KR19990074154A - Wafer measuring device using lens descent limit sensor - Google Patents

Abstract

Lens falling distance that prevents wafer breakage or lens breakage caused by the lens colliding with the wafer when the lens making up the measuring equipment for measuring the silicon wafer is close to the wafer and the measurement is not performed. A wafer measuring device using a limiting sensor.

According to an aspect of the present invention, there is provided a semiconductor measuring apparatus including a stage on which a wafer is seated, a lens capable of horizontally and vertically moving in proximity to the wafer, wherein the stage sensor detects movement of the stage, and is installed at one side of the lens and is vertical. It includes a limit sensor for detecting a moving distance, the stage sensor and the limit sensor is connected, and a control unit for limiting the distance between the lens and the wafer by receiving each sensing signal.

Therefore, according to the present invention, since the measurement distance between the lens and the wafer is controlled by the sensor, damage to the wafer and the lens is prevented and the measurement is smoothly performed.

Description

Wafer measuring device using lens descent limit sensor

The present invention relates to a wafer measuring device using a lens falling distance limiting sensor, and more particularly, when a lens forming a measuring device for measuring a silicon wafer is in close proximity to a wafer, the measurement is not performed or a normal control operation is performed. The present invention relates to a wafer measuring device using a lens falling distance limit sensor for preventing wafer breakage or lens breakage caused by a lens colliding with a wafer.

Various types of semiconductor devices are manufactured using silicon wafers, and various fields of inspection are performed to ensure normal processes from time to time during the process. In particular, in order to prevent and minimize the consumption of production costs due to defects, inspections are being strengthened in major semiconductor processes.

These inspections are largely divided into optical image processing (Optical Image Processing) and laser scattering (Laser Scattering) method, the microscope is widely used as a device for such inspection.

In the conventional microscope for inspecting wafers, inspection is performed by placing a wafer under test on a predetermined stage, focusing by adjusting the height of the lens and the stage. With the height of the stage fixed, measurements are made at each position while focusing the lens in the direction of the stage where the wafer is placed.The lens is broken or scratched due to the lens falling too much due to loosening or other mechanical abnormalities. (Scratch) etc. occurred, and in severe cases, the lens was broken and the measurement was delayed.

That is, in the related art, a device for limiting the distance is not provided to maintain a proper distance from the wafer when the lens is lowered, and there is a problem of failing to maintain the distance at an appropriate level and causing wafer damage and lens damage.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wafer measuring apparatus using a lens falling distance limiting sensor which is improved to prevent the damage of the wafer and the lens by maintaining a proper distance between the lens and the wafer by providing a sensor on the side of the lens. .

1 is a view showing an embodiment of a wafer measuring apparatus using a lens falling distance limit sensor according to the present invention.

※ Explanation of codes for main parts of drawing

10: Stage 12: Wafer

14: Screw 16: Stage Sensor

18: Lens 20: Limit Sensor

22: control unit

The wafer measuring apparatus using the lens falling distance limit sensor according to the present invention for achieving the above object is a semiconductor measuring equipment having a stage on which the wafer is seated, a lens capable of horizontal and vertical movement in close proximity to the wafer, A stage sensor for detecting a movement of a stage, a limit sensor installed at one side of the lens and detecting a vertical movement distance, and connected to the stage sensor and the limit sensor, and receiving respective sensing signals to It is provided with a control unit for limiting the distance.

The limit sensor may be installed at least one side of the end of the lens.

In addition, the control unit preferably limits the operation so that the lens is no longer close when the limit distance between the lens and the wafer is set to the limit distance.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

According to the embodiment of the present invention according to Figure 1, the wafer 12 is placed on the stage 10 forming the measurement equipment, the screw 14 for moving the stage 10 up and down is installed at the bottom, On the other side of 14), a stage sensor 16 is provided.

The upper part spaced apart from the stage 10 by a predetermined distance is provided with a limit sensor 20 on both sides of the lens 18 is symmetrical.

The stage sensor 16 and the limit sensor 20 are connected to the control unit 22, respectively, and are configured to determine the distance between the wafer 12 and the lens 18.

In the embodiment according to the present invention configured as described above, when the wafer 12 is loaded on the stage 10 and placed in an appropriate position, the operator manipulates the screw 14 so that the stage 10 maintains the proper height. The stage sensor 16 then outputs a signal corresponding to the predetermined position in consideration of the thickness of the wafer 12 to the controller 22.

The operator then operates the microscope to bring the lens 18 close to the wafer 12. At this time, the proximity distance is set differently according to the inspection item, but the limit sensor 20 takes into account the distance between the end of the lens 18 and the limit sensor 20 and outputs a sensing signal of the distance to the controller 22. do.

The controller 22 grasps the sensing signals of the stage sensor 16 and the limit sensor 20 as described above, and grasps the maximum falling distance of the lens 18 according to the height of the stage 10. The lens driver (not shown) is controlled so as not to fall abnormally.

As described above, according to the embodiment of the present invention, the distance between the lens 18 and the wafer 12 is detected by the limit sensor 20, and the driving of the lens 18 is controlled by the controller 22. There is an advantage that the damage caused by the collision of the lens 18 and the wafer 12 is prevented.

Therefore, according to the present invention, since the measurement distance between the lens and the wafer is controlled by the sensor, damage to the wafer and the lens is prevented and the measurement is smoothly performed.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (4)

A semiconductor measuring apparatus comprising a stage on which a wafer is seated and a lens capable of horizontal and vertical movement in proximity to the wafer, A stage sensor detecting a movement of the stage; A limit sensor installed at one side of the lens to detect a vertical movement distance; And A control unit connected to the stage sensor and the limit sensor and configured to limit a distance between the lens and the wafer by receiving respective sensing signals; Wafer measuring apparatus using a lens falling distance limit sensor characterized in that it comprises a. The method of claim 1, wherein the limit sensor, Wafer measuring apparatus using the lens falling distance limit sensor, characterized in that installed on the side of the end of the lens. The method of claim 1, wherein the limit sensor, Wafer measuring apparatus using the lens falling distance limit sensor, characterized in that at least one is installed. The method of claim 1, wherein the control unit, And a limit distance between the lens and the wafer is set so that when the lens approaches the limit distance, the lens is restricted from being moved further.