The present invention generally relates to the field of fabricating integrated circuits, and more particularly relates to a method and apparatus for cleaning semiconductor wafers.
During the integrated circuit fabrication process, a wet cleaning process is essential for obtaining high quality integrated circuits. After a dry etching process, a wafer needs to be cleaned to remove residual photoresist, organics produced during the dry etching process, and film material attached on a surface of the wafer. The main chemical solution for cleaning the wafer includes, for example SC1, BOE and SPM which is a mixture of H2SO4 and H2O2. Thereinto, the temperature of SPM is higher than 90° C. and the SPM is used for removing the residual photoresist and organics. Generally, there are two ways to clean the wafer in the industry. One is batch cleaning and the other is single wafer cleaning, both of which will be comparatively described.
The batch cleaning is capable of cleaning a plurality of wafers every time. An apparatus for batch cleaning includes mechanical transmission devices and several cleaning tanks. A plurality of wafers can be cleaned in one of the cleaning tanks simultaneously, so the efficiency of batch cleaning is high and about four hundred wafers can be cleaned per hour. Moreover, because the chemical solution in the cleaning tanks is circulated, therefore, the chemical solution can be reused and the cost of batch cleaning is reduced, especially for high temperature chemical solution, like 120° C. SPM, for the high temperature SPM is expensive, so the cleaning cost can be reduced by using the batch cleaning. However, with the line width of integrated circuit shrinking continuously, the disadvantages of the batch cleaning are exposed visibly. During the batch cleaning process, the wafers are put in the cleaning tanks vertically, which easily causes cross contamination. Specially, if one of the wafers in one of the cleaning tanks has metal or organic contaminants, all the wafers cleaned in the same cleaning tank are contaminated. After cleaned, the wafers are taken out of the cleaning tanks vertically. At this time, if the chemical solution in the cleaning tanks has some tiny organic contaminants, the tiny organic contaminants will adhere to the surfaces of the wafers along with the chemical solution. Once the wafers are dried, the tiny organic contaminants on the wafers are very hard to remove.
The single wafer cleaning can only clean a piece of wafer every time. An apparatus of single wafer cleaning includes mechanical transmission devices and several independent single wafer cleaning modules. The cleaning and drying processes of one wafer are finished in one single wafer cleaning module. After cleaning a piece of wafer, the chemical solution in the single wafer cleaning module is drained and new chemical solution is supplied to the single wafer cleaning module to clean another piece of wafer, avoiding cross contaminant. The single wafer cleaning can effectively remove particles and film material, but the single wafer cleaning has a limitation in use of high temperature chemical solution, such as SPM which temperature is higher than 90° C., because the high temperature chemical solution is hard to recycle.
Both the batch cleaning and the single wafer cleaning have their own advantages and disadvantages. Only adopting the batch cleaning or the single wafer cleaning cannot achieve the best cleaning effect and also cannot meet the needs of modern process. Therefore, inventing a new method and apparatus which combine the advantages of the batch cleaning and the single wafer cleaning will be a great contribution to the integrated circuit fabrication process.
Accordingly, an object of the present invention is to provide a method for cleaning semiconductor wafer. The method includes the following steps: taking at least two wafers from a cassette in a load port and putting said wafers into a first tank filled with chemical solution; after said wafers have been processed in the first tank, taking said wafers out of the first tank and keeping said wafers in wet status; putting said wafers into a second tank filled with liquid; after said wafers have been processed in the second tank, taking said wafers out of the second tank and keeping said wafers in wet status; putting one of said wafers on a chuck inside a single wafer cleaning module; rotating the chuck while applying chemical solution on said wafer; applying deionized water on said wafer; drying said wafer; taking said wafer out of the single wafer cleaning module and then putting said wafer back to the cassette in the load port.
Accordingly, another object of the present invention is to provide an apparatus for cleaning semiconductor wafer. In one embodiment, the apparatus includes a first cassette, at least one first tank, a second tank, at least two single wafer cleaning modules, two turnover mechanisms, a first robot, a second robot and a third robot. The first cassette is located in a load port for loading a plurality of wafers. The first tank is filled with chemical solution. The second tank is filled with liquid. The single wafer cleaning modules are used for cleaning and drying single wafer. The two turnover mechanisms are used for turning the wafers put therein. One turnover mechanism is disposed adjacent to the first tank and the other turnover mechanism is disposed adjacent to the second tank. The first robot is equipped with at least two wafer loading arms for taking at least two wafers from the first cassette and putting the at least two wafers in the turnover mechanism adjacent to the first tank. The second robot is used for taking the at least two wafers from the turnover mechanism and putting the at least two wafers into the first tank and the second tank successively. After the at least two wafers are immersed into the first tank and the second tank respectively for a period of time, the second robot takes the at least two wafers out of the second tank and puts the at least two wafers in the turnover mechanism adjacent to the second tank. The third robot is equipped with at least two wafer loading arms for taking the at least two wafers out of the turnover mechanism adjacent to the second tank and putting one of the at least two wafers into one of the single wafer cleaning modules for performing single wafer cleaning and drying processes, wherein the at least two wafers are kept in wet status all the time before single wafer cleaning and drying processes are performed. Finally, the first robot takes the wafer out of the single wafer cleaning module and puts the wafer back to the first cassette.
