JP3070745B2 - Defect inspection method and apparatus, and semiconductor manufacturing method using the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a defect inspection method and apparatus for inspecting a state of a defect generated on a wafer during a semiconductor LSI manufacturing process, and a method for manufacturing a semiconductor using the same. About the method.

[Conventional technology]

Conventionally, detection of foreign matter on LSI wafer samples during the manufacturing process,
A method described in Japanese Patent Application Laid-Open No. 60-218845 has been known for improving the efficiency of observation and analysis. That is, the optical foreign matter detection head and the observation head by electron beam (SEM) and the analysis head by XMA are set side by side on the same vacuum chamber, and (1)
After detecting foreign matter on the entire surface of the sample mounted on the stage,
(2) This is a method (integrated type) of moving the stage under the observation / analysis head and performing SEM observation / XMA analysis of each foreign substance detected in (1) (FIG. 15). In this method, the sample is fixed and mounted on the same stage,
Since the series of operations (2) can be performed, there is an advantage in the device configuration that the sample alignment function is not required.
Once the sample is removed from the stage, and the sample is mounted on the instrument again to observe and analyze the previously detected foreign matter, there is no sample position detection function. -There is a unique problem that analysis (tracking between processes) cannot be performed.

(A) For example, in order to quantify the effects of washing and drying, it is necessary to perform the flow shown in FIG. (1),
In (2), detection and observation of foreign matter adhering to the sample in advance
Analysis is performed, washing and drying are performed in (3) and (4), and foreign matter detection, observation and analysis are performed again in (5) and (6). B) residual foreign matter,
(C) The newly attached foreign matter is specified, and the effect of the cleaning method (the number and ratio of the above (a) to (c)) can be quantified as shown in FIG. Further, individual foreign substances are subjected to elemental analysis using an X-ray microanalyzer or the like, whereby substances of the removed and remaining foreign substances can be determined. This compares the effects of the cleaning methods α and β,
The characteristics of each washing method can be quantitatively determined.

However, since the conventional apparatus does not have a function of detecting the position of the sample, it is necessary to detect and observe the foreign substances detected and observed in (1) and (2) again in (5) and (6) for tracking between processes. Can not. If the foreign matter detection (5) is performed, the remaining foreign matter k can be observed and analyzed (6), but the removed foreign matter i, j cannot be observed (removal trace). (Observe traces of removal
Analyze for a detailed assessment of the wash. Furthermore, when foreign matter is present in the vicinity, it becomes difficult to identify the removed foreign matter, the remaining foreign matter, and the newly attached foreign matter, and the work of tracking the foreign matter between processes is completely impossible.

As a conventional technique, it is conceivable to mechanically align the sample with the external reference pin (three-point pin) of the sample. In this case, the accuracy of sample position reproducibility (by mounting on the same three-point pin) is ± It is about 100 μm, and it is difficult to achieve the above object. Furthermore, different devices (foreign matter inspection device and foreign matter
(Analyzer), a positioning error of about ± 150 μm occurs because the arrangement error of the three-point pin is superimposed on the reproducibility accuracy.

(B) In the conventional device, the foreign matter detected in (1) is SE in (2).
Although M observation and XMA analysis are possible, they cannot be analyzed with other analyzers such as an ion microanalyzer and infrared analysis. For example, XMA is suitable for analysis of inorganic substances, but infrared analysis is suitable for analysis of organic substances such as photoresist. As described above, in the conventional apparatus, various and detailed analyzes cannot be performed unless a plurality of observation / analysis heads are prepared. However, installing a plurality of observation / analysis heads on a vacuum chamber has a problem that requires a large space, and is not practical.

Representative methods required for observation and analysis of semiconductor samples are described in detail in the following literature.

1) Otaka et al .: Semiconductor process evaluation equipment, Hitachi review, V
ol.68, No.9 (1986) pp37 2) Sugawara: 1987 Edition Japan Semiconductor Yearbook, 3rd edition latest technical information, Chapter 2 Process and material technology, Section 5 Thin film formation, pp.415, Press Journal ( 1987). 3) Kawazu: Evaluation and Inspection Technology in Wafer Process, Electronic Materials, Vol.24, No.8 (1985) pp24, (Industrial Research Committee) 4) Integrated Precision Cleaning System Technology for Semiconductors and Electronic Components, Chapter 3, Chapter Section 1, pp29-30, Realize Inc. (1986) These observation and analysis methods have a very narrow field of view (usually about 10 μm). Essential for work.

[Problems to be solved by the invention]

In the above prior art, (A) no consideration is given to coordinates on a sample such as a wafer, and once the sample is removed from the apparatus, reproducibility of coordinates cannot be obtained.

(B) Since there is only one observation / analysis head, various types of detailed analysis cannot be performed.

There is a problem that.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a defect inspection method and apparatus for outputting a defect position in absolute coordinates so that a defect on a sample can be analyzed, and a semiconductor manufacturing method using the same.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a foreign matter detection head with a sample position detection function to obtain the absolute coordinates of a sample.

Further, the present invention stores the absolute coordinates in an external storage device, and inputs the stored coordinates to various types of observation / analysis devices,
Various observation and analysis methods can be applied.

In the present invention, it is necessary to provide a sample position detecting function also in the observation / analysis device. In addition, the observation function (SE
If the position of the sample is detected by using an M image, an ion beam scanning image, etc., it is not necessary to add a dedicated position detection function.

