JPH0282517A - Pattern formation - Google Patents

Abstract

PURPOSE:To prevent the yield from being lowered owing to conductive foreign matter without reducing the number of removal from a water by changing a distance from the peripheral part of the wafer depending upon the position on the peripheral part of the wafer to selectively expose the peripheral part of the wafer. CONSTITUTION:A peripheral part of a wafer is exposed corresponding to a region without any pattern, the region including a region 16 which is formed by selectively exposing 3mm of the peripheral part of the wafer through a positive type photoresist. At the same time, a region which is a unexposed 13 due to a pawl 11 of a 1:1 reflection projecting exposure device, is exposed by controlling an exposure device 5 using an exposed location adjusting section 6 such that a distance from the wafer peripheral part is larger 0.5mm than the shape of the pawl 11 of the 1:1 reflection projecting exposure device. Thus, there is completely eliminated the region which is the unexposed portion of the negative type photoresist along the wafer peripheral part, and hence any conductive foreign matter an be prevented from occurring upon etching of a passivation film to keep the number of removal of a semiconductor device from the wafer to slight reduction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a pattern forming method. In particular, the present invention relates to a pattern forming method that selectively exposes the periphery of a wafer on which a photoresist is applied over the entire surface of the wafer on which a pattern is to be formed.

[Prior art 1] The conventional technology, as disclosed in Japanese Unexamined Patent Publication No. 79227/1983, is to remove a wafer with a diameter of 3 to 5 mm from the periphery of a wafer coated with photoresist on the entire surface.
Selective exposure was performed by irradiating UV light in a circular shape of ~5 mm.

[Problem to be solved by the invention] However, the conventional technology is a technology for positive type photoresists using hard and brittle resin, and does not uniformly expose the entire periphery of the wafer. Ta. If the photoresist applied to the wafer is not a positive type photoresist but a negative type photoresist, the selective exposure of the wafer's periphery must not be uniform but the distance from the wafer's periphery must be varied depending on the position of the wafer's periphery. In certain cases, appropriate treatment was not possible. As shown in FIG.
00FA), the focal point (FO
In order to align the wafer (CUS), the wafer was pressed against three or four claws 1 on the wafer disk of the wafer exposure device. FIG. 4 shows the positional relationship between the unexposed portion 13 and the wafer 1 due to the three claws. This claw is made of a metal that does not transmit light and is never exposed to light, and in the case of negative type photoresist, this phenomenon occurs.
This means that the negative type photoresist disappears in the areas where this occurs. In this case, if the process is photo-etching of the passivation film, the passivation film on a part 15 of the pattern of the semiconductor device 14 formed on the wafer will be removed by etching as shown in FIG. Then, the insulating film under the conductive wiring pattern of the semiconductor device 14 is also etched, and the conductive wiring pattern is peeled off from the wafer, resulting in generation of conductive foreign matter. If the generated conductive foreign matter adheres to the wafer, it will cause a short circuit between the conductive wiring and the gate electrode, resulting in a defective semiconductor device. In addition, they become protrusions on the wafer, causing unevenness in the thickness of the photoresist in the photolithography process, inhibiting normal pattern formation, causing pattern defects, and lowering yield.

In addition, the length of the unexposed portion 13 due to the claw is 5 to 6 mm from the peripheral edge of the wafer, and if the photoresist is removed by selectively exposing the wafer peripheral part by 5 to 6 mm using conventional technology, In particular, in the case of 4-inch (100 mm) wafers, the area in which semiconductor devices can be formed is 88 mm to 90 m.
m, which greatly reduces the number of semiconductor devices that can be formed on one wafer and is no longer an acceptable value.

The present invention solves these problems in the conventional technology, and its purpose is to provide a technology that prevents a decrease in yield due to conductive foreign matter without reducing the number of semiconductor devices that can be removed from a wafer. .

[Means for Solving the Problems] The pattern forming method of the present invention accomplishes the above-described method by selectively exposing the wafer periphery by changing the distance from the wafer periphery depending on the position of the wafer periphery. Solve problems.

[Embodiment] FIG. 1 is a block diagram of an embodiment of the present invention. FIG. 2 is a wafer plan view of an embodiment of the present invention.

The facet portion 3 of the rotating wafer 1 is detected by the facet detection portion 4, and upon receiving the signal, the control portion 9 moves the exposure portion 5 to a predetermined distance from the peripheral portion depending on the position of the peripheral portion 2 of the wafer 1. UV light was irradiated to the periphery of the wafer while being moved by the position adjustment unit 6 to expose the negative type photoresist attached to the wafer so that it remained even after the phenomenon occurred. As shown in FIG. 2, the exposed area 16 is a pattern-free area formed by selective exposure of the peripheral 3 mm of the wafer of the positive type photoresist by the conventional technique shown by the dotted line in FIG. At the same time, the periphery of the wafer is exposed to light in a corresponding manner, and at the same time, the distance from the wafer periphery is adjusted by adjusting the exposure part 5 to the unexposed part 13 using the claw of the 1:1 reflection projection type exposure device. 0.0 from the shape of the claw of the 1:1 reflection projection exposure device.
Exposure was controlled to increase the size by 5 mm. By doing this, there is no unexposed area of the negative type photoresist at the periphery of the wafer, and as a result, it is possible to completely prevent the generation of the above-mentioned conductive foreign matter during etching of the passivation film. Furthermore, the number of semiconductor devices removed from the wafer could be kept to a slight decrease.

[Effect of the Invention J As described above, according to the present invention, the distance from the wafer periphery is changed depending on the position of the wafer periphery, and the wafer periphery is selectively exposed to light, thereby removing conductive foreign particles. This has the effect of preventing this occurrence, eliminating any drop in yield, and minimizing the decrease in the number of semiconductor devices that can be produced.

The effects of the present invention are clear as described above, and it is possible to not only selectively expose the periphery of the wafer at a uniform distance from the periphery, but also to selectively expose the wafer at a uniform distance from the periphery. This is attempted to be carried out by changing the , and various methods other than those of the embodiments are conceivable. Similar effects can be obtained by methods such as moving the rotation axis while rotating the wafer rather than the exposure section, or having two or more exposure sections and selecting the exposure section to be used depending on a predetermined position. Moreover, the effects of the present invention can be applied not only to semiconductor devices but also to all devices that undergo photoetching.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the present invention. FIG. 2 is a plan view of a wafer according to an embodiment of the present invention. FIG. 3 is a schematic diagram of the relationship between the unexposed area and the wafer due to the claw of the 1:1 reflection projection type exposure apparatus. FIG. 4 is a diagram showing an example of the arrangement of claws in a wafer in a 1:1 reflection projection exposure apparatus. FIG. 5 is a schematic diagram of the periphery of the wafer. 1... Wafer 2... Peripheral part 3... Facet part 5, 7, 8, 9, 11, 12, l3, 14, l5, l6, facet detection part, exposure part, exposure part position adjustment part UV light source Quartz fiber control part claw Unexposed area by wafer chuck claw Defected part of semiconductor device passivation film Exposed area Applicant Seiko Epson Corporation Agent Patent attorney Masaharu Kamiyanagi (and 1 other person) Figure 1 ￥41￥1 No. 2nd class 3rd paper map

Claims (1)

[Claims] (1) In a pattern forming method that selectively exposes the periphery of a wafer on which a photoresist is applied to the entire surface of the wafer on which a pattern is to be formed, the exposure is performed at a distance from the wafer's periphery depending on the position of the wafer's periphery. A pattern forming method characterized in that the pattern formation method is performed by changing the .