According to another embodiment, an apparatus for cleaning semiconductor wafer includes a first cassette, at least one first tank, a second tank, at least two single wafer cleaning modules, two turnover mechanisms, a buffer area, a first robot, a second robot and a third robot. The first cassette is located in a load port for loading a plurality of wafers. The first tank is filled with chemical solution. The second tank is filled with liquid. The single wafer cleaning modules are used for cleaning and drying single wafer. The two turnover mechanisms are used for turning the wafers put therein. One turnover mechanism is disposed adjacent to the first tank and the other turnover mechanism is disposed adjacent to the second tank. The buffer area is used for temporarily receiving the wafers. The first robot is equipped with at least two wafer loading arms for taking at least two wafers from the first cassette and putting the at least two wafers into the buffer area. The third robot is equipped with at least two wafer loading arms for taking the at least two wafers out of the buffer area and putting the at least two wafers in the turnover mechanism adjacent to the first tank. The second robot is used for taking the at least two wafers from the turnover mechanism and putting the at least two wafers into the first tank and the second tank successively. After the at least two wafers are immersed into the first tank and the second tank respectively for a period of time, the second robot takes the at least two wafers out of the second tank and puts the at least two wafers in the turnover mechanism adjacent to the second tank. Then the third robot takes the at least two wafers out of the turnover mechanism adjacent to the second tank and puts one of the at least two wafers into one of the single wafer cleaning modules for performing single wafer cleaning and drying processes, wherein the at least two wafers are kept in wet status all the time before single wafer cleaning and drying processes are performed. Finally, the first robot takes the wafer out of the single wafer cleaning module and puts the wafer back to the first cassette.
According to another embodiment, an apparatus for cleaning semiconductor wafer includes a first cassette, at least one first tank, a second tank, at least two single wafer cleaning modules, two turnover mechanisms, a first robot and a second robot. The first cassette is located in a load port for loading a plurality of wafers. The first tank is filled with chemical solution. The second tank is filled with liquid. The single wafer cleaning modules are used for cleaning and drying single wafer. The two turnover mechanisms are used for turning the wafers put therein. One turnover mechanism is disposed adjacent to the first tank and the other turnover mechanism is disposed adjacent to the second tank. The first robot is equipped with at least three wafer loading arms, one of which takes at least two wafers from the first cassette and puts the at least two wafers in the turnover mechanism adjacent to the first tank. The second robot is used for taking the at least two wafers from the turnover mechanism and putting the at least two wafers into the first tank and the second tank successively. After the at least two wafers are immersed into the first tank and the second tank respectively for a period of time, the second robot takes the at least two wafers out of the second tank and puts the at least two wafers in the turnover mechanism adjacent to the second tank. Then one of the wafer loading arms of the first robot takes the at least two wafers out of the turnover mechanism adjacent to the second tank and puts one of the at least two wafers into one of the single wafer cleaning modules for performing single wafer cleaning and drying processes, wherein the at least two wafers are kept in wet status all the time before single wafer cleaning and drying processes are performed. Finally one of the wafer loading arms of the first robot takes the wafer out of the single wafer cleaning module and puts the wafer back to the first cassette.
As described above, the present invention combines the batch cleaning and the single wafer cleaning together, developing the advantages of the batch cleaning and the single wafer cleaning. Adopting the method and apparatus of the present invention can effectively remove organics, particles and film material after the wafers undergo a dry etching process. The high temperature process can be performed by the batch cleaning to remove the organics since the high temperature chemical solution can be recycled and reused in the batch cleaning process and, acid mist produced during the batch cleaning process can be controlled well. The particles and film material are removed by the single wafer cleaning. Because the wafers are kept in wet status all the time before single wafer cleaning and drying processes are performed, contaminants on the wafers are easily removed by single wafer cleaning.
The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof, with reference to the attached drawings, in which:
Referring to
Every load port 110 can be used for receiving a first cassette (not shown). A plurality of wafers are loaded in the first cassette. Generally, there are twenty five pieces of wafers loaded in the first cassette. In order to raise the cleaning efficiency of the apparatus 100, the apparatus 100 can include more than one load port 110. In the preferred embodiment, there are four load ports 110 arranged side by side. It should be recognized that the number of load port 110 is not limited in four.
