JPS59231811A - Defects inspection apparatus - Google Patents

Abstract

PURPOSE:To display a defective part of a pattern clearly by a method wherein an inspection apparatus is composed of a detecting part which detects two patterns, a comparing which compares the detection signals and a display part which displays a pattern image in accordance with the compared result. CONSTITUTION:Two pattern signals detected by a pattern detecting part 8 are transmitted to a comparing part 11 and compared by a comparing circuit 14 by every picture element. If both signal levels conform to a prescribed relation, the pattern signals are put into a coincidence memory with a coordinate signal and if they do not, into a non-coincidence memory. A display part 17 receives the signals from the memories 15, 16 and sets different darkness signals and color signals corresponding to the picture element of coincident coordinates and the picture element of non-coincident coordinate and displays a pattern image on a monitor TV19 in accordance with those signals. With this constitution, the defective part of the pattern can be clearly displayed and corrected easily and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an apparatus for detecting all pattern defects occurring in photomask patterns, and more particularly to a defect inspection apparatus that displays defects and makes it easy to correct them.

[Background technology]

1 of semiconductor devices! ! The IJ nography process, which is one of the I-forming processes, requires a photomask on which a circuit pattern is formed. This photomask forms a pattern with an opaque film such as a chrome film on a transparent substrate such as glass.
Since this chromium film pattern is formed by a cutting method, so-called pattern defects are likely to occur. Such pattern defects cause defects in circuit patterns formed on the wafer surface, so they must be detected and corrected.

The conventional method for inspecting this type of pattern defect is to display a pattern formed on a photomask using all-optical and electrical means on a monitor television under equal pressure magnification. A method was used to detect it. When repairing this pattern defect, the repairer visually inspects the displayed pattern and uses, for example, a laser beam to completely burn out and repair the pattern defect.

However, with this device, when pattern defects occur over a wide range, it is not easy to visually check the pattern defects on the display and confirm the outline of the normal pattern, and the above-mentioned correction work is difficult. There are problems in that it becomes difficult, tends to cause defective corrections, and has a low product yield. However, this method cannot automate the detection and correction of pattern defects, and is disadvantageous in terms of production speed and product cost.

[Purpose of the invention]

The object of the present invention is to provide a defect inspection device that can clearly display all pattern defects and make corrections easily and accurately, thereby improving product yield and production efficiency. Our goal is to provide the following.

′=i An object of the present invention is to provide a defect inspection device that can automate the detection and correction of pattern defects, thereby improving production efficiency and reducing costs.

The above and other objects and novel features of the present invention include:
It will be clear from the description in this specification and the accompanying drawings.

[Outline of the invention] A summary of representative inventions disclosed in this application is as follows.

That is, a detection unit that independently detects at least two pattern groups, and T and J that compare these detection patterns.
By providing the northern part and a display section that displays pattern defects so that they can be visually distinguished based on the comparison results, υ
The contours of pattern defects, etc. can be clearly recognized, and accurate corrections can be made thereby to improve yields and moving vehicles.

[Embodiment 1] FIG. 1 shows an FC example in which the present invention is applied to a photomask pattern defect inspection apparatus, and in particular, an embodiment in which a pattern correction apparatus is completely incorporated. In the figure, reference numeral 1 denotes a photomask to be pattern inspected (j), which is placed horizontally on an XY table 2 and a table 3 placed on soil. This XY table 2 can be moved in horizontal XY directions by an XY drive unit 4,
The 2-table 3 can be moved up and down by the 2-drive section 5. Above the photomask 1, a pattern detection unit 8 is provided which includes fc two objective lenses 6.7 spaced apart appropriately. These objective lenses 6.7 each engrave two patterns among the plurality of repeating patterns formed on the photomask 1, and each pattern is reciprocally engraved, in other words, the same pattern portion is placed in the field of view. It's in. The optical signals detected by each objective lens 6.7 are converted into N'A signals by a photoelectric element 9.1o such as an industrial television camera or a COD, and sent to the comparing section 11.

The comparison unit 11 uses both signals and the coordinate signal from the XY drive unit 4 to determine the amount of deviation between both signals in the position deviation detection circuit 12, and based on this amount of deviation, the deviation correction circuit 13 synchronizes both signals. become Further, both synchronized signals are sent to the comparison circuit 14, where they are compared together with the coordinate signal from the XY drive section 4. Then, the matching coordinates and the mismatching coordinates of both signals are determined, and these are input into the matching memory 15 and the mismatching memory 16.

