This application claims the benefit of Japanese Priority Patent Application JP 2014-086177 filed on Apr. 18, 2014, the entire contents of which are incorporated herein by reference.
The present technology relates to a substrate treatment device which detects a residue of a metal film remaining on a surface (polished surface) of a substrate after polishing.
Conventionally, a substrate treatment device having a polishing section that polishes a substrate such as a semiconductor wafer to remove a metal film formed on the substrate, and a cleaning section that cleans and dries the substrate polished by the polishing section, has been known. At the polishing section, for example, a polishing face is formed by pasting a polishing pad on an upper face of a polishing table, a surface to be polished of a substrate such as a semiconductor wafer held at a polishing head (substrate holding mechanism) is brought into pressure contact with the polishing face, and chemical mechanical polishing (CMP) is performed, in which the surface to be polished is polished so as to be smooth by way of relative movement between the polishing face and the surface to be polished, the relative movement being caused by rotation of the polishing table and rotation of the polishing head, while slurry is supplied to the polishing face.
While in a CMP device, a metal film excessively formed on the substrate is removed through polishing in this manner, there is a case where a metal film is not sufficiently removed and remains as a residue on a surface (polished surface) of the substrate after polishing, for example, when an operation failure of the device occurs. Therefore, conventionally, a device has been proposed, in which a sensor head which is provided (buried) inside the polishing table, is made to rotate along with the polishing table during polishing of the wafer so as to acquire film thickness data while passing across the surface of the wafer. For example, JP2013-222856A discloses such a device.
However, the conventional device can merely acquire film thickness data at the time when the sensor head comes below the wafer (film thickness data of part of the wafer, instead of film thickness data of the whole wafer), and there is also a limit to measurement accuracy of the film thickness because the conventional device acquires film thickness data while rotating along with the polishing table.
It is desirable to provide a substrate treatment device capable of detecting a metal film remaining as a residue on a polished surface of a substrate after polishing with high accuracy.
One aspect of the substrate treatment device includes a polishing section that polishes a surface to be polished of a substrate to remove a metal film formed on the surface to be polished, a cleaning section that cleans and dries the substrate polished by the polishing section, and a temporary table on which the substrate is temporarily placed after being polished by the polishing section, and a sensor that detects a metal film remaining on the polished surface of the substrate is provided at the temporary table.
The substrate treatment device of one embodiment includes a polishing section that polishes a surface to be polished of a substrate to remove a metal film formed on the surface to be polished, a cleaning section that cleans and dries the substrate polished by the polishing section, and a temporary table on which the substrate is temporarily placed after being polished by the polishing section, and a sensor that detects a metal film remaining on the polished surface of the substrate is provided at the temporary table.
According to this configuration, the sensor is provided at the temporary table on which the substrate is temporarily placed after being polished. It is therefore possible to detect a metal film remaining as a residue on the polished surface of the substrate placed on the temporary table using the sensor provided at the temporary table. In this case, it is possible to detect the metal film on the polished surface of the substrate after being polished with higher accuracy than in a case where a sensor is provided (buried) inside the polishing table as in the conventional device.
Further, in the substrate treatment device of the embodiment, the temporary table may be provided between the polishing section and the cleaning section, and the substrate polished by the polishing section may be temporarily placed on the temporary table before being cleaned by the cleaning section.
According to this configuration, the sensor is provided at the temporary table provided between the polishing section and the cleaning section. It is therefore possible to detect the metal film on the polished surface of the substrate placed on the temporary table with high accuracy using the sensor provided on the temporary table before the substrate polished by the polishing section is cleaned by the cleaning section.
Further, in the substrate treatment device of the embodiment, the sensor may be configured to be able to detect a metal film on the whole surface of the polished surface of the substrate placed on the temporary table.
According to this configuration, it is possible to detect the metal film on the whole surface of the polished surface of the substrate placed on the temporary table using the sensor provided at the temporary table. It is therefore possible to detect the metal film over the whole surface of the polished surface of the substrate with high accuracy, while the sensor buried inside the polishing table as in the conventional device can only detect a residue of the metal film on only part of the polished surface of the substrate.
Further, in the substrate treatment device of the embodiment, the sensor may be an eddy current type sensor.
