JPH0362010B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an alignment method used for dividing and transferring a continuous or uninterrupted pattern of a relatively large area onto a substrate, particularly for liquid crystal devices and This invention relates to an alignment method used in the manufacture of integrated circuits, etc.

[Conventional technology]

In recent years, in the field of manufacturing the above-mentioned liquid crystal devices and integrated circuits, it has been desired to form continuous or uninterrupted patterns over large areas.

Especially in the field of CCD and line sensors,
It is strongly desired to form a continuous rectangular pattern over a large area.

In order to maintain pattern continuity, it is most convenient to form an integrated pattern on a large area substrate using a single mask of the same size by optical lithography or the like.

However, although large-area substrates can be made without particular difficulty, manufacturing large masks is difficult to realize. This is mainly due to technical difficulties and the associated increase in manufacturing costs.

[Problems to be solved by the present invention]

The present invention has been made in view of the above circumstances, and its purpose is to provide an alignment method that makes it possible to form a relatively large continuous pattern on a substrate by dividing transfer. .

[Means to solve the problem]

In order to achieve this object, the present invention provides an alignment method used for dividing and transferring a pattern onto a substrate S.
Hold the board at one of the alignment marks 4
a, 4b to align one of the pattern components to one area of the substrate, and another one of the alignment marks 5a, 5b to align the pattern component to another area of the substrate. The other one is aligned.

In addition, in an alignment method used for dividing transfer onto a patterned substrate S, the substrate is held by a holder 3 provided with a plurality of alignment marks 4a, 4b, and 5a, 5b, and one of the alignment marks 4a, 4b is The first transfer operation is carried out after aligning one of the constituent parts of the pattern to one area of the substrate using the alignment marks 5a and 5b, and the other one of the alignment marks 5a, 5b is used to align one of the constituent parts of the pattern to one area of the substrate. After the other one of the constituent parts of the pattern is aligned, the next transfer operation is performed.

[Effect]

According to the invention, the respective mutually complementary pattern components are aligned on the substrate by respective alignment marks on the holder. As a result, the pattern components transferred onto the substrate are aligned with each other, ensuring continuity of the pattern on the substrate. Therefore, according to the present invention, it is possible to form a relatively large-area continuous pattern on a substrate even using a relatively small-area mask such as currently available masks.

Further, according to the present invention, the pattern transfer area on the substrate onto which the continuous pattern is transferred is divided into at least two areas, and the pattern transfer is performed continuously for each area.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the alignment method of this invention will be explained in detail based on the Example shown in the figure.

Referring to FIG. 1, a substrate S such as a glass plate, a silicon wafer, etc. has a pattern transfer area 1 on its surface.
(indicated by broken lines), and a continuous pattern is transferred onto this region 1.

In this embodiment, the pattern transfer area 1 is divided into an upper half area and a lower half area with respect to the center line C (FIG. 2).

The holder 3 releasably holds the substrate S by suitable means. Alignment marks 4a, 4b, 5a and 5b are formed on the holder 3, and the center line C of the pattern transfer area 1 (FIG. 2)
and arranged in a predetermined positional relationship with respect to each other. Alignment marks 4a and 4
b is for the upper half area of the pattern transfer area 1;
Alignment marks 5a and 5b are for the lower half area of region 1.

These alignment marks can be formed on the holder by known optical phosphorography techniques using a mask 20 as shown in FIG. That is, the mask 20 on which the corresponding alignment marks are formed is placed on or above the holder 3 so that the center of the mask 20 coincides with the center of the holder 3. The mask 20 is then irradiated by an illumination source (not shown), and the photoresist coated on the holder 3 is exposed to the light beam transmitted through the mask 20. As a result, alignment marks 4a, 4b, 5a and 5b are transferred onto holder 3. The image of the alignment mark is then visualized using a known developing method.

A suitable material is selected for the holder 3 in order to maintain a precise positional relationship between the alignment marks without being affected by environmental conditions such as ambient temperature.

Alignment and pattern transfer according to the present invention will be described in more detail.

First, the substrate S is held by a holder. The positioning accuracy of the substrate S depends on mechanical positioning by the holder.

After positioning the substrate S, the pattern is transferred to the pattern transfer area 1 by the method shown in FIGS. 2-4.

