KR100632044B1 - Apparatus for cleaning a semiconductor wafer and method using the same - Google Patents

Abstract

The present invention relates to an apparatus and a method for cleaning a wafer, wherein the wafer transfer robot 113 sequentially transfers the wafer (W) to a plurality of cleaning tanks (120,..., 160) supplied so that chemical or ultrapure water overflows. In the apparatus to be injected into the washing, each of the cleaning tank (120, ..., 160) is installed for each upper end, and detects whether the chemical or ultrapure water overflows to the top of the cleaning tank (120, ..., 160) Receiving a detection signal output from the plurality of overflow detection units 181,..., 185 and the overflow detection units 181,... Recognizing that the chemical or ultrapure water does not overflow from (120, ...., 160) includes a control unit 190 for controlling the wafer transfer robot 113 to move the wafer (W) to a predetermined position Detects the overflow of chemical or ultrapure water from the bath, and If not overflowed, the wafer can be transported to a safe position for follow-up to prevent the chemicals from overflowing from the cleaning bath, preventing the wafer from being cleaned properly or water spots due to exposure to the top of the wafer. Thereby improving the yield of the wafer.

Description

Wafer cleaning apparatus and method {APPARATUS FOR CLEANING A SEMICONDUCTOR WAFER AND METHOD USING THE SAME}

1 is a block diagram showing a conventional wafer cleaning apparatus,

2 is a block diagram showing a wafer cleaning apparatus according to the present invention,

3 is a block diagram showing a wafer cleaning apparatus according to the present invention;

4 is a flowchart illustrating a wafer cleaning method according to the present invention.

<Description of Symbols for Main Parts of Drawings>

111 body 112 cassette lift

113: wafer transfer robot 120, ....., 160: cleaning tank

170: ultrapure water supply unit 181, ....., 185: overflow detection unit

190 control unit 210 alarm generation unit

The present invention relates to a wafer cleaning apparatus and a method, and more particularly, to detect a chemical or ultrapure water overflow from a cleaning tank, and to transfer the wafer to a safe position when the chemical or the like does not overflow from the cleaning tank. An apparatus and method for cleaning a wafer to be taken.

In general, in order to manufacture a semiconductor device, various unit processes, such as a diffusion process, an etching process, a chemical vapor deposition process, and a cleaning process, are performed. One of the most basic processes among these unit processes is a cleaning process.

The cleaning process is a process for removing various contaminants adhering to the wafer in various steps performed to manufacture the semiconductor device.

The apparatus used for the conventional wafer cleaning will be described with reference to the accompanying drawings.

1 is a block diagram showing a conventional wafer cleaning apparatus. As shown, the conventional wafer cleaning apparatus 1 is provided with a cassette lift 12, a wafer transfer robot 13, and a plurality of cleaning tanks 20, ..., 60 inside the main body 11. .

The cassette lift 12 is a position where the wafer cassette C on which the plurality of wafers W are mounted is loaded / unloaded into the main body 11 from the position where the wafer transfer robot 13 supports the wafer W. Move up and down.

The wafer transfer robot 13 separates the wafers W from the wafer cassette C lifted by the cassette lift 12 and feeds them into the respective cleaning tanks 20,. W) is mounted on the wafer cassette (C).

The cleaning tanks 20,..., 60 are chemical baths 20 and 50 that are supplied with chemicals to clean the inside, and rinse baths 30 and 40 that are supplied with ultrapure water to perform rinse cleaning. And it consists of the dry bath 60 which supplies a chemical | cleaning and ultrapure water, and washes and dry.

The cleaning tanks 20,..., 60 increase the cleaning effect of the wafer W injected into the inside by overflowing the chemical or ultrapure water supplied inside.

The chemical baths 20 and 50 and the dry bath 60 have external baths on the outside so that the movement paths of the chemicals discharged during overflow differ from the movement paths of ultrapure water discharged from the other baths 30 and 40. (21, 51, 61) are provided, respectively. Therefore, the chemicals overflowed from the chemical baths 20 and 50 and the dry bath 60 do not mix with the ultrapure water overflowed from the rinse baths 30 and 40 so as to purify and recycle the overflowed ultrapure water.

The chemical baths 20 and 50 and the dry bath 60 are also supplied with ultrapure water in the same manner as the rinse baths 30 and 40 in order to adjust the concentration of the chemicals supplied inward to the process conditions.

Each of the cleaning tanks 20,... 60 is connected to an ultrapure water supply line 71 so that ultrapure water is supplied from the ultrapure water supply unit 70.

