JPS584988B2 - Charging status visual confirmation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for visually confirming which part of a charged object is electrically charged and approximately how much charge is applied to the object. If you can know which part of your throat is charged and the extent of the charge, it will be easier to take countermeasures, and you will be able to take effective measures to remove the charge.

For example, phosphorography technology is essential to manufacturing semiconductor devices, and photo masks are also essential for this.

A so-called work mask used in a normal manufacturing process is produced by transferring a mask pattern.

The transfer process is performed by placing a mask on the surface of a glass substrate in which a metal film and a photoresist film are sequentially formed, and then placing a mask closely on the photoresist film and irradiating it with ultraviolet rays. .

Such a transfer operation is repeatedly performed on a number of workpiece masks using one mask, and the metal film pattern portion of the mask gradually becomes electrically charged.

Eventually, after the transfer was completed, the mask mask and workpiece mask came into close contact with each other, making it difficult to separate them. Accidents that result in damage often occur.

Since the electrification of the masks changes depending on the metal film pattern, not all masks are necessarily charged to the same state.

Therefore, as described above, if the state of charge can be visually checked, countermeasures and removal of charge can be smoothly carried out.

The present invention provides a method for visually checking the charged state of an object using an extremely simple device, and this will be explained below.

FIG. 1 is an explanatory diagram of essential parts showing an example of an apparatus for carrying out the present invention.

In the figure, PT is an image pickup tube, PTl is a transparent conductive film electrode,
PT2 is a photoconductive film, PT3 is a cathode, ■s is a dielectric thin film, DP is a display device, and MK is a charged object.

As the image pickup tube PT in this apparatus, for example, a vidicon with some modifications can be used.

Although not shown, a glass plate may be interposed between the dielectric thin film IS and the transparent conductive film electrode PTI. Saran: Dow Chemical Company, USA) can be used.

Now, in the above device, the charged object MK is transferred to the dielectric thin film ■
When pressed against s, the charged state of object MK changes to dielectric thin film I.
s and further to the photoconductive film PT2.

When positive charges exist in the photoconductive film PT2, that is, the target, the ten charges are reduced by scanning the target with an electron beam from the cathode PTa.

At the same time, since charging is performed from the power source via the electrode PTt, it is sufficient to send this as a signal to the display device DP for display.

FIG. 2a is an explanatory diagram showing the charging state of the charged object MK, and when the charged object MK is subjected to the operation described in connection with FIG. 1, the cathode ray tube CR in the display device Dp
As shown in Figure 2, a white (high brightness) display is displayed on T, and by looking at its position, shape, area, etc., it can be visually confirmed which part of the charged object MK is charged and to what extent. can do.

As can be seen from the above description, according to the present invention, a charged object is pressed against an image pickup tube coupled to a display device through a dielectric thin film, and the charged state of the object is transferred to the target of the image pickup tube. By scanning the target with an electron beam from the cathode, a signal based on the transferred charge is extracted and sent to a display device for display. Patterns of high and low brightness appear depending on the state.

Therefore, the charged state of the object can be easily checked visually, and this allows
If it is found that the mask is heavily charged, a highly reliable working mask can be obtained by not using this mask for transfer.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a main part showing an example of an apparatus for carrying out the present invention, and FIG. 2 is an explanatory diagram for explaining a charging state and its display state. In the figure, PT is an image pickup tube, PTt is a transparent conductive film electrode,
PT2 is a photoconductive film, PT3 is a cathode, Is is a dielectric thin film, DP is a display device, MK is a charged object, and CRT is a cathode ray tube.

Claims (1)

[Claims] 1. Press a charged object against the image pickup tube through a dielectric thin film,
The charged state of the charged object is transferred to the target of the image pickup tube, the target is scanned with an electron beam from the cathode of the image pickup tube, a signal based on the charged state is extracted, and the signal is added to a display device to display a pattern of the charged state. A charging state visual confirmation method that is characterized by displaying.