According to this configuration, it is possible to detect a residue of the metal film remaining on the polished surface of the substrate with high accuracy using the eddy current type sensor.
Further, in the substrate treatment device of the embodiment, the sensor may be an infrared laser type sensor.
According to this configuration, it is possible to detect a residue of the metal film remaining on the polished surface of the substrate with high accuracy using the infrared laser type sensor.
Further, in the substrate treatment device of the embodiment, the sensor may be an infrared camera type sensor.
According to this configuration, it is possible to detect a residue of the metal film remaining on the polished surface of the substrate with high accuracy using the infrared camera type sensor.
According to the embodiment, it is possible to detect a metal film remaining as a residue on the polished surface of the substrate after polishing with high accuracy.
A substrate treatment device according to an embodiment of the present invention will be described below using the drawings. In the present embodiment, an example of a substrate treatment device which polishes a substrate through chemical mechanical polishing (CMP) will be described.
The load/unload part 2 includes two or more (four in the present embodiment) front load parts 20 on which wafer cassettes for stocking a number of wafers (substrates) are placed. These front load parts 20 are disposed adjacent to the housing 1 and arranged along a width direction (direction perpendicular to a longitudinal direction) of the substrate treatment device. On the front load part 20, an open cassette, an SMIF (Standard Manufacturing Interface) pod or an FOUP (Front Opening Unified Pod) can be mounted. Here, the SMIF and the FOUP are airtight containers which accommodate wafer cassettes inside and which have an environment maintained independent from outer space by being covered by partition walls.
Further, a travelling mechanism 21 is laid along the lines of the front load parts 20 in the load/unload part 2, and two transporting robots (loaders) 22 which can move along a direction in which the wafer cassettes are arranged are provided on the travelling mechanism 21. The transporting robots 22 can access the wafer cassettes mounted on the front load part 20 by moving on the travelling mechanism 21. Each transporting robot 22 has two hands at an upper side and at a lower side, and the upper and lower hands can be respectively used for different purposes, that is, the upper hand is used to return the treated wafer to the wafer cassette, while the lower hand is used to take the wafer prior to treatment out from the wafer cassette. Further, the lower hand of the transporting robot 22 is configured to rotate around its axial center so that the wafer can be inverted.
Because the load/unload part 2 is a region which requires most to be maintained clean, the inside of the load/unload part 2 is always maintained higher pressure than any of the outside of the substrate treatment device, the polishing section 3 and the cleaning section 4. The polishing section 3 is the dirtiest region because it uses slurry as a polishing solution. Therefore, a negative pressure is applied to the inside of the polishing section 3, so that the pressure is maintained lower than the internal pressure of the cleaning section 4. At the load/unload part 2, a filter fan unit (not illustrated) having a clean air filter such as a HEPA filter, an ULPA filter and a chemical filter is provided, and clean air obtained by removing particles, toxic vapor and toxic gas is always blown out from this filter fan unit.
The polishing section 3 which is a region where a wafer is polished (smoothed), includes a first polishing unit 3A, a second polishing unit 3B, a third polishing unit 3C and a fourth polishing unit 3D. These first polishing unit 3A, second polishing unit 3B, third polishing unit 3C and fourth polishing unit 3D are, as illustrated in
As illustrated in
In a similar manner, the second polishing unit 3B includes a polishing table 30B to which the polishing pad 10 is attached, a top ring 31B, a polishing solution supply nozzle 32B, a dresser 33B and an atomizer 34B. Further, the third polishing unit 3C includes a polishing table 30C to which the polishing pad 10 is attached, a top ring 31C, a polishing solution supply nozzle 32C, a dresser 33C and an atomizer 34C. Further, the fourth polishing unit 3D includes a polishing table 30D to which the polishing pad 10 is attached, a top ring 31D, a polishing solution supply nozzle 32D, a dresser 33D and an atomizer 34D.
A transporting mechanism for transporting the wafer will be described next. As illustrated in
Further, a second linear transporter 7 is disposed adjacent to the third polishing unit 3C and the fourth polishing unit 3D. This second linear transporter 7 is a mechanism for transporting the wafer among three transporting positions (a fifth transporting position TP5, a sixth transporting position TP6 and a seventh transporting position TP7 in order from the load/unload part side) which are along a direction the polishing units 3C, 3D are arranged.
