JPH0612241B2 - Sample inspection device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sample inspection device, and more specifically, to a mechanism for rotating, tilting, or moving a sample such as a wafer by a joystick.

[Prior Art] To date, various mechanisms for rotating and tilting a sample such as a wafer by operating a joystick have been proposed. However, what can accurately convey the operation of the joystick to the sample is limited.

As a general type of this kind of mechanism used in the oblique light inspection device used in the process of inspecting the wafer for scratches, dust, distortion, etc., the inclination angle of the joystick and its direction are electrically detected, Based on the detection result, the stage for adsorbing the wafer is tilted via an electric actuator such as a motor.

Also, a mechanism in which a joystick and a stage are directly connected by an axis and a stage is directly moved about a certain point on the axis has been tried.

[Problems to be solved] However, since the motion of the stage includes rotation, tilting, and vertical motion, the former method in which these are realized by electrical control is performed between the movement of the joystick and the movement of the stage. There is a problem that a sensory shift is likely to occur. To avoid this, complicated and sophisticated electric control is required, which is extremely expensive.

Further, the latter device that directly connects the joystick and the stage cannot be evaluated in terms of the accuracy of the tilt angle of the stage and the operability.

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a sample inspection apparatus capable of accurately transmitting the movement of a joystick to a stage and performing an efficient inspection without complicated electrical control. To do.

[Means for Solving the Problems] In order to achieve the above object, the present invention is characterized by having the following configuration.

(1) A joystick that can be tilted in an arbitrary direction around a certain fixed point, a tilt relay shaft to which the tilt of the joystick is transmitted through a transmission means, and a tilt relay shaft attached to the tilt relay shaft. First movable axially
A free rotating node, a sample mounting table supported by a support shaft swingable around the second free rotating node as a fulcrum, a third free rotating node attached to the support shaft and movable in the axial direction of the support shaft, A connecting shaft that connects the first universal rotary node and the third universal rotary node; and a supporting unit that includes a fourth universal rotary node and rotatably supports the connecting shaft with the fourth universal rotary node as a rotation center.
It is characterized by having.

(2) The supporting means of (1) has vertical moving means for vertically moving the fourth freely rotatable node together with the second freely rotatable node, and when the sample mounting table moves to a predetermined height, It is characterized in that the first rotatable joint and the movement fulcrum of the tilting relay shaft are arranged so as to substantially coincide with each other.

[Embodiment] An embodiment of the sample inspection apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an outline of an apparatus according to an embodiment of the present invention.

A joystick 1 is joined to the parallel four-bar linkage mechanism 2. The parallel four-bar linkage mechanism 2 includes four rotary nodes 3, 4, 5, and 6, a rotary shaft 7, a parallel rod 8 and two rods 9 and 10, and the rotary shaft 7 is a rotary bearing 1.
By 1, it does not move back and forth and left and right. Therefore, the examiner tilts the joystick 1 in an arbitrary direction with the center of rotation of the rotator 3 as a fulcrum, or gives a rotary motion while tilting the joystick 1, thereby causing the motion to the parallel four-bar linkage mechanism 2, particularly the rod 10. I can tell. The shaft 12 integrated with the rod 10 reproduces the tilting / rotating motion of the joystick 1.

A linear motion bearing 13 having a degree of freedom in the axial direction is provided on the shaft 12. The linear motion bearing 13 is provided with a universal rotary joint mechanism 14 that can rotate in any direction (angle). Since various universal rotary joint mechanisms are well known, detailed description thereof will be omitted. The universal rotary joint mechanism 14 can rotate in a free direction (angle) according to the movement of the shaft 12 and the connecting portion 22, and can move in the axial direction together with the linear motion bearing 13. It is obvious that these mechanisms have joints capable of articulating in any directions, and can be replaced by various mechanisms having degrees of freedom in the axial direction.

Reference numeral 15 is a universal rotary joint mechanism.

Reference numeral 17 denotes a stage on which a sample to be inspected, for example, a semiconductor wafer 16 is mounted, and a support shaft 18 for supporting the stage is joined to the bottom of the center of the stage. The support shaft 18 has a universal rotary joint mechanism 19 connected to an on-stage external movement mechanism described later.
The stage performs tilting / rotating motion corresponding to the motion of the joystick with the center of rotation as a fulcrum.

A linear motion bearing 20 is arranged on the support shaft 18 below the free rotation node mechanism 19. The linear motion bearing 20 is provided with a universal rotary joint mechanism 21 that can rotate in any direction (angle), and has a rotation center at the center of the shaft.

The two universal rotary joint mechanisms 14 and 21 are the universal rotary joint mechanism 15
Since it is connected by the connecting shaft 22 via the, the rotary shaft mechanism 1 is centered on the rotation center of the rotary shaft mechanism 15.
4 and 21 rotate.

Further, the connecting shaft 24, which is connected to the universal rotary node mechanisms 15 and 19 and is supported by the linear motion bearing 23, is moved in the arrow direction by the vertical movement actuator 25 to move the stage 17 up and down.

The operation of the embodiment having the above configuration will be described below.

When the joystick 1 is tilted by θ as shown in Fig. 2,
The shaft 12 inclines through the parallel four-bar linkage 2 by θ ′ (θ = θ ′ because the parallel four-bar linkage is used). This axis 12
Since the connecting shaft 22 tends to rotate around the rotation center of the universal rotary joint mechanism 15 due to the inclination of the support shaft 18,
Also try to tilt θ ″.

