JPH03242922A - Exposing apparatus of peripheral part of plate-shaped body and exposing method of periphery of wafer - Google Patents

Abstract

PURPOSE:To make it possible to expose the peripheral part of a plate-shaped body to be processed in an arbitrary shape by providing an optical fiber for irradiation and by disposing an emission end thereof so that it can move on the periphery of the plate-shaped body. CONSTITUTION:An apparatus has an optical fiber 9 of which an incidence end 9a is disposed at a position of receiving a light from a light source and of which an emission end 9b is so provided as to face the surface of the peripheral part of a plate-shaped body 1. A moving mechanism 10 which moves the emission end 9b of the optical fiber 9 within a plane being parallel to the surface of the plate-shaped body 1 and at least in two directions being at a right angle to each other, a control mechanism 4 controlling the moving mechanism 10 and a rotating mechanism 3 rotating the plate-shaped body 1, are equipped. In other words, the emission end 9b of the optical fiber 9 applying the light can be moved to an arbitrary position on the periphery of the plate-shaped body 1. According to this constitution, peripheral exposure can be executed irrespective of the shape of the plate-shaped body and the shape of an unnecessary resist.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides an apparatus for exposing the periphery of a plate-shaped object for removing unnecessary resist on the periphery of a wafer, which causes dust in the semiconductor manufacturing process, in a developing process. and a wafer peripheral exposure method.

[Prior Art] When manufacturing semiconductor devices such as ICs and LSIs, in order to form fine patterns, a resist is applied to the surface of a silicon wafer, etc., and then exposed and developed to form a resist pattern. Using the pattern as a mask, processes such as ion implantation, etching, and lift-off are performed. Typically, a resist film is applied over the entire surface of the wafer using a spin code method. During this coating process, the wafer is rotated to make the film thickness uniform.

The wafer on which the resist film has been applied is carried out while gripping the periphery of the wafer. At this time, the resist on the gripping portion may peel off. This peeling is also caused by rubbing against the walls of a container such as a wafer cassette.

If such an accident occurs, it becomes impossible to form a correct pattern, resulting in a decrease in yield.

The reduction in yield caused by unnecessary resist or dust on the periphery of the wafer has become a serious problem, especially now that integrated circuits are becoming more sophisticated and smaller.

Therefore, recently, in order to remove unnecessary resist around the wafer in a development process in addition to the exposure process for pattern formation, a peripheral exposure method has been used to perform separate exposure. This peripheral exposure method for sea urchins involves rotating a wafer coated with resist and irradiating the periphery of the sea urchin with light guided by a light guide fiber to circularly expose the sea urchin.

Note that the technology related to peripheral exposure is disclosed in, for example, Japanese Patent Application No. 1983-
It is described in No. 224531 and Japanese Patent Application No. 63-277455.

[Problems to be Solved by the Invention] However, the shape of the portion where the resist that needs to be removed in the development step is formed is not uniform.

For example, the shape and position of a portion that will become a holding portion in a later step varies depending on the wafer and the type of holding mechanism. In addition, the wafer is exposed to light in the shape of a substrate using a stepper-type reduction projection exposure device (hereinafter referred to as a stepper), but the shape of the part where the pattern for 1 chip cannot be drawn correctly depends on the size of 1 chip, etc. It varies depending on the wafer usage design, etc.

That is, as shown in FIG. 4, even though the unnecessary resist portion IA of the wafer l is step-like, the conventional exposure apparatus exposes the periphery of the wafer to a constant width in an annular manner. It is not possible to deal with stepped shapes such as this.

If you try to do this forcibly, you will have no choice but to perform a wide circumferential exposure from the edge of the wafer, which will result in exposing the necessary resist portions.

