JPH0458169B2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field of the invention The present invention relates to a pattern exposure apparatus.

(b) Technical background The present invention is an industrial camera (so-called ITV camera).
This paper presents an automatic positioning method for an exposure apparatus that uses a camera to read the coordinates of a substrate position mark displayed on the camera and aligns an exposure mask substrate and a pattern-formed substrate to be exposed with a predetermined accuracy in a short time. It is.

(c) Problems with the Prior Art Conventionally, for example, an exposed pattern-formed substrate to be processed and an exposed resist mask substrate must be precisely aligned before pattern exposure.

FIG. 1 is a perspective view illustrating a method of positioning a pattern-formed substrate on the exposed side on an apparatus base using a three-point abutting method.

In the figure, 1 is the base of the exposure apparatus, 2 is the semi-transparent (milky white) ceramic substrate on the exposed side that forms the circuit pattern that is carried into the base, and 3 is the X coordinate of the exposed substrate 2, for example. 4 and 5 are pillars embedded in the base 1 for side positioning, 4 and 5 are pillars for Y-coordinate side positioning with respect to the substrate 2, and 6 is a transparent mask substrate (glass with a thickness of 1 to 1.6 mm) on which a resist pattern for exposure is formed. board)
It is. The peripheral edge of the mask substrate 6 is mechanically fixed to a mask substrate mounting section of an exposure apparatus. Arrows P1 and P2 in the figure indicate positioning abutments against the substrate 2 placed on the base.

After the substrate 2 has been positioned at the abutments P1 and P2, the base 1 is lifted in the direction of the thick arrow to bring it into close contact with the mask substrate 6, and then the pattern is exposed and printed by ultraviolet light irradiation from above the substrate 6. .

When the exposure and printing is completed, the base is lowered, and the exposed pattern-forming substrate is sent to an etching process for pattern generation by a belt mechanism or the like, and the next substrate 2 is carried onto the base 1.

However, in the conventional method of abutting the substrate before irradiation with ultraviolet light, the mask substrate 6 fixed to the apparatus side is
and the exposed pattern forming substrate 2 are positioned visually, so the accuracy is low;
Further, there is a problem in that positioning takes time.

(d) Purpose of the invention The purpose of the present invention is to solve the above-mentioned problems.

The present invention automatically performs positioning between the substrates before the exposure in such a pattern exposure apparatus by using alignment marks marked on each substrate and displaying these on an industrial camera. That's true.

(e) Structure of the Invention The above object is such that an exposure mask substrate and a patterned substrate to be exposed, which has been roughly positioned with respect to the exposure mask substrate by a three-point abutment jig, are placed in a blank space.
A plurality of alignment marks are provided on each of the exposure mask substrate and the patterned substrate to be exposed. Pattern exposure characterized by comprising a plurality of cameras integrally having a plurality of cameras, and an insertable and removable optical path difference compensating plate for compensating for the camera optical path difference in the space d between the overlapping substrates between the objective lens and the exposure mask substrate. This is achieved by the device.

(f) Embodiments of the Invention Hereinafter, embodiments of positioning between substrates using a plurality of cameras of the present invention will be described with reference to the drawings. FIG. 2 is a perspective view of an embodiment of the pattern exposure apparatus, and FIG. 3 is a diagram illustrating an outline of a method for aligning substrates using a plurality of cameras in FIG. 2.

The configuration of the main parts of the exposure apparatus of the present invention will be explained in detail from the perspective view of FIG.

In the figure, both 10 and 11 are cameras, and below them there is an objective lens formed integrally with the camera, and above is the field of view of the camera constituting the position detection section. 12 is an illumination lamp attached to the objective lens 18; 13 is a lamp that illuminates the back surface of the pattern-forming substrate 2 to be exposed; and 14 is the camera-side illumination lamp 1.
The mask substrate 6 illuminated by 2 and the empty 〓d
Each position mark 15 of the pattern-formed substrate 2 to be exposed (substrate to be exposed 2) located below through the
15', a glass plate serving as an optical path difference compensating plate for the camera 10 or 11 for focusing;
are the position marks patterned in advance on the corners of each substrate. The position mark 15 may be a cross shape as shown in the figure, or a square mark with a black gradation that can be easily read within the field of view of the camera.

The glass plate 14 located at the position shown by the solid line in the figure is used to detect the alignment mark 15' on the side of the mask substrate 6 and the exposed substrate 2 where there is a gap d in the figure. On the other hand,
When detecting the alignment mark 15 on the mask substrate 6, the mask substrate 6 is slid to the dotted line position.

The space d between the substrates is a gap for protecting the mask from scratches by avoiding sliding of the substrates when carrying in and out of the exposed substrate with respect to the mask substrate 6 fixed on the exposure apparatus side.

