KR20020008684A - Semiconductor manufacturing device having an impurity cleaning apparatus - Google Patents

Abstract

PURPOSE: A semiconductor fabricating equipment with an alien substance cleaning device is provided to remove alien substances or impurities from a wafer or a reticle. CONSTITUTION: An air injection portion(402) is connected with an air supply source(428). The air injection portion(402) has a regulator(426) for controlling a pressure of air supplied from the air supply source(428). The regulator(426) is operated manually or automatically by a sense signal from a sensor and a control signal from a control portion. The first solenoid valve(427) is arranged between the air supply source(428) and the regulator(426). Impurities passing the regulator(426) are filtered by a filter(425). The air passing the filter(425) is injected to a bottom of a wafer by an air shower(420). An alien substance absorption portion(401) is connected with a vacuum supply source(414). The alien substance absorption portion(401) is formed with a vacuum duct(410) and the second solenoid valve(412).

Description

Semiconductor Manufacturing Equipment with Foreign Material Cleaning Device {SEMICONDUCTOR MANUFACTURING DEVICE HAVING AN IMPURITY CLEANING APPARATUS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly, to a semiconductor manufacturing apparatus having a cleaning apparatus capable of removing foreign substances or impurities from a wafer or a reticle.

BACKGROUND OF THE INVENTION A semiconductor device or a semiconductor chip is generally manufactured by processing a wafer formed of silicon using semiconductor equipment. Wafers are typically manufactured as semiconductor devices or semiconductor chips through a series of semiconductor device manufacturing processes such as lithography, exposure, ion implantation, chemical and mechanical polishing (CMP), chemical or physical vapor deposition, and plasma etching.

During the semiconductor device manufacturing process, an exposure process is a process of aligning a wafer on which a photoresist is stacked so that a pattern of a reticle can be transferred to a wafer on a wafer stage, and then exposing the wafer to ultraviolet rays. It is made using an exposure apparatus, commonly referred to as a stepper).

Such exposure processes and steppers for performing the exposure processes are issued to U.S. Patent Nos. 5,706,076 (issued to Minoru Takeda on Jan. 6, 1998), 5,781,277 (issued to Kazunori Iwamoto on July 14, 1998), 5,526,093. (issued to Kazhiro Takahachi on June 11, 1996) and 5,842,824 (issued to Kenji Nishi on Dec. 1,1998).

Recently, in performing the above exposure process, generation of particles has become an important problem. Impurities on reticles and wafers, the most important components of steppers, can cause fatal degradation in process. In addition, in view of the fact that the pattern of the semiconductor device is becoming smaller, the treatment of impurities is a very important problem in improving the quality of the semiconductor device.

1 is a block diagram showing a path through which a wafer is transferred in a conventional stepper. As shown in FIG. 1, the wafer is spin-coated with a photoresist on a spinner (S1).

The photoresist coated wafer is transferred to a wafer transfer stage on a stepper (S2), which is typically done by a robot, such as a handler.

The wafer transferred to the wafer transport stage is transferred back to the wafer preliminary alignment stage by the handler (S3), where alignment of the wafer and alignment of the edges are performed.

Subsequently, the wafer is transferred to the wafer stage (S4), and ultraviolet rays are irradiated onto the wafer from the wafer stage, so that a predetermined pattern is formed on the upper surface of the wafer.

However, in the above process, when the wafer is coated on the spinner and then transferred to the stepper, foreign substances such as surfactants enter the wafer and cause a defect of the product.

On the other hand, Figure 2 is a block diagram showing an impurity inspection process of the conventional reticle is shown. As shown in FIG. 2, the impurity inspection process of the conventional reticle includes selecting a process to proceed (S5), selecting a reticle (S6), and transferring the reticle to a reticle loader (S6). , And checking the impurities in the reticle portion (S7).

In this process, the first selected reticle is loaded through the reticle loader system when the process is performed in the stepper. At this time, the facility inspects the reticle surface for impurities using a laser and displays the result to the operator.

In this process, if there are a lot of impurities, the operator performs the washing process again in the room for managing the reticle, and then proceeds with the process again.

The present invention has been made to overcome the problems of the prior art, an object of the present invention is to provide a semiconductor manufacturing apparatus having a cleaning device capable of removing foreign substances or impurities on the wafer or reticle during the exposure process It is about.