The display section 17 has a video circuit 18 that receives the output of each of the patterns 15 and 16, and can display a pattern image on the screen of a monitor television 19 based on the coincidence or mismatch of each signal and its coordinate signal. At this time, the density (black and white TV) and color (color TV) of the pattern image should be different between the matching signal and the mismatching signal! Performs quantitative processing.

On the other hand, a pattern correction device 20 is attached to one of the animal lenses 6 of the pattern detection section 8.

That is, the pattern correction device 20 is fully equipped with a laser light source 21, a shutter 22 that can completely block the laser light outputted from the laser light source 21, an aperture 23 and a half mirror 24 that narrow down the laser beam and adjust the energy. By appropriately controlling these laser light source 21, shutter 22, and aperture 23 with the controller section 25, the chromium film forming the pattern on the surface of the photomask 1 can be burnt little by little. The controller section 25 is manual;
Automatic operation is possible, and in this example, the signal safe output 7 from the video circuit 18 of the display section 17 is operated by the controller section 25.
'1 can also be controlled.

In the figure, 26 is an automatic focusing mechanism that operates between the animal lens 6 (7) and the two tables 10.

According to the above configuration, the two pattern signals detected by the pattern detection section 8 are sent to the comparison section 11 as air signals, and the two pattern signals detected by the pattern detection section 8 are sent to the comparison section 11 as air signals.
3, they are corrected so that they are directly facing each other on the coordinates, and then the comparison circuit 14 compares each of them with pixel position. As a result of the comparison, if both signal levels have a predetermined relationship, the data is stored in the match memory 15, and if not, the data is stored in the match memory 16.
is input together with the coordinate signal. Then, the display section 17 receives the signals from the memories 15 and 16, sets different density signals and color signals according to the picture elements with matching coordinates and the picture elements with non-matching coordinates, and based on these, 9. i%=7
-ft,=wl 9/<J-yell, o. For example, when using a color television, as shown in FIG.
, the portion Pb that exists only in the other pattern P2 is displayed in red, and the portion Pci that exists only in the other pattern P2 is displayed in blue. As a result of kneading, pattern defects are displayed in red and clear, and even if the range of pattern defects is wide, the outline of the pattern can be clearly recognized.

Therefore, based on the display of this pattern defect, the correction Nagisa controls the controller unit 25 to apply the laser beam to the pattern defect on the photomask 1, thereby burning out the ROM film and correcting it to the required pattern shape. can. In this case, if only one pattern PR is to be corrected, only the red portion Pb of the monitor television 19 will be corrected. Note that in this example 1, the controller section 25 is connected to the display section 1.
Since it can be controlled by the signal No. 7, the correction described above can be performed completely automatically. In the case of black-and-white televisions, pattern defects can be recognized by differences in image density.

〔effect〕

(1) Consists of a detection section that detects two patterns, a comparison section that compares the detection signals, and a display section that displays pattern defective parts so that they can be visually distinguished based on the comparison results. Therefore, pattern areas and pattern defect areas can be clearly distinguished based on differences in total density and color, and the outline of the pattern can be accurately recognized based on stiffness.

(2) Since pattern contours can be accurately recognized, pattern defects can be corrected accurately and easily, thereby improving product yield and production efficiency.

(3) Compare the controller that controls the correction device.
Since automatic control is performed based on the fc signal, pattern defects can be automatically corrected.

The invention made by the present inventor will be specifically explained based on Examples. Needless to say, the configurations of the pattern detection section, comparison section, and display section can be changed as appropriate.

[Application field]

In the above explanation, the invention made by the present inventor was mainly applied to a photomask pattern deletion inspection device, which is the background field of application, and the fc case was explained.
The present invention is not limited to this, and the furnace can be used, for example, to inspect defects in patterned photoresist films and other pattern inspections.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a display state of a monitor television displaying pattern defects. 1... Photomask, 2... XY table, 3...
2 table, 4...XY drive unit, 6, 7...animal lens, 8...pattern detection unit, 11...comparison unit, 1
4... Comparison circuit, 17... Display section, 19... Monitor TV, 20... Correction device, 21... Laser main pusher, 25... Controller section.

Claims (1)

[Scope of Claims] (2) A pattern detection section that independently detects the same portion of at least two patterns, and a phantom that detects and compares the two patterns fc with the same coordinates by these pattern detection sections. A defect inspection device characterized in that it is provided with a ratio part and a display part for displaying two different pattern parts of the phantom ratio il, 7'c so as to be distinguishable from the other pattern parts. 2. The defect inspection device according to claim 1, wherein the display section displays the pattern on a monochrome or color monitor television screen. 3. The defect inspection device according to claim 1, wherein the display section has different colors and densities of different pattern parts from all pattern parts.