JPH07230948A - Mask aligner - Google Patents

Abstract

PURPOSE:To cope with the alignment from a microscopic interval to a wide interval. CONSTITUTION:Two mirrors 6, having a total reflection function, are provided on the inclined surfaces of a pair of parallelograms formed in V-shape by closely adhering their inner sides on the lower surface with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask aligner effective for mask alignment when manufacturing integrated circuits, sensors and the like, and more particularly to a mask aligner capable of accommodating a minute gap (about 5 mm). .

[0002]

2. Description of the Related Art Generally, when manufacturing integrated circuits, sensors, etc., the mask position in the next step is relatively aligned with the pattern formed on a silicon substrate, and the mask pattern is applied to a resist by ultraviolet light. There is a step of baking (so-called mask alignment / exposure). In this case, the mask and the substrate are separated in parallel by several tens of μm, the X-axis, the Y-axis and the rotation are manually aligned while viewing the enlarged image with a microscope, or a registration mark (target) is attached in advance.
The position of the mark is optically detected (for example, the fact that the reflectance is different is used) to automatically adjust the position, and then the mask is brought into close contact with the substrate by an appropriate means to perform exposure.

In such a process, a single-lens two-field microscope or a double-lens two-field microscope is usually used. In the former case, however, the magnification and the field of view are determined by the objective lens, so that a wide interval (30 mm or more) is used. ) Alignment is not available. In addition, it is difficult to replace the relay lens, and the optical system is complicated and therefore expensive. On the other hand, the latter can deal with alignment at wide intervals and can easily set magnification, but has a problem that it cannot deal with alignment at minute intervals (about 5 mm) because two objective lenses collide with each other.

The present invention solves the above-mentioned problems of the conventional ones, and can sufficiently deal with the alignment of a minute interval and the alignment of a wide interval, and the mask aligner is simple and inexpensive. It is intended to provide.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a pair of prisms provided close to or in close contact with each other and having an emission interval wider than an incidence interval, and this prism. And a pair of objective lenses each of which is provided above each of which is movable in the horizontal direction, and an object to be aligned located in the visual field of each prism is guided to each objective lens through each prism. It is a thing.

[0006]

According to the present invention, by adopting the above-mentioned means, the object to be aligned located in the visual field of each prism is guided to each objective lens through each prism. In this case, since the respective prisms are provided close to or in close contact with each other, it is possible to sufficiently deal with the alignment of minute intervals.

[0007]

Embodiments of the present invention shown in the drawings will be described below. 1 to 3 show an embodiment of a mask aligner according to the present invention, FIG. 1 is a schematic view showing the whole, FIG. 2 is a partially enlarged view of what is shown in FIG. 1, and FIG. It is explanatory drawing which showed the relationship between the objective lens of what is shown, and a prism part.

That is, this mask aligner has a base 1
Microscope unit 3 attached to the base frame 2 standing upright
And the substrate 12 and the mask 12 which are provided on the base 1 so as to face the microscope unit 3 and are to be aligned on the upper surface side, and the mounted substrate 12 and mask 12 are It is provided with a sample table 11 capable of adjusting the rotational position in the XY directions.

The microscope section 3 is provided above the prism section 4 and the prism section 4 for capturing the images of the substrate 12 and the mask 12 placed on the sample table 11, and is arranged to face the prism section 4. It has a pair of objective lenses 8 and 8 for guiding the emitted image to a pair of eyepiece lenses 10 and 10.

The prism portion 4 has a V-shaped groove 7a whose upper and lower surfaces are open at the center thereof, and an upper end portion of which is substantially U fixed to the base frame 2 via a bolt or the like (not shown). A prism-shaped prism holder 7 and a groove 7 in the groove 7a.
The pair of parallelogram prisms 5 and 5 are mounted so as to match the shape of a. In this case, the prism holder 7 is arranged so that the upper and lower surfaces of each parallelogram prism 5 are oriented in the horizontal direction. The mounting position of the above with respect to the base frame 2 is adjusted.

On each inclined surface of each parallelogram prism 5, mirrors 6 having a total reflection function are integrally provided by vapor deposition or the like with the reflecting surface inside (prism side), and the inside inclination The lower ends of the mirrors 6, 6 located on the surface are in close contact with each other.

The pair of objective lenses 8 and 8 are attached to the base frame 2 above the prism holder 7, and a pair of movable members 9 are horizontally movable within a predetermined range. , 9 and are movable together with the movable members 9, 9 in a horizontal direction within a predetermined range.

In this case, one objective lens 8 faces the upper surface of one parallelogram prism 5, the other objective lens 8 faces the upper surface of the other parallelogram prism 5, and each objective lens The respective objective lenses 8 and 8 are attached to the respective movable members 9 and 9 so that the optical axis of 8 is oriented in the vertical direction, and one objective lens 8 is provided on the upper surface of the one parallelogram prism 5. The moving range of each movable member 9, 9 in the horizontal direction is adjusted so that the entire range can be captured and the other objective lens 8 can capture the entire range of the upper surface of the other parallelogram prism 5.