1 is a block diagram showing a path in which a wafer is transferred in a conventional stepper.

2 is a block diagram showing an impurity test process of a conventional reticle.

Figure 3 is a plan view showing a stepper having an impurity washing apparatus according to an embodiment of the present invention.

4 is a front view of the impurity washing apparatus shown in FIG.

Figure 5 is a plan view showing that the impurity washing apparatus according to the present invention is applied to the cleaning of the reticle.

6 is a block diagram showing a wafer transfer process according to the present invention.

7 is a block diagram showing a reticle inspection process according to the present invention.

<Description of the symbols for the main parts of the drawings>

300: reticle cleaning stage 410: vacuum duct

420: air shower 425: filter

426: regulator 500: stepper

510: wafer transport stage 520: wafer pre-alignment stage

530: wafer stage 540: spinner

550: edge sensor 560: alignment mark sensor

In order to achieve the above object, the present invention, the foreign matter buried in the wafer is separated from the wafer by jetting air toward the wafer transferred to the wafer transport stage of the stepper consisting of the wafer transport stage, the wafer pre-alignment stage and the wafer stage It provides a semiconductor manufacturing apparatus characterized in that it comprises air injecting means and the foreign matter suction means for sucking the foreign matter separated by the air injection means to discharge to the outside.

The air injection means is connected to an air source regulator for regulating the pressure of the air supplied from the air source, a first solenoid valve disposed between the air source and the regulator to open and close the inflow of air, the air passed through the regulator And a filter for filtering impurities contained in the air and an air shower disposed at the bottom of the wafer to inject air toward the bottom of the wafer.

The foreign matter suction means is connected to a vacuum source, and includes a vacuum duct disposed adjacent to the air shower to suck foreign matter separated from the wafer, and a second solenoid valve for opening and closing the vacuum source.

The air jetting means and the foreign matter suction means are also provided in the reticle cleaning stage to remove foreign substances on the reticle.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 shows a stepper 500 with a cleaning device 400 according to the present invention. Although the cleaning apparatus 400 according to the present invention is illustrated as being applied to the stepper 500, the present invention is not limited thereto and may be applied to various semiconductor devices requiring cleaning and removal of foreign matter.

As shown in Fig. 3, the stepper 500 pre-aligns the wafer transport stage 510 for storing the wafer w to be processed, and the wafer w transferred from the wafer transport stage 510. And a wafer stage 530 for more precisely aligning the wafer w transferred from the wafer pre-aligning stage 520. The wafer prealignment stage 520 is disposed between the wafer transfer stage 510 and the wafer stage 530.

A photoresist is coated on the upper surface of the wafer w stored in the wafer transport stage 510. The photoresist coating operation is performed by spin coating in a spinner 540, and the wafer w on which the photoresist is spin coated is transferred to the wafer transfer stage 510 by a first handler 512. .

Second and third handlers 522 and 532 are disposed in the preliminary alignment stage 520. The second handler 522 transfers the wafer w stored in the wafer transfer stage 510 to the wafer pre-alignment stage 520. In addition, the second handler 522 serves to return the wafer w transferred from the wafer stage 530 to the wafer pre-alignment stage 520 after the exposure operation is completed, to the wafer transfer stage 510. do.

The third handler 532 transfers the wafer w transferred to the wafer prealignment stage 520 by the second handler 522 to the wafer stage 530, and further, the wafer stage 530. The wafer w on which the exposure operation is completed is returned to the wafer pre-alignment stage 520. The third handler 522 pivots at an angle of about 120 degrees. Thus, the position of the wafer w returned to the wafer pre-alignment stage 520 is opposite to its initial position.

An edge sensor 550 and an alignment mark sensor 560 are installed in the wafer preliminary alignment stage 520. The edge sensor 550 is for detecting a flat zone of the wafer w, and typically includes a light emitting device and a light receiving device. In addition, the alignment mark sensor 560 is for detecting the alignment mark formed on the side of the wafer. Since the alignment mark of the wafer w is detected by the alignment mark sensor 560 in the state where the flat zone is primarily detected by the edge sensor 550, more accurate preliminary preparation of the wafer w is performed. Sorting is possible.

