JPS6053464B2 - Wafer alignment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wafer alignment apparatus for aligning a mask having a predetermined pattern to a semiconductor wafer.

In this type of wafer alignment device, a semiconductor wafer having a photoresist layer on the surface is placed on a wafer mounting table, and
Further, a mask having a predetermined pattern is placed on the wafer, and the two are brought into close contact with each other, and the pattern of the mask is printed onto the photoresist layer on the wafer.

At this time, the air existing between the wafer and the mask becomes partially sealed, and it takes time to maintain the two in a predetermined position and bring them into contact. When separating the mask from the wafer, it takes time to separate the mask because it is difficult for air to enter between the two. This difficulty in separation is especially true when using chrome masks;
Moreover, this is remarkable when using a vacuum contact method. SUMMARY OF THE INVENTION An object of the present invention is to provide a wafer alignment device that facilitates close contact between a wafer placed on a wafer mounting table and a mask.

The gist of the present invention to achieve this object is to provide a substantially flat surface on which a wafer is placed, a gas supply port exposed at the center of this surface, and a peripheral portion of the surface surrounding the gas supply port. a wafer mounting table having a plurality of gas suction ports exposed to the wafer, a mechanism for holding a mask facing the wafer, a semiconductor wafer placed on the surface of the mounting table, and gas supplied from the gas supply port. and a mechanism for raising the central portion of the semiconductor wafer and adsorbing the peripheral portion of the semiconductor wafer to the mounting table by sucking gas from the gas suction port; The semiconductor wafer is brought into contact with the mask, and then the gas supply and gas suction are stopped to remove the swelling at the center of the semiconductor wafer, and the semiconductor wafer and mask are gradually brought into close contact from the center to the periphery of the semiconductor wafer. A semiconductor wafer aligning apparatus is characterized in that it has a mechanism for aligning a semiconductor wafer.

The center portion of the wafer placed on the wafer mounting table is raised by the air blowing action from the air outlet, and the peripheral portion is raised above the wafer mounting table by the air suction action from the air suction port. is adsorbed to. This makes it possible to cause the wafer warpage, so that it is extremely easy to bring the wafer and the mask into close contact with each other and to separate them (separation). Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

In FIGS. 1 and 2, reference numeral 11 denotes a wafer mounting table constructed according to the present invention.

The wafer mounting table 11 is provided with a plurality of air blowing ports 12 at appropriate intervals in the center thereof, and air suction ports 13 are provided in the periphery thereof distributed at approximately equal intervals in the circumferential direction. The air outlets 12 communicate with each other through an annular communication hole 14, and are connected to a compressed air source through a communication hole 16 that opens on the side surface of the mounting table 11. Further, the air suction ports 13 are communicated with each other through an annular communication hole 17, and are connected to a vacuum device through a communication hole 18 opened in the side surface of the mounting table 11 in the same manner as described above. Wafer mounting table 1
A wafer 21 having a photoresist layer is placed on the surface of the wafer 1, and a mask 22 is placed on top of the wafer 21.

The wafer 21 may be, for example, a semiconductor wafer, and the mask 22 may be, for example, a chrome mask. The wafer 21 and the mask 22 can be brought onto the wafer mounting table 11 using a vacuum chuck or vacuum tweezers, and can be carried there. Now, after the alignment of the wafer and the mask is completed, when the wafer and the mask are brought into close contact, air is blown out from the air outlet 12 and air is sucked in from the air suction port 13 to center the wafer 21 as shown in the figure. The portion is raised upward, and the peripheral portion is suctioned onto the wafer mounting table 11.

In this way, when the wafer 21 is deflected and the mask 22 is placed on the wafer 21, the two will come into contact only at the central raised part of the wafer 21, and there will be no air contact between the two. Therefore, the mask 22 can be easily positioned at a predetermined position on the wafer 21. Thereafter, if air blowing and air suction are stopped to release the bulging deformation of the wafer 21, the wafer 21 and the mask 22 can easily be brought into close contact from the center to the periphery. After the pattern of the mask 22 is printed and exposed on the wafer 21, air is blown out from the air outlet 12 and air is sucked in from the air suction port 13 again to warp the wafer 21 as shown in the figure and perform mask separation. .

Also in this case, since air can freely enter between the wafer 21 and the mask 22 from the peripheral direction, the mask 22 can be easily separated from the wafer 21. As described above, according to the present invention, it is possible to easily bring the wafer placed on the wafer table into close contact with the mask and to separate them.

Moreover, the present invention has practical effects in that it is possible to obtain a wafer aligning device that has a simple structure, is highly reliable, and can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the wafer aligning apparatus according to the present invention, and FIG. 2 is a plan view taken from the line ■-■'' in FIG. 1. Explanation of symbols, 11... ...Wafer mounting table, 12...
Air outlet, 13... Air intake port, 14,
16, 17, 18...Communication hole, 21...Wafer, 22111 mask.

Claims (1)

[Claims] 1. A mask having a predetermined pattern and a photosensitive film formed on the first main surface of the wafer.
A pattern corresponding to a predetermined pattern of the mask is formed by irradiating light onto the first main surface of the wafer through the mask while in contact with the first main surface of the wafer over substantially the entire main surface of the wafer. A wafer aligning device that performs exposure for transferring onto the photosensitive film on the main surface of the mask, the device comprising: (a) facing the main surface of the mask and in contact with the second main surface of the wafer; (b) a wafer mounting table having a substantially flat suction surface capable of holding the wafer in a substantially flat shape by vacuum suction; and (b) a gap provided approximately at the center of the wafer mounting table for supplying or vacuum suction. and (c) a relative position of the wafer, which is outside the first gas supply and suction hole of the wafer mounting table and has the center of the wafer mounting table as the center of a circle. a plurality of second gas supply and suction holes arranged on or near a circumference corresponding to a peripheral portion of the wafer; After aligning the pattern with the main surface of the mask and the first main surface of the wafer close to each other, the gas supply and suction from the first and second gas supply and suction holes on the wafer mounting table are turned on. By controlling the central part of the main surface of the wafer to protrude from the main surface of the mask, the wafer is brought into close contact with the wafer from the center to the peripheral part in order, and after completion of exposure, the wafer mounting table is A wafer aligning apparatus characterized in that the wafer is sequentially peeled from the periphery of the wafer by controlling the gas supply and suction of the first and second gas supply and suction holes on the top.