Abstract:
A temperature controlling system for use in a chemical mechanical planarization (CMP) system having a linear polishing belt, a carrier capable of applying a substrate over a preparation location over the linear polishing belt is provided. The temperature controlling system includes a platen having a plurality of zones. The temperature controlling system further includes a temperature sensor configured determine a temperature of the linear polishing belt at a location that is after the preparation location. The system also includes a controller for adjusting a flow of temperature conditioned fluid to selected zones of the plurality of zones of the platen in response to output received from the temperature sensor.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates generally to chemical mechanical planarization apparatuses, and more particularly to methods and apparatuses for improved uniformity in chemical mechanical planarization applications via controlling temperature of a polishing pad.  
           [0003]    2. Description of the Related Art  
           [0004]    In the fabrication of semiconductor devices, there is a need to perform chemical mechanical planarization (CMP) operations. Typically, integrated circuit devices are in the form of multi-level structures. At the substrate level, transistor devices having diffusion zones are formed. In subsequent levels, interconnect metallization lines are patterned and electrically connected to the transistor devices to define the desired functional device. As is well known, patterned conductive layers are insulated from other conductive layers by dielectric materials, such as silicon dioxide. As more metallization levels and associated dielectric layers are formed, the need to planarize the dielectric material grows. Without planarization, fabrication of further metallization layers becomes substantially more difficult due to the variations in the surface topography. In other applications, metallization line patterns are formed in the dielectric material, and then, metal CMP operations are performed to remove excess material.  
           [0005]    A chemical mechanical planarization (CMP) system is typically utilized to polish a wafer as described above. A CMP system typically includes system components for handling and polishing the surface of a wafer. Such components can be, for example, an orbital polishing pad, or a linear belt polishing pad. The pad itself is typically made of a polyurethane material or polyurethane in conjunction with other materials such as, for example a stainless steel belt. In operation, the belt pad is put in motion and then a slurry material is applied and spread over the surface of the belt pad. Once the belt pad having slurry on it is moving at a desired rate, the wafer is lowered onto the surface of the belt pad. In this manner, wafer surface that is desired to be planarized is substantially smoothed, much like sandpaper may be used to sand wood. The wafer may then be cleaned in a wafer cleaning system.  
           [0006]    [0006]FIG. 1A shows a linear polishing apparatus  10  which is typically utilized in a CMP system. The linear polishing apparatus  10  polishes away materials on a surface of a semiconductor wafer  16 . The material being removed may be a substrate material of the wafer  16  or one or more layers formed on the wafer  16 . Such a layer typically includes one or more of any type of material formed or present during a CMP process such as, for example, dielectric materials, silicon nitride, metals (e.g., aluminum and copper), metal alloys, semiconductor materials, etc. Typically, CMP may be utilized to polish the one or more of the layers on the wafer  16  to planarize a surface layer of the wafer  16 .  
           [0007]    The linear polishing apparatus  10  utilizes a polishing belt  12 , which moves linearly in respect to the surface of the wafer  16 . The belt  12  is a continuous belt rotating about rollers (or spindles)  20 . A motor typically drives the rollers so that the rotational motion of the rollers  20  causes the polishing belt  12  to be driven in a linear motion  22  with respect to the wafer  16 .  
           [0008]    A wafer carrier  18  holds the wafer  16 . The wafer  16  is typically held in position by mechanical retaining ring and/or by vacuum. The wafer carrier positions the wafer atop the polishing belt  12  so that the surface of the wafer  16  comes in contact with a polishing surface of the polishing belt  12 .  
           [0009]    [0009]FIG. 1B shows a side view of the linear polishing apparatus  10 . As discussed above in reference to FIG. 1A, the wafer carrier  18  holds the wafer  16  in position over the polishing belt  12  while applying pressure to the polishing belt. The polishing belt  12  is a continuous belt typically made up of a polymer material such as, for example, the IC 