JPS62248225A - Positioning device - Google Patents

Abstract

PURPOSE:To enable positioning of a reticle and a wafer to be easily performed with high precision, by arranging a rotatable transparent glass plate, which is parallel and flat plane, on an optical path between the reticle and a projectional optical system, and then rotating the glass plate. CONSTITUTION:An electronic circuit pattern on the surface of a reticle 1 is projected and exposed on a plane of a wafer 4 with a given multiplying power in a projectional optical system 3. After a wafer stage is moved by one-shot in a constant amount, the positioning of the reticle 1 and the wafter 4 is performed to determine the shift between both of them by a measuring means. The amount of the shift is corrected by minute adjustment of rotating the glass plate 2 around axes A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an alignment device used in an exposure device for manufacturing semiconductor devices, and in particular to a reticle on which an electronic circuit pattern is formed and a wafer on which the electronic circuit pattern is projected.・This is a positioning device with a simple configuration that can perform minute alignment with high precision.

(Prior Art) With the development of semiconductor integration technology, recent semiconductor manufacturing equipment is required to have an exposure apparatus with high resolution and high throughput. In these exposure apparatuses, a so-called stepper has recently been widely used, which uses a projection optical system to reduce and project a fine pattern of electronic circuits on a reticle surface onto a wafer surface and print the pattern in steps.

This stepper can easily obtain a relatively high resolution, and because it exposes parts of the surface in one or two parts, it can reduce the influence of distortion on the wafer. It has features such as being less susceptible to the effects of

However, in order to obtain high resolution in a stepper, it is necessary to align the position of the reticle and wafer with high precision.

Among these, so-called TTL aligns the position of the reticle and wafer for each shot via a projection optical system.

The die-pie-die alignment method is currently used in many exposure apparatuses because it allows for highly accurate positioning although the throughput decreases to some extent.

Conventionally, when aligning the reticle and the way, the X million 1 cil-Y direction and the 0 (rotation) direction s! 1t
``For each shot, both or one of the reticle stage and wafer stage is driven. However, with these 75G, the fine adjustment of the reticle and wafer is
Mechanically, it is very difficult to do so. Also, among these methods, one method is to drive the reticle stage, but if the reticle is aligned with a certain reference point, the reference point may be misaligned, resulting in a mistake. Since this method does not depend on the projection magnification of the projection optical system as it does on the reticle side, it is technically very difficult to satisfy this requirement when high-precision and quick driving is required.

Further, there is a drawback that a component error in the O direction occurs due to driving in the X direction and the Y direction.

(Problems to be Solved by the Invention) The present invention provides minute positional alignment between the reticle and the wafer in both directions.
It is an object of the present invention to provide a positioning device suitable for an exposure device for semiconductor manufacturing, which can easily and highly accurately perform reticle stage or wave stage movement in the Y direction with a simple configuration. .

(Means for Solving the Problem) When projecting a pattern on a V-ticle surface at a predetermined magnification onto a V-ticle surface through a projection optical system, 1. By arranging a parallel plane glass plate and adjusting the position of the glass plate, alignment between the reticle and the wafer was achieved.

Other features of the invention are described in the Examples.

(Embodiment) FIG. 1 is a schematic diagram of a part of an optical system according to an embodiment of the present invention.

In the figure, 1 is a reticle on which an electronic circuit pattern is formed, and is uniformly illuminated by an illumination system (not shown). 3
4 is a projection optical system, 4 is a wafer, and 2 is a parallel plane transparent glass plate, which is rotatably mounted in the optical path between the lens 1 and the projection optical system 3. In particular, in this embodiment, the glass plate 2 is arranged along two axes A perpendicular to the optical axis 31 of the projection optical system 3.
, is rotatably attached to the turning sash of B.

In the figure, the case where the angle R is tilted is shown as gold.

In this embodiment, the electronic circuit pattern on the surface of the reticle is viewed at a predetermined magnification using the projection optical system 3, for example.

The image is projected and exposed onto the four surfaces of the wafer at a reduced magnification.

After the wafer stage is moved a certain amount after one shot, the resolution 1 and the wafer 4 are aligned 1tIi, and the deviation t between the two is determined by a measuring means (not shown). Then, the amount of deviation at this time is slightly adjusted and corrected by rotating the glass plate 2 around the axis A and axis B. This allows, for example, one point 11 on the surface of the reticle 1 to be corrected.
The positions of the reticle 1 and the wafer 4 are aligned by moving the reticle 1li from a point 41 indicated by a dotted line to a point 42 indicated by a solid line.

For example, as a glass plate, the thickness is 3 cm and the size is 150 x 150.
When considering the projection magnification of the projection optical system 3 using a lens of m, if the glass plate is tilted by 1', a deviation of 0.06 μm can be obtained on the eight faces of the sea urchin.

Regarding the quality of alignment between the reticle and the wafer in this embodiment, for example, the present applicant previously published Japanese Patent Application Laid-Open No. 55-34490.
This is carried out by the method proposed in Japanese Patent Application Laid-Open No. 53-135653.

That is, alignment marks for position alignment are provided directly above the reticle and the wafer, and the spatial relationship between these alignment marks is scanned with a laser beam, and the scattered light flux generated from the alignment marks is photoelectrically converted.

The alignment apparatus of this embodiment can be particularly well applied to an exposure apparatus for semiconductor manufacturing that uses an excimer laser as a light source.

For example, pulsed emission of excimer laser? If you use this, you can perform exposure without having to keep the wafer stage stationary.
1 on th@fly exposure syst
emK can be applied. That is, by moving the stage metal at a constant speed, aligning the positions of the reticle and wafer during the stage movement between each shot, and rotating the glass plate, it is possible to correct the slight deviation t between the two more easily and quickly. I can do it.

In the faceplate embodiment, if one glass plate is insufficient for the amount of deviation, two or more glass plates may be used.In addition, in this embodiment, a glass plate is placed in the optical path between the projection optical system and the wafer. It may be provided.

(Effects of the Invention) According to the present invention, a rotatable parallel flat transparent glass plate is arranged in the optical path between the reticle and the projection optical system, and the reticle and wafer are separated by fully rotating the glass plate. Easy and highly accurate! ! An alignment device act capable of alignment can be achieved.

In particular, this rIL assembly is suitable for semiconductor manufacturing, where minute positioning of the reticle and wafer can be done quickly and with high precision by simply rotating the glass plate without moving the gold stage. fL can be achieved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a portion of an optical system according to an embodiment of the present invention. In the figure, 1 indicates a reticle S2 is a glass plate, 3 indicates a projection optical system, and 4
Fi wafer, 31 optical axes.

Claims (1)

[Claims] When projecting a pattern on a reticle surface onto a wafer surface at a predetermined magnification via a photographing optical system, a transparent parallel plane glass plate is placed in the optical path between the reticle and the projection optical system, and the glass plate An alignment apparatus characterized in that the reticle and the wafer are aligned by adjusting the arrangement position of the reticle and the wafer.