JPH04278407A - All-directionally optical-cutting shape measuring apparatus - Google Patents

Abstract

PURPOSE:To efficiently detect the three-dimensional shape of an object by rotating an objective lens for a projecting light, an objective lens for a detected light and a photographing device around a vertical line as a rotating axis, and projecting slit beams from many directions to the same measuring point. CONSTITUTION:A sample stage 1 is moved and a common focusing position of an objective lens 3 for a projecting light and an objective lens 4 for a detected light is agreed with a measuring position of an object placed on the sample stage 1. While a rotating axis 9 is sequentially rotated, slit beams are cast to the same measuring position from many directions. An image of the reflecting slit beams is photographed at 5. The image data of the reflecting slit beams photographed at 5 is output to an image processor 11 via a supporting body 10 and arm image signal line 13. The processor 11 stores the data in a frame memory and processes the image. The operating result, is displayed at a personal computer 12 via an image signal line 15. Accordingly, the three-dimensional shape of the object can be easily and effectively detected by totally evaluating the images from many directions.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional shape measuring device for fine patterns of ICs (integrated circuits) and the like.

There has been remarkable progress in increasing the degree of integration of semiconductor devices, but in order to further increase the degree of integration while maintaining high reliability, it is necessary to fully understand the fine shape of semiconductor devices.

0003

2. Description of the Related Art A light cutting method is a method for measuring the three-dimensional shape of an object to be measured. This method irradiates the object to be measured with slit light from one direction, receives an image of the slit light reflected from the object, and performs arithmetic processing using an image processing device to form a three-dimensional shape of the object. It can be measured non-contact and non-destructively in the atmosphere.

0004

[Problem to be solved by the invention] Since the slit light illuminates the object to be measured from only one direction, it may not always be possible to obtain an appropriate image due to the reflection or refraction of the slit light on the object to be measured. be. For example, depending on the shape of the object to be measured, the slit light may be blocked midway and not illuminate the target area, or may be reflected in a direction where it cannot be received, making it impossible to measure the three-dimensional shape.

[0005] To solve this problem, the object to be measured is rotated in a horizontal plane, slit light is irradiated from multiple directions at the same measurement point, and the three-dimensional shape is determined by comprehensively judging the images from the multiple directions. need to ask. However, when the object to be measured is rotated, a deviation occurs between the measurement point and the irradiation position of the slit light, so the sample stage on which the object to be measured is placed must be moved and aligned each time.

The purpose of the present invention is to eliminate this drawback, and to irradiate an arbitrary measurement point on an object with slit light from multiple directions without adjusting the position of the object. An object of the present invention is to provide an omnidirectional optical cutting shape measuring device that can efficiently measure the three-dimensional shape of an object to be measured.

[0007]

[Means for solving the problem] The above purpose is to
A sample stand (1) movable in the Z-axis direction, and a sample stand (1) that can move in the Z-axis direction.
); a light projection objective lens (3) that projects a slit light onto an object to be measured placed on the top; a slit light generation source (2) that generates the slit light; It has a light-receiving objective lens (4) that receives the slit light, and an imager (5) that images the slit light received by the light-receiving objective lens (4).
3) and the light-receiving objective lens (4) are mutually coupled, and the light-emitting objective lens (3) and the light-receiving objective lens (4) on the sample stage (1) are connected to each other. This is achieved by an omnidirectional optical cutting shape measuring device that is rotatable about a vertical line (8) passing through a common focal point with the rotation axis. A frame memory (6) that stores video information captured by the image pickup device (5) and a CPU that performs arithmetic processing on the video information stored in the frame memory (6).
(7) Three-dimensional shapes can be measured by providing

[0008]

[Operation] The operation will be explained using the principle explanatory diagram shown in FIG. In the figure, 1 is a sample stage on which the object to be measured can be placed and movable in the X, Y, and Z directions, 2 is a slit light source,
Reference numeral 3 designates a light projection objective lens that projects the slit light generated by the slit light generation source 2 onto an object to be measured (not shown) placed on the sample stage 1; A light-receiving objective lens receives the reflected slit light, and 5 is an imager that captures an image received by the light-receiving objective lens 4. 6 is a frame memory that stores information captured by the imager 5, and 7 is a CPU that processes the information stored in the frame memory and outputs three-dimensional shape information.