The wafer stage 530 is provided with a plurality of optical sensors 534. The optical sensor 534 is for positioning the wafer w in position on the wafer stage 530. Signals detected by the photosensors 534 are input to a controller (not shown), which operates a wafer positioning device based on signals input from the photosensors 534. Thus, the position of the wafer w is finely adjusted. By this positioning operation, it is possible to prevent the phenomenon in which a thin film is overlaid on the wafer w.

Here, the overlay phenomenon means that an offset occurs between the first film layer stacked on the wafer w and the second film layer stacked on the first film layer.

Reference numeral 536 denotes an ultraviolet ray generating device, which serves to form a photoresist pattern on the wafer w by irradiating ultraviolet rays onto the aligned wafer w. The photoresist pattern forming operation is performed through a mask.

Meanwhile, the wafer cleaning apparatus 400 is disposed at the bottom of the wafer transport stage 510 to which the wafer w is transported. The cleaning apparatus sucks and discharges foreign substances separated from the wafer w by the air jetting device 402 and the air jetting device 402 to release the foreign matter from the wafer w. It is provided with a foreign material suction device 401.

As shown in detail in FIG. 4, the air injector 402 includes a regulator 426 connected to an air source 428 to regulate the pressure of air supplied from the air source 428. The operation of the regulator 426 is preferably performed automatically by the signal from the sensor and the control of the controller, but can be operated manually. The regulator 426 regulates the pressure of air typically to 30 psi for efficient foreign material removal.

A first solenoid valve 427 is disposed between the air supply source 428 and the regulator 426 to open and close the inflow of air, and impurities contained in the air passing through the regulator 426 are filtered by the filter 425. Filtered. The filter 425 is preferably a filter of approximately 0.001㎛. Air passing through the filter 425 is injected toward the bottom surface of the wafer w through an air shower 420 disposed at the bottom of the wafer w. The air shower 420 may be in the form of an injection duct in which a plurality of holes are formed, or may be in the form of an injection duct in which one opening is formed on an upper surface thereof. The shape and structure of the air shower 420 may be appropriately modified depending on the system to which it is applied.

The foreign matter suction device 401 is connected to the vacuum source 414, and is disposed adjacent to the air shower 420 to suck the foreign matter separated from the wafer w and the vacuum duct 410. And a second solenoid valve 412 for opening and closing 414. The reason why the vacuum duct 410 is disposed adjacent to the air shower 420 is to efficiently collect foreign substances separated from the wafer w.

Hereinafter, the operation of the stepper 500 having the above configuration will be described with reference to FIG.

First, the wafer w is spin-coated with a photoresist in the spinner 540 (S10). The wafer w spin-coated with the photoresist is transferred to the wafer transfer stage 510 by the first handler 512 (S20).

In the wafer transfer stage 510, the wafer w waits for the next process to proceed. In this state, the cleaning device 400 operates to remove foreign substances on the wafer (W30).

That is, when the wafer w is seated on the wafer transport stage 510, the sensor detects this and transmits a wafer detection signal to the controller. As the wafer sensing signal is input from the sensor, the controller opens the first solenoid valve 427 so that air flows from the air supply 428 to the regulator 426.

The incoming air is adjusted to have a predetermined pressure while passing through the regulator 426, and is introduced into the air shower 420 while impurities are removed through the filter 425.

The air introduced into the air shower 420 is ejected toward the bottom surface of the wafer to release foreign substances from the wafer.

On the other hand, as the air injection process proceeds, the controller applies an open signal to the second solenoid valve 412 to communicate the vacuum source 414 with the vacuum duct 410. Therefore, since the foreign matters separated from the wafer by the air shower 420 are sucked into the vacuum duct 410 by the vacuum formed in the vacuum duct 410, the wafer may be reloaded by the floating of the foreign matter. The problem of contamination does not occur.

In this state in which the foreign matter on the wafer is removed, the second handler 522 transfers the wafer w waiting on the wafer transport stage 510 to the wafer pre-alignment stage 520 (S40). In this case, the wafer w transferred to the wafer pre-alignment stage 520 by the second handler 522 is positioned between the edge sensor 550 and the alignment mark sensor 560.

In this position, the wafer w is rotated at a predetermined speed by a rotating device (not shown), and the rotation of the wafer w causes the edge sensor 550 to detect the flat zone of the wafer w. Until it continues.