An object of the present invention is to provide a peripheral part exposure apparatus for a plate-shaped object and a wafer peripheral exposure method that can expose the peripheral part of a plate-shaped object to be processed into an arbitrary shape.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a light source, an input end is arranged at a position to receive light from the light source, and an output end is arranged on a peripheral surface of a plate-like object. Optical fibers provided facing each other, a moving mechanism that moves the output ends of the optical fibers in at least two directions perpendicular to each other within a plane parallel to the surface of the plate-like object, and a control that controls the moving mechanism. mechanism and
The structure includes a rotation mechanism that rotates the plate-like object.

Further, when the target of peripheral exposure is a wafer, the output end of the optical fiber that guides the light from the light source is placed facing the wafer peripheral area, and the output end is connected to two mutually orthogonal lines in a plane parallel to the wafer. The optimal method is to expose the periphery of the wafer in a stepwise manner while moving the wafer in the direction 1', and then rotate the wafer 90 degrees, each of which is repeated.

[Operation] According to the above-described means, the output end of the optical fiber that irradiates light can be moved to any position on the periphery of the plate-shaped object. Therefore, peripheral exposure can be performed regardless of the shape of the plate-like object and the shape of the unnecessary resist.

Further, by rotating the plate-like object by the rotation mechanism, the moving distance of the moving mechanism can be shortened, and the configuration of the moving mechanism can be simplified and the burden of control can be reduced.

Furthermore, when targeting a wafer, exposure is performed while moving the output end of the optical fiber to approximately 1/4 of the periphery of the circular wafer, and after this exposure is completed, the wafer is rotated 90 degrees and the next 1/4 of the wafer is exposed. By repeating the operation of exposing 4 four times, the peripheral exposure of the entire circumference is completed.

As a result, even if the unnecessary part of the resist is stepped,
It becomes possible to perform peripheral exposure without exposing the necessary resist.

[Embodiment] FIG. 1 is a perspective view showing an embodiment of the present invention. Here, a wafer is used as an example of a plate-like object.

A wafer 1 to be processed is vacuum-adsorbed onto a rotary stage 2, and this rotary stage 2 is rotationally driven by a drive mechanism 3 equipped with a motor. Note that the drive mechanism 3 is controlled by a control device 4.

The exposure section is composed of an optical system, an optical fiber, and a moving mechanism. The optical system includes a lamp 5 as a light source, and an elliptical condenser mirror 6 that condenses and reflects the light from the lamp 5. A reflecting mirror 7 that reflects the light from this elliptical condensing mirror 6 in the horizontal direction. and a shutter 8 disposed so as to be able to enter and exit the output optical path of the reflecting mirror 7.
Consists of.

An input end 9a of an irradiation optical fiber 9 is disposed at the condensing position of the reflecting mirror 7, and an output end 9b thereof is movably disposed around the wafer l. Further, the irradiation light from the irradiation optical fiber 9 is projected onto the irradiation surface in a rectangular manner. The arm 11 has an edge detection photosensor (not shown) that is movably provided together with the output end 9a, and the position of the output end 9b is determined according to a signal from the edge detection photosensor. Control.

The output end 9b of the irradiation optical fiber 9 is held by the arm 11 of the moving mechanism 10. The arm 11 is the moving mechanism 1
It is configured to be freely movable in the X-Y directions by a plurality of motors provided at the 0.

Next, the operation of the embodiment having the above configuration will be explained according to FIGS. 1 and 2.

First, in the case where the plate-shaped object is a disk-shaped wafer l as shown in FIGS. 1 and 2, a method of peripheral exposure will be explained.

In the control device 4, the width and length of the resist-unnecessary portion of the object to be processed is stored in advance as data. Then, according to the data read from this memory, the control device 4 controls the movement of the arm 11 of the movement mechanism IO.

(1) First, the wafer l is placed on the rotation stage 2 and vacuum-adsorbed. Next, while starting edge detection by the photosensor described above, the output end 9b is moved in the Y direction in FIG. position to expose the periphery of the image. This position is a in Figure 2.
There is a position where a point is exposed, and in this state, the shutter 8 is opened (taken out from the optical path). Thereby, the light from the lamp 5 reaches the output end 9b via the irradiation optical fiber 9, and irradiates the wafer l in a rectangular shape from point a to the edge.