[Action]

The sample position detection function is performed before the foreign substance detection, detects the position of a specific mark so that the position does not change even if the sample goes through the process, and provides the absolute coordinates of the foreign substance on the sample based on this. If there is no mark on the sample (mirror wafer or the like), the outer shape position of the sample may be detected. As a result, even if the sample is removed from the foreign matter detection head, the reproducibility of the coordinates can be ensured, so that (a) foreign matter tracking between processes (b) various kinds of foreign matter observation and analysis work become possible.

The present invention has an effect of easily performing the above (a) and (b).

As the position detection function, for example, magnification 100 times (object lens 2
When a microscope image of ⁽ 0x + 5x relay lens) is picked up by a 2 / 3-inch TV camera, one pixel of the TV camera is 0.27 μm, and a position detection accuracy of 1 μm or less can be obtained.

〔Example〕

The sample position detection method will be described with reference to FIGS.

FIG. 6 shows the absolute coordinates (X _i ,
X _i ). Here, the chips on the sample 200 are arranged in a matrix by the grating 220 (scribe line).

The coordinate origin 210 is the intersection of the grid (extended line) 220 and selects an appropriate point on or outside the sample. In this embodiment, the lattice
Point 210 at the lower left of the extension of 220 was selected.

FIG. 7 (a) is an enlarged view of the chip (d, n) where the foreign matter i exists. Foreign matter position (x from bottom left of tip (d, n)
_i, as y _i), the absolute coordinates of the foreign matter i is _{X i = Wx (d-1} ) + x i ‥‥‥‥ (1) Y i = Wy (n-1) + y i ‥‥‥‥ and (2) Become. Next, tracking between processes will be described.

FIG. 7 (b) shows a cross section of the sample AA '. The layer 30 is on the base material 400, and forms the connection hole 30a and the chip boundary 30b.

In the next step, exposure film formation based on the pattern design in FIG.
Processing is performed to form a connection hole 32a and a new chip boundary 32b on the layer 32 (FIG. 9).

9 (b) shows a section taken along the line AA 'in FIG. 9 (a), and FIG. 9 (c) shows a section taken along the line BB' in FIG. 9 (a).

Here, it is necessary to perform the alignment of the holes 30a and 32a with high accuracy.

In the example shown in FIG. 9, a defect (hole) is generated in the layer 32 due to the foreign matter i generated in the previous step. However, the foreign matter j is removed during the process and disappears in the next process. In the present invention, since the absolute coordinates are used, the above process tracking can be performed. Here, the analysis of the removed foreign matter j and the remaining foreign matter i is performed, and a measure for preventing the generation of the foreign matter i is performed between the previous process and the next process. Focusing on this will help prevent defects. Here, since the removed foreign matter j does not cause a defect in the next process, no countermeasure is necessary.

It is an object of the present invention to enable an efficient and quick measure for the first time by specifying (narrowing down) the purpose and target of the measure in this way.

FIG. 10 shows a method for detecting the position of the reference point φ of the foreign matter position (x _i , y _i ) according to the present invention. A reticle 40 (double line) is engraved in the position detection microscope field of view, and if the center line of this double line is aligned with the center of the boundary 30b (or 32b), the boundary 30b, Even if the size of 32b is different, the reference point φ is always accurately positioned. (After all, the intersection of the center line of the grid 220 becomes the reference point φ.) In the example of FIG.
_x1 = _{ε x2,} easily by the ε _y1 = ε _y2.

A method other than the present invention will be described with reference to FIGS. 11 and 12, and the advantages of the present invention will be clarified and described. FIG. 11 (b) shows a cross section AA 'of FIG. 11 (a). In this example, since the lower left points φ ′ and φ ″ of the boundaries 30b and 32b are used as reference points in each process, a coordinate error occurs in the process tracking operation described above.

In the present invention, as shown in FIG. 13, when the sample does not have a pattern like the mirror surface wafer 200a, the position detection field
41 is moved to each of the feature points of sample 200a, and
By measuring X _{1 to} X ₃ , Y ₁ and Y ₂ , the origin 210 ′ is obtained.

With the above position detection method, absolute coordinates can be easily obtained even when the sample is a mirror surface.

In the case of a wafer with a pattern, the intersection 2
As another method other than using the coordinate origin as 10, use of an alignment mark 221 used in an exposure apparatus such as a stepper (reduced projection exposure apparatus) as shown in FIG. 17 can be considered.
Also in this case, it is necessary to select a mark in consideration of a position error between processes.

That is, in the “absolute coordinates” of the present invention, it is a necessary condition that the mark 221 is selected and detected so that no positional displacement occurs between processes. In the example shown in FIG. 17, the coordinate origin 210a is used.

FIGS. 1 to 3 show an embodiment of a foreign matter detecting apparatus using the above-described position detecting (or positioning) function.

(A) Position detection / foreign matter detection stage separation method (FIG. 1) In the embodiment shown in FIGS. 1 (a) to (d), the position detecting part A and the foreign matter detecting part B are separately installed, S (20
0 or 200a) by the position detection unit A, and
The sample S is transferred to the foreign substance detecting section B by 3 and, after the foreign substance is detected, the absolute coordinates of each detected foreign substance are stored in the external storage medium 8, and the observation / analysis device D uses the coordinates. This is a method for analyzing individual foreign substances.

Here, the external storage medium 8 has the following forms as shown in FIG.

