TW201602712A - Exposure mask manufacturing method - Google Patents

Abstract

The object of the present invention is to provide an exposure mask manufacturing method capable of manufacturing an exposure mask at low cost by using simple steps in contrast to the conventional method. The solution is a manufacturing method of an exposure mask for wafer processing, which includes a groove forming step ad a light shielding material embedding step. The groove forming step is to form a groove, which has a depth not reaching a back surface of a transparent plate, on a region of a surface side of the transparent plate which has a size larger than a processed wafer and is light trans-missive. The light shielding material embedding step is to embed a light shielding material having light shielding property in the groove.

Description

Exposure cover manufacturing method Field of invention

The present invention relates to a method of fabricating an exposure mask for use in processing wafers.

Background of the invention

In a small and lightweight electronic device represented by a mobile phone, a device chip including an electronic circuit such as an IC or an LSI has become a necessary configuration. The element wafer can be manufactured by, for example, dividing a surface of a wafer formed of a material such as a plurality of lines by a predetermined number of divisions called streets, and after forming an electronic circuit in each area, The wafer is cut along this scribe line.

When the wafer is cut, for example, when the cutting blade that rotates at a high speed is cut into the scribe line of the wafer, the cutting blade and the wafer are relatively moved in a direction parallel to the scribe line. However, in this method, since the wafer is mechanically removed along the dicing street, the bending strength of the element wafer tends to decrease.

Further, in this method, since the cutting knives must be individually cut after accurately positioning the cutting knives with respect to the dicing streets, it takes a long time until the end of the machining. This problem is used in cutting A wafer with a large number of predetermined lines is particularly deep.

Then, in recent years, a method of cutting a wafer by plasma etching has been proposed (see, for example, Patent Document 1). In this method, since the entire surface of the wafer can be processed by plasma etching once, the number of division lines to be processed is increased by the miniaturization of the element wafer, the size of the wafer, and the like, and the processing time is almost No need to change.

Moreover, since the wafer is not mechanically scraped, the defect at the time of processing can be suppressed, and the bending strength of the element wafer can be maintained high. In this method, an exposure cover in which a light-shielding film pattern formed of chromium is formed on the surface of a glass substrate (see, for example, Patent Document 2) is used, and etching is formed on the front and back surfaces of the wafer. Resist membrane used.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. 2006-114825

Patent Document 2: Japanese Patent Laid-Open No. 62-229151

Summary of invention

However, since the exposure cover described above is manufactured through a complicated process of forming a light shielding film, coating a protective film, patterning a protective film, and etching a light shielding film, and the price is high, if the exposure cover is used, This will result in higher processing costs for the wafer.

The present invention has been made in view of the above problems, and its object It is to provide a method of manufacturing an exposure cover which can manufacture an exposure cover inexpensively in a simple procedure as compared with the conventional method.

A method of manufacturing an exposure cover according to the present invention is a method of manufacturing an exposure cover for wafer processing, comprising a groove forming step and a light shielding material embedding step, wherein the groove forming step is performed on a wafer having a process a transparent and transparent transparent plate corresponding to a surface side of the dicing street of the wafer forms a groove having a depth not lower than a back surface of the transparent plate, and the light shielding material embedding step is to embed the light shielding property in the groove Shading material.

In the present invention, it is preferable that the light shielding material embedding step is performed by an embedding means having an ink jet nozzle.

Further, in the present invention, preferably, in the light shielding material embedding step, after the light shielding material is coated on the entire surface of the transparent plate on which the groove is formed, and the light shielding material is embedded in the groove, The light shielding material that has been coated on a surface other than the groove of the transparent plate is removed.

The manufacturing method of the exposure cover of the present invention comprises a groove forming step and a light shielding material embedding step, wherein the groove forming step is to form a scribe line corresponding to the wafer on the surface side of the transparent transparent plate and the depth is not up to the back surface of the transparent plate In the groove, the light shielding material embedding step is to embed a light shielding material having a light blocking property in the groove.

Therefore, it is possible to manufacture an exposure cover having a light-shielding pattern corresponding to the scribe line of the wafer without passing through the pattern of the coating of the protective film or the pattern of the protective film and the complicated etching of the light-shielding film. As such, according to the present invention It is possible to provide a method of manufacturing an exposure cover which can be inexpensively manufactured by a simple method as compared with the conventional method.

11‧‧‧ wafer

11a, 21a‧‧‧ surface

11b, 21b‧‧‧ back

11c‧‧‧out week

12‧‧‧ grinding device

13‧‧‧Component area

14‧‧‧ Keeping the table

15‧‧‧ remaining area of the periphery

16‧‧‧ Spindle

17‧‧‧Cut Road (segmentation line)

18‧‧‧ wheel seat

19‧‧‧ components

2‧‧‧Cutter

20‧‧‧ grinding wheel

20a‧‧·round abutment

20b‧‧‧grinding grindstone

21‧‧‧Transparent board

23‧‧‧ trench

25‧‧‧Liquid

27‧‧‧ shading materials

29‧‧‧Shade film (shading material)

4‧‧‧Inkjet nozzles (buried means)

1(A) is a perspective view showing a configuration example of a wafer in a schematic manner, and FIG. 1(B) is a cross-sectional view showing a configuration example of a wafer in a schematic manner.