However, the illustrated exposed substrate 2 placed on the base carried in
is the conventional three-point abutment method (see Figure 1).
Rough positioning is performed.

A lamp 13 that illuminates from the back surface of the exposed substrate.
Using the translucency of the ceramic substrate 2, the alignment mark 15' is irradiated to illuminate the silhouette. Furthermore, the lamp 13 is also effective when the position mark within the field of view of the camera by the vertical illumination lamp 12 lacks sharpness due to a decrease in contrast.

When the glass plate 14 attached to the camera side sequentially reads the mark 15' on the exposed substrate side and the mark 15 on the mask substrate side using the optical refractive index of the glass, the space d of the marks 15, 15' within the field of view of the camera is Clear position mark detection is achieved by simply inserting and removing the glass and compensating for camera optical path differences to eliminate focus blur.

Incidentally, the mask substrate thickness is 1.6 mm, and the empty space is d = 0.95 mm.
In this case, the focusing glass plate 14 has a thickness of about 3.2 mm.

However, once the mutual positioning of multiple cameras between the boards is completed, which will be explained below, the space d is closed (the base 1 is raised).
Exposure for pattern transfer is performed.

Note that since the focusing glass plate 14 is provided between the objective lens 18 and the exposure mask substrate 6 without any parts installed around it, it is easy to insert and remove it, and the camera that is integrally equipped with the objective lens 18 also becomes larger. Never.

Next, an overview of the substrate positioning method using the cameras 10 and 11 before the pattern exposure will be explained with reference to FIG.

In FIG. 3, 16 is the field of view of the mutual board positioning marks 15, 15' image taken from the camera 10 side, and 17 is the field of view of the mutual board positioning marks 15, 15' image taken from the camera 11 side. It is. The orthogonal solid lines are the coordinate axes X, Y of the mask substrate fixed to the exposure apparatus, and the orthogonal dotted lines are the coordinate axes X', Y' of the substrate to be exposed carried into the base 1.

The figure shows the detected coordinate origin deviation ΔX, deviation ΔY, and inclination Δθ of the substrate, which has been roughly positioned using the three-point abutting method (see FIG. 1).

The camera detection positional deviation △X is determined by reading the position mark coordinate values of x ₁ and x ₁ ′ and x ₂ and x ₂ ′ in the left and right fields of view 16 and 17, and automatically calculates △X from this. . The positional deviation ΔY between the substrates is also calculated from the two position mark reading data of y ₁ and y ₁ ' and y ₂ and y ₂ '.

The exposure apparatus of the present invention has a positional deviation △X between substrates,
, △Y, and inclination △θ are detected by optical pattern recognition means, the detected data is converted from analog to digital, and this is input to the servo motor on the base 1 side to automatically connect the mutual boards. The positioning is now done.

However, when installing multiple cameras, there is no mechanical error that occurs when a single camera moves to read marks attached to left and right fixed positions, that is, when the camera moves horizontally. time) to improve together.

(g) Effects of the Invention According to the pattern exposure apparatus of the present invention described in detail above, which performs optical mark detection and mutual positioning of substrates using detection marks, positioning can be performed with high accuracy.
Executed at 20μm or less. Further, there is an advantage that the working time for positional alignment between substrates is significantly shortened. From this point of view, if this is applied to the pattern exposure process of IC manufacturing, it is expected to have great industrial effects, such as significantly improving productivity.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the positioning of the patterned substrate to be exposed using the three-point abutting method;
This figure is a perspective view showing a positioning embodiment of the pattern exposure apparatus of the present invention, and FIG. 3 is a diagram illustrating an outline of the method of positioning mutual substrates shown in FIG. 2. In the figure, 1 is the base of the device, 2 is a pattern-formed substrate to be exposed, 6 is a mask substrate, 10 and 11 are cameras,
12 is a lamp, 13 is an illumination lamp on the back side of the substrate 2, 14 is a focusing glass plate, 15 is a position mark, 16 and 17 are camera field of view for photographing the position mark, and 18 is an objective lens.

Claims (1)

[Claims] 1. The exposure mask substrate 6 and the pattern-formed substrate 2 to be exposed, which has been roughly positioned with respect to the exposure mask substrate 6 by a three-point abutment jig, are overlapped with a gap d in between, and the exposure mask substrate 6 In addition, a plurality of alignment marks are provided on each of the pattern-formed substrates 2 to be exposed, and a plurality of cameras 11 are provided that image the marks in accordance with the positions of the alignment marks, and that have integrally provided objective lenses below. A pattern exposure apparatus characterized in that it further comprises an insertable and removable optical path difference compensating plate 14 for compensating for a camera optical path difference in a space d between the overlapping substrates between the objective lens and the exposure mask substrate 6.