Then, within the range included on the lower surface of each of the pair of parallelogram prisms 5 and 5 mounted on the prism holder 7 as described above, that is, within the range of O to X or the range of O to Y in FIG. The inside is the field of view of each parallelogram prism 5, and the images of the substrate 12 and the mask 12 which are the objects to be aligned 12 located in this field of view are captured by each parallelogram prism 5, and each parallelogram is shown. It is reflected by the mirrors 6 of each inclined surface of the prism 5, is emitted from the upper surface side of each parallelogram prism 5, is guided to each objective lens 8, and is guided from each objective lens 8 to each eyepiece lens 10. is there.

That is, the substrate 1 located near the point O in the figure
2 or the mask 12, or the substrate 12 or the mask 12 located near the X point or the Y point, they are surely caught on the lower surface side of each parallelogram prism 5, and each parallelogram prism The light is reflected by the mirrors 6, 6 on each inclined surface of the prism 5 and emitted from the upper surface side of each parallelogram prism 5. Since each objective lens 8 located above each parallelogram prism 5 is movable within a range where the entire upper surface of each parallelogram prism 5 can be captured, each parallelogram prism 5 can be moved. Each image emitted from the upper surface side of the prism 5 is surely incident on each objective lens 8 and guided to each eyepiece lens 10.

Therefore, by setting the area and the inclination angle of the upper and lower surfaces of each parallelogram prism 5 to appropriate values, the mask 12 is placed at a predetermined position on the substrate 12 when manufacturing integrated circuits, sensors and the like. In the so-called mask aligning process for positioning, it is possible to sufficiently cope with the alignment of a minute interval (about 5 mm) and the alignment of a wide interval (30 mm or more), which were difficult in the past, and it is possible to improve versatility. become.

Further, the mask aligner according to the present embodiment configured as described above is provided with a pair of parallelogram prisms 5 and 5 provided with mirrors 6 and 6 having a total reflection function on each inclined surface.
And a pair of objective lenses 8 movably provided in the horizontal direction so as to face the pair of parallelogram prisms 5 and 5.
Since it has a simple structure composed of eight, it does not require any expensive optical system to form an image and an inexpensive one can be provided.

Although a pair of parallelogram prisms 5 and 5 are provided in the prism portion 4 in the above description, the same action and effect can be obtained by providing a pair of triangular prisms. In this case, the inclined surface of the triangular prism may be configured to have a total reflection function. Further, even if the parallelogram prisms 5 and 5 are not used and only the mirrors 6 and 6 are mounted on the prism holder 7 at a predetermined angle, the same operation and effect can be obtained.
Further, the incident surface of each of the parallelogram prisms 5 and 5 may be curved so as to have a lens function to be used as a space-saving close-up / down lens.

[0019]

According to the present invention, the object to be aligned located in the visual field of each prism is guided to each objective lens through each prism. Since the respective prisms are provided close to or in close contact with each other, the object to be aligned can be reliably caught within the range of the lower surface of each prism. In addition, the interval between the exits formed by each prism is wider than the interval between the entrances, and each objective lens provided above each prism is movable in the horizontal direction. The image emitted from is surely guided to each objective lens. Therefore, it is possible to sufficiently deal with the alignment of minute intervals and the alignment of wide intervals. In addition, since it has a simple structure in which a pair of objective lenses is movably provided above a pair of prisms, and an expensive optical system or the like is not required for forming an image at all, an inexpensive one is used. It has an excellent effect that it can be provided.

[Brief description of drawings]

FIG. 1 is a schematic view showing an entire embodiment of a mask aligner according to the present invention.

FIG. 2 is a partially enlarged view of what is shown in FIG.

FIG. 3 is an explanatory diagram showing the relationship between the objective lens and the prism portion shown in FIG.

[Explanation of symbols]

 1 ... Base 2 ... Base frame 3 ... Microscope part 4 ... Prism part 5 ... Parallelogram prism 6 ... Mirror 7 ... Prism holder 7a ... Groove 8 ... Objective lens 9 ... Movable member 10 ... Eyepiece 11 ... Sample stand 12 ... Alignment object

Claims (1)

[Claims] 1. A pair of prisms (5) (5), which are provided close to or in close contact with each other and have an emission interval wider than an incidence interval, and the prisms (5) (5).
A pair of objective lenses (8) and (8) each of which is provided above each of which is movable in the horizontal direction, and is positioned within the visual field of each prism (5) (5). A mask aligner characterized in that 12) is guided to each objective lens (8) (8) via each prism (5) (5).