JPS5936740B2 - Mask production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an optical mask having a fine pattern, particularly a striped fine pattern.

For example, in the target of a storage tube, silicon 5, for example, is coated on the inner surface of the face plate 1 of the tube as shown in FIG.
An electrode 2 made of one layer is disposed, an insulating layer 3 made of SiO2 is formed by oxidizing the surface of the electrode 2, and this insulating layer 3 is photo-etched so that a part of the electrode 2 is exposed. Some are formed in a stripe shape (extended in parallel to the direction intersecting the beam scanning line direction).

Although not shown in the drawings, a target electrode made of a conductive layer is entirely deposited on the inner surface of the face plate, and is extended in parallel to the direction intersecting the beam scanning line direction through an insulating layer such as SiO2. There is also a target constructed by depositing first and second electrode groups each having a plurality of striped electrodes formed in a comb-teeth shape. Such a striped insulator layer 3
Alternatively, the striped electrode groups are all formed using photo-etching technology, but the line width and pitch of the stripes are extremely fine; for example, the line width of the stripes is 5μ and the pitch is 10μ. Because of the extremely fine details, it is extremely difficult to create a photomask when forming these by photoetching.

On the other hand, as a method for manufacturing a mask having a stripe pattern, a manufacturing method using, for example, a repetitive exposure apparatus 4 shown in FIG. 1 has been proposed.

When the stripe pattern is minute, the original image is created at high magnification (1,000 to 2,000 times), and the original image is scaled down to form several to dozens of striped light-transmitting areas as shown in Figure 2. An original optical mask (master reticle) 5 having 6 [A, B, C, D] is provided. This original optical mask 5 is fixed to the apparatus 4 shown in FIG. 1, and a photographic plate 8 is placed on a table T placed opposite to the original optical mask 5. The light transmitting part 6 of the mask 5 is continuously moved uniaxially in the longitudinal direction, that is, in the X direction, and the shutter 9 is moved continuously during that time.
Exposure is applied from a lamp 10 which is kept open and the amount of light is constant. 11 is a lens.

Next, every time the uniaxial exposure in the X direction is completed, the photographic plate 8 is
Dimensions of the original optical mask 5 in the direction (total width a of the light transmitting section 6)
) and perform exposure in the X direction again. (See FIG. 4) After all the exposure steps are completed, development is performed to obtain a mask with a pattern consisting of a large number of striped light-transmitting parts and light-blocking parts. However, in this case, in order to prevent pattern mismatch that occurs at the seam portion when the original optical mask 5 is relatively moved in the Y direction and exposed, the original optical mask 5 is moved in the intermediate direction as shown in FIG. Light transmitting part 6 [B, C]
When the line width is 11, the light transmitting parts 6 [A, D
) line width 12 is 1/21, +α (α is the overlap at the joint, 1.25μ in the case of a storage tube target, α=
1μ).

For this reason, as shown in FIG.
At the joint portion 12a, the line width 1 to be exposed is exposed twice with a width of 1/21 +α, and as the amount of exposure increases, a dimensional change in line width occurs. This change in line width appears as uneven pitch, and when a television image is obtained by forming, for example, a storage tube target using a mask made by such exposure, the seam appears as stripes. Image quality deteriorates. In view of this, the present invention provides a method for manufacturing a mask with a stripe pattern that does not cause any change in line width due to exposure unevenness even though the repetitive exposure device 4 shown in FIG. 2 is used.

First, as shown in FIG.
Original optical mask 14 consisting of one pattern of C] with equal pitch.
will be established.

This original optical mask 14 is fixed to the repetitive exposure device 4 shown in FIG. 2, and an object to be exposed, such as a photographic plate 8, which will eventually become a mask, is placed on the table 7 opposite thereto. Next, for example, in the case of a long stripe pattern, the photographic plate is continuously moved uniaxially in the X direction, while the shutter is opened for exposure. Next, each time the exposure in the X direction is completed, the photographic plate 8 is moved in the Y direction at a certain feed pitch and exposure in the X direction is performed again, and this operation is repeated. That is, this feed lip pitch has a predetermined pitch based on the pitch P of the light transmitting portion 6 of the original optical mask 14, that is, in this example, as shown by the dotted line in FIG. 6 (corresponding to the original optical mask 14). 1 pitch at a time. Note that this feed lip pitch is selected to be a predetermined pitch smaller than the total width a of the light transmitting section 6. Therefore, in the Y direction, as shown in FIG. 6, multiple exposure is performed multiple times in the same exposure section 12, that is, in this example, three times through the light transmitting sections A, B, and C. After all the exposure steps are completed, development is performed to obtain the intended mask in which the exposed portions 12 of FIG. 6 are light-transmitting portions.

Further, using the mask thus obtained as a master mask, further masks with the same pattern can be manufactured using a well-known technique (for example, photoetching technique, etc.). According to the present invention described above, when the dry plate 8 and the original optical mask 14 are moved relative to each other to sequentially expose a predetermined pattern, multiple exposures are performed the same number of times for all exposed areas, so that all It is possible to apply an average exposure amount to each exposed area, eliminate uneven exposure, and obtain a group of stripes having a uniform line width over the entire surface.

Note that even if there is a portion where multiple exposure is not performed between the start and end of exposure, this portion may be deleted from the effective area as an unnecessary portion. When a mask with a fine stripe pattern was produced through such multiple exposure, it was found that no periodic line width changes due to exposure unevenness occurred, and a good mask was obtained.

Therefore, the mask manufacturing method according to the present invention can be applied to, for example, manufacturing a mask for forming a target of a storage tube, and can also be suitably applied to manufacturing various masks that require a similar striped pattern. .

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a target of a storage tube to explain the present invention, FIG. 2 is a layout diagram showing an example of a repetitive exposure device to explain the present invention, and FIG. 3 is a conventional mask manufacturing method. 4 is a plan view showing the exposure state by the conventional mask manufacturing method. FIG. 5 is a plan view of the original optical mask used in the present invention. FIG. 6 is a plan view showing the original optical mask used in the present invention. FIG. 3 is a plan view showing an exposure state according to the mask manufacturing method of FIG. 4 is a repetitive exposure device, 7 is a table, 8 is a photographic plate, 9 is a shutter, 10 is a lamp, 13 [A, B, C] is a striped light transmitting part, 14 is an original optical mask, and 12 is an exposed part. be.

Claims (1)

[Claims] 1. An original optical mask consisting of a plurality of light transmitting parts arranged at equal pitches and an exposed object that will eventually become a mask are placed opposite each other, and the original optical mask and the exposed object are aligned with the above pitch as a reference. A method of manufacturing a mask in which the same exposure area is exposed multiple times by relatively moving at a predetermined pitch.