CN111158216A

CN111158216A - Exposure device

Info

Publication number: CN111158216A
Application number: CN201811336271.9A
Authority: CN
Inventors: 方凤云
Original assignee: Shanghai Xiyue Photoelectric Technology Co ltd
Current assignee: Shanghai Xiyue Photoelectric Technology Co ltd
Priority date: 2018-11-08
Filing date: 2018-11-08
Publication date: 2020-05-15

Abstract

The invention discloses an exposure device, which comprises a mask table and a mask plate positioned on the mask table, wherein a plurality of exposure graphs are drawn on the mask plate, exposure light sources are respectively arranged at the corresponding positions of the exposure graphs above the mask plate, a fixed loading platform and a base material positioned on the fixed loading platform are arranged below the mask table, the size of the base material is equivalent to that of the mask plate, a plurality of projection objectives are arranged between the mask plate and the base material, and the projection objectives correspond to the positions of the exposure graphs on the mask plate. According to the exposure device, a plurality of exposure patterns are drawn on the same mask plate, a large-size projection objective is replaced by a plurality of projection objectives, the exposure patterns on the mask plate are imaged on a base material through the corresponding projection objectives respectively, the movement of a carrying platform is not needed, the use of an expensive movable exposure carrying platform is avoided, the production cost is reduced, and the processing precision is ensured.

Description

Exposure device

Technical Field

The present invention relates to the field of integrated circuit technology, and more particularly, to an exposure apparatus including a plurality of projection objectives.

Background

A lithography machine, also known as a mask alignment exposure machine. The general photoetching process comprises the procedures of cleaning and drying the surface of a silicon wafer, coating a base, spin-coating a photoresist, soft drying, alignment exposure, post-drying, developing, hard drying, etching and the like. Lithography machines are classified into contact exposure, proximity exposure, and projection exposure.

Contact exposure: the mask is in direct contact with the photoresist layer. The resolution ratio of the exposed pattern is equivalent to that of the pattern on the mask plate, and the equipment is simple. Contact exposure is classified into soft contact, hard contact, and vacuum contact, depending on the manner in which force is applied.

Proximity exposure: a tiny gap is reserved between the mask plate and the base layer of the photoetching glue, the gap is about 0-200 mu m, the damage of the mask plate caused by the direct contact with the photoetching glue can be effectively avoided, the mask and the base layer of the photoetching glue can be used durably, the service life of the mask is long, the pattern defects are few, and the proximity type photoetching glue is most widely applied to the modern photoetching process.

Projection exposure: the exposure is realized by using an optical system to collect light between the mask and the photoresist, and the size of the mask is generally 4 times that of the pattern to be transferred. The advantages are that: the resolution is improved; the mask is easier to manufacture; the influence of defects on the mask is reduced. Projection exposure is classified into scanning projection exposure, step-and-repeat projection exposure, and scanning step-and-step projection exposure.

In the manufacture of integrated circuits, it is sometimes necessary to expose 2-3 patterns of 0.4mm x 0.4mm in size on a substrate, the patterns being spaced apart by 120mm or more on the substrate. At present, in a stepper in the ic industry, the maximum exposure range is 33mm × 26mm each time, and patterns spaced at such a distance can only be exposed in a split manner, that is, a first pattern is exposed, and then the exposure stage moves to the next position to expose another pattern. This requires high precision in the movement of the exposure stage.

The imaging precision of the stepping exposure machine is very high, the moving precision of the exposure carrying platform is also very good, but the price is high, and the manufacturing cost is more than 300 million dollars.

Disclosure of Invention

The invention aims to solve the problem that the traditional stepping exposure machine is expensive, and provides an exposure device comprising a plurality of projection objective lenses.

In order to achieve the purpose, the invention adopts the following technical scheme: an exposure device comprises a mask table and a mask plate located on the mask table, wherein a plurality of exposure patterns are drawn on the mask plate, exposure light sources are respectively arranged at corresponding positions of the exposure patterns above the mask plate, a fixed loading platform and a base material located on the fixed loading platform are arranged below the mask table, the size of the base material is equivalent to that of the mask plate, a plurality of projection objectives are arranged between the mask plate and the base material, and the projection objectives correspond to the exposure patterns on the mask plate in position.

And the exposure patterns on the mask plate correspond to the exposure light sources and the projection objectives one to one respectively.

The projection objective is provided with a plurality of projection objectives, and compared with a single large-size projection objective, the production cost is greatly reduced.

Wherein, the number of the exposure patterns is 2-3.

Wherein, the exposure pattern is square, and the size is 0.4mm multiplied by 0.4 mm.

Wherein the substrate is a silicon wafer.

The ultraviolet light beam generated by the exposure light source irradiates the mask plate on the mask platform, when the ultraviolet light beam passes through the mask plate, diffraction can be generated, and the pattern of the mask plate is imaged on the substrate through the projection objective.