The wafer is transported to the polishing units 3A, 3B by the first linear transporter 6. As described above, the top ring 31A of the first polishing unit 3A moves between the polishing position and the second transporting position TP2 by swing operation of a top ring head. Therefore, the wafer is passed to the top ring 31A at the second transporting position TP2. In a similar manner, the top ring 31B of the second polishing unit 3B moves between the polishing position and the third transporting position TP3, and the wafer is passed to the top ring 31B at the third transporting position TP3. The top ring 31C of the third polishing unit 3C moves between the polishing position and the sixth transporting position TP6, and the wafer is passed to the top ring 31C at the sixth transporting position TP6. The top ring 31D of the fourth polishing unit 3D moves between the polishing position and the seventh transporting position TP7, and the wafer is passed to the top ring 31D at the seventh transporting position TP7.
A lifter 11 for receiving the wafer from the transporting robot 22 is disposed at the first transporting position TP1. The wafer is passed from the transporting robot 22 to the first linear transporter 6 via this lifter 11. A shutter (not illustrated) which is provided at the partition wall 1a between the lifter 11 and the transporting robot 22, is configured to be open when the wafer is transported so that the wafer can be passed from the transporting robot 22 to the lifter 11. Further, a swing transporter 12 is disposed among the first linear transporter 6, the second linear transporter 7 and the cleaning section 4. This swing transporter 12 has a hand which can move between the fourth transporting position TP4 and the fifth transporting position TP5, and the wafer is passed from the first linear transporter 6 to the second linear transporter 7 by the swing transporter 12. The wafer is transported to the third polishing unit 3C and/or the fourth polishing unit 3D by the second linear transporter 7. Further, the wafer polished at the polishing section 3 is transported to the cleaning section 4 by way of the swing transporter 12.
The swing arm 166 is configured to rotate around a rotation axis of a motor of the swing mechanism 162, which is not illustrated, by driving of the motor. By this means, the inverting mechanism 167 and the grasping mechanism 170 integrally rotate, and the grasping mechanism 170 moves among the fourth transporting position TP4, the fifth transporting position TP5 and the temporary table 180.
The grasping mechanism 170 has a pair of grasping arms 171 for grasping the wafer W. At both ends of each of the grasping arms 171, chucks 172 for grasping an outer edge of the wafer W are provided. These chucks 172 are provided to project downward from both ends of the grasping arms 171. Further, the grasping mechanism 170 includes an opening and closing mechanism 173 for moving the pair of grasping arms 171 in a direction approaching or separating from the wafer W.
To grasp the wafer W, the grasping mechanism 170 is lowered by the driving mechanism 165 until the chucks 172 of the grasping arms 171 are located on the same plane with the wafer W while the grasping arms 171 are open. Then, the opening and closing mechanism 173 is driven to move the grasping arms 171 to approach each other, and the outer edge of the wafer W is grasped with the chucks 172 of the grasping arms 171. In this state, the grasping arms 171 are raised by the driving mechanism 165.
The inverting mechanism 167 has a rotation shaft 168 coupled to the grasping mechanism 170, and a motor (not illustrated) for rotating this rotation shaft 168. By the motor driving the rotation shaft 168, the whole grasping mechanism 170 rotates by 180 degrees, so that the wafer W grasped by the grasping mechanism 170 is inverted. In this manner, because the whole grasping mechanism 170 is inverted by the inverting mechanism 167, the wafer does not have to be passed between the grasping mechanism and the inverting mechanism as in the conventional device. Note that, when the wafer W is transported from the fourth transporting position TP4 to the fifth transporting position TP5, the inverting mechanism 167 does not invert the wafer W, and the wafer W is transported in a state where the surface to be polished is directed downward. Meanwhile, when the wafer W is transported from the fourth transporting position TP4 or the fifth transporting position TP5 to the temporary table 180, the wafer W is inverted by the inverting mechanism 167 so that the polished surface is directed upward.
