JPS612325A - High energy beam machine - Google Patents

Abstract

PURPOSE:To make exposure processing highly precise while increasing throughout by a method wherein the continuous movement of a wafer placed on a stage is synchronized with excimer laser beam oscillated and permeating through a reticle to irradiate the wafer by the pulse of laser beam. CONSTITUTION:A stage 2 provided to place a wafer 1 thereon is controlled by a driving system 3 in the horizontal X, Y directions as well as in the vertical Z direction while a mirror 4 is fixed to one side of the stage 2 to locate said stage 2 by means of a laser interferometer 5. On the other hand, an optical system such as a lens 6, a reticle 7 and a light source 8 oscillating excimer laser beam are successively arranged above the stage 2. The light source 8 is synchronized with the movement of stage 2 to oscillated the laser beam pulsatively while these light source and stage 2, etc. may be controlled by CPU9 precisely and securely.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a high-energy beam processing device, for example, a reduction exposure device that intermittently exposes a portion of a photosensitive agent coated on the surface of a continuously moving wafer to light by an excimer laser that passes through a reticle. Related to high energy beam processing equipment such as.

[Background technology]

As the degree of integration of semiconductor products increases, circuit patterns are becoming increasingly finer. The minimum line width of an IC pattern is about to become 1 μm or less after passing through 3 μm and 2 μm. In exposure technology under such circumstances, direct-on-wafer (DSW), ie, wafer stepper technology, has appeared. This wafer stepper technology uses step-and-repeat steps to
This technology transfers the pattern to the entire wafer by reducing the size of the reticle pattern using a lens and sequentially projecting it directly onto a portion of the wafer. Since this technology uses a divided transfer method, it has high resolution and overlay accuracy, and is excellent in terms of yield. However, since it must be stopped after each divided transfer, the throughput (wafer processing The problem is that it is inferior to other exposure systems in terms of performance. For this wafer stepper, for example, (
1) Sem1conductor World, 1
982.

May issue, pp. 37-45, ``Overview of light exposure aiming for SI'' by the editorial department of this magazine, (2) Electronic materials, 19
1982, March issue, pp. 75-80, "Reduction projection exposure system NSR system" by Nakafuki, (3), Electronic materials,
It is discussed in the document entitled "Vertical small projection exposure system Optimetrix 8000 series" by Shoji in the March issue of 1984, pages 37-41.In addition, in these documents, it is stated that the resolution of exposure depends on the light used for exposure. The shorter the wavelength, the better. In order to improve productivity, it is important to increase the moving speed of the stage on which the wafer is placed and to make its stopping accuracy high. is listed.

As one method for increasing the speed of the stage,
Although progress is being made to make the stage lighter.

Since a stage weighing several tens of kilograms is moved and stopped, the stage speed is limited to several hundred m5ec/ and a pitch of 10 mm. In addition, as described in the above-mentioned literature, in the conventional apparatus, the exposure time is 0.3 to 0.4.
seconds [Reference (1)], stage movement speed is 150 m/s [
Reference (3)), the average positioning time in the 10+@stepping operation is 0.37 seconds.

On the other hand, there is an excimer laser as a light source having optical properties suitable for semiconductor processing, and in recent years, this excimer laser has begun to be widely used in semiconductor manufacturing technology. For excimer lasers, for example, (4), 5oli
d 5tate technology, Japanese version, V
ol, 7. Nn2. (1984), 49-5.
"Applications of excimer lasers in microelectronics" by Tim McGrath on page 4 (5
), Machines and Tools, Vol. 28, Na4 (19
84).

It is described in the document entitled "Current status and future of high-energy beam processing" by Yosumi, pages 9-19. For example, the above-mentioned document (4) introduces an example in which an excimer laser is used for exposure, etching, doping, deposition, and annealing.

As stated in the above literature, excimer lasers are somewhat lacking in coherence compared to other laser beams, but
This actually makes it difficult for interference to occur on the sample surface, and because the wavelength is as short as 200 nm to 400 nm,
Good resolution. Furthermore, in optical phosphorography, the output determines the exposure time, but in this respect, since excimer lasers have high output, the exposure time can be shortened.

For this reason, the inventor of the present invention aims to irradiate a moving wafer with an excimer laser in pulses corresponding to the movement of the wafer, thereby sequentially exposing the photosensitizer coated on the surface of the wafer. , realized that it is possible to improve the throughput in an exposure apparatus, and created the present invention.

[Purpose of the invention]

An object of the present invention is to provide a technique that can improve throughput in light irradiation treatment of a workpiece.

Another object of the present invention is to provide a processing technique with high precision in light irradiation processing.