(A) Computer 8a, communication to LAN (Local Area Network), etc. (b) Memory of 8b such as floppy disk, MT (Magnetic Tape), cassette tape, etc. (c) Communication between foreign object inspection device (A + B) and analyzer D 8c (d) Visual / manual input by printer output 8d (e) Visual / manual input 8e by display output The configuration of each is as follows.

In this method (a), the transport mechanism 13 is used, and it is important that the transport mechanism 13 does not cause a displacement of the sample S when transferring the sample. Further, in this method, since the position detection A and the foreign matter detection stage B are divided, the above operations can be performed simultaneously, and the throughput is the same.
That is, the device configuration is as follows.

That is, the defect inspection apparatus shown in FIG. 1A includes: a first sample mounting mechanism 1 for mounting a sample S to be inspected; an illuminating means 2 for illuminating the sample; An optical unit 3 having one detector, a scanning unit 4 for scanning a detection visual field of the optical unit on the sample, a first position detecting unit 5 for detecting a scanning position of the sample by the scanning, A signal processing circuit 6 for sequentially processing an output signal of the detector in the detection visual field; and a storage circuit 7 for inputting and storing a coordinate position from the position detecting means 5 as a position of a defect processed by the signal processing circuit. An external storage medium 8 connected to the storage circuit, a second sample mounting mechanism 9 for mounting the sample, and a second detector for detecting the position of the sample on the second sample mounting mechanism 9. Second position detecting means 10 having an output signal of the second detector. To calculate the amount of displacement of the sample from the reference position.
Positioning means 12 for correcting the amount of displacement by moving the second mounting mechanism, and a transport mechanism 13 for transferring the sample from the first mounting mechanism to the second mounting mechanism. The displacement amount of the sample on the second mounting mechanism 9 is calculated by the second
The sample is transferred to the first mounting mechanism 1 by the transport mechanism 13 after the position is corrected by the position detecting means 10 and the position shift amount calculating circuit 11 and the position adjusting means 12 corrects the position shift. After the sample is illuminated by the illuminating means 2 and a defect on the sample is detected by the optical means 3, the scanning means 4, and the signal processing means 6, the storage coordinate position of the storage circuit 7 is stored in the external storage medium 8. Is configured to be stored.

Further, the defect inspection apparatus shown in FIG. 1 (b) comprises: a first sample mounting mechanism 1 for mounting a sample S to be inspected; an illuminating means 2 for illuminating the sample; An optical unit 3 having one detector, a scanning unit 4 for scanning a detection visual field of the optical unit on the sample, a first position detecting unit 5 for detecting a scanning position of the sample by the scanning, A signal processing circuit 6 for sequentially processing an output signal of the detector in the detection visual field; a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit; An external storage medium 8 connected to the storage circuit; a second sample mounting mechanism 9 for mounting the sample; and a second detector for detecting the position of the sample on the second sample mounting mechanism 9. A second position detecting means 10 and an output signal of the second detector A displacement calculating circuit 11 for processing and calculating a displacement from a reference position, a transport mechanism 13 for transferring the sample from the first mounting mechanism to a second mounting mechanism, the transport mechanism and the position Positioning means 14 for moving a distance commensurate with the amount of displacement, wherein the amount of displacement of the sample on the second mounting mechanism 9 is determined by the second
The position of the sample is transferred to the first mounting mechanism 1 by the transport mechanism 13 by using the position detecting means 10 and the displacement calculating circuit 11 to correct the displacement by the positioning means 14. Simultaneously, the sample is illuminated by the illuminating means 2, the optical means 3, the scanning means 4, and the signal processing means 6 detect defects on the sample. It is configured to store in the external storage medium 8.

Further, the defect inspection apparatus shown in FIG. 1 (c) comprises: a first sample mounting mechanism 1 for mounting a sample S to be inspected; an illuminating means 2 for illuminating the sample; An optical unit 3 having one detector, a scanning unit 4 for scanning a detection visual field of the optical unit on the sample, a first position detecting unit 5 for detecting a scanning position of the sample by the scanning, A signal processing circuit 6 for sequentially processing an output signal of the detector in the detection visual field; a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit; An external storage medium 8 connected to the storage circuit; a second sample mounting mechanism 9 for mounting the sample; and a second detector for detecting the position of the sample on the second sample mounting mechanism 9. A second position detecting means 10 and an output signal of the second detector A displacement calculating circuit 11 for processing and calculating the displacement of the sample from the reference position
A transfer mechanism 13 for transferring the sample from the first mounting mechanism to the second mounting mechanism; and a coordinate correction circuit 15 for correcting a storage coordinate position output from the storage circuit. The amount of displacement of the sample on the mounting mechanism 9 of the second
Is calculated by the position detecting means 10 and the position shift amount calculating circuit 11, and the position shift amount is input to the coordinate correcting circuit 15, and the sample is transferred to the first mounting mechanism 1 by the transport mechanism 13. Then, the sample is illuminated by the illuminating means 2, and the optical means 3, the scanning means 4, and the signal processing means 6 detect a defect on the sample. The correction circuit 15 is configured to correct the positional deviation and store the result in the external storage medium 8.

