference pattern; and performing a predetermined inspection on the specific pattern whose position is determined. A semiconductor inspection apparatus having inspection means for performing the inspection. 7. When at least two or more of the plurality of reference patterns are properly detected on a predetermined pattern of the semiconductor device, the specific pattern position determining means determines whether or not the plurality of reference patterns are properly detected. 7. The semiconductor inspection device according to claim 6, wherein the position of the specific pattern is determined based on a relative positional relationship. 8. The semiconductor inspection apparatus according to claim 7, wherein the predetermined pattern of the semiconductor device is a pattern formed by a film formed on a semiconductor wafer. 9. A semiconductor device comprising:
Storing a plurality of reference patterns corresponding to the specific pattern, detecting whether each of the stored plurality of reference patterns is appropriately arranged on a predetermined pattern of the semiconductor device, A semiconductor inspection method that determines a position of the specific pattern based on a state of each arrangement of a reference pattern, and performs a predetermined inspection on the specific pattern whose position is determined. 10. A method for determining the position of a specific pattern, comprising: detecting at least two or more of the plurality of reference patterns on a predetermined pattern of the semiconductor device; 10. The semiconductor inspection method according to claim 9, wherein the method is performed based on a relative positional relationship. 11. The semiconductor inspection method according to claim 10, wherein the predetermined pattern of the semiconductor device is a pattern formed by a film formed on a semiconductor wafer.