The temporary table 180 has a base plate 181, a plurality of (two in
The grasping mechanism 170 inverted by the inverting mechanism 167 enters into a gap between the horizontal part 183b of the horizontal rod 183 and the base plate 181 while grasping the wafer W, and, when all the pins 184 are located below the wafer W, rotation of the grasping mechanism 170 by the swing mechanism 162 is stopped. When the grasping arms 171 are open in this state, the wafer W is placed on the temporary table 180. The wafer W placed on the temporary table 180 is transported to the cleaning section 4 by the transporting robot of the cleaning section 4, which will be described next.
A temporary table 203 for a wafer is provided between the upper side secondary cleaning module 202A and the lower side secondary cleaning module 202B. An upper side drying module 205A and a lower side drying module 205B arranged along the longitudinal direction are disposed inside the drying room 194. These upper side drying module 205A and the lower side drying module 205B are isolated from each other. Filter fan units 207, 207 for supplying clean air into the drying modules 205A, 205B are provided at upper parts of the upper side drying module 205A and the lower side drying module 205B. The upper side primary cleaning module 201A, the lower side primary cleaning module 201B, the upper side secondary cleaning module 202A, the lower side secondary cleaning module 202B, the temporary table 203, the upper side drying module 205A and the lower side drying module 205B are fixed to a frame which is not illustrated via bolts, or the like.
A first transporting robot 209 which can move upward and downward is disposed in the first transporting room 191, and a second transporting robot 210 which can move upward and downward is disposed in the second transporting room 193. The first transporting robot 209 and the second transporting robot 210 are respectively movably supported by support shafts 211, 212 extending in the longitudinal direction. The first transporting robot 209 and the second transporting robot 210 have driving mechanisms such as motors inside and can freely move upward and downward along the support shafts 211, 212. The first transporting robot 209 has upper and lower hands as with the transporting robot 22. As indicated with a dotted line in
The first transporting robot 209 operates to transport the wafer W among the temporary table 180, the upper side primary cleaning module 201A, the lower side primary cleaning module 201B, the temporary table 203, the upper side secondary cleaning module 202A and the lower side secondary cleaning module 202B. The first transporting robot 209 uses the lower hand to transport the wafer prior to cleaning (the wafer to which slurry adheres) and uses the upper hand to transport the wafer after cleaning. The second transporting robot 210 operates to transport the wafer W among the upper side secondary cleaning module 202A, the lower side secondary cleaning module 202B, the temporary table 203, the upper side drying module 205A and the lower side drying module 205B. Because the second transporting robot 210 transports only the cleaned wafer, the second transporting robot 210 has only one hand. The transporting robot 22 illustrated in
Because the cleaning section 4 includes two primary cleaning modules and two secondary cleaning modules, it is possible to configure a plurality of cleaning lines which clean a plurality of wafers in parallel. A “cleaning line” refers to a transfer path used when one wafer is cleaned by the plurality of cleaning modules inside the cleaning section 4. For example, as illustrated in
Further, it is also possible to clean and dry a plurality of wafers with a predetermined time difference in two parallel cleaning lines. Cleaning the wafers with a predetermined time difference provides the following advantages. The first transporting robot 209 and the second transporting robot 210 are used in common by the plurality of cleaning lines. Therefore, when cleaning or drying treatment of a plurality of wafers is finished at the same time, these transporting robots cannot transport the wafers immediately, which may degrade throughput. To avoid such a problem, by cleaning and drying the plurality of wafers with a predetermined time difference, it is possible to transport the treated wafers immediately using the transporting robots 209, 210.
Because slurry adheres to the polished wafer, and copper as a metal wiring may corrode by the slurry, it is not preferable that the wafer is left for a long period of time in that state. Because the cleaning section 4 includes two primary cleaning modules, even when a preceding wafer is cleaned by any of the upper side primary cleaning module 201A and the lower side primary cleaning module 201B, it is possible to clean the wafer by carrying the wafer into the other primary cleaning module. It is therefore possible to clean the polished wafer immediately, so that it is possible to prevent copper from corroding as well as realize high throughput.