The first robot 120 is equipped with at least two wafer loading arms. One of the wafer loading arms can be used for taking the plurality of wafers out of the first cassette located in the load port 110 and putting the plurality of wafers in a turnover mechanism 131 of the batch cleaning device 130, as shown in
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The third robot 140 is equipped with at least one wafer loading arm for taking a piece of wafer from the batch cleaning device 130 every time after the wafer processed in the batch cleaning device 130 and putting the piece of wafer in one of the single wafer cleaning modules 150 to perform single wafer cleaning and drying processes. In order to keep the wafer in wet status all the time before the wafer is put into the single wafer cleaning module 150 to perform the single wafer cleaning and drying processes, a shower head 170 is disposed on the wafer loading arm for spraying deionized water onto the wafer held by the wafer loading arm through a nozzle 171 connecting with the shower head 170, as shown in
The single wafer cleaning module 150 can be used for cleaning and drying single wafer. For raising the cleaning efficiency, there are several single wafer cleaning modules 150 and the several single wafer cleaning modules 150 have a variety of arrangements. In the preferred embodiment, there are ten single wafer cleaning modules 150 which are arranged in two rows and five columns. It should be recognized that the number of single wafer cleaning modules 150 and the arrangements of the single wafer cleaning modules 150 can be selected flexibly according to the practical applications. Every single wafer cleaning module 150 has a chuck disposed inside a single wafer cleaning chamber. The plurality of wafers are taken from the batch cleaning device 130 in wet status after processed in the batch cleaning device 130 and respectively put on the chuck to be processed. After the wafer is put on the chuck, rotate the chuck and apply chemical solution on the wafer to cleaning the wafer, and then apply deionized water on the wafer. Both the chemical solution and the deionized water are applied on the wafer by using spray nozzles. Then, dry the wafer. Finally, take the dried wafer out of the single wafer cleaning module 150 and put the dried wafer back to the first cassette by using the first robot 120. The chemical solution applied on the wafer can be one kind of the following, such as diluted hydrogen chloride solution, SC1 solution, both the diluted hydrogen chloride solution and SC1 solution, SC2 solution, ozone water solution and functional water doped by gas and NH4OH, wherein, the gas is hydrogen gas with concentration of 1.6 ppm, and concentration of NH4OH is less than 100 ppm. Preferably, prior to drying the wafer, a kind of chemical solution is applied on the wafer. The kind of chemical solution can be one kind of the following, such as diluted hydrogen chloride solution, SC1 solution and SC2 solution. The method of drying the wafer includes rotating the chuck and applying IPA solution on the wafer. Preferably, apply megasonic wave during single wafer cleaning process.
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Accordingly, a method for cleaning semiconductor wafer of the present invention is summarized as below:
In step 1: taking at least two wafers from the first cassette in the load port 110 and putting the wafers into the first tank 137 filled with chemical solution;
In step 2: after the wafers have been processed in the first tank 137, taking the wafers in wet status out of the first tank 137 and putting the wafers into the second tank 138 filled with liquid;
In step 3: after the wafers have been processed in the second tank 138, taking the wafers in wet status out of the second tank 138 and putting one of the wafers on the chuck inside one single wafer cleaning module 150;
In step 4: rotating the chuck while applying chemical solution on the wafer;
In step 5: applying deionized water on the wafer;
In step 6: drying the wafer; and
In step 7: taking the wafer out of the single wafer cleaning module 150 and then putting the wafer back to the first cassette in the load port 110.
As described above, the present invention combines the batch cleaning and the single wafer cleaning together, developing the advantages of the batch cleaning and the single wafer cleaning for cleaning the wafers. The apparatus and method can effectively remove organics, particles and film material after a dry etching process. The high temperature process can be performed in the batch cleaning device 130 to remove the organics since the high temperature chemical solution can be recycled in the batch cleaning device 130 and the acid mist produced during the batch cleaning process can be controlled well. The particles and film material are removed in the single wafer cleaning modules 150. Besides, the wafers are kept in wet status all the time before the wafers are put in the single wafer cleaning modules 150 to be cleaned and dried, making the contaminants adhered on the wafers being removed easily.
The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to those skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.
