JP2911297B2 - X-ray exposure method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to an X-ray exposure method for transferring a pattern on a mask onto a substrate using soft X-rays.

[0002]

2. Description of the Related Art An X-ray exposure method is a semiconductor manufacturing process in which a mask composed of an X-ray transmitting support film and an absorber pattern is irradiated with soft X-rays, and a desired pattern is transferred onto a substrate by light transmitted through the mask. It is. The soft X-ray used in the X-ray exposure method has a wavelength that is about two orders of magnitude shorter than the ultraviolet light used in the conventional light exposure method, so that the effect of diffraction can be reduced and a high resolution can be obtained.

[0003]

In the X-ray exposure method as well, when the transfer dimension is reduced to about 0.1 μm, the resolution is deteriorated due to the influence of diffraction. In order to improve the resolution, it is necessary to narrow the gap between the mask and the wafer,
For example, in order to obtain a resolving power of 0.1 μm or less,
It is necessary to narrow it to 0 μm or less. However, the narrowing of the gap causes particles adhering to the wafer to come into contact with the mask and damage the X-ray transmission supporting film of the mask, or the particles generated from the particles due to the contact may contaminate the wafer. was there.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an X-ray exposure method capable of preventing the above-mentioned mask breakage and improving reliability, and having a high resolution by narrowing a gap between the mask and the wafer. is there.

[0005]

The present invention relates to an X-ray exposure apparatus having a wafer stage, a wafer stage position measuring mechanism, a wafer stage feed control / drive mechanism, a wafer and a mask handling mechanism as minimum components, and a high particle height. And a mechanism for feeding back position information of the detected particles to a wafer stage feed control system, which is provided before the step-and-repeat exposure. -It is characterized by detecting a tickle.
If the height of the detected foreign matter exceeds a predetermined value, exposure or step-feeding is performed with a sufficient gap, detouring of the chip is performed, or particles on the chip are removed. As a result, it is possible to prevent contact between the mask and the particles, and to avoid dust from the particles due to breakage or contact of the mask.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

[First Embodiment] In FIG. 1, reference numeral 1 denotes a wafer stage of an X-ray exposure apparatus and a position measurement / feed control / drive mechanism of the wafer stage; 2, a mask handling mechanism; 3, a laser light source; A detection part of a particle comprising a light receiving mechanism for scattered light, 5 is a mask, 6 is a wafer, 7 is a particle on the wafer, 8 is laser irradiation light, 9 is laser scattered light, and 10 is squeezed. Nozzle of air, 11 is compressed air flow, 12
Is a beam line of synchrotron radiation, and 13 is an X-ray exposed by synchrotron radiation.

After the wafer 6 has been transferred to the stage 1, the particles are detected by step and repeat, and the chip is exposed under the condition that the gap between the mask 5 and the wafer 6 is 10 μm. As a result of detecting the chip portion to which the particle 7 having a height of 10 μm is attached by the detection unit 4,
Exposure was performed by expanding the gap to 20 μm using Stages 1 and 2. As a result, it was possible to prevent the mask 5 from being damaged. Further, since exposure was possible at a gap of 10 μm at other chip locations, the transfer pattern of the mask 5 by the exposure X-rays 11 was 0.1 μm on other chips.
Was obtained. The detection of the particle 7 is a sequence performed during alignment and exposure of other chips on the wafer 6, and as a result, it was possible to prevent a decrease in throughput due to the detection of the particle.

[Embodiment 2] After the wafer 6 is transferred to the stage 1, the particles are detected by step-and-repeat, and the chip is mounted under the condition that the gap between the mask 5 and the wafer 6 is 10 μm. Exposure was performed. As a result of detection of the chip portion to which the particle 7 having a height of 10 μm was attached by the detection section 4, the stage 1 was circumvented by the stage 1 to avoid the chip. As a result, it has become possible to prevent the mask 5 from being damaged. Further, since exposure was possible at a gap of 10 μm at other chip locations, the transfer pattern of the mask 5 by the exposure X-ray 13 on the other chip had a resolution of 0.1 μm.