Compared with the prior art, the invention has the following beneficial effects: according to the exposure device, a plurality of exposure patterns are drawn on the same mask plate, a large-size projection objective is replaced by a plurality of projection objectives, the exposure patterns on the mask plate are imaged on a base material through the corresponding projection objectives respectively, the movement of a carrying platform is not needed, the use of an expensive movable exposure carrying platform is avoided, the production cost is reduced, and the processing precision is ensured.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a schematic view of an exposure apparatus according to the present invention.

Wherein: the mask comprises a mask table 1, a mask plate 2, an exposure pattern 3, an exposure light source 4, a fixed stage 5, a base material 6 and a projection objective 7.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

As shown in fig. 1, an exposure apparatus includes a mask stage 1, a mask 2 located on the mask stage 1, a plurality of exposure patterns 3 drawn on the mask 2, exposure light sources 4 respectively disposed at corresponding positions of the exposure patterns 3 above the mask 2, a fixed stage 5 and a substrate 6 located on the fixed stage 5 disposed below the mask stage 1, the size of the substrate 6 is equivalent to that of the mask 2, a plurality of projection objectives 7 are disposed between the mask 2 and the substrate 6, and the projection objectives 7 correspond to the positions of the exposure patterns 3 on the mask 2.

The patterns on the mask 2 correspond to the exposure light sources 4 and the projection objectives 7 one to one.

Wherein, the number of the exposure patterns 3 is 2-3.

Wherein, the exposure pattern 3 is square, and the size is 0.4mm multiplied by 0.4 mm.

Wherein the substrate 6 is a silicon wafer.

Wherein, the photo-thermal separation device is arranged at the interface of the exposure light source 4, and the photo-thermal separation device can block infrared rays at the same time of transmitting ultraviolet rays and visible light, so that the heat of the exposure light source 4 is reduced to irradiate the mask plate, and the influence of the heat effect of the light source on the exposure effect is reduced. The photo-thermal separation device is heat insulation glass.

The projection objective 7 is a vertical full-refraction and full-symmetry structure with the magnification of-1, the function of large-field (44mm multiplied by 44mm) exposure can be realized, and the distortion error can be minimized by the full-symmetry structure; due to the realization of a large exposure field, the application range of the exposure device is greatly enhanced, the productivity of a user is improved from another aspect, and the cost is saved for the user.

Wherein the conjugate distance of the projection objective 7 is sufficiently large to ensure spatial thermal isolation of the reticle 2 and the substrate 6.

Processing a plurality of exposure patterns 3 on the same mask 2 according to the requirements of relative positions and angles, installing an exposure light source 4 at a corresponding position above the exposure patterns 3, arranging a projection objective 7 at a corresponding position below the exposure patterns 3, irradiating ultraviolet light beams generated by the exposure light source 4 in the exposure patterns 3 on the mask 2, diffracting when the light beams pass through the mask 2, and imaging the exposure patterns 3 on a base material 6 through the projection objective 7.

The exposure device of the invention adopts a plurality of small-sized projection objectives 7 to replace one large-sized projection objective, thereby reducing the cost; the exposure device processes a plurality of exposure patterns 3 on the same mask 2 according to the relative positions and angles of the exposure patterns 3, images on a substrate 6 through a projection objective 7, and has higher processing precision compared with a stepping exposure machine; the exposure device of the invention does not need the base material 6 to move, avoids using an expensive movable exposure carrying platform and reduces the production cost.

The foregoing detailed description is given by way of example only, to better enable one of ordinary skill in the art to understand the patent, and is not to be construed as limiting the scope of what is encompassed by the patent; any equivalent alterations or modifications made according to the spirit of the disclosure of this patent are intended to be included in the scope of this patent.

Claims

1. The exposure device is characterized by comprising a mask table (1) and a mask (2) positioned on the mask table (1), wherein a plurality of exposure graphs (3) are drawn on the mask (2), exposure light sources (4) are respectively arranged at corresponding positions of the exposure graphs (3) above the mask (2), a fixed carrying platform (5) and a base material (6) positioned on the fixed carrying platform (5) are arranged below the mask table (1), the size of the base material (6) is equivalent to that of the mask (2), a plurality of projection objectives (7) are arranged between the mask (2) and the base material (6), and the positions of the projection objectives (7) correspond to those of the exposure graphs (3) on the mask (2).

2. The exposure apparatus according to claim 1, wherein the patterns on the reticle (2) correspond one-to-one to the exposure light source (4) and the projection objective (7), respectively.

3. An exposure apparatus according to claim 1, wherein the number of the exposure patterns (3) is 2 to 3.

4. The exposure apparatus according to claim 1, wherein the exposure pattern (3) has a square shape with a size of 0.4mm x 0.4 mm.

5. The exposure apparatus according to claim 1, wherein the substrate (6) is a silicon wafer.