Number | Name | Date | Kind |
---|---|---|---|
4493606 | Foulke et al. | Jan 1985 | A |
4936328 | Yatabe | Jun 1990 | A |
RE33341 | Lee et al. | Sep 1990 | E |
5240557 | Dyer et al. | Aug 1993 | A |
5269643 | Kodama et al. | Dec 1993 | A |
5327921 | Mokuo | Jul 1994 | A |
5374153 | Nishi | Dec 1994 | A |
5406092 | Mokuo | Apr 1995 | A |
5482068 | Kitahara | Jan 1996 | A |
5503171 | Yokomizo | Apr 1996 | A |
5505577 | Nishi | Apr 1996 | A |
5544421 | Thompson et al. | Aug 1996 | A |
5566076 | Kuroda | Oct 1996 | A |
5595412 | Kudo et al. | Jan 1997 | A |
5603777 | Ohashi | Feb 1997 | A |
5664337 | Davis et al. | Sep 1997 | A |
5730162 | Shindo et al. | Mar 1998 | A |
5762084 | Krusell et al. | Jun 1998 | A |
5836736 | Thompson et al. | Nov 1998 | A |
5853496 | Honda | Dec 1998 | A |
5862823 | Kamikawa | Jan 1999 | A |
5887602 | Iwama | Mar 1999 | A |
6021791 | Dryer et al. | Feb 2000 | A |
6050275 | Kamikawa | Apr 2000 | A |
6074515 | Iseki | Jun 2000 | A |
6091498 | Hanson et al. | Jul 2000 | A |
6138695 | Shibao | Oct 2000 | A |
6279724 | Davis | Aug 2001 | B1 |
6345947 | Egashira | Feb 2002 | B1 |
6532975 | Kamikawa | Mar 2003 | B1 |
6575178 | Kamikawa | Jun 2003 | B1 |
6637446 | Frost et al. | Oct 2003 | B2 |
6672820 | Hanson et al. | Jan 2004 | B1 |
6942738 | Nelson et al. | Sep 2005 | B1 |
7357842 | Ishikawa et al. | Apr 2008 | B2 |
8002511 | Kamikawa et al. | Aug 2011 | B2 |
8216391 | Mokuo | Jul 2012 | B2 |
9324602 | Shinohara et al. | Apr 2016 | B2 |
20010043856 | Woodruff | Nov 2001 | A1 |
20020009357 | Hanson et al. | Jan 2002 | A1 |
20020016067 | Yamagata | Feb 2002 | A1 |
20020036002 | Nakatou | Mar 2002 | A1 |
20020037207 | Yamasaki et al. | Mar 2002 | A1 |
20020081181 | Yokomori et al. | Jun 2002 | A1 |
20020092547 | You | Jul 2002 | A1 |
20020100496 | Chang | Aug 2002 | A1 |
20030017034 | Davis | Jan 2003 | A1 |
20030051972 | Davis | Mar 2003 | A1 |
20030091410 | Larson et al. | May 2003 | A1 |
20030188447 | Nelson et al. | Oct 2003 | A1 |
20030202871 | Thompson | Oct 2003 | A1 |
20030230384 | Su et al. | Dec 2003 | A1 |
20040129300 | Ohshimo et al. | Jul 2004 | A1 |
20040211449 | Yokomoto | Oct 2004 | A1 |
20050051195 | Kamikawa | Mar 2005 | A1 |
20050072358 | Katsuoka | Apr 2005 | A1 |
20060099339 | Hashizume | May 2006 | A1 |
20060177586 | Ishida | Aug 2006 | A1 |
20060185692 | Moran et al. | Aug 2006 | A1 |
20070221254 | Izumi | Sep 2007 | A1 |
20080223411 | Mokuo | Sep 2008 | A1 |
20090067959 | Takahashi et al. | Mar 2009 | A1 |
20090097950 | Tanaka | Apr 2009 | A1 |
20100068014 | Mitsuyoshi | Mar 2010 | A1 |
20110000512 | Toshima | Jan 2011 | A1 |
20110041764 | Webb et al. | Feb 2011 | A1 |
20110126860 | Hyakutake | Jun 2011 | A1 |
20110135428 | Kim et al. | Jun 2011 | A1 |
20110264260 | Hong | Oct 2011 | A1 |
20120234358 | Takemura | Sep 2012 | A1 |
20120308346 | Keigler | Dec 2012 | A1 |
20130061888 | Sato | Mar 2013 | A1 |
Number | Date | Country |
---|---|---|
1929085 | Mar 2007 | CN |
201375944 | Jan 2010 | CN |
201956323 | Aug 2011 | CN |
H07183268 | Jul 1995 | JP |
H09199461 | Jul 1997 | JP |
19990088436 | Dec 1999 | KR |
20040070807 | Aug 2004 | KR |
200842965 | Nov 2008 | TW |
Entry |
---|
International Search Report issued in PCT/CN2012/085403 dated Sep. 5, 2013 (2 pages). |
Written Opinion of the International Searching Authority issued in PCT/CN2012/085403 dated Sep. 5, 2013 (4 pages). |
Office Action issued in corresponding Chinese Application No. 201280077256.1 dated Nov. 23, 2016, and English translation thereof (17 pages). |
Office Action issued in corresponding Korean Application No. 10-2015-7012686 dated Nov. 5, 2018, and English translation thereof (12 pages). |
Number | Date | Country | |
---|---|---|---|
20190273003 A1 | Sep 2019 | US |
Number | Date | Country | |
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Parent | 14647996 | US | |
Child | 16377894 | US |