On the ultrapure water supply line 71, a supply valve 72 and a flow meter 73 for grasping the supply amount of ultrapure water are respectively installed to open and close the supply of ultrapure water to the cleaning tanks 20, ..., 60, respectively.

The bath 50 of any one of the chemical baths 20 and 50 is provided with a circulation line 74 between the lower end and the external bath 51 so as to circulate and reuse the overflowed chemical, and on the circulation line 74. A pump 75 for circulating the chemical, a heater 76 for heating the chemical to a predetermined temperature during circulation, and a filter 77 for filtering foreign substances included in the circulated chemical are provided.

The dry bath 60 is installed inside the case 62 in which the lid 62a is opened and closed at the upper side and the outlet 62b is formed at the lower side, and the wafer W is dried inside the case 62. A plurality of injection nozzles 63 for injecting isopropyl alcohol (IPA) are installed.

The conventional wafer cleaning apparatus 1 includes a plurality of wafers W mounted on the wafer cassette C lifted by the cassette lifter 112 by the wafer transfer robot 113, respectively. 50, and then sequentially rinsed and dried in a dry bath 60, which is the cleaning tank 60 located last after cleaning the chemical or rinse.

The cleaning effect is enhanced by overflowing the chemical or ultrapure water when cleaning the wafer W in each of the cleaning baths 20,.

However, the connection part of the chemical supply line (not shown) for supplying the chemicals to the cleaning tanks (20, ..., 60) or the ultrapure water supply line (71) for supplying ultrapure water is damaged so that chemical or ultrapure water leaks to the cleaning tank ( If the overflow from the 20, ..., 60 is not normal, the cleaning of the wafer W introduced into the cleaning tank 20, ..., 60 may not be performed properly, and the top of the wafer W may be There was a problem that the reject (reject) is caused by a defect occurs in the subsequent process due to exposure to the air (water mark) occurs.

 The present invention is to solve the above-mentioned conventional problems, an object of the present invention is to detect the overflow of the chemical or ultrapure water from the cleaning tank to transfer the wafer to a safe position when the chemical does not overflow from the cleaning tank to follow Wafer cleaning apparatus and method that prevents overflow of chemicals from the cleaning tank and prevents water wafers from being exposed due to the air being exposed to air by allowing the action to be taken, thereby improving the yield of the wafer. To provide.

The present invention for realizing the above object is a device for cleaning wafers by sequentially feeding the wafers into a plurality of cleaning tanks supplied so that chemical or ultrapure water overflows, each of which is installed at each upper end of the cleaning tank. A plurality of overflow detectors for detecting whether the chemical or ultrapure water overflows and outputting a detection signal, and receiving a detection signal output from the plurality of overflow detectors, the chemical or ultrapure water does not overflow from the cleaning tank Recognizing, it characterized in that it comprises a control unit for controlling the wafer transfer robot to move the wafer to the cleaning tank that the ultrapure water is properly overflowed in the plurality of cleaning tanks.

In addition, the present invention is a method for sequentially cleaning the wafer in a plurality of cleaning tanks supplied so that the chemical or ultrapure water is overflowed, separating the wafer from the wafer cassette, and in the cleaning tank to be injected to clean the wafer Detecting whether the chemical or ultrapure water overflows; if the chemical or ultrapure water overflows, injecting the wafer into the overflowing cleaning tank; And when the time required for cleaning after the wafer is added to the cleaning tank has elapsed, it is determined whether there is another cleaning tank to remove and insert the wafer from the cleaning tank. Performing the checking step and the cleaning tank If other cleaning Joe to be input from the taken out wafer it is characterized in that it comprises the step of unloading the wafer mounted on the wafer cassette.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

2 is a block diagram showing a wafer cleaning apparatus according to the present invention, Figure 3 is a block diagram showing a wafer cleaning apparatus according to the present invention. As shown, the wafer cleaning apparatus 100 according to the present invention has a cassette lift 112, a wafer transfer robot 113, a plurality of cleaning tanks 120,... 160 inside the main body 111. Each of the tops of the cleaning tanks 120,..., 160 is installed with a plurality of overflow detection units 181,..., 185, and overflow detection units. Receiving a detection signal from the control unit 190 to control the wafer transfer robot 113.

The cassette lifter 112 is controlled by the controller 190 so that the wafer transfer robot 113 is loaded from the loading / unloading position in the main body 111 to the wafer cassette C on which the plurality of wafers W are mounted. ) To the position where it supports.

The wafer transfer robot 113 is controlled by the control unit 190 to separate the wafers W from the wafer cassette C lifted by the cassette lift 112, and the respective cleaning tanks 120, ..., 160 are separated. The wafer W, which has been charged or cleaned, is mounted on the wafer cassette C.