Light projecting objective lens 3 and light receiving objective lens 4
are arranged so as to focus on the same point on the object to be measured placed on the sample stage 1, respectively. The slit light generation source 2, the light-emitting objective lens 3, the light-receiving objective lens 4, and the imager 5 are assembled integrally and their mutual positional relationship is fixed.
The structure is such that it can rotate about a vertical line 8 passing through a common focal point with the rotation axis.

The sample stage 1 is rotated by rotating the slit light generating source 2, the light emitting objective lens 3, the light receiving objective lens 4, and the imager 5, which are integrally constituted, about a vertical line 8 as a rotation axis. It is now possible to irradiate the same measurement point on the object with slit light from multiple directions without moving and adjusting the position of the object. It becomes possible to measure the three-dimensional shape of the object extremely easily and efficiently.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An omnidirectional optical cutting shape measuring device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a configuration diagram of an omnidirectional optical cutting shape measuring device according to the present invention. In the figure, the same parts as those shown in FIG. 1 are indicated by the same symbols. The slit light generation source 2, the light-emitting objective lens 3, the light-receiving objective lens 4, and the imager 5 are arranged vertically through the common focal point of the light-emitting objective lens 3 and the light-receiving objective lens 4 on the sample stage 1. It is fixed to a rotating shaft 9 whose central axis is the line, and this rotating shaft 9 is connected to the support 1.
0 is rotatably mounted. 11 is an image processing device, 12 is a personal computer, 13
is a video signal line from the imager 5, 14 is a control line from the computer 12, and 15 is a video signal line from the image processing device.

The sample stage 1 is moved to the measurement position of the object to be measured (not shown) placed on the sample stage 1 to a common focal point of the light emitting objective lens 3 and the light receiving objective lens 4. The rotation axis 9 is sequentially rotated to irradiate the same measurement position of the object with slit light from multiple directions, and an image of the reflected slit light is captured by the imager 5.

Information on the reflected slit light image from the object to be measured, which is imaged by the imager 5, is stored in a frame memory of a normal image processing device 11 via a video signal line 13, and image processing calculations are performed. is sent to the personal computer 12 via the video signal line 15 and displayed. Control signals for the system, such as movement of the sample stage 1, rotation of the rotating shaft 9, and control of the image processing device 11, are output from the personal computer 12 via a control line 14.

Since the image pickup device 5 rotates around the rotation axis 9, the video signal line 13 from the image pickup device 5 is outputted to the image processing device 11 via the stationary support 10. However, if the range of rotation of the rotating shaft 9 is small, it may be output directly from the imager 5. Furthermore, depending on the scale of the device, the image processing device 11 may be fixed to the rotating shaft 9 in the same way as the image pickup device 5.

[0016] It goes without saying that the measurement results of the three-dimensional shape can be used not only for display but also for controlling other machines.

[0017]

[Effects of the Invention] As explained above, in the omnidirectional light cutting shape measuring device according to the present invention, the slit light generation source, the light emitting objective lens, the light receiving objective lens, and the imager are integrally assembled, Since the rotation axis is a vertical line that passes through the common focal point of the light emitting objective lens and the light receiving objective lens on the sample stage, the same measurement point on the measured object can be measured in multiple directions without moving the measured object. Images from multiple directions can be captured by irradiating slit light from the center, and by image processing the images from multiple directions, the three-dimensional shape of the object to be measured can be accurately and efficiently measured.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention.

FIG. 2 is a configuration diagram of an omnidirectional optical cutting shape measuring device.

[Explanation of symbols]

1 Sample stage 2 Slit light source 3 Objective lens for light projection 4 Objective lens for light reception 5 Imaging device 6 Frame memory 7 CPU 8 Center line of rotation 9 Rotation axis 10 Support 11 Image processing device 12 Personal computer

Claims (2)

[Claims] Claim 1: A sample stage (1) movable in X, Y, and Z axis directions, and a light projection objective lens that projects a slit light onto an object to be measured placed on the sample stage (1). (3), a slit light generation source (2) that generates the slit light, a light receiving objective lens (4) that receives the slit light reflected from the object to be measured, and the light receiving objective lens (4). an imager (5) that images the slit light received by the
The light emitting objective lens (3) and the light receiving objective lens (
4) is a vertical line (8) that passes through the common focal point of the light emitting objective lens (3) and the light receiving objective lens (4) on the sample stage (1). An omnidirectional optical cutting shape measuring device characterized by being rotatable as a rotation axis. 2. A frame memory (6) for storing video information captured by the image pickup device (5), and a CPU (7) for processing the video information stored in the frame memory (6).
2. The omnidirectional optical cutting shape measuring device according to claim 1, further comprising: ).