JPH0213835A - Inspector - Google Patents

Abstract

PURPOSE:To achieve a quick setting of position in the inspection with a scanning electron microscope by storing a position data intended for precision inspection with the scanning electron microscope into a memory means beforehand in the inspection with an optical microscope. CONSTITUTION:First, a sample, for example, a wafer 5 is inspected visually with an optical microscope 2. In the case of a micropattern unable to be discrimi nated with the optical microscope 2, a coordinates data of a part involved is stored into a memory section of a host computer 4 using an input means 6. In the inspection with a scanning electron microscope 3, the coordinates data is transferred to the scanning electron microscope 3 from the host computer 4. The scanning electron microscope 3 is so set automatically based on the coordinates data that a position to be inspected on the wafer 5 is where an electron beam is irradiated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inspection apparatus suitable for inspecting wafers and the like in the manufacturing process of semiconductor integrated circuits, for example.

[Prior Art] Generally, in the process of manufacturing semiconductor integrated circuits, when inspecting a wafer, the inspection is first performed using an optical microscope, and in the case of a fine pattern that cannot be distinguished with an optical microscope, scanning is further performed. Inspections are performed using a type electron microscope.

That is, as shown in FIG. 3, the wafer 5 to be inspected is set on the optical microscope 2°, and the operator IO visually inspects it. With this 2° optical microscope, when the size of the integrated circuit pattern is about 2 μm or less, it is difficult to distinguish the shape of defects on the wafer 5 due to the narrow resolution and depth of focus.

In such a case, the inspection will be performed using a scanning electron microscope (SEM) 3o;
The area that can be inspected with a scanning electron microscope 3° is narrower than that of an optical microscope 2°, at about several tens of microns square.
When inspecting at 2°, the position on the wafer 5 to be inspected with the scanning electron microscope 3° is determined in advance as a reference on the wafer 5 when inspecting with the optical microscope 2°. Check the coordinates from the location.

Thereafter, the wafer 5 is set on a sample stage of a 9° main body of a scanning electron microscope 3° via a preliminary evacuation chamber 7°. Then, the operator IO searches for the reference position on the wafer 5, and further searches for inspection positions sequentially using coordinates checked in advance using this position as a reference and inspects that part in detail.

[Problems to be Solved by the Invention] Conventionally, in the inspection using a scanning electron microscope, the operator has to search and inspect each inspection position on the wafer that has been checked in advance with an optical microscope. Therefore, there is a problem that it takes a lot of time and effort.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to save an operator the trouble of searching for an inspection position in a scanning electron microscope and enable efficient inspection.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides an inspection apparatus including an optical microscope and a scanning electron microscope, including a storage means for storing data input from the optical microscope. The optical microscope is provided with manual means for manually inputting the data specifying the position to be inspected on the sample, and the scanning electron microscope is provided with manual means for manually inputting the data specifying the position to be inspected on the sample, and the scanning electron microscope is provided with: The position to be inspected on the sample is
A drive control means is provided for driving and controlling the sample stage so that it is at a predetermined position where it is irradiated with the electron beam.

[Function] According to the above configuration, when inspecting with an optical microscope, data specifying a position to be inspected with a scanning electron microscope is inputted and stored in advance in the storage means. In the inspection of a microscope, the sample stage is driven based on the data in the storage means, and the position to be inspected is automatically set to a predetermined position where the electron beam is irradiated. This eliminates the need for the operator to search for each location to be inspected.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an inspection apparatus according to an embodiment of the present invention, and parts corresponding to the conventional example in FIG. 3 are given the same reference numerals.

The inspection device 1 of this embodiment stores an optical microscope 2, a scanning electron microscope 3 integrated with the optical microscope 2, and data input from the optical microscope 2, and scans this data as necessary. It is comprised of a host computer 4 as a storage means for transferring data to a model electron microscope 3.

In this inspection device 1, as in the past, a sample, for example, a wafer 5, is first visually inspected using an optical microscope 2, and in the case of a fine pattern that cannot be distinguished by the optical microscope 2, a scanning type The electron microscope 3 is used to examine that part in detail.

The optical microscope 2 is provided with an input means 6 for manually inputting the inspection position on the wafer 5 to be inspected by the scanning electron microscope 3 as coordinate data, and further includes:
A transport means (not shown) is provided for transporting the wafer 5 to the preliminary evacuation chamber 7 of the scanning electron microscope 3 after the inspection with the optical microscope 2 is completed.