Further, the defect inspection apparatus shown in FIG. 1 (d) comprises: a first sample mounting mechanism 1 for mounting a sample S to be inspected; an illuminating means 2 for illuminating the sample; An optical unit 3 having one detector, a scanning unit 4 for scanning a detection visual field of the optical unit on the sample, a first position detecting unit 5 for detecting a scanning position of the sample by the scanning, A signal processing circuit 6 for sequentially processing an output signal of the detector in the detection visual field; a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit; An external storage medium 8 connected to the storage circuit; a second sample mounting mechanism 9 for mounting the sample; and a second detector for detecting the position of the sample on the second sample mounting mechanism 9. A second position detecting means 10 and an output signal of the second detector A displacement amount calculating circuit 11 for processing and calculating a displacement amount from a reference position; a transport mechanism 13 for transferring the sample from the first mounting mechanism to the second mounting mechanism; And a detection position correcting means 16 for correcting the output of the means.
The position of the sample is transferred to the first mounting mechanism 1 by the transport mechanism 13 by inputting the amount of the positional shift to the detected position correcting means 16. The sample is illuminated by the illumination means 2, and when a defect on the sample is detected by the optical means 3, the scanning means 4, and the signal processing means 6, the detection position correction means 16 detects a position shift. It is configured to perform correction and store the storage coordinate position of the storage circuit 7 in the external storage medium 8.

(I) Position detection / foreign matter detection head separation method (FIG. 2) FIGS. 2 (a) to 2 (d) show an embodiment.

In this method, since the stage is common, simultaneous work cannot be performed, but the transfer mechanism 13 is unnecessary.

That is, the defect inspection apparatus shown in FIG. 2A includes a sample mounting mechanism 1 for mounting a sample S to be inspected, an illuminating means 2 for illuminating the sample, and a first detection for detecting a defect on the sample. Optical means 3 having a detector; scanning means 4 for scanning a detection field of the optical means on the sample; first position detection means 5 for detecting a scanning position of the sample by the scanning; A signal processing circuit 6 for sequentially processing an output signal of the detector in the above, a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit, An external storage medium 8 connected to a circuit; second position detecting means 10 having a second detector for detecting the position of the sample on the sample mounting mechanism; and processing an output signal of the second detector. Where the amount of displacement of the sample from the reference position is calculated It is amount calculation circuit 11
Positioning means 12 for correcting the amount of displacement by moving the mounting mechanism; and moving the sample from the position of the second position detecting means 10 to the optical means 3.
And a transfer mechanism 13 for transferring the sample to the position of the sample. The position shift amount of the sample at the position of the position detecting means 10 is calculated by the second position detecting means 10 and the position shift amount calculating circuit 11, After correcting the positional deviation by the positioning means 12, the sample is transferred to the position of the optical means 3 by the transport mechanism 13, the sample is illuminated by the illumination means 2, the optical means 3 and the scanning means 4 After detecting a defect on the sample by the signal processing unit 6 and the signal processing unit 6, the storage coordinate position of the storage circuit 7 is stored in the external storage medium 8.

A defect inspection apparatus shown in FIG. 2 (b) comprises: a sample mounting mechanism 1 for mounting a sample S to be inspected; an illuminating means 2 for illuminating the sample; and a first detection for detecting a defect on the sample. Optical means 3 having a detector; scanning means 4 for scanning a detection field of the optical means on the sample; first position detection means 5 for detecting a scanning position of the sample by the scanning; A signal processing circuit 6 for sequentially processing an output signal of the detector in the above, a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit, An external storage medium 8 connected to a circuit; second position detecting means 10 having a second detector for detecting the position of the sample on the sample mounting mechanism; and processing an output signal of the second detector. To calculate the amount of misalignment from the reference position Circuit 11 and an optical unit 3 from the position of the second position detecting means 10 the sample
And a positioning mechanism 14 for moving the transport mechanism and a distance commensurate with the amount of positional deviation, and the amount of positional deviation of the sample at the position of the position detecting means 10 is determined. When the sample is transferred to the position of the optical means 3 by the transport mechanism 13 by the second position detecting means 10 and the position shift amount calculating circuit 11, the position adjusting means 14 calculates the position shift. The correction is performed simultaneously, the sample is illuminated by the illuminating means 2, and the optical means 3, the scanning means 4, and the signal processing means 6 detect defects on the sample. Is stored in the external storage medium 8.

A defect inspection apparatus shown in FIG. 2C includes a sample mounting mechanism 1 for mounting a sample S to be inspected, an illuminating means 2 for illuminating the sample, and a first detection for detecting a defect on the sample. Optical means 3 having a detector; scanning means 4 for scanning a detection field of the optical means on the sample; first position detection means 5 for detecting a scanning position of the sample by the scanning; A signal processing circuit 6 for sequentially processing an output signal of the detector in the above, a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit, An external storage medium 8 connected to a circuit; second position detecting means 10 having a second detector for detecting the position of the sample on the sample mounting mechanism; and processing an output signal of the second detector. Where the amount of displacement of the sample from the reference position is calculated It is amount calculation circuit 11
And moving the sample from the position of the second position detecting means 10 to the optical means 3.
And a coordinate correction circuit 14 for correcting the storage coordinate position output from the storage circuit, and the position shift amount of the sample at the position of the position detection means 10 2 is calculated by the position detecting means 10 and the positional shift amount calculating circuit 11, and the positional shift amount is input to the coordinate correcting circuit 15, and the sample is transferred to the position of the optical means 3 by the transport mechanism 13. Then, the sample is illuminated by the illuminating means 2, and the optical means 3, the scanning means 4, and the signal processing means 6 detect a defect on the sample. The correction circuit 15 is configured to correct the positional deviation and store the result in the external storage medium 8.