The cleaning tanks 120,..., 160 are chemical baths 120, 150 for supplying chemicals to the inside, and rinse baths 130, 140 for rinsing the supply of ultrapure water, and chemical cleaning. In addition, ultra-pure water is supplied to perform the cleaning and drying as well as the dry bath 160, in addition to these may be made of various combinations, it is supplied to the inside to increase the cleaning effect of the wafer (W) injected into the inside Chemical or ultrapure water overflows.

Chemical baths (120,150) and dry baths (160, 150, 150) supplied with chemicals in the cleaning tank (120, ...., 160) of the ultra pure water overflowed from the chemical and rinse bath (130, 140) overflowed for the recycling of ultrapure water External baths 121, 151, and 161 are provided on the outside to different the discharge paths.

The cleaning tanks 120,..., 160 are provided with an ultrapure water supply line 171, a supply valve 172, and a flow meter 173, respectively, for supplying ultrapure water supplied from the ultrapure water supply unit 170 as in the prior art. In one chemical bath 150, a circulation line 174, a pump 175, a heater 176, and a filter 177 are installed, respectively, and the dry bath 160 may dry the wafer (W). In order to provide a plurality of injection nozzles 163 for injecting isopropyl alcohol (IPA), the cover 162a and the outlet 162b are respectively provided inside the case 162.

The overflow detectors 181,..., 185 detect a chemical or ultrapure water overflowed from the washing tanks 120,..., 160, and output a detection signal to the controller 190. As the liquid level sensor, it is provided for each upper end of the cleaning tank (120,..., 160).

The overflow detectors 181,..., 185 are used to accurately detect chemical or ultrapure water that overflows from the washing tanks 120,..., 160. ) Is preferably installed at the upper end of the outer surface of the cleaning tank (120, ..., 160) that is the point where the chemical or ultrapure water overflows and descends by passing through the upper end.

The controller 190 receives the detection signals output from the plurality of overflow detectors 181,..., 185 and does not overflow the chemical or ultrapure water from the washing tanks 120,..., 160. Recognizing that the wafer transfer robot 113 is controlled to wait the wafer (W) at a predetermined position.

If the controller 190 recognizes that the chemical or ultrapure water does not overflow from the cleaning tanks 120,..., 160 by the detection signal received from the overflow detectors 181,. (W) is moved into the cleaning tank overflowing from the cleaning tanks 130 and 140 filled with ultrapure water.

On the other hand, it is preferable that the alarm generating unit 210 for generating an alarm when the overflow from the cleaning tank (120, .... 160) is not properly provided.

The alarm generating unit 210 has a chemical or ultrapure water from the cleaning tank 120,..., 160 due to the detection signal received from the overflow detection unit 181,..., 185. Receives a control signal generated when the flow is not recognized and generates an alarm to the outside by the generation of an alarm sound or the blinking of the alarm light so that the operator can take further action.

In the wafer cleaning apparatus 100 according to the present invention having such a structure, the wafer transport robot 113 separates the plurality of wafers W separated from the wafer cassette C lifted by the cassette lift 112. When the cleaning process such as chemical liquid, rinse, drying, etc. is added to each of the 120, ..., 160, the overflow detection unit checks whether the chemical or ultrapure water is properly overflowed from the cleaning tank (120, ..., 160). If the chemical or ultrapure water does not flow properly from the cleaning tanks 120,..., And 160 through 181,..., 185, the controller 190 moves the wafer W to a predetermined position, that is, Ultrapure water is filled in the cleaning tanks 120,..., 160 and the ultrapure water is moved to the cleaning tank where the ultrapure water overflows. Therefore, the cleaning tank 120,..., 160 that does not overflow prevents the water W from being properly cleaned or the generation of water marks on the portions exposed to the air.

In the wafer cleaning method according to the present invention, as shown in FIG. 4, a step (S10) of separating the wafer (W) from the wafer cassette (C) and a cleaning tank (120,... Detecting the overflow in step S20 (S20), injecting the wafer (W) into the overflowing cleaning tank (120, ..., 160) (S30), and after the wafer (W) to clean The step S40 of checking whether the required time has elapsed, the step S50 of determining whether there are other cleaning tanks 120,..., 160 to which the wafer W is to be introduced, and the wafer W are processed. Attaching to the cassette (C) and the step of unloading (S60).

The step S10 of separating the wafer W from the wafer cassette C is performed when the wafer cassette C on which the plurality of wafers W are to be cleaned is loaded into the main body 111 (S11). The wafer cassette C loaded by 112 is raised to the working position of the wafer transfer robot 113 to separate the plurality of wafers W from the wafer cassette C by the wafer transfer robot 113 (S12). .

