Patent Application
20170352573
This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2016-113501, filed on Jun. 7, 2016, the entire content of which is incorporated herein by reference.
The present application relates to a substrate processing apparatus.
Chemical mechanical polishing (CMP) apparatuses are known as apparatuses for polishing substrate surfaces in manufacturing semiconductor devices. In a CMP apparatus, a polishing pad is stuck to a top surface of a polishing table to form a polishing surface. This CMP apparatus pushes a surface to be polished of a substrate held by a top ring against the polishing surface and rotates the polishing table and the top ring while supplying slurry as a polishing liquid to the polishing surface. This causes the polishing surface and the surface to be polished to relatively move slidably, and the surface to be polished is thereby polished.
Regarding flattening techniques including CMP, there are a wide variety of materials to be polished and requirements for polishing performance (e.g., flatness, polishing damage, and further productivity) are becoming stricter in recent years. With an introduction of more refined semiconductor devices, there is a growing demand for polishing performance and cleanliness in CMP apparatuses.
Under such circumferences, substrates may be processed using polishing pads smaller in size than the substrates to be processed in the CMP apparatuses (e.g., U.S. Pat. No. 6,561,881). Generally, a polishing pad smaller in size than a substrate to be processed can flatten locally generated unevenness on a substrate, polish only specific parts of the substrate or adjust the amount of polishing in accordance with the position of the substrate, and provides excellent controllability.
On the other hand, new flattening methods are also being proposed, and a catalyst referred etching (hereinafter, referred to as “CARE”) method is one such example. In the presence of a processing liquid, the CARE method generates a seed of reaction with a surface to be polished from within the processing liquid only in the vicinity of a catalyst material, causes the catalyst material and the surface to be polished to come closer to or come into contact with each other, and can thereby selectively make etching reaction occur on the surface to be polished (e.g., WO2015/159973, pamphlet). For example, with an uneven surface to be polished, selective etching of convex parts is made possible by causing the convex parts and the catalyst material to come closer to or come into contact with each other and it is possible to further flatten the surface to be polished.
Furthermore, a polishing speed and an etching speed of a substrate depend on a temperature of a region where the surface of a substrate and a pad come into contact with each other. Therefore, in order to flatten the substrate accurately, it is desirable to control the temperature of the region where the surface of the substrate and the pad come into contact with each other.
In a polishing apparatus that polishes a substrate surface from above, the substrate is held from below by means of vacuum suction using a rotatable table. Conventionally, a table that holds a substrate has a groove pattern for suctioning formed on the surface of a flat table, the substrate is directly placed on the table and vacuum-suctioned. Therefore, a non-flat part of the table may affect the substrate placed thereon and affect flatness of the surface of the polished substrate. For example, when the substrate is vacuum-suctioned to the table, the substrate does not come into contact with the non-flat part of the table. For this reason, a gap may be produced between the table and the substrate, air may leak from the gap and the suction rate of the substrate may decrease. Furthermore, since the material used for the table is generally a high hardness material, the reverse side of the substrate contacting the table is susceptible to damage. On the other hand, to reduce damage to the reverse side of the substrate, the table may be made of resin which has relatively low hardness, but a resin-made table generally has poor flatness.
With the CARE method and CMP, a processing speed (polishing speed, etching speed) of a wafer Wf generally depends on a temperature of a substrate surface to be processed. Therefore, to control the temperature of the substrate surface to be processed, a temperature-adjusted chemical solution or pure water may be supplied to the substrate surface so as to adjust the surface temperature of the substrate through heat exchange between the liquid and the substrate. However, since the temperature-adjusted chemical solution or pure water is supplied to the substrate surface through a channel, the temperature of the liquid reaching the substrate surface may be different from a set temperature depending on its environment. Furthermore, since the chemical solution or pure water remains in the channel, even when the set temperature of the liquid is changed, the temperature of the liquid supplied to the substrate does not immediately change. Furthermore, the temperature of the substrate surface may exceed the set temperature (overshoot) or fall below the set temperature (undershoot) due to heat accumulation of the table. Furthermore, the closer to a supply port of the temperature-adjusted liquid a portion of the substrate is, the greater the effect of temperature adjustment becomes and the less likely it is for a temperature distribution of the substrate surface to become uniform. Moreover, it is not possible to control the temperature distribution of the substrate surface and it is difficult to control the substrate temperature.
It is an object of the present invention to mitigate or solve at least some of the above-described problems.