A defect inspection apparatus shown in FIG. 2D includes a sample mounting mechanism 1 for mounting a sample S to be inspected, an illuminating means 2 for illuminating the sample, and a first detection for detecting a defect on the sample. Optical means 3 having a detector; scanning means 4 for scanning a detection field of the optical means on the sample; first position detection means 5 for detecting a scanning position of the sample by the scanning; A signal processing circuit 6 for sequentially processing an output signal of the detector in the above, a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit, An external storage medium 8 connected to a circuit; second position detecting means 10 having a second detector for detecting the position of the sample on the sample mounting mechanism; and processing an output signal of the second detector. To calculate the amount of misalignment from the reference position Circuit 11 and an optical unit 3 from the position of the second position detecting means 10 the sample
And a detection position correcting means 16 for correcting the output of the first position detecting means. The position shift amount of the sample at the position of the position detecting means 10 2 is calculated by the position detecting means 10 and the position shift amount calculating circuit 11, and the position shift amount is input to the detection position correcting means 16, and the sample is moved to the position of the optical means 3 by the transport mechanism 13. The sample is illuminated by the illumination means 2, and when a defect on the sample is detected by the optical means 3, the scanning means 4, and the signal processing means 6, the detection position correction means 16 detects a position shift. It is configured to perform correction and store the storage coordinate position of the storage circuit 7 in the external storage medium 8.

(C) Position detection / foreign matter detection integrated type (Fig. 3) In this method, the method (15), (17) in which the detector 20 for foreign matter detection is used as a position detector, and both methods are used as separate detectors (ie, Installation method for foreign matter detection 20 and position detection 21) (1
6) and (18).

 The features of the mechanism are as follows.

That is, the defect inspection apparatus shown in FIG. 3A includes a sample mounting mechanism 1 for mounting a sample S to be inspected, an illuminating means 2 for illuminating the sample, and a detector 20 for detecting a defect on the sample. Optical means 3 having; scanning means 4 for scanning a detection field of the optical means on the sample; first position detection means 5 for detecting a scanning position of the sample by the scanning; A signal processing circuit 6 for sequentially processing an output signal of the detector 20; a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit; An external storage medium 8 connected to a sensor, a displacement calculating circuit 11 for processing an output signal of the detector 20 to calculate a displacement of the sample from a reference position, and moving the mounting mechanism. The positioning means 12 for correcting the amount of displacement. And, optical means 3 a positional shift amount of the sample on the mounting mechanism 1
After the correction by the positioning means 12, the sample is illuminated by the illuminating means 2, the optical means 3, the scanning means 4, and the signal processing means. After detecting a defect on the sample by 6, the storage coordinate position of the storage circuit 7 is stored in the external storage medium 8.

The defect inspection apparatus shown in FIG. 3 (b) includes a sample mounting mechanism 1 for mounting a sample S to be inspected, an illuminating means 2 for illuminating the sample, and a first detection for detecting a defect on the sample. Optical means 3 having a detector 20 and a second detector 21 for detecting the position of the sample
Scanning means 4 for scanning a detection field of view of the optical means on the sample; first position detection means 5 for detecting a scanning position of the sample by the scanning; A signal processing circuit 6 for sequentially processing an output signal; a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit; and an external device connected to the storage circuit. A storage medium 8; a position calculating circuit 11 for processing an output signal of the second detector 21 to calculate an amount of displacement of the sample from a reference position; and an amount of displacement by moving the mounting mechanism. And a position shift amount of the sample on the mounting mechanism 1 is calculated by the second detector 21 and the position shift amount calculating circuit 11, and After correcting the displacement, the sample is illuminated by the illumination means 2. After detecting a defect on the sample by the first detector 20, the scanning means 4, and the signal processing means 6, the storage coordinate position of the storage circuit 7 is stored in the external storage medium 8. Have been.

The defect inspection apparatus shown in FIG. 3 (c) comprises: a sample mounting mechanism 1 for mounting a sample S to be inspected; an illuminating means 2 for illuminating the sample; and a first detection for detecting a defect on the sample. Optical means 3 having a detector 20; scanning means 4 for scanning a detection field of view of the optical means on the sample; first position detecting means 5 for detecting a scanning position of the sample by the scanning; A signal processing circuit 6 for sequentially processing an output signal of the detector 20 in the field of view; a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit; An external storage medium 8 connected to the storage circuit; a displacement amount calculation circuit 11 for processing an output signal of the detector 20 to calculate a displacement amount of the sample from a reference position; And a coordinate correction circuit 15 for correcting the stored coordinate position. Then, the displacement amount of the sample on the mounting mechanism 1 is calculated by the optical means 3 and the displacement amount calculation circuit 11, and the displacement amount is input to the coordinate correction circuit 15, and the sample is After illuminating by the illumination means 2 and detecting defects on the sample by the optical means 3, the scanning means 4 and the signal processing means 6, the storage coordinate position of the storage circuit 7 is shifted by the coordinate correction circuit 15. The data is corrected and stored in the external storage medium 8.