The coordinate data input by the optical microscope 2 is transferred to the host computer 4 and stored in the storage section of the computer 4.

In the main body 9 of the scanning electron microscope 3, based on the coordinate data transferred from the host computer 4 during inspection,
A drive control means 8 is provided for driving and controlling a sample stage (not shown) so that the position to be inspected on the wafer 5 is a predetermined position where the electron beam is irradiated.

An inspection procedure using the inspection apparatus I having the above configuration will be explained.

First, the wafer 5 to be inspected is set on the optical microscope 2,
Operator IO performs visual inspection. At this time, since the size of the integrated circuit pattern is about 2 μm or less,
If there is a part where it is difficult to determine the shape of the defect, etc., and this part is to be inspected in detail using the scanning electron microscope 3, the position of the part is inputted as coordinate data along with the reference position. From 6 onwards, the information is manually stored in the host computer 4.

For example, as shown in FIG. 2, there is a pattern at point 0 on the wafer 5 that cannot be determined by the optical microscope 2.
When attempting to inspect this zero point in detail using the scanning electron microscope 3, the operator IO inputs the coordinates of predetermined reference positions, for example, points A and B from the input means 6. At the same time, coordinate data corresponding to the position of point 0 when these points A and B are referenced is inputted from the input means 6.

When the input of coordinate data and visual inspection by the optical microscope 2 are completed in this way, the wafer 5 is automatically transported by the transport means to the preliminary exhaust chamber 7 of the scanning electron microscope 3, and the inside of this preliminary exhaust chamber 7 is After being evacuated, it is transported and set into the main body 9 of the scanning electron microscope 3.

In the inspection using the scanning electron microscope 3, the operator 10 sequentially adjusts the reference positions, that is, points A and B, so that they are at predetermined positions where the electron beam is irradiated, as in the past. .

That is, first, the positions of point A and point B, which serve as references, are aligned. After that, the drive control means 8 of the scanning electron microscope 3
Based on the coordinate data transferred from the host computer 4, the sample stage is driven and controlled so that the zero point to be inspected is automatically adjusted to a predetermined position where the electron beam is irradiated.

In this way, in the scanning electron microscope 3, the operator 1
By aligning the positions with 0 as the reference, the sample stage is thereafter driven so that the position to be inspected is automatically set to a predetermined position. Therefore, when there are a large number of positions to be inspected, conventionally the operator 10 had to search for the positions to be inspected one by one, but this operation is no longer necessary, and inspections can be carried out efficiently.

Furthermore, in this embodiment, after the zero-point inspection by the scanning electron microscope 3, the wafer 5 is transferred to the optical microscope 2 again,
Macroscopic inspection may be performed centering on the 0 point.

In the above embodiment, the host computer 4 is provided, but in another embodiment of the present invention, the coordinate data may be written in a storage medium such as a floppy disk, and the scanning electron microscope 3 may read the data from this storage medium. The drive control of the sample stage may also be performed using the following methods.

Further, although the above-mentioned embodiment describes the case where a wafer is inspected, the present invention is not limited to wafers, and can of course be applied to other samples.

[Effects of the Invention] As described above, according to the present invention, data indicating a position on a sample to be inspected with a scanning electron microscope is stored in advance, and upon inspection, based on the data, The sample stage is driven and controlled so that the inspection position is automatically set to a predetermined position, which eliminates the need for the operator to search for the inspection position one by one, as in the conventional case. It becomes possible to conduct an inspection.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of an embodiment of the present invention, Figure 2 is a plan view of a wafer for explaining input of coordinate data,
FIG. 3 is a schematic diagram of a conventional example. ■...Inspection device, 2.2o...Optical microscope, 3.3o...Scanning electron microscope, 4...Host computer (storage means), 5...Wafer, 6...Input means , 8... Drive control means, 10... Operator.

Claims (1)

[Claims] (1) In an inspection device comprising an optical microscope and a scanning electron microscope, a storage means for storing data input from the optical microscope is provided, and the optical microscope is configured to specify a position on the sample to be inspected. An input means for inputting the data is provided, and the scanning electron microscope is configured to determine, based on the data in the storage means, a position to be inspected on the sample at a predetermined position to be irradiated with the electron beam. 1. An inspection apparatus characterized by being provided with drive control means for driving and controlling a sample stage so that