Detecting an overflow in the cleaning tanks 120,... 160 to which the wafers W are to be introduced (S20) may detect the wafers W separated by the wafer transfer robot 113 from the wafer cassette C. The chemical or ultrapure water in the cleaning tanks 120,... 160 to which the wafers W are to be introduced when the wafers are sequentially added to the plurality of cleaning tanks 120,... 160 by the wafer transfer robot 113. The overflow detection unit (181, ..., 185) detects whether the overflow.

The step (S30) of injecting the wafer (W) into the overflow cleaning tank (120, ..., 160) is chemical in the cleaning tank (120, ..., 160) to inject the wafer (W) for cleaning Alternatively, the overflow of the ultrapure water through the overflow detectors 181, ..., 185, which are liquid level sensors installed at the top of each of the cleaning tanks 120, ..., 160, may cause the chemical or ultrapure water to overflow. The wafers W are introduced into the cleaning tanks 120,... 160.

The step S40 of checking whether the time required for cleaning after the wafer W is passed (S40) is performed after the wafer W is put into the cleaning tanks 120,..., 160 where the chemical or ultrapure water overflows. Check whether the time required for cleaning has elapsed in the bath 120... 160.

Determining whether there are other cleaning tanks 120,..., 160 to which the wafers W are to be inserted (S50) may be cleaned after the wafers W are inserted into the cleaning tanks 120,... When the time required for elapses, the wafer W is removed from the cleaning tanks 120, ..., 160, and it is determined whether there is another cleaning tank to be injected (S50). Detecting whether the chemical or ultrapure water overflows in the cleaning tank (120, ..., 160) (S20) or less to perform the cleaning tank 120, .. .., 160).

The step S60 of mounting and unloading the wafer W on the wafer cassette C determines whether there is another cleaning tank 120,..., 160 to which the wafer W is to be injected (S50). If there is no other cleaning tank to remove and insert the wafer W from the cleaning tanks 120, ..., 160, the wafer transfer robot 113 mounts the wafer W to the wafer cassette C (S61). ) The wafer cassette C is unloaded from the main body 111 for the subsequent process (S62).

After the wafer W is put into the cleaning tanks 120,... 160, the wafer W is placed in the cleaning tanks 120,... 160 in step S40. When the time required for cleaning after the input has not elapsed, a step (S41) of detecting whether the chemical or ultrapure water overflows properly in the cleaning tank (120,... desirable. Accordingly, while the wafers W are introduced into the cleaning tanks 120,... 160, the chemicals or ultrapure water may overflow properly to detect whether the cleaning is properly performed.

Detecting whether the chemical or ultrapure water overflows in the cleaning tanks 120, ..., 160 to be injected to clean the wafer W (S20) or the cleaning tank 120, in which the wafer W is inserted In step (S41) of detecting whether the chemical or ultrapure water does not overflow in step (.41), an alarm generating step of generating an alarm sound or flashing of an external light when the chemical or ultrapure water does not overflow ( S70) is preferably provided.

Detecting whether the chemical or ultrapure water overflows in the cleaning tanks 120,..., 160 to be injected to clean the wafer W (S20) or the cleaning tank 120 into which the wafers W are inserted. In step (S41) of detecting whether the chemical or ultrapure water does not overflow in step (S41), when the chemical or ultrapure water does not overflow, the wafer W overflows in the cleaning tanks 130 and 140 filled with ultrapure water. It is provided with a step (S80) to wait to put into the washing tank is detected.

In step S80, the wafer W is introduced into the cleaning tank in which the ultrapure water is filled in the cleaning tank 130, 140 and detected to be overflowed, and then waits (S80). Alternatively, if there is no overflow of the chemical or ultrapure water from the cleaning tanks 120, ..., 160 into which the wafer W is injected, it is detected whether there is a cleaning tank that overflows properly in the cleaning tanks 130 and 140 filled with ultrapure water ( S81) The wafer W is introduced into the cleaning tank overflowing from the cleaning tanks 130 and 140 filled with ultrapure water (S82).

Detecting whether there is a cleaning tank overflowing properly in the cleaning tanks 130 and 140 filled with ultrapure water (S81). To minimize damage to the wafer (W).