The defect inspection apparatus shown in FIG. 3D includes a sample mounting mechanism 1 for mounting a sample S to be inspected, an illuminating means 2 for illuminating the sample, and a first detection for detecting a defect on the sample. Optical means 3 having a detector 20 and a second detector 21 for detecting the position of the sample
Scanning means 4 for scanning a detection field of view of the optical means on the sample; first position detection means 5 for detecting a scanning position of the sample by the scanning; A signal processing circuit 6 for sequentially processing an output signal; a storage circuit 7 for inputting and storing a coordinate position from the position detecting means as a position of a defect processed by the signal processing circuit; and an external device connected to the storage circuit. A storage medium 8, a position shift amount calculation circuit 11 that processes an output signal of the second detector 21 to calculate a position shift amount from a reference position, and corrects a storage coordinate position output from the storage circuit. A coordinate correction circuit 15; and a second detector for detecting the amount of displacement of the sample on the mounting mechanism 1.
21 and the displacement calculating circuit 11, the displacement is input to the coordinate correcting circuit 15, the sample is illuminated by the illumination means 2, the first detector 20 and the scanning means After a defect on the sample is detected by the signal processing means 4 and the signal processing means 6, the coordinate position of the storage circuit 7 is corrected by the coordinate correction circuit 15 and stored in the external storage medium 8. ing.

Also, the absolute coordinate position of the defect on the sample stored in the external storage medium 8 provided in each of the defect inspection apparatuses shown in FIGS. 1 to 3 is input, and each of the absolute coordinate positions is used for another defect inspection. Move the sample so that it is within the observation field of the magnified image or photoelectric conversion image by an optical device that combines optical elements such as a device, an optical microscope, a fluorescence microscope, an infrared microscope, a polarization microscope, a differential interference microscope, and a laser Raman. Can be observed.

The external storage medium 8 included in each of the above-described defect inspection devices.
Input the absolute coordinate position of the defect on the sample stored by the SEM, X-ray microanalyzer (XM
A) The analysis and identification can be performed by moving the sample so as to enter the analysis area of an analyzer using X-ray, electron beam, ion beam, etc. such as Auger analysis.

The external storage medium 8 included in each of the above-described defect inspection devices.
Enter the absolute coordinate position of the defect on the sample stored in the sample and move the sample so that each of the absolute coordinate position is within the measurement range of an electrical continuity test device such as an electric tester, a laser tester, and an EB tester. The nearby electric characteristics can be measured.

Further, the present invention can be applied to electrical characteristic inspection. [Super LSI
Device Handbook, pp. 255, 256, Science Forum, (1983)] based on the absolute coordinates based on the evaluation of the causal relationship (fatality) between the output results of the electrical characteristics test and foreign matter (fatality) (Fig. 16). If it can be grasped quantitatively, the yield (electrical failure rate) can be estimated based on the foreign matter to be dealt with, the priority of the process to be dealt with, and the foreign matter generation status in the middle of the process, so that the input amount can be optimized.

In FIG. 16, since the ratio of the foreign matter generated in the process N to the electrical failure is large (has a large influence), it is necessary to take a countermeasure. However, in the process M, the countermeasure is small because the influence is small. In addition, [Furukawa: Trends of LSI Non-Contact Diagnosis Technology, Monthly
Semiconductor World, Vol.7, No.6, pp.114-124 Press Journal (1988)] has an electron beam tester, [Nagase: Failure analysis system by laser scanning method, electronic materials, separate volume, "Technology of Ultra LSI" Pp.122-126 (Showa 55), Industrial Research Committee] describes an electrical characteristic inspection using a laser beam tester, and the present invention can be applied to these characteristic inspections.

Further, the present invention can be applied to defect correction and foreign matter removal. [Ochiai: Focused ion beam device, electronic material, separate volume "Super LSI manufacturing and testing device, 1989 edition" pp. 94-99 Industrial Research Committee], a correction device as described in [DJ Elliott: Photoablation of
Resist Coated Alignment Targets to Improve VLSI P
attern Overlay, SPIE Proceedings VoL. 774, pp. 172-17
5 (1987)], remedy of defects by removing foreign matter,
Helps to secure good products.

 The above is summarized in Table 1 below.

Further, the present invention can be applied not only to the inspection result of foreign matter but also to a defect inspection result output from an appearance defect inspection apparatus that comprehensively detects disconnection, short circuit, dirt, foreign matter and the like of a pattern.

LSI defects are classified as follows. The foreign matter detection unit (B) of the present invention can be applied to a defect detection function for inspecting the following appearance defects.

FIG. 26 shows an example of tracking between processes according to the present invention. It can be understood that the foreign matter generated in the process N causes a pattern defect (short circuit) in the next process N + 1.

This is the case where A + B = foreign matter inspection and D = defect inspection are used in Table 1 No. 1. This can be realized by the flow shown in FIG. Further, the size of each foreign substance detected by A + B is measured by an optical microscope (D ₁ ), and thereafter, whether or not it becomes a pattern defect is quantified by a defect inspection device (D ₂ ). To get the graph. In this case, the defect rate of the foreign matter pattern of 0.75 μm or more is 30% or more. Therefore, in the mass production line, the foreign matter of 0.75 μm or more was detected in the process N, and the quality inspection was performed based on the number of the generated foreign matter.

FIG. 19 shows an example of No. 3 (Table 1). In this case, the foreign matter having a size of 0.5 μm or more in the process N has poor electrical characteristics (50
% Or more), it is possible to determine the foreign matter management standard of the foreign matter inspection in the process N to be 0.5 μm.

FIG. 20 (FIG. 21) shows an example in which No. 1 (No. 2) and No. 3 in Table 1 are combined. In this example, a comparison between the effects of cleaning α and cleaning β was shown. According to the flow shown in FIG. 20, (a)
In each of cleaning α and (b) cleaning β, removal is performed for each substance and material.
By quantifying the remaining and newly attached foreign matter (FIG. 21), it is possible to more clearly grasp the difference in the effects of the cleaning α and β as compared with the case of FIG.

