JPH07111952B2 - Glass mask in photolithography process - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a registration mark of a glass mask in a photolithography process.

[Conventional technology]

In recent years, in order to manufacture a semiconductor device or the like, positioning of a glass mask and a wafer in a repeated photolithography process is performed by a reticle pattern which is a group of a plurality of chips in advance in order to reduce each chip pattern or chip area of the glass mask. This is performed by aligning the alignment mark provided on the wafer with the alignment mark provided on the wafer.

Conventionally, the method of aligning the glass mask and the alignment mask of the wafer is to first set the glass mask on the mask aligner, then look for the alignment mark of this glass mask, and put it in the microscope field of view of the mask aligner, and Under the glass mask, the wafer is moved, and the alignment mark provided on the wafer is searched through the microscope and the glass mask to match these alignment marks.

[Problems to be Solved by the Invention]

However, in the above-described conventional alignment marks, the field of view of the microscope is narrow, for example, several hundreds of μm, so when the reticle size increases, for example, a dozen mm square, the spacing between the alignment marks also increases, and the alignment marks also increase. There is a problem that it takes a lot of time to detect the.

Of course, the number of alignment marks in the reticle may be increased in order to reduce the distance between the alignment marks, but in this case, there is a problem in that misalignment such as alignment with different alignment marks occurs.

In view of the above-mentioned problems, an object of the present invention is to provide an alignment mark for a glass mask in a photolithography process that can reduce the alignment mark detection time.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a glass mask in a photolithography process, which is surrounded by scribe lines provided in a grid pattern in the horizontal and vertical directions and has a plurality of rectangular chip patterns, Among them, the alignment mark portions formed in the corners of the chip pattern selected in advance and the horizontal and vertical guide lines that are formed on the scribe line and intersect at the corners in which the alignment marks are formed It is characterized by having.

[Work]

In the present invention, since a plurality of intersecting guide lines for positioning the glass mask and the wafer are provided in the vicinity of the alignment mark parts, the alignment mark parts can be easily detected by searching the intersection points of the guide lines.

〔Example〕

An embodiment of the alignment mark of the glass mask in the photolithography process of the present invention will be described below. FIG. 1 is a plan view of the glass mask, FIG. 2 is an enlarged view of the reticle, and FIG. 3 is a partially enlarged view of the alignment mark. Show and explain.

That is, in FIG. 1, reference numeral 1 denotes a glass mask made of a quartz (silicon oxide) material that transmits a desired wavelength of ultraviolet light, for example, UV light, and the back surface of the glass mask 1 reflects the UV light and the like. A reticle pattern 2 made of chrome or the like is formed.

Further, as shown in FIG. 2, the reticle pattern 2 has a plurality of rectangular shapes surrounded by a plurality of scribe lines 3 provided in a grid pattern at predetermined intervals in the vertical (Y) direction and the vertical (X) direction. Is formed by the chip pattern 4.

Further, as shown in FIG. 3, alignment marks 5a are formed at the corners of the predetermined IC chip pattern 4, and on the scribe lines 3 in the Y and X directions near the alignment marks 5a. A reticle line 5b, which is a guideline for the alignment mark portion 5a, is formed.

Next, how to align the alignment marks in such a glass mask will be described.

First, the field of view of the microscope of the mask aligner is moved in the X direction (or Y direction) of the glass mask 1 and then moved in the Y direction (or X direction).
Direction) reticle line 5b. After that, the field of view of the microscope is moved in the Y direction (or X direction) along the reticle line 5b in the Y direction (or X direction), and the X direction (or Y direction) is moved.
Search for reticle line 5b. Thus, it is possible to easily find the alignment mark portion 5a near the intersection of the reticle lines 5b in the Y direction and the X direction.

Subsequently, the alignment mark portion 5a of the glass mask 1 is fixedly placed in the microscope field of view of the mask aligner, and the wafer is transferred through the microscope and the glass mask 1 by the first exposure phenomenon of the photoresist film by the glass mask 1. Alignment mark part 5a of the reticle line 5b
Detects the wafer by moving it in the X and Y directions. After that, the alignment mark portion 5a of the glass mask 1 is aligned with the alignment mark portion 5a of the wafer, and the glass mask 1 is positioned on the wafer. However, in the first photolithography process on the wafer, it is not necessary to position the glass mask 1 on the wafer.

The reticle line 5b may be a solid line or a dotted line as long as it can be sufficiently confirmed in the field of view of the microscope, and if the width of the reticle line 5b does not hinder other processes, it is confirmed by the microscope. It goes without saying that it is good if it is one.

〔The invention's effect〕

As described above, according to the present invention, the glass mask,
Since the alignment mark portion for positioning the wafer and a plurality of guide lines intersecting in the vicinity of the alignment mark portion are arranged, the alignment mark portion can be easily detected by searching for the intersection of the guide lines. The alignment mark portion on the wafer transferred by the glass mask can be easily detected by searching for the intersection of the similarly transferred guide lines. Therefore, the time required for detecting the alignment mark can be shortened, and the time in the photolithography process can be shortened, so that the above-mentioned problems can be solved by the unique effects such as improved workability.

[Brief description of drawings]

1 to 3 show an embodiment according to the present invention. FIG. 1 is a plan view of a glass mask, FIG. 2 is an enlarged view of a reticle, and FIG. 3 is a partially enlarged view of a registration mark. is there. 1 ... glass mask, 2 ... reticle pattern, 3 ...
Scribe line, 4 chip pattern, 5a alignment mark, 5b reticle line (guideline).

Claims (1)

[Claims] 1. A glass mask used in a photolithography process, comprising a plurality of chip patterns each having a rectangular shape and surrounded by scribe lines provided in a grid pattern in a horizontal direction and a vertical direction, wherein one of the chip patterns selected in advance. A photo alignment mark portion formed at a corner of the chip pattern, and horizontal and vertical guide lines formed on the scribe line and intersecting at the corner where the alignment mark is formed. Glass mask in the lithography process.