[Embodiment 3] After the wafer 6 is transferred to the stage 1, the particles are detected by step-and-repeat, and the chip is mounted under the condition that the gap between the mask 5 and the wafer 6 is 5 μm. Exposure was performed. The height is 1 by the detector 4
As a result of detecting a chip portion where the particle 7 of 0 μm adhered, the particle 7 was removed by the compressed air flow 11. As a result, it has become possible to prevent the mask 5 from being damaged. In addition, since exposure was possible at a gap of 10 μm at other chip locations, exposure X
The transfer pattern of the mask 5 by the line 13 has a resolution of 0.1 μm.

[Embodiment 4] In FIG. 2 , 6 is a wafer, 7 is particles on the wafer, 14 is a chip to which particles 7 are attached,
6, 17, 18, 19, and 20 are other chips on the wafer. According to Example 1, a tungsten wiring pattern was exposed, wiring was formed by etching, and an insulating film was applied over the entire surface of the wafer, and then exposure for contact was performed. For alignment at the time of contact exposure, an alignment mark formed on a chip at the time of forming a tungsten wiring pattern was used. In the present embodiment, the chips 14, 15, 16
The above alignment sequence detects the alignment mark and determines the amount of rotation and expansion / contraction of the wafer 6 in the alignment. However, the tungsten 7 is not exposed on the chip 14 due to the adhesion of the particles 7, and the alignment mark is displayed on the chip 14. Was not formed. Therefore, the alignment mark position on the chip 14 is calculated from the detection results of the alignment marks on the peripheral chips 17, 18, 19, and 20, and the rotation / expansion amount of the wafer 6 is calculated based on the calculated position. changed. As a result, the alignment between the two layers could maintain the same high accuracy as when no particles were attached on the wafer.

[0012]

As described above, according to the present invention, it is possible to prevent the breakage of the mask due to the contact of the particles adhered on the wafer and to improve the resolution by narrowing the gap between the mask and the wafer.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of the configuration of the present invention.

FIG. 2 is a diagram illustrating a detection mark of a registration mark on a wafer according to the present invention;
The conceptual diagram which shows the change of a can.

[Explanation of symbols]

1: wafer stage and wafer stage position measurement / feed control / drive mechanism 2: X-ray mask handling mechanism 3: laser light source
4: particle detection portion, 5: X-ray mask, 6: wafer, 7: particle,
8: Laser irradiation light, 9: Laser scattered light, 10: Compressed air nozzle, 11: Compressed air flow 12: Beam line of synchrotron radiation, 13: Exposure X-ray by synchrotron radiation, 14: chip with particles attached, 15, 16, 17, 18, 19, 20: chip

──────────────────────────────────────────────────続 き Continued on the front page (72) Eiji Takeda, Inventor 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Inventor Hiroaki Oizumi 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside Hitachi Central Research Laboratory (72) Inventor Takashi Soga 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside Hitachi Central Research Laboratory Co., Ltd. (72) Inventor Toshihiko Tanaka 16-1 Wadai, Tsukuba-city, Ibaraki Pref. (56) References JP-A-63-72118 (JP, A) JP-A-63-122121 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/027 G03F 7 / 20

Claims (3)

(57) [Claims] In an X-ray exposure method in which a mask on which a desired exposure pattern is formed is arranged close to the surface of a wafer and exposure by X-rays is performed in a step-and-repeat manner, the wafer is exposed before the exposure. Performing a foreign matter inspection on the wafer to specify a position where a foreign matter having a height equal to or more than a predetermined height is present; and, in order to prevent the mask from being damaged by contact with the foreign matter, the predetermined size or more on the wafer surface In a position where a foreign substance having a height of 3 mm is present, the gap between the mask and the wafer is increased to a height at which the damage of the mask due to the contact between the mask and the foreign substance can be prevented, and then the step feed of the wafer is performed. Performing an X-ray exposure method. 2. An X-ray exposure method in which a mask on which a desired exposure pattern is formed is arranged close to a surface of a wafer and exposure by X-rays is performed in a step-and-repeat manner. Performing a foreign matter inspection on the wafer to specify a position where a foreign matter having a height equal to or more than a predetermined height is present; and, in order to prevent the mask from being damaged by contact with the foreign matter, the predetermined size or more on the wafer surface Performing a step feed of the wafer while avoiding a position where a foreign substance having a height of 3 mm is present. 3. X-ray exposure according to claim 1 or 2.
Semiconductor device manufactured by pattern formation
Place.