Fig. 2(A) schematically shows a perspective view of the groove forming step, and Fig. 2(B) is a cross-sectional view schematically showing the transparent plate after the groove forming step.

Fig. 3(A) is a partial cross-sectional side view showing the step of embedding the light shielding material in a pattern, and Fig. 3(B) is a perspective view schematically showing the transparent plate after the step of embedding the light shielding material.

4(A) is a cross-sectional view showing a modification of the light-shielding material embedding step in a mode, and FIG. 4(B) is a perspective view schematically showing a modification of the light-shielding material embedding step.

Form for implementing the invention

Embodiments of the present invention will be described with reference to the accompanying drawings. The manufacturing method of the exposure cover of this embodiment includes a groove forming step (see FIGS. 2(A) and 2(B)), and a light shielding material embedding step (see FIGS. 3(A) and 3(B)).

In the groove forming step, a groove corresponding to the dicing street of the wafer and having a depth less than the back surface of the transparent plate is formed on the surface side of the transparent transparent plate. In the light-shielding material embedding step, a light-shielding material having a light-shielding property is buried in the groove of the transparent plate. Hereinafter, a method of manufacturing the exposure cover of the present embodiment will be described in detail.

First, the processing using the exposure cover of this embodiment will be described. Wafer. 1(A) is a perspective view showing a configuration example of a wafer in a schematic manner, and FIG. 1(B) is a cross-sectional view showing a configuration example of a wafer in a schematic manner.

As shown in FIG. 1(A) and FIG. 1(B), the wafer 11 is a substantially circular plate member formed of, for example, a semiconductor material such as tantalum, and the surface 11a is divided into a central element region 13, and The peripheral remaining area 15 is surrounded by the element region 13.

The element region 13 is further divided into a plurality of regions by dicing lines (divided lines) 17 arranged in a lattice shape, and elements 19 such as ICs are formed in each region. The outer periphery 11c of the wafer 11 is subjected to chamfering processing with an arc.

In the method of manufacturing an exposure cover according to the present embodiment, an exposure cover having a light shielding pattern corresponding to the scribe line 17 of the wafer 11 described above can be manufactured. Specifically, first, a groove forming step of forming a groove corresponding to the dicing street 17 of the wafer 11 on the transparent plate is performed. 2(A) is a perspective view schematically showing a groove forming step, and FIG. 2(B) is a cross-sectional view schematically showing a transparent plate after the groove forming step.

As shown in Fig. 2 (A) and Fig. 2 (B), the transparent plate 21 as a base material of the exposure cover is a substantially circular plate formed of a transparent material such as glass or resin, and has a diameter of For example, it is larger than the diameter of the wafer 11. However, the transparent plate 21 may be formed to have the same diameter as the wafer 11. In other words, the transparent plate 21 may be of a size larger than the wafer 11 or more.

Further, the transparent plate 21 is provided with any optical characteristics required for the exposure cover. Specifically, for example, the transparent plate 21 is transparent to light of a predetermined wavelength used for curing the protective material. However, the transparent plate 21 does not Be sure to be transparent to visible light.

As shown in Fig. 2(A), in the groove forming step, the cutting blade 2 that rotates at a high speed is cut into the surface 21a of the transparent plate 21, and the cutting blade 2 and the transparent plate 21 are relatively moved in the horizontal direction. Here, the cutting blade 2 is cut into a region corresponding to the dicing street 17 of the wafer 11. Further, the cutting depth of the cutting blade 2 is set such that the cutting blade 2 does not reach the back surface 21b of the transparent plate 21.

Thereby, the groove 23 corresponding to the dicing street 17 of the wafer 11 and having a depth less than the back surface 21b of the transparent plate 21 can be formed on the surface 21a side of the transparent plate 21. When the grooves 23 corresponding to all the dicing streets 17 of the wafer 11 are formed, the groove forming step is ended.

After the groove forming step, a light shielding material embedding step is performed in which a light shielding material having a light blocking property is buried in the groove 23 of the transparent plate 21. Fig. 3(A) is a partial cross-sectional side view showing the step of embedding the light shielding material in a pattern, and Fig. 3(B) is a perspective view schematically showing the transparent plate 21 after the step of embedding the light shielding material.

In the light-shielding member embedding step, for example, as shown in FIG. 3(A), the ink-jet nozzle (buried means) 4 disposed on the surface 21a side of the transparent plate 21 is moved along the groove 23 while being in the groove 23. A liquid 25 having a light-shielding property typified by a nano metal ink is dropped.

Thereafter, as shown in FIGS. 3(A) and 3(B), by drying and hardening the liquid 25 supplied to the groove 23, a linear light-shielding material corresponding to the dicing street 17 of the wafer 11 can be formed. 27. When the light shielding material 27 is embedded in all the grooves 23 of the transparent plate 21, the exposure cover is completed.