In the wafer cleaning method according to the present invention, a plurality of wafers W separated from the wafer cassette C by the wafer transfer robot 113 are added to each cleaning tank 120,... When the cleaning process such as drying is performed, the cleaning tank 120,..., 160 detects whether the chemical or ultrapure water overflows properly, and the wafer W is introduced or the cleaning tank 120,... .160, if the overflow of the chemical or ultrapure water does not go well, an alarm is triggered to the outside to prompt the operator to take further action, and the wafer W is exposed to air, causing water marks. In order to prevent such defects from occurring, ultrapure water is filled in the cleaning tanks 120,..., 160 and the ultrapure water is moved to a cleaning tank that overflows properly.

According to the preferred embodiment of the present invention as described above, by detecting the overflow of the chemical or ultrapure water from the cleaning tank to transfer the wafer to a safe position to take a follow-up action if the chemical or the like does not overflow from the cleaning tank As the chemicals and the like do not overflow from the bath, the wafer is not cleaned properly or the top of the wafer is exposed to air to prevent water spots from occurring, thereby improving the yield of the wafer.

As described above, the apparatus and method for cleaning a wafer according to the present invention detects that the chemical or ultrapure water overflows from the cleaning bath and transfers the wafer to a safe position to take follow-up when the chemical or the like does not overflow from the cleaning bath. In this way, the chemicals and the like do not overflow from the cleaning tank, so that the wafer is not cleaned properly or the top of the wafer is exposed to air to prevent water spots from occurring, thereby improving the yield of the wafer.

What has been described above is only one embodiment for carrying out the wafer cleaning apparatus and method according to the present invention, the present invention is not limited to the above-described embodiment, as claimed in the following claims Without departing from the gist of the present invention, those skilled in the art to which the present invention pertains to the technical spirit of the present invention to the extent that various modifications can be made.

Claims (7)

An apparatus for cleaning wafers by sequentially feeding wafers into a plurality of cleaning tanks supplied so that chemical or ultrapure water overflows, Installed in each upper end of the washing tank, and a plurality of overflow detecting units detecting whether the chemical or ultrapure water overflows to the upper end of the washing tank and outputting a detection signal; Receiving the detection signals output from the plurality of overflow detection units and recognizing that the chemical or ultrapure water does not overflow from the cleaning tank, the wafer is moved to the cleaning tank where the ultrapure water overflows properly in the plurality of cleaning tanks. Control unit for controlling the wafer transfer robot Wafer cleaning apparatus comprising a. delete The method of claim 1, Alarm generation unit for receiving an alarm to the control signal generated when the controller recognizes that the chemical or ultrapure water does not overflow from the cleaning tank by the detection signal received from the overflow detection unit Wafer cleaning apparatus comprising a further. In the method of cleaning by sequentially input the wafer into a plurality of cleaning tanks supplied so that the chemical or ultrapure water overflows, Separating the wafer from the wafer cassette (S10); Detecting whether the chemical or ultrapure water overflows in the cleaning bath to be injected to clean the wafer (S20); If the chemical or ultrapure water in the cleaning tank overflows, injecting the wafer into the overflowing cleaning tank (S30); Checking whether the time required for cleaning after the wafer is put into the cleaning tank has been elapsed (S40); When the time required for cleaning after the wafer is added to the cleaning tank has passed, it is determined whether there is another cleaning tank to take out the wafer from the cleaning tank, and if there is another cleaning tank, the overflow detection step (S20) and the cleaning tank are inserted. Performing a step S30 and the time elapsed checking step S40; If there is no other cleaning tank to remove and insert the wafer from the cleaning tank, mounting and unloading the wafer in the wafer cassette (S60). Wafer cleaning method comprising a. The method of claim 4, wherein In the step S40 of checking whether the time required for cleaning after the wafer is added to the cleaning bath has elapsed, the chemical or the wafer is inserted into the cleaning bath when the time required for cleaning after the wafer is not added to the cleaning bath has elapsed. Detecting whether ultrapure water overflows (S41) Wafer cleaning method comprising a further. The method of claim 5, In step S20 of detecting whether the chemical or ultrapure water overflows in the cleaning tank to be injected to clean the wafer, or in step S41 of detecting whether the chemical or ultrapure water overflows in the cleaning tank into which the wafer is introduced. Step (S70) for generating an alarm when detecting that the chemical or ultrapure water does not overflow Wafer cleaning method comprising a further. The method of claim 5, In step S20 of detecting whether the chemical or ultrapure water overflows in the cleaning tank to be injected to clean the wafer, or in step S41 of detecting whether the chemical or ultrapure water overflows in the cleaning tank into which the wafer is introduced. When detecting that the chemical or ultrapure water does not overflow, the wafer is put into the cleaning tank that is detected to overflow in the cleaning tank filled with ultrapure water (S80) Wafer cleaning method comprising a further.

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