The above and other objects and novel features of the present invention are as follows:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

That is, the wafer stepper of the present invention is configured to synchronously irradiate a wafer placed on a stage and continuously moved with excimer laser light that has been oscillated and transmitted through a reticle in a pulsed manner. Since the repeated partial exposure of the photosensitive material on the wafer surface is performed without stopping the stage, throughput can be improved. Furthermore, since the excimer laser has a short wavelength and low coherence, the resolving power of the photosensitive material is high, so that highly accurate exposure processing can be achieved and the manufacturing yield can be improved.

〔Example〕

FIG. 1 is a schematic diagram showing an outline of a reduction projection exposure apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view showing the exposure state of a wafer.

As shown in FIG. 1, the wafer stepper of the present invention has a stage 2 on which a wafer 1 is placed.

This stage 2 has two positions in the plane's X, Y directions and vertical direction.
The direction is controlled by a drive system 3. Further, a mirror 4 is attached to the side surface of the stage 2. This mirror 4 is used for position measurement of the stage 2 by a laser interferometer 5.

On the other hand, above the stage 2, an optical system such as a lens 6, a reticle 7, and a light source 8 that oscillates an excimer laser are arranged in this order. The light source 8 is oscillated in a pulsed manner in synchronization with the movement of the stage 2. Said stage 2. The light source 8 and the like are accurately and reliably controlled by a CPU (central control unit) 9.

In such a wafer stepper, after the wafer 1 coated with a photosensitive agent is placed on the stage 2, the stage 2 is driven (scanned) by a drive system 3, as shown by the two-dot chain line in FIG. be done. During this scanning, the position of the stage 2 is accurately detected by the laser interferometer 5, and this detection information is sent to the CPU 9. therefore,
The CPU 9 causes the light source 8 to emit light in a pulsed (stroboscopic) manner based on the information sent from the laser interferometer 5, so that the 1/1o pattern of the reticle 7 is partially applied to the photosensitizer on the surface of the wafer 1. transcribed. One irradiation (one shot) of the light source 8 is waited for a time of 1o-wasec, and as shown in FIG. 2, a portion of a rectangular block 1o with the letter A written in the center is exposed. Note that the stage 2 is continuously moving at a speed of 100 mn/see, for example.

Therefore, the distance that the wafer 1 moves during irradiation with excimer laser light is 0.01 .mu.m, which is sufficiently smaller than the required resolution of 1 .mu.m, submicron, or micron, and highly accurate exposure can be achieved.

The time required per shot in this embodiment is as follows. Note that the part in parentheses indicates the conventional case. Exposure time is 10-W5ec (0.3~0.4sec)
, stage movement time is 0.2 sec (0.8 sec (0.2 sec for stage movement, 0.2 sec for starting and stopping the stage) since stage 2 moves continuously.
c)).

〔effect〕

■0 According to the wafer stepper of the present invention, since the continuously moving wafer 1 is irradiated with excimer laser light in synchronization, there is no need to start and stop the stage 2 as in the conventional case. The effect is that processing time can be significantly shortened and throughput can be improved.

2. The wafer stepper according to the present invention is 200-4.OO
Since the exposure light source is an excimer laser that has a short wavelength of nm and is less likely to cause interference, it has the advantage of high resolution, high precision exposure, and even submicron exposure.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, the light source may be a laser that performs pulse oscillation (repetitive pulse oscillation) other than the excimer laser, or an electron beam.

[Application field]

In the above explanation, the invention made by the present inventor was mainly applied to the exposure technology in semiconductor device manufacturing, which is the background field of application, but the invention is not limited thereto. It can be applied to technology such as marking of products.

The present invention is applicable to at least processing techniques such as processing by light irradiation treatment or heating processing by light irradiation treatment.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an overview of a reduction projection exposure apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view showing the exposure state of a wafer. 1... Wafer, 2... Stage, 3... Drive system,
4... Mirror, 5... Laser interferometer, 6... Lens, 7... Reticle, 8... Light source, 9... CPU (central control unit), 10... block. Figure 1 Figure 2

Claims (1)

[Claims] 1. Consisting of a stage on which a workpiece is placed, and a beam generator that emits a high-energy beam in a pulsed manner to the workpiece, the stage and the beam generator are In addition to being relatively movable, the beam generator is configured to irradiate the workpiece with an energy beam in pulses in synchronization with the movement of the workpiece that continuously moves relative to the beam generator. High-energy beam processing equipment characterized by: 2. A high-energy beam processing device characterized by irradiating a continuously moving wafer in pulses with an excimer laser that has passed through a reticle to partially expose a photosensitive agent coated on the surface of the wafer.