 22 to 24 show an example of No. 2 (Table 1).

FIG. 22 shows foreign matter detection (A +
B) and analysis of individual foreign substances (D). Here, photoresist particles were present around the wafer, and it was determined that the photoresist spin (rotation) coating device was defective (caused by the re-adhesion of excess photoresist scattered around), and a countermeasure was taken. In this example, the above cause could be pursued for the first time by displaying only the photoresist and other foreign matters separately.

FIG. 23 shows the result of evaluating the wafer transfer step. In this case, there were Si debris around the wafer, which was caused by contact between the transfer mechanism and the Si wafer.

FIG. 24 shows the defect detection (A + B) after the exposure and development steps and the analysis of individual defects (D). In this case, since the remaining photoresist is commonly present at the end of each exposure unit (one exposure area on the stepper), the stepper may have an insufficient exposure amount (irradiation unevenness) in this part. understood.

FIG. 25 shows a composite example of No. 1 and No. 2 (Table 1). The pattern defect 34 (A + B) is observed (D ₁ ), and the result of the short circuit 34 is obtained. As a result of analyzing (D ₂ ) the short-circuited portion 34, (a) in the case of the same material as that of 34 = 400 (shown in FIG. 25 (b) as an AA ′ cross section in FIG. 25 (a)) (b) 34 = 33 and 〃 (shown in FIG. 25 (c) as an AA ′ cross section in FIG. 25 (a).) Either of the cases (a) and (b) above. When this is found, the cause of the short circuit can be estimated, so that countermeasures can be taken.

As described above, according to the present invention, (1) it is easy to pursue the cause of the defect and the countermeasure is easy. (2) the quantification of the effect of the cleaning method, etc. (3) the foreign matter management level (size, number et.
c) can be determined.

Further, the present invention provides an image pickup device (CCD, MID
(Mos Image Device)), LCD panel (TFT),
It can be widely applied to electronic component samples such as high-density wiring boards for computers.

〔The invention's effect〕

As described above, according to the present invention, it is possible to quantitatively grasp the change in the situation of the defect between the processes, and to estimate the yield based on the defect to be dealt with, the priority of the process to be dealt with, and the defect occurrence status. The effect that can be performed.

Further, according to the present invention, there is an effect that the defect can be removed and corrected, and the defect can be analyzed and identified by a device different from the device that performs the defect inspection.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing each embodiment of the defect inspection apparatus according to the present invention, FIG. 2 is a schematic configuration diagram showing each embodiment of the defect inspection apparatus according to the present invention, and FIG. FIG. 4 is a schematic diagram showing an embodiment of the defect inspection apparatus, FIG. 4 is a flow chart showing an example of the object of the present invention, and FIG. 5 is a flow chart shown in FIG. , FIG. 6 is a plan view showing the absolute position coordinates of the foreign matter according to the present invention, FIG. 7 is a plan view showing a partially enlarged view of FIG. 6, and AA ′ 8 is a cross-sectional view, FIG. 8 is a plan view showing another example different from FIG. 7, and FIG. 9 is a plan view showing a case where a foreign substance is present in the example shown in FIG.
AA 'sectional view and BB' sectional view, FIG. 10 is an enlarged view of the microscope field of view showing the positioning of the grating center line according to the present invention, and FIG. Fig. 12,
The figure is an enlarged view of the microscope field of view for each step, FIG. 13 is a plan view showing the absolute position coordinates of the foreign matter of the mirror wafer according to the present invention,
FIG. 14 is a diagram showing various forms of an external storage medium according to the present invention, FIG. 15 is a diagram showing a schematic configuration of a conventional defect analyzer,
FIG. 16 is a diagram showing a correlation between a foreign substance detected by the present invention and an electrical characteristic defect, FIG. 17 is a diagram showing an example of inter-process tracking according to the present invention, and FIG. FIG. 19 shows the pattern defect rate 4 in FIG. 19, FIG. 19 shows the electrical characteristic failure rate between steps obtained by the present invention, FIG. 20 shows the foreign matter analysis flow according to the present invention, FIG. FIG. 20 is a view showing a change in the number of foreign matters of organic and inorganic foreign matters according to the flow shown in FIG. 20, and FIG. FIG. 23 (D), FIG. 23 shows the results of evaluating the wafer transfer process according to the present invention, and FIG. 24 shows the defect detection (A + B) and the individual defects after the exposure and development processes obtained by the present invention. Fig. 25 shows the analysis (D) of the present invention. FIG. 26 is a view showing the observation field of view of the short-circuited portion of the circuit pattern on the wafer and the cross-sectional view thereof. FIG. FIG. 3 is a diagram showing pattern defects. 1,9 ... Sample mounting mechanism, 2 ... Illumination means, 3 ... Optical means, 4 ... Scanning means, 5,10 ... Position detection means, 6 ... Signal processing circuit, 7 ... Storage circuit, 8 , 8a to 8e: external storage medium, 11: positional deviation amount calculation circuit, 12: positioning means, 13: transport mechanism, 14, 15: coordinate correction circuit, 16: detection position correction means, 20 , 21 ... Detector, 30a ... Connection hole, 30b, 32b ... Chip boundary, 200,200a, S ... Sample, 210,210 '... Coordinate origin, 220 ... Grid.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-15939 (JP, A) JP-A-63-66447 (JP, A) JP-A-60-31235 (JP, A) JP-A 64-64 69023 (JP, A) JP-A-64-15944 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01B 11/00-11/30 102 G01N 21/84-21/958 H01L 21/64-21/66