Further, when it is necessary to perform only primary cleaning, as illustrated in
Each cleaning module 201A, 201B, 202A and 202B has a detector (not illustrated) that detects a failure. If a failure occurs at any of the cleaning modules 201A, 201B, 202A and 202B, the detector detects this and transmits a signal to the control section 5. The control section 5 selects a cleaning line which averts the cleaning module which does not work and switches the current cleaning line to a newly selected cleaning line. Note that while two primary cleaning modules and two secondary cleaning modules are provide in the present embodiment, the present invention is not limited to this, and three or more primary cleaning modules and/or three or more secondary cleaning modules may be provided.
Further, a temporary table may be provided in the first cleaning room 190. For example, as with the temporary table 203, a temporary table can be provided between the upper side primary cleaning module 201A and the lower side primary cleaning module 201B. When a given cleaning module does not work, two wafers can be transported to the temporary table 180 (see
Concentration of a cleaning solution used at the primary cleaning modules 201A, 201B may be made different from concentration of a cleaning solution used at the secondary cleaning modules 202A, 202B. For example, the concentration of the cleaning solution used at the primary cleaning modules 201A, 201B is made higher than the concentration of the cleaning solution used at the secondary cleaning modules 202A, 202B. It is considered that typically, cleaning effect is substantially proportional to concentration of the cleaning solution and a cleaning period. Therefore, by using a cleaning solution with high concentration in primary cleaning, even if the wafer is contaminated badly, it is possible to make a period of the primary cleaning substantially equal to a period of secondary cleaning.
A characteristic structure of the substrate treatment device of the present embodiment will be described next with reference to
When, as a result of detecting a metal film remaining on the surface (polished surface) of the wafer W using the sensors 7, 8, abnormality is detected (for example, when a thickness of the detected metal film is greater than a predetermined reference value), identification information of the wafer W for which abnormality is detected is transmitted to the control section 5, and the wafer is controlled not to proceed to the subsequent process after cleaning and drying process (for example, the wafer is extracted and discarded). Further, when abnormality is detected, it is also possible to take action to stop transporting of the subsequent wafer W to the polishing tables 30A to 30D to prevent secondary damage.
According to the substrate treatment device of the present embodiment, sensors 7, 8 are provided at the temporary table 180 on which the wafer W is temporarily placed after being polished. It is therefore possible to detect a metal film remaining as a residue on the surface (polished surface) of the wafer W placed on the temporary table 180 using the sensors 7, 8 provided at the temporary table 180. In this case, it is possible to detect a metal film on the surface (polished surface) of the wafer W after polishing with higher accuracy than a case where a sensor is provided (buried) inside the polishing table as in the conventional device.
Further, in the present embodiment, the sensors 7, 8 are provided at the temporary table 180 between the polishing section 3 and the cleaning section 4. It is therefore possible to detect a metal film (metal film remaining as a residue) on the polished surface of the wafer W placed on the temporary table 180 with high accuracy using the sensors 7, 8 provided at the temporary table 180 before the wafer W polished by the polishing section 3 is cleaned by the cleaning section 4.
Further, in the present embodiment, it is possible to detect a metal film on the whole surface of the polished surface of the wafer W placed on the temporary table 180 using the sensors 7, 8 provided at the temporary table 180. It is therefore possible to detect a residue of the metal film over the whole surface of the polished surface of the wafer W with high accuracy while in the conventional device, a sensor buried inside the polishing table can detect a residue of a metal film of only part of the polished surface of the wafer W.
For example, the sensors 7, 8 are eddy current type sensors. In this case, it is possible to detect a residue of a metal film remaining on the polished surface of the wafer W with high accuracy using the eddy current type sensors. Further, the sensors 7, 8 may be infrared laser type sensors or infrared camera type sensors. In this case, it is possible to detect a residue of a metal film remaining on the polished surface of the wafer W with high accuracy using the infrared laser type sensors or the infrared camera type sensors.
While the embodiments of the present invention have been described above using examples, the present invention is not limited to them, and can be changed or modified according to purposes within the scope of the claims.
As described above, the substrate treatment device according to the present invention provides an advantage of being capable of detecting a metal film remaining as a residue on a polished surface of a substrate after polishing with high accuracy, and is useful as being used as a chemical mechanical polishing (CMP) device, or the like.
Number | Date | Country | Kind |
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2014-086177 | Apr 2014 | JP | national |