In this embodiment, two real element masks 6A having complementary half portions of one complete pattern are used.
and 6B are used according to the number of areas of the pattern transfer area 1. In addition to the area of the pattern, the circuit is provided with alignment marks 8a and 8b or 9a and 9b, respectively, which correspond to the alignment marks 4a and 4b (or 5a and 5b) of the substrate S.

The positional relationship between these alignment marks is determined in advance as follows. The positional relationship between alignment marks 8a, 8b, 9a and 9b of masks 6A and 6B is such that the masks are placed side by side such that the pattern components are precisely connected to each other to define a precisely continuous pattern. is established when the alignment marks 4a, 4b, 5a and 5b of the holder 3 are exactly the same or exactly correspond to the positional relationship between the alignment marks 4a, 4b, 5a and 5b. By using known electron beam patterning methods etc.
While accurately maintaining the above-mentioned positional relationship, these alignment marks 8a, 8b, 9a and 9b
can be easily formed on the masks 6A and 6B, respectively.

For example, if it is desired to first transfer the pattern to the upper half area of pattern transfer area 1,
The mask 6A is placed on or above the upper half area of the substrate S until the spacing between the bar elements 10 of the alignment mark 8 and the alignment mark 4 are equal to each other as shown in FIG. The position of mask 6A relative to the substrate is adjusted by means of alignment marks 4a, 4b, 8a and 8b, for example in a manner as disclosed in US Pat. No. 4,167,677. Once this is accomplished, a precise positional relationship is established between the mask 6A and the upper half area of the substrate S, thus providing exposure of the upper half area of the substrate. As a result, the pattern forming portion formed on the mask 6A is transferred onto the upper half area of the pattern transfer area 1. During this exposure, the lower half area of the substrate is protected from the exposure beam by a suitable shielding element.

Next, the similar pattern transfer method is applied to pattern transfer area 1.
This is done for the lower half of the area. This is done after or prior to processing the photoresist material for the upper half area of region 1.

After completing the first pattern transfer through the masks 6A and 6B for the upper and lower half areas of region 1, the substrate S is released from the holder 3.

As shown in FIGS. 2 and 4, masks 6A and 6B provide additional alignment marks 7a and 7b (or 11a and 1), respectively.
1b). During exposure of the substrate S, these alignment marks are simultaneously transferred onto a region 2 (see FIG. 1) of the substrate S between the outer boundary of the substrate S and the pattern transfer region 1. The alignment marks 7a and 7b (or 11a and 11b) transferred in this way are used to perform alignment when repeating pattern transfer to the same area of the pattern transfer area 1, that is, to perform alignment with the area to which the pattern has already been transferred. It is used to achieve overlay accuracy between the pattern components to be transferred to this area.

The degree of continuity of the pattern components transferred to pattern transfer area 1 may be slightly inferior to the continuity obtained with a single large-area mask covering area 1, but this is due to It is negligible when manufacturing certain types of integrated circuits.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to form a relatively large continuous pattern on a substrate by division transfer.

[Brief explanation of drawings]

FIG. 1 is a plan view schematically showing a substrate held by a holder, FIGS. 2 and 4 are plan views schematically showing the alignment and pattern transfer method of the present invention, and FIG. 5 is an enlarged view showing alignment marks during alignment, and FIG. 5 is a plan view showing a mask for forming alignment marks on the holder of FIG. 1. S...Substrate, 1...Pattern transfer area, 3...Holder, 4a, 4b, 5a, 5b...Alignment mark, 20...Mask.

Claims (1)

[Claims] 1. In an alignment method used for dividing and transferring a pattern onto a substrate, the substrate is held by a holder having a plurality of alignment marks, and one of the alignment marks is used to align the substrate. aligning one of the pattern components in one area and aligning another one of the pattern components in another area of the substrate using another one of the alignment marks; An alignment method characterized by: 2. In an alignment method used for dividing and transferring a pattern onto a substrate, the substrate is held by a holder having a plurality of alignment marks, and one of the alignment marks is used to transfer the pattern onto one area of the substrate. A first transfer operation is performed after aligning one of the constituent parts of the pattern, and another one of the constituent parts of the pattern is transferred to another area of the substrate using another one of the alignment marks. An alignment method characterized by performing the next transfer operation after aligning.