Claims (15)

(57) [Claims] An inspection unit for inspecting a sample to be inspected, detecting a defect present on the sample to be inspected, storing a position of the defect as a position in the absolute coordinate system on the sample to be inspected, A predetermined process is performed on the test sample, and the test sample subjected to the predetermined process is inspected again to detect a defect present on the test sample, and the absolute coordinates of the detected defect on the test sample are detected. A defect inspection method comprising: comparing a position in a system with a position of the stored defect in an absolute coordinate system on the sample to be inspected; and outputting information on a defect on the sample to be inspected based on the comparison result. . 2. The method according to claim 1, wherein the output information on the defect on the sample to be inspected is a result of removing a defect detected before performing the predetermined process from a defect detected after performing the predetermined process. 2. The defect inspection method according to claim 1, wherein the defect inspection information is information. 3. A sample to be inspected is inspected by a first means to detect a defect present on the sample to be inspected, and a position of the detected defect is output as a position in the absolute coordinate system on the sample to be inspected. And a defect inspection method for observing or analyzing the defect using a second unit based on the output information on the position in the absolute coordinate system on the sample to be inspected. 4. The defect inspection method according to claim 3, wherein said observation or analysis is performed using an electron beam. 5. A defect detection means and a defect analysis means using a common coordinate system, and a position of a defect on a specimen to be inspected detected by said defect detection means is stored in a storage medium or a communication medium as data of said common coordinate system. A defect inspection method, wherein the defect is sent to defect analysis means via the means, and the defect analysis means analyzes a defect on the sample to be inspected based on the data of the common coordinate system. 6. A sample to be inspected is inspected by using a defect detecting means to detect a defect present on the sample to be inspected, and the position of the detected defect is defined as a position on the sample to be inspected in an absolute coordinate system. Storing, inspecting the inspected sample using an electrical characteristic inspecting means to detect a defect in the electric characteristic, and storing the detected position of the electric characteristic defect in the absolute coordinate system on the inspected sample and the storage. A defect position in the absolute coordinate system on the sample to be inspected, and outputting information based on the result of the comparison. 7. A pattern in which a large number of identical patterns are formed in a grid on the sample to be inspected, and a plurality of absolute coordinate systems on the sample to be inspected are formed in a grid on the sample to be inspected. The defect inspection method according to any one of claims 1 to 6, wherein the intersection is set based on the intersection of the lattices or the outer shape of the sample to be inspected. 8. A defect detecting means for inspecting a sample to be inspected to detect a defect present on the sample to be inspected, and detecting a position of the defect detected by the defect detecting means in an absolute coordinate system on the sample to be inspected. Output means for outputting as a position, and means for observing or analyzing a defect detected by the defect detection means based on a position in the absolute coordinate system on the inspection sample output from the output means. Defect inspection equipment. 9. The defect inspection apparatus according to claim 7, wherein the means for observing or analyzing the defect observes or analyzes the defect using an electron beam. 10. The defect inspection apparatus according to claim 8, wherein said output means outputs said defect information by communication. 11. A semiconductor wafer before performing a predetermined process is inspected to detect a defect existing on the semiconductor wafer, and the position of the detected defect is stored as a position in a coordinate system on the semiconductor wafer. Performing the predetermined process on the semiconductor wafer, detecting the semiconductor wafer subjected to the predetermined process again to detect a defect present on the semiconductor wafer,
The position of the detected defect in the coordinate system on the semiconductor wafer is compared with the position of the stored defect in the coordinate system on the semiconductor wafer to identify the defect that has occurred in the predetermined step, A method of manufacturing a semiconductor, wherein the semiconductor wafer is processed by managing the predetermined process based on information. 12. The semiconductor device according to claim 11, wherein managing the predetermined step based on the information on the specified defect is to reduce generation of foreign matter in the predetermined step. Manufacturing method. 13. A method for inspecting a semiconductor wafer before passing through the intermediate step in a process in the process of manufacturing the semiconductor LSI to detect a defect existing on the semiconductor wafer, and determining a position of the detected defect in the semiconductor LSI. Stored as the position of the coordinate system on the wafer, perform the process of the intermediate process on the semiconductor wafer, inspect the semiconductor wafer that has been subjected to the process of the intermediate process again, and exist on the semiconductor wafer. Detect a defect, identify the defect that occurred in the predetermined process by comparing the position of the detected defect in the coordinate system on the semiconductor wafer with the position of the stored defect in the coordinate system on the semiconductor wafer, A method of manufacturing a semiconductor, comprising: estimating a yield of a semiconductor wafer in the manufacturing process based on the information on the specified defect. 14. The method of manufacturing a semiconductor according to claim 13, wherein the yield of the semiconductor wafer in the manufacturing process is an electrical failure rate of the semiconductor wafer. 15. A semiconductor wafer which has undergone an intermediate step in a semiconductor LSI manufacturing process is inspected by using a defect detecting means to detect a defect present on the semiconductor wafer, and the detected defect is detected on the semiconductor wafer. The position of the coordinate system is stored, the semiconductor wafer is inspected by using an electric characteristic inspection unit to detect a defect in the electric characteristic, and the position of the detected electric characteristic defect in the coordinate system on the semiconductor wafer. A method of manufacturing a semiconductor, comprising: comparing a position of the stored defect with a coordinate system on the semiconductor wafer; and controlling the intermediate process based on the comparison result to process the semiconductor wafer.