According to a first aspect, a substrate processing apparatus is provided. The substrate processing apparatus includes a table for holding a substrate, a resin film attached to a top surface of the table and a heater provided inside the table, in which the top surface of the table is formed of ceramics, the top surface of the table defines an opening connectable to a vacuum source, the resin film is formed of polyimide, and the resin film define a through hole at a position corresponding to the opening of the table when the resin film is attached to the top surface of the table. According to such an aspect, it is possible to form a flat table using a ceramic, high hardness material, and support the substrate via a relatively less hard resin film to thereby reduce a possibility of damaging the substrate while maintaining high flatness of the top surface of the table. Furthermore, the resin-made film is less hard than the table and deformable to a certain degree, and it is thereby possible to improve a state of contact between the table and the substrate and suppress air leakage during vacuum suctioning. It is also possible to control the temperature of the substrate surface to be processed and control the substrate processing speed using a heater. It is also possible to control hardness of the resin-made film using the heater.
According to a second aspect, the substrate processing apparatus according to the first aspect includes a temperature sensor to measure a surface temperature of the substrate held on the table. According to such an aspect, it is possible to measure the surface temperature of the substrate using the temperature sensor, and thereby control the surface temperature of the substrate so that the substrate surface has an optimum temperature.
According to a third aspect, the substrate processing apparatus according to the second aspect includes a controller that can communicate with the temperature sensor and the heater, and the controller is configured so as to control the heater based on the temperature measured by the temperature sensor. According to such an aspect, the controller can perform control so that the substrate surface has a desired temperature.
According to a fourth aspect, in the substrate processing apparatus according to the third aspect, the table includes a plurality of regions, the heater includes a plurality of heaters arranged at positions corresponding to the plurality of regions of the table and the controller is configured so as to control the plurality of heaters independently of each other. According to such an aspect, it is possible to form a desired temperature distribution on the substrate surface and control a substrate processing speed for each region.
Hereinafter, embodiments of a substrate processing apparatus according to the present invention will be described with reference to the accompanying drawings. In the attached drawings, identical or similar elements are assigned identical or similar reference numerals, and duplicate description relating to the identical or similar elements in the respective embodiments will be omitted. Features shown in each respective embodiment are also applicable to the other embodiments unless they are inconsistent with each other.
The substrate processing apparatus 10 is provided with a table 20 to hold a substrate, a head 30 provided with a pad that holds a catalyst, a processing liquid supply section 40, a swing arm 50, a conditioning section 200 and a control section 300. The table 20 is provided with a substrate holding surface and configured to hold a wafer Wf as a kind of substrate on the substrate holding surface. In the present embodiment, the table 20 holds the wafer Wf such that a surface to be processed of the wafer Wf faces up. In the present embodiment, the table 20 is provided with a vacuum suction mechanism including a vacuum suction plate to vacuum-suction the reverse side (surface opposite to the surface to be processed) of the wafer Wf as a mechanism to hold the wafer Wf. As a vacuum suction scheme, either one of the two schemes may be used: a point suction scheme using a suction plate including a plurality of suction holes connected to a vacuum line on the suction surface and a surface suction scheme including (e.g., concentric) grooves on the suction surface to suction the wafer through connection holes to a vacuum line provided in the grooves. However, an arbitrary publicly known mechanism can be used as the mechanism for holding the wafer Wf, and for example, a clamp mechanism that clamps the front side and the reverse side of the wafer Wf on at least one of peripheral edges of the wafer Wf or a roller chuck mechanism that holds a side face of the wafer Wf on at least one of peripheral edges of the wafer Wf may be used. Such a table 20 is configured so as to be rotatable using a drive section motor or an actuator (not shown).
The head 30 of the embodiment shown in
The processing liquid supply section 40 is configured to supply a processing liquid PL to the surface of the wafer Wf. Here, the number of processing liquid supply sections 40 is one in
As shown in
In the embodiment shown in
As described above, the table 20 is configured to be rotatable. As shown in
As described above, the ceramic table 20 can attain a table whose top surface 24 has a high degree of flatness, but since it has high hardness, when the wafer Wf is directly placed on the table 20, the wafer Wf may be damaged. In the embodiment in
In the embodiment shown in
According to the CARE method or CMP, the processing speed of the wafer Wf (polishing speed, etching speed) depends on the temperature of the surface of the wafer Wf. In the embodiment shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-113501 | Jun 2016 | JP | national |
