JPH0629171A - Semiconductor substrate unloading method, exposure apparatus and manufacture of semiconductor - Google Patents

Abstract

PURPOSE:To obtain an unloading method which can confirm exposure of a wafer without development at the time of processing the wafer with the exposure apparatus. CONSTITUTION:A wafer 17 having completed the exposure processing on an exposure stage 16 is moved up to a rotatable stage 18 with a transfer arm 19. If the exposure process includes a defect, the wafer 14 is rotated on the rotatable stage 18 to change the position of the wafer having completed the normal exposure and the orientation flag. Therefore, it can be confirmed without development whether the wafer has completed the exposure process and it is no longer necessary for exposure processing to conduct separation of resist and coating of resist for the reexposure process. As a result, productivity can be improved remarkably through reduction of load on the workers and improvement of throughput of semiconductor device manufacture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo process for manufacturing a semiconductor device, and more particularly to a method for unloading a semiconductor substrate.

[0002]

2. Description of the Related Art In recent semiconductor device manufacturing, 0.50 μm is becoming a mass production technology according to a process rule. this is,
In terms of degree of integration, SRAM is 4M and DRAM is 16M. In order to deal with this degree of integration, multilayer wiring technology and advanced planarization technology have been developed. Further, in order to cope with this miniaturization, the exposure apparatus used in the photo process is required to have a high resolution optical system and a high precision alignment mechanism. As these requirements increase, the possibility of error factors in the exposure apparatus increases.

An exposure apparatus used in a photo process of manufacturing a semiconductor device generally has a function of detecting the orientation flat of the semiconductor substrate by an optical sensor or the like when the semiconductor substrate is carried into the semiconductor device, and aligning the orientation flat. have. When the semiconductor substrate is carried in by arm conveyance, the orientation flat is carried out even after the carry-out. Normally, in mass-production semiconductor manufacturing, semiconductor substrates are processed in units of 25 or 50. In this case, when all the semiconductor substrates have completed the exposure process, the orientation flats of all the semiconductor substrates are in a uniform state. The same can be said for a semiconductor substrate that has not been exposed due to an alignment error or the like.

FIG. 3 shows a schematic diagram of a method of carrying in and out a semiconductor substrate (hereinafter referred to as a wafer) in a conventional exposure apparatus. Usually, the wafer carrier 31 capable of stocking 25 wafers is transferred one by one into the exposure apparatus by the extraction arm 32. The orientation flats of the wafer 33 transferred by the extraction arm 32 are usually scattered and not aligned in a fixed direction. Next, the wafer 33
Is conveyed to a rotary stage 38, where it is rotated several times by the rotary stage 38, the position of the orientation flat is detected by an optical sensor 35, and the orientation flat is aligned in a fixed direction like the wafer 34. Then, the wafer 3 is transferred using the transfer arm 39.
4 is conveyed to the exposure stage 36. After the wafer 37 transferred to the exposure stage 36 is exposed, it is returned to the wafer carrier by using the transfer arm 39 and the extraction / insertion arm 32. At this time, since the rotary stage 38 does not rotate, the wafer on which the orientation flat is positioned has the orientation flat oriented in the same direction on the wafer carrier 31.

[0005]

However, the above-mentioned conventional technique has the following problems. Generally, in the exposure of the semiconductor device in the photo process, a large amount of processing is performed such as carry-in → orientation flat detection and alignment → semiconductor substrate alignment → exposure → carry-out. In addition, since the photomask is carried out, alignment and the baseline check of the exposure equipment are performed, the semiconductor substrate is not exposed because the alignment cannot be performed due to some unexpected factors during the above processing or processing abnormalities in the previous process. In this case, since the orientation flats of all the semiconductor substrates are aligned after being carried out by the above-mentioned technique, it is not possible to specify the semiconductor substrate that has not been exposed due to an error. In addition, a photoreactive material called a positive resist, which is currently used in a photo process, changes an exposed portion into a substance which is easily dissolved in a developing solution by a photoreaction. However, it is usually difficult to visually confirm whether or not the semiconductor substrate is exposed immediately after the exposure. Therefore, the present condition is to confirm whether or not the semiconductor substrate after the exposure processing has been exposed after the development. Therefore, in order to identify the unexposed semiconductor substrate, it was necessary to actually develop the semiconductor substrate and confirm it with a metallographic microscope or the like. In this case, a great deal of time and labor was required because the resist had to be stripped and the resist applied again in order to subject the unexposed semiconductor substrate to the exposure treatment again.

