JP2000188249A - Aligner and manufacture of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve light exposure accuracy by enabling to monitore parameters on a photosensitive substrate, in an environment close to actual environment. SOLUTION: This aligner is provided with a substrate chuck for holding a photosensitive substrate, to which a pattern formed on an original plate is to be transferred through light exposure, a stage moving in two-dimensional directions within a reference plane while holding the substrate chuck, and sensors for detecting parameters on the photosensitive substrate held on the substrate chuck. The aligner performs suitable light exposure over the photosensitive substrate held on the chuck on the basis of detection results of the sensors. Sensors 11, 12 and 13 are provided on a chuck 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for manufacturing a semiconductor integrated circuit or a liquid crystal device and a device manufacturing method using the same, and more particularly, to a substrate chuck for holding a photosensitive substrate such as a wafer on an xy stage. And a device manufacturing method using the same.

[0002]

2. Description of the Related Art Conventionally, when a semiconductor element or a liquid crystal device is manufactured through a photolithography process, a pattern of an original plate such as a reticle is formed on a substrate such as a wafer having a surface coated with a photosensitive agent such as a photoresist. An exposure apparatus that performs transfer via a projection optical system is used. Generally, such a conventional exposure apparatus is provided with a wafer chuck for holding a wafer on an xy stage.

[0003]

However, according to the conventional exposure apparatus, the function of the wafer chuck is merely to hold the wafer in a flat state, and the above parameters are different from those of the wafer chuck. Since the monitoring is performed at different positions, the environment is different from the actual wafer environment, and there is a limit in improving the accuracy in the exposure process.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure apparatus and a device manufacturing method capable of monitoring parameters relating to a photosensitive substrate in an environment closer to an actual environment in view of the problems of the related art.

[0005]

In an exposure apparatus, a substrate chuck is a structure that moves in close contact with a photosensitive substrate when a pattern of an original is actually printed on the photosensitive substrate due to its physical position and structure. From the uneven illuminance of the exposure source,
This is the most desirable structure for monitoring parameters such as the ambient temperature of the photosensitive substrate and acceleration when the photosensitive substrate moves.

Focusing on this point, in the present invention, a substrate chuck for holding a photosensitive substrate onto which a pattern formed on an original is transferred by exposure, and holding the substrate chuck to move in a two-dimensional direction within a reference plane. And a sensor for detecting parameters relating to the photosensitive substrate held on the substrate chuck, and performing appropriate exposure on the photosensitive substrate held on the substrate chuck based on the detection result. In the exposure apparatus, the sensor is provided on the substrate chuck.

The device manufacturing method of the present invention is characterized in that a device is manufactured by using such an exposure apparatus and performing appropriate exposure based on the detection result of a sensor provided on the substrate chuck. And

According to this, when the pattern of the original is actually printed on the photosensitive substrate, the parameters related to the photosensitive substrate are monitored on the substrate chuck that moves in close contact with the photosensitive substrate. Parameters are monitored. Therefore, the accuracy in the exposure step is improved.

[0009]

In a preferred embodiment of the present invention, the sensor is, for example, an acceleration sensor for detecting the degree of vibration of the stage as the parameter, and is held on the substrate chuck as the parameter. A temperature sensor for detecting the ambient temperature of the photosensitive substrate or an illuminance sensor for detecting, as the parameter, illuminance unevenness of exposure light on the substrate surface of the photosensitive substrate held on the substrate chuck.

The acceleration sensor determines the acceleration or the moving state of the photosensitive substrate necessary for positioning the stage that moves while holding the substrate chuck, and moves in close contact with the photosensitive substrate when the original pattern is actually printed on the photosensitive substrate. Monitoring with high precision on the substrate chuck. The temperature sensor monitors the ambient temperature or the temperature environment of the photosensitive substrate with high accuracy on a substrate chuck that moves in close contact with the photosensitive substrate when the original pattern is actually printed on the photosensitive substrate. The illuminance sensor accurately measures uneven illuminance on the substrate surface on a substrate chuck that moves in close contact with the photosensitive substrate when actually printing the pattern of the original on the photosensitive substrate.

[0011] The sensor may be plural. In this case, when the pattern of the original is actually printed on the photosensitive substrate, a plurality of parameters are simultaneously monitored on a substrate chuck that moves in close contact with the photosensitive substrate, thereby improving the accuracy in the exposure process. Further, by providing an acceleration sensor, a temperature sensor, and an illuminance sensor in combination and monitoring a plurality of parameters simultaneously, exposure with higher precision is performed.

There may be a plurality of sensors or one sensor for detecting unevenness in illuminance. When there are a plurality, the illuminance unevenness on the actual photosensitive substrate surface is accurately monitored. In one case, in order to detect illuminance non-uniformity, for example, a means for moving one sensor in the radial direction of the substrate chuck and a means for rotating the substrate chuck are provided.