When the flat zone of the wafer w is detected, the alignment mark sensor 560 detects the alignment mark formed on the side of the wafer w, wherein the wafer w is the alignment mark sensor 560. Fine rotation by the rotary device until the alignment mark is detected by the). When the pre-alignment operation for the wafer w is completed, the third handler 532 is operated to transfer the wafer w to the wafer stage 530 (S50).

When the wafer w is transferred to the wafer stage 530, a plurality of optical sensors 534 installed on the wafer stage 530 detect the position of the wafer w. The optical sensor 534 is a precision sensor device and continuously transmits an electric signal according to the position of the wafer w to the controller. The controller operates the wafer positioning device based on the signals input from the photosensors 534 to finely adjust the position of the wafer w, thereby bringing the wafer w into position on the wafer stage 530. Position it.

When the alignment operation on the wafer w is completed, the controller applies an electric signal to the ultraviolet ray generator 536 to irradiate the ultraviolet ray on the wafer w on which alignment is completed. The ultraviolet irradiation is performed via a reticle in which a predetermined pattern is formed.

In this case, since the wafer maintains a state in which foreign substances are removed, even when using a reticle having a very precise pattern, pattern formation may be very easy.

On the other hand, Figure 5 shows that the cleaning device 200 according to the present invention is applied to the reticle cleaning stage 300 to remove the foreign matter on the reticle (R). Here, the configuration and operation of the cleaning device 200 is the same as the cleaning device 400 shown in FIG. 5, except that the nitrogen source 328 is used instead of the air source 428. The reason why nitrogen is used instead of air is that the compound contained in the air may damage the reticle (R).

7 is a block diagram illustrating a process of cleaning the reticle R.

As illustrated in FIG. 7, the foreign material removing process of the reticle R may include selecting a process to proceed (S60), selecting a reticle R (S70), and a reticle R in a reticle loader. ) Transfer step (S80), the reticle (R) washing step (S90) and the step of inspecting the impurities in the reticle portion (S100).

Since the reticle cleaning step S90 proceeds to the same mechanism as the wafer cleaning process, a detailed description thereof will be omitted below.

As described above, according to the present invention, since the wafer and the reticle can be pre-cleaned, there is an advantage of reducing the risk of defects in the reticle in the reticle inspection process and forming a precise reticle pattern on the wafer.

In addition, according to the present invention, since the defective rate of the product is reduced, there is an effect that the productivity of the product can be improved.

Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various improvements or modifications are possible within the scope of the technical idea of the present invention, and such improvements or modifications also belong to the present invention. Will be appreciated by those skilled in the art.

Claims (3)

Air ejection means for ejecting air toward the wafer transported to the wafer transport stage of the stepper consisting of a wafer transport stage, a wafer pre-alignment stage, and a wafer stage to release foreign matters from the wafer from the wafer; And And a foreign material suction means for sucking foreign substances separated by the air injection means and discharging them to the outside. According to claim 1, The air injection means is connected to an air source regulator for regulating the pressure of the air supplied from the air source, a first solenoid valve disposed between the air source and the regulator to open and close the inflow of air, A filter for filtering impurities contained in the air passing through the regulator and an air shower disposed at the bottom of the wafer to inject air toward the bottom of the wafer, and the foreign matter suction means is connected to a vacuum source, And a vacuum duct disposed adjacent to the air shower to suck foreign matter separated from the wafer, and a second solenoid valve for opening and closing the vacuum supply. A regulator for ejecting air toward the reticle to be transferred to the reticle cleaning stage to remove foreign substances from the reticle from the reticle, a regulator connected to an air source to regulate the pressure of air supplied from the air source, the air source and the regulator A first solenoid valve disposed between opening and closing the inflow of air, a filter for filtering impurities contained in the air passing through the regulator, and an air shower unit disposed at a bottom of the reticle to inject air toward the bottom of the reticle Air injection means comprising; And And a vacuum duct disposed to adsorb and discharge the foreign matter separated by the air jetting means to the outside, the vacuum duct disposed adjacent to the air shower to suck foreign matter separated from the wafer, and a second solenoid valve for opening and closing the vacuum source. A semiconductor manufacturing apparatus comprising: a foreign material suction means.