At this time, the shafts 12 and 18 try to rotate about the rotation centers of the rotary joint 6 and the universal rotary joint mechanism 19, respectively, so that adjustment with the connecting shaft 22 that attempts to rotate around the rotary center of the universal rotary joint mechanism 15 is performed. is necessary. In this embodiment, the universal rotary joint mechanisms 14 and 21 are joined to the linear motion bearings 13 and 20 so that the center of rotation thereof can move in the axial direction together with the linear motion bearings. Therefore, the inclination of the joystick 1 can be smoothly transmitted to the stage 17.

The relationship between the tilt θ of the joystick and the tilt θ ″ of the stage is as follows.

First, a case where the respective rotation centers of the universal rotary joint mechanism 15, the rotary shaft 6, and the universal rotary joint mechanism 19 are on a straight line will be described.

Each rotary joint mechanism 1 with the joystick not tilted
When the distances between the centers of rotation of 9, 21, 6, and 14 and the center of rotation of the universal rotary joint mechanism 15 are α ′, β ′, α, β, respectively, the joystick inclination θ and the stage inclination θ ″.
A certain proportional relationship can be recognized with.

However, when α′β = αβ ′ θ = θ ″ When α′β> αβ ′ θ> θ ″ When α′β <αβ ′ θ <θ ″ Next, the universal rotary joint mechanism 15 and the rotary joint 6 The case where the respective rotation centers of the universal rotary joint mechanism 19 are not on a straight line will be described.

 At the position of 15 ', θ> θ "When at the position of 15", it changes within the range of θ <θ ".

In this embodiment, they are arranged so that θ = θ ″,
The arrangement can be changed according to the purpose of use.

Next, the vertical movement of the connecting shaft 24 will be described.

The connecting shaft 24 supported by the linear motion bearing 23 moves up and down in the direction of the arrow by the action of the vertical movement actuator 25,
The freely rotatable joint mechanisms 15 and 19 and the connecting shaft 2 that are connected
2, the stage 17 can rotate freely through the rotary joint mechanisms 14 and 21.
Move up and down.

The center of rotation of the universal rotary joint mechanism 14 is the parallel four-joint link mechanism 2
It is possible to descend until the center of rotation of the rotary node 6 of FIG.

The detailed structure of the parallel four-bar linkage 2 and the shaft 12 is shown. FIG. 3-b is viewed from the same direction as FIG. 1, and FIG. 3-a is viewed from the left side surface.

Regardless of the position of the immediately preceding joystick, the stage can be accurately held in the initial position by lowering the universal rotary joint mechanism 14 until it coincides with the rotation center of the rotary shaft 6.

With this mechanism, the test sample on the stage can be smoothly and efficiently replaced by the sample replacement means (not shown).

The present invention can be modified in various ways other than the above embodiments, and these are also included in the present invention as long as the technical idea is the same.

[Effects of the Invention] As is apparent from the above description, according to the present invention,
It is possible to freely set the height relationship between the joystick and the sample inspection surface while maintaining the operability. Further, the tilt angle and the tilt direction of the joystick can be accurately transmitted to the sample mounting table without requiring complicated electrical control. Furthermore, according to the present invention, since there is no time lag between the operation of the joystick and the actual movement of the sample mounting table when performing an equivalent operation through complicated electrical control,
The inspector can perform the inspection with a natural feeling.

Further, according to the embodiment, when the sample mounting table is at the inspection position, the operation of the sample mounting table is made to follow the operation of the joystick, and the height of the sample mounting table is returned to a predetermined position. Since the tilt can be canceled, the test sample can be placed in a fixed state, and the test sample can be easily replaced.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an apparatus according to an embodiment of the present invention, and FIG.
FIG. 3 is a diagram for explaining the operation of the apparatus of FIG. 1, FIG. 3 is a partially enlarged view for explaining the joining of the parallel four-bar linkage mechanism and the shaft, and FIG. 3-a is the left side surface of FIG. Therefore, FIG. 3-b is a view seen from the same direction. 1 ... Joystick 2 ... Parallel four-node link mechanism 14, 15, 19, 21 ... Free rotary node mechanism 11, 23 ... Linear motion bearing 17 ... Stage

Claims (2)

[Claims] 1. A joystick capable of tilting at an arbitrary angle in an arbitrary direction around a certain fixed point, a tilt relay shaft to which the tilt of the joystick is transmitted via a transmission means, and a tilt relay attached to the tilt relay shaft. A first rotatable joint that is movable in the axial direction of the shaft, a sample mounting table that is supported by a support shaft that is capable of swinging about the second rotatable joint, and is attached to the support shaft in the axial direction of the support shaft. A movable third rotatable joint, a connecting shaft connecting the first rotatable joint and the third rotatable joint, and a fourth rotatable joint, the fourth rotatable joint having the fourth rotatable center as a rotation center. A sample inspecting device, comprising: a supporting unit that rotatably supports the device. 2. The supporting means according to claim 1 has vertical moving means for vertically moving the fourth freely rotatable node together with the second freely rotatable node, and when the sample mounting table moves to a predetermined height. Is arranged so that the first free rotation node and the fulcrum of movement of the tilting relay shaft substantially coincide with each other.