When a sensor for detecting uneven illuminance is provided,
There is provided a means for adjusting the height of the substrate chuck so that illuminance unevenness at the height position of the photosensitive substrate during exposure can be detected.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a wafer chuck of an exposure apparatus according to a first embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a wafer chuck for holding a wafer, which is formed of a porous member for sucking the wafer. Reference numeral 11 denotes an acceleration sensor for detecting the degree of vibration of a stage that moves in a two-dimensional direction in a reference plane while holding the wafer chuck 10 when actually printing a reticle pattern on a wafer. When printing a pattern on a wafer, a plurality of temperature sensors 13 for detecting the ambient temperature of the wafer held by the wafer chuck 10 are provided.
Above are a plurality of illuminance sensors for detecting illuminance unevenness of the exposure source. The acceleration sensor 11, the temperature sensor 12, and the illuminance sensor 13 are provided on the wafer chuck 10.

FIG. 2 is a block diagram showing the structure of the exposure apparatus of the present embodiment in which the wafer chuck 10 is incorporated. As shown in FIG. 1, the exposure apparatus includes a wafer chuck 10 for holding a photosensitive wafer 8 onto which a pattern formed on a reticle 9 is transferred, and a two-dimensional direction in a reference plane for holding the wafer chuck 10. And an xy stage 14 that moves to

In this exposure apparatus, prior to the operation of printing the pattern of the reticle 9 on the wafer 8, light from the exposure source 23 is applied to the wafer chuck, and the illuminance sensor 1
3, the illuminance distribution on the wafer chuck 10 is detected in advance. At this time, since there is a difference in the thickness of the wafer 8 between the upper surface of the wafer chuck 10 and the actual wafer 8 surface, the difference in the thickness of the wafer 8 can be corrected by the height correction mechanism 15. Then, based on the illuminance distribution data, the illuminance when the pattern of the reticle 9 is actually printed on the wafer 8 can be corrected by the illuminance unevenness correction lens 22.

When the pattern of the reticle 9 is actually printed on the wafer 8, the wafer 8 is suction-held by the wafer chuck 10, and the pattern of the reticle 9 is printed by light from the exposure source 23 in a step-and-repeat manner. Therefore, the vibration generated when the stage 14 holding the wafer chuck 10 moves in the two-dimensional direction also vibrates the wafer 8 itself. However, high-precision printing can be performed by directly detecting the degree of vibration of the wafer 8 by the acceleration sensor 11 provided on the wafer chuck 10 and performing feedback control of the mount 20 to suppress the vibration. .

Further, the temperature at a plurality of points on the wafer chuck 10 when the pattern is actually printed is detected by the temperature sensor 12, and based on the detected temperature,
It is also possible to correct the influence on the wafer 8 due to the distortion of the member of the wafer chuck 10 due to the temperature gradient.

As described above, the acceleration sensor 11, the temperature sensor 12, and the illuminance sensor 13 individually provided on the wafer chuck 10 realize improvement in accuracy in the exposure process.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a block diagram showing a structure of an exposure apparatus according to a second embodiment of the present invention, and FIG. 3 shows a wafer chuck incorporated therein. In this case, only one illuminance sensor 13 is provided on the wafer chuck 10, and a mechanism for moving the illuminance sensor 13 on the radius line of the wafer chuck 10 is provided. Further, a mechanism 16 for rotating the wafer chuck 10 once in a state where the wafer is not held is provided. Other configurations are the same as those of the first embodiment.

In this exposure apparatus, prior to the operation of printing the pattern of the reticle 9 on the wafer 8, when light from the exposure source 23 is irradiated on the wafer chuck 10, the illuminance sensor 13 Move on a radius line. The wafer chuck 10 itself starts rotating in synchronization with the movement of the illuminance sensor. By these two operations, the illuminance distribution on the wafer chuck 10 is detected in advance. At this time, since there is a difference in the thickness of the wafer 8 between the upper surface of the wafer chuck 10 and the actual surface of the wafer 8, the difference in the thickness of the wafer 8 can be corrected by the height correction mechanism 15. Then, based on the illuminance distribution data, it is possible to correct the illuminance when actually printing the pattern of the reticle 9 on the wafer 8. The acceleration sensor 11 and the temperature sensor 12 provided on the wafer chuck 10 operate in the same manner as in the first embodiment.

In this embodiment, a mechanism for moving the illuminance sensor 13 on the wafer chuck 10 and a mechanism 16 for rotating the wafer chuck 10 are provided, so that it is possible to detect the illuminance distribution on the wafer surface in more detail. Thus, the accuracy of the exposure process can be improved.