Therefore, the present invention solves the above problems, and an object of the present invention is to expose a semiconductor substrate that has not been exposed in an exposure apparatus for some reason without developing it. Another object of the present invention is to provide a method of unloading a semiconductor device, which can select and perform exposure processing again in a short time.

[0007]

[Means for Solving the Problems] (1) In a semiconductor substrate having an orientation flat, the semiconductor substrate is carried in from a semiconductor substrate carrier capable of storing at least two semiconductor substrates, and the orientation flat of the semiconductor substrate. After detecting the position of and aligning the orientation flat to any position,
In a device having a function of loading the semiconductor substrate into a predetermined position and unloading it again to the semiconductor substrate carrier after the work is completed, when the device does not operate normally, the orientation flat of the semiconductor substrate is set. An orientation flat of the semiconductor substrate after the semiconductor substrate has been loaded into the device and has been normally operated, and an orientation flat of the semiconductor substrate after the semiconductor substrate has been loaded into the device and has not been normally operated. Characterized by changing the position of the orientation flat. (2) An exposure apparatus having a function of detecting an orientation flat of a semiconductor substrate and aligning the position in a photo step of manufacturing a semiconductor device has the function described in the means (1).

(3) In the exposure apparatus having the carry-out method described in the above-mentioned means (1), the position of the orientation flat of the semiconductor substrate is changed according to the exposure state and the carry-out is carried out.

(4) In manufacturing a semiconductor device, the exposure apparatus according to the above-mentioned means (2) and the above-mentioned means (3) is used.

[0010]

EXAMPLE First, a first example will be described.

FIG. 1 shows a schematic view of an embodiment of the present invention. As shown in FIG. 3 of the prior art, the method of transporting the exposure apparatus is as follows. Usually, the wafer carrier 31 capable of stocking 25 wafers is transferred one by one into the exposure apparatus by the extraction arm 32. The orientation flats of the wafer 33 transferred by the extraction arm 32 are usually scattered and not aligned in a fixed direction.
Next, the wafer 33 is transferred to the rotary stage 38, where it is rotated several times by the rotary stage 38.
The position of the orientation flat is detected by the optical sensor 35, and the orientation flat is aligned in a certain direction like the wafer 34. Then, the transfer arm 39
The wafer 34 is transferred to the exposure stage 36 by using. Up to this point, the same operation is performed in the embodiment of the present invention. In FIG. 1, the wafer 17 exposed on the exposure stage 16 is transferred to the rotary stage 1 by the transfer arm 19.
Moved to 8. Here, in the prior art, no operation is performed by the rotary stage 18. However, in one embodiment of the present invention, when the wafer being loaded is not exposed due to some factor, for example, an alignment error due to the influence of the underlayer of the wafer or a wafer transfer error occurs. In this case, the wafer 14 being unloaded is rotated by the rotary stage 18. This operation is the greatest feature of the present invention. Wafer 14 being rotated
According to the presence or absence of the orientation flat, the optical sensor 15 can recognize the orientation flat, and at the same time can detect the rotation time of one rotation. By adjusting the rotation time, the unexposed wafer 14 is rotated 180 degrees with respect to the wafer 17 on the exposure stage 16 as shown in the figure, and is unloaded to the wafer carrier 11 by the insertion / removal arm 12.

At present, resists widely used for fine processing are almost indistinguishable from each other visually before and after exposure. Therefore, in the conventional carrying-out method, the presence or absence of the exposure can be confirmed only after the development. Therefore, if the wafer is not exposed due to some factors, it can be confirmed only by the conventional technique after the development.Therefore, in order to perform the exposure processing on the wafer again, the resist is peeled off, and a large process of applying the resist is performed. Although it was necessary to carry out the process, in the present invention, the presence or absence of the exposure can be confirmed by the position of the orientation flat of the wafer after being carried out, so that the development process is not necessary. Therefore, since the exposure process can be performed immediately, a significant improvement in throughput can be achieved, and the effects of reducing the burden on the operator and improving the efficiency of semiconductor device manufacturing are brought about.

Next, a second embodiment will be described.