As described above, the method of manufacturing the exposure cover of the present invention includes the step of forming a groove and the step of forming a light shielding material, the step of forming the groove being transparent A groove 23 corresponding to the dicing street 17 of the wafer 11 and having a depth less than the back surface 21b of the transparent plate 21 is formed on the surface 21a side of the bright plate 21, and the light shielding material embedding step is to embed the light shielding material 27 having a light blocking property in the groove 23.

Therefore, it is possible to manufacture an exposure cover having a light-shielding pattern corresponding to the dicing street 17 of the wafer 11 without passing through the coating of the protective film, the patterning of the protective film, and the complicated etching of the light-shielding film. As described above, according to the present embodiment, it is possible to provide a method of manufacturing an exposure cover which can manufacture an exposure cover inexpensively by a simple method as compared with the conventional method.

Furthermore, the present invention is not limited to the description of the above embodiments, and various modifications can be made. For example, in the above-described embodiment, the light-shielding material 27 is embedded in the groove 23 by a so-called ink jet method in which the liquid 25 is dropped by the ink-jet nozzle 4, but the light-shielding material 27 is embedded in the groove 23. The method is not limited to this.

4(A) is a cross-sectional view showing a modification of the light-shielding material embedding step in a mode, and FIG. 4(B) is a perspective view schematically showing a modification of the light-shielding material embedding step. First, as shown in FIG. 4(A), in the light shielding material embedding step of the modification, a light shielding film (light shielding material) 29 that covers the entire surface 21a of the transparent plate 21 is formed. The light shielding film 29 is a metal film formed by, for example, a sputtering method or a CVD method, and a part of the light shielding film 29 is buried in the groove 23 as shown in FIG. 4(A).

Next, one portion of the light shielding film 29 is removed, and the surface 21a of the transparent plate 21 is exposed. The removal of the light shielding film 29 is performed by, for example, the grinding device 12 shown in Fig. 4(B). The grinding device 12 is provided with a holding table 14 that sucks and holds the transparent plate 21. A rotating mechanism (not shown) is disposed below the holding table 14 and The holding table 14 is rotated in the form of a vertical axis by the rotation mechanism.

The surface (upper surface) of the holding table 14 is a holding surface that sucks and holds the back surface 21b side of the transparent plate 21. On this holding surface, the suction force (not shown) formed inside the holding table 14 acts on the suction pressure (not shown) to generate an attractive force for attracting the transparent plate 21.

A main shaft 16 that rotates around a vertical axis is disposed above the holding table 14. The main shaft 16 is lifted and lowered by a lift (not shown). A disc-shaped wheel base 18 is fixed to the lower end side of the main shaft 16, and a grinding wheel 20 is mounted in this wheel base 18.

The grinding wheel 20 is provided with a wheel base 20a formed of a metal material such as aluminum or stainless steel. On the annular lower surface of the wheel base 20a, a plurality of grinding stones 20b are fixed over the entire periphery.

When the light shielding film 29 is removed, first, the back surface 21b side of the transparent plate 21 is brought into contact with the holding surface of the holding table 14, and the negative pressure of the suction source acts. Thereby, the transparent plate 21 can be sucked and held by the holding table 14 in a state where the light shielding film 29 of the covering surface 21a is exposed upward.

Next, when the holding table 14 and the main shaft 16 are respectively rotated in a predetermined direction, the main shaft 16 is lowered, and as shown in FIG. 4(B), the grinding grindstone 20b is brought into contact with the light shielding film 29. The spindle 16 is lowered at a feed speed suitable for the grinding of the light shielding film 29.

As shown in FIG. 3(B), when the light shielding film 29 is ground until the surface 21a of the transparent plate 21 is exposed, a light shielding material 27 which is a part of the light shielding film 29 remains in the groove 23. As described above, in the case where the light shielding material embedding step of the modification is carried out, the same exposure cover as in the above embodiment can be manufactured.

Further, in the above-described modification, the light shielding material 27 is left in the groove 23 by grinding the light shielding film 29, but the light shielding film 29 may be removed by another method such as etching, and the light shielding material 27 may remain in the groove. In the groove 23.

In addition, the configuration, the method, and the like of the above-described embodiments can be appropriately modified and implemented without departing from the scope of the invention.

21‧‧‧Transparent board

21a‧‧‧Surface

21b‧‧‧Back

23‧‧‧ditch

25‧‧‧Liquid

27‧‧‧ shading materials

4‧‧‧Inkjet nozzles (buried means)

Claims (3)

A method for manufacturing an exposure cover, which is a method for manufacturing an exposure cover for wafer processing, comprising: a groove forming step corresponding to a transparent plate having a size larger than a processed wafer and transparent to the wafer In the region on the surface side of the dicing street, a groove having a depth not reaching the back surface of the transparent plate is formed, and a light shielding material embedding step is performed, and a light shielding material having a light blocking property is buried in the groove. A method of manufacturing an exposure cover according to claim 1, wherein the light shielding material embedding step is performed by an embedding means having an ink jet nozzle. The method of manufacturing an exposure cover according to claim 1, wherein in the light shielding material embedding step, after the light shielding material is coated on the entire surface of the transparent plate on which the groove is formed, and the light shielding material is buried in the groove, The light shielding material that has been coated on a surface other than the groove of the transparent plate is removed.