<Embodiment of Device Manufacturing Method> Next, an embodiment of a device manufacturing method using the above-described exposure apparatus will be described. FIG. 5 shows a flow of manufacturing micro devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin film magnetic heads, micro machines, etc.). In step 1 (circuit design), a device pattern is designed. Step 2 is a process for making a mask on the basis of the designed pattern. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon or glass.
Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer produced in step 4, and includes an assembly process (dicing, bonding),
It includes steps such as a packaging step (chip encapsulation). In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 6 shows the wafer process (step 4).
The detailed flow of is shown. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist processing), a resist is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus or exposure method to align and print the circuit pattern of the mask on a plurality of shot areas of the wafer.
Step 17 (development) develops the exposed wafer.
In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeating these steps,
Multiple circuit patterns are formed on the wafer.

By using the production method of this embodiment, it is possible to produce a large-sized device, which was conventionally difficult to produce, at low cost.

[0026]

As described above, according to the present invention,
When a pattern of an original is actually printed on a photosensitive substrate, parameters relating to the photosensitive substrate can be monitored on a substrate chuck that moves in close contact with the photosensitive substrate, that is, in an environment closer to the actual environment. Therefore, it is possible to improve the accuracy in the exposure process.

Further, by providing an acceleration sensor on the substrate chuck required for positioning the stage which moves in the reference plane two-dimensionally while holding the substrate chuck, the actual movement state of the photosensitive substrate can be monitored with high accuracy. can do.

By providing a temperature sensor on the substrate chuck for measuring the ambient temperature of the photosensitive substrate held on the substrate chuck, the actual temperature environment of the photosensitive substrate can be monitored with high accuracy.

Further, by providing a plurality of sensors on the substrate chuck, when actually printing the pattern of the original on the photosensitive substrate, a plurality of parameters are simultaneously monitored on the substrate chuck moving in close contact with the photosensitive substrate to perform exposure. The accuracy in the process can be improved.

Further, by providing illuminance sensors for measuring the illuminance unevenness of the exposure source on the substrate surface of the photosensitive substrate held by the substrate chuck on a plurality of substrate chucks, the illuminance unevenness on the actual substrate surface can be accurately monitored. can do.

Further, by providing a combination of a plurality of acceleration sensors, temperature sensors, and illuminance sensors on the substrate chuck, it is possible to provide a more accurate exposure apparatus and device manufacturing method.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a wafer chuck according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an exposure apparatus having the wafer chuck of FIG.

FIG. 3 is a view showing a structure of a wafer chuck according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of an exposure apparatus having the wafer chuck of FIG.

FIG. 5 is a flowchart showing a device manufacturing method that can use the exposure apparatus of the present invention.

FIG. 6 is a detailed flowchart of a wafer process in FIG. 5;

[Explanation of symbols]

8: wafer, 9: reticle, 10: wafer chuck, 1
1: acceleration sensor, 12: temperature sensor, 13: illuminance sensor, 14: stage, 15: wafer chuck height adjustment mechanism, 16: wafer chuck rotation mechanism, 20: mount,
21: stage normal plate, 22: illumination unevenness correction lens, 2
3: exposure source.

Claims (9)

[Claims] 1. A substrate chuck for holding a photosensitive substrate onto which a pattern formed on an original is transferred by exposure, a stage for holding the substrate chuck and moving two-dimensionally in a reference plane, and A sensor for detecting a parameter relating to the photosensitive substrate held in the exposure apparatus that performs an appropriate exposure on the photosensitive substrate held on the substrate chuck based on the detection result, the sensor is the An exposure apparatus provided on a substrate chuck. 2. The exposure apparatus according to claim 1, wherein the sensor is an acceleration sensor for detecting a degree of vibration of the stage as the parameter. 3. The exposure apparatus according to claim 1, wherein the sensor is a temperature sensor for detecting an ambient temperature of a photosensitive substrate held on the substrate chuck as the parameter. 4. The sensor according to claim 1, wherein the sensor is an illuminance sensor for detecting illuminance unevenness of exposure light on a substrate surface of the photosensitive substrate held on the substrate chuck as the parameter. 4. The exposure apparatus according to claim 3. 5. The exposure apparatus according to claim 1, wherein a plurality of the sensors are provided. 6. The exposure apparatus according to claim 4, wherein the number of the illuminance sensors is plural. 7. The apparatus according to claim 1, wherein the illuminance sensor is one, and includes means for moving the sensor in a radial direction of the substrate chuck and means for rotating the substrate chuck in order to detect illuminance unevenness. The exposure apparatus according to claim 4, wherein 8. A device for adjusting the height of the substrate chuck so that the illuminance sensor can detect illuminance unevenness at a height position of the substrate surface of the photosensitive substrate during exposure. An exposure apparatus according to claim 4, 6, or 7. 9. A device is manufactured by performing an appropriate exposure based on a detection result of a sensor provided on a substrate chuck using the exposure apparatus according to any one of claims 1 to 8. Device manufacturing method.