(2) Next, the light is emitted from the output end 9b toward position b, and then the light is moved in the X direction.

(2) Next, it is moved in the Y direction from position b to position C without emitting light from the output end 9b.

(2) Next, move from the C position to the d position in the X direction without emitting light from the output end 9b.

■Here, rotate the rotation stage 2 by 90" and
turn it sideways.

(2) Next, the operations from (1) to (4) above are repeated, and when the two exposures are completed, the rotary stage 2 is rotated 90 degrees.

■Furthermore, by repeating the steps from ■ to ■ twice,
Exposure of the entire periphery of the wafer l is completed.

Note that the shutter 8 is rotated 90' in order to prevent the pattern forming section 100 from being exposed to light.
The shutter 8 is closed.

FIG. 3 shows a case where the plate-like object is a rectangular object 12 such as a printed circuit board or a liquid crystal board. The processing in this case is as follows.

■Similar to the case of wafer 1, a square v is placed on the rotation stage 2.
The lJ12 is mounted and vacuum-adsorbed, the edge is detected by a photosensor, and the output end is placed at a predetermined position.

(2) Then, the shutter is opened and the moving mechanism 10 is driven to move the output end 9b along the side e, exposing the peripheral edge of the - side. In this case, the emission end 9b may be moved from the X direction or from the -X direction.

(2) Next, the rotary stage 2 is rotated 90' to move the output end 9b to the corner of the side f, and then move the output end 9b toward the other end 0 to expose the side f.

(2) Next, the rotary stage 2 is rotated 90 degrees, and the same process as (2) is repeated to expose the side g.

0 Next, by executing the same process as in (2) above, the surrounding peripheral portions are exposed, and the exposure of the peripheral portions on the four sides is completed.

As described above, by adding the operation of rotating the rotary stage 2 in 90'' increments during exposure, the moving distance of the arm 11 in the X direction and the Y direction can be reduced, and the structure of the moving mechanism IO can be simplified. can do.

[Effects of the Invention] Since the present invention is configured as described above, it produces the following effects.

In the apparatus for exposing the periphery of a plate-shaped object according to claim (1), the periphery exposure can be performed regardless of the shape of the plate-shaped object and the unnecessary resist, and the movement operation of the moving mechanism can be reduced. However, it is possible to reduce the peripheral exposure processing time, simplify the configuration of the moving mechanism, and reduce the burden on the control 1.

In the wafer peripheral exposure method according to claim (2),
Even if the unnecessary portion of the resist is stepped, peripheral exposure can be performed without exposing the necessary resist.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a plan view when the plate-like object is a wafer, Fig. 3 is a plan view when the plate-like object is a rectangular object, and Fig. 4 is a plan view when the plate-like object is a wafer. FIG. 3 is a plan view of a plate-like object in which unnecessary portions are formed in a step-like manner. In the figure, 1: Wafer 2: Rotation stage 3: Drive mechanism 4: Control device 5: Lamp 9: Optical fiber for irradiation 9a: Input end 9b: Output end 10: Movement mechanism 2 11: Arm

Claims (2)

[Claims] (1) a light source; an optical fiber whose input end is disposed at a position to receive light from the light source and whose output end faces the peripheral surface of the plate-like object; A moving mechanism that moves the plate-like object in at least two directions perpendicular to each other within a plane parallel to the surface of the plate-like object, a control mechanism that controls the moving mechanism, and a rotation mechanism that rotates the plate-like object. This is an exposure device for the periphery of a plate-shaped object. (2) The output ends of the optical fibers that guide light from the light source are arranged to face the wafer periphery, and the output ends are arranged perpendicularly to each other in a plane parallel to the wafer.
A method for exposing the periphery of a plate-shaped object, characterized in that the periphery of the wafer is exposed in a stepwise manner while moving in one direction, and then the operation of rotating the wafer by 90 degrees is repeated in each case to expose the entire periphery of the wafer. .