FIG. 2 shows an embodiment of the present invention. In recent years, an exposure apparatus for manufacturing a semiconductor device incorporates a large number of sequences because of the demand for high resolution and high alignment accuracy. Therefore, since there are various kinds of errors when carrying out and carrying out, the position of the orientation flat of the wafer 21 is changed depending on the exposure state as shown in FIG. 2 as a method for identifying the error. For example, the state (A) is normally exposed, the state (B) is unexposed due to an error during conveyance, the state (C) is unexposed due to a wafer alignment error, and the state (D) is an exposure sequence. The position of the orientation flat of the wafer 21 is changed so that the cause of the non-exposure such as the non-exposure due to the parameter error of (4) can be specified. By adding such a function, it is possible to limit the types of errors, which is useful for reducing the work at the time of reprocessing.

An embodiment of the present invention has been described above. In addition to the above, 1) The main unloading function is installed in the length measuring SEM equipped with the registration measuring device, the wafer foreign matter inspection device, and the automatic measuring function.

2) The unexposed wafer is carried out to a wafer carrier different from the normally exposed wafer.

3) Exposure apparatus or measuring apparatus having separate units for the orientation flat detection unit for carrying in and the orientation flat detection unit for carrying out 4) The carrying out method of the present invention is used as a processing apparatus or measurement for other semiconductor device manufacturing processes. Used in equipment.

Needless to say, the same effects as those of the embodiment of the present invention can be obtained.

[0019]

In the photo process of manufacturing a semiconductor device,
In a semiconductor substrate having an orientation flat, a loading operation of the semiconductor substrate is performed from a semiconductor substrate carrier capable of storing at least two semiconductor substrates, a position of the orientation flat of the semiconductor substrate is detected, and the orientation is set at an arbitrary position. After matching the flats, in a device having a function of carrying in the semiconductor substrate in a predetermined position and carrying out the semiconductor substrate carrier again after the work is completed, when the device does not operate normally, The orientation flat of the semiconductor substrate is normally operated after the semiconductor substrate is loaded into the apparatus, and the orientation flat of the semiconductor substrate and the semiconductor substrate is normally operated after being loaded into the apparatus. There was no orientation of the semiconductor substrate By carrying out by changing the position of the rat, it is possible to confirm the position of the orientation flat of the wafer after unloading without developing the presence or absence of exposure of the wafer, no longer need to perform confirmation by development. Therefore, when performing the re-exposure process, unlike the conventional technique, it is possible to perform the exposure process in a short time without the need to perform a large number of steps such as resist stripping and resist coating, which reduces the burden on the operator and significantly increases the throughput of semiconductor device manufacturing. The result is an improvement in productivity.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a conventional wafer loading / unloading method.

[Explanation of symbols]

11 ... Wafer carrier 12 ... Extracting arm 13 ... Carrying out wafer 14 ... Wafer during processing 15 ... Optical sensor 16 ... Exposure stage 17 ... Wafer after exposure 18 ... Rotating stage 19 ... Transfer arm 21 ... Wafer 31 ... Wafer carrier 32 ... Extraction arm 33 ... Loading wafer 34 ... Wafer after orientation flat detection 35 ... Optical sensor 36 ... -Exposure stage 37 ... Wafer after exposure processing 38 ... Rotation stage 39 ... Transfer arm

Claims (4)

[Claims] 1. In a semiconductor substrate having an orientation flat, the semiconductor substrate is carried in from a semiconductor substrate carrier capable of storing at least two semiconductor substrates, the position of the orientation flat of the semiconductor substrate is detected, and the position of the orientation flat is arbitrarily determined. In the device having a function of loading the semiconductor substrate in a predetermined position after aligning the orientation flat with the position of, and carrying out to the semiconductor substrate carrier again after the work is completed, the device normally operates. If not, the orientation flat of the semiconductor substrate is moved to the device after the semiconductor substrate is loaded into the device, and the orientation flat of the semiconductor substrate is normally operated. Of the semiconductor substrate Unloading method of a semiconductor substrate, which comprises carrying out by changing the position of the station flat. 2. An exposure apparatus having a function according to claim 1 in an exposure apparatus having a function of detecting an orientation flat of a semiconductor substrate and aligning the position in a photo step of manufacturing a semiconductor device. 3. An exposure apparatus having the carry-out method according to claim 1, wherein the position of an orientation flat of the semiconductor substrate is changed according to an exposure state and the exposure apparatus is carried out. 4. A method of manufacturing a semiconductor device, wherein the exposure apparatus according to claim 2 or 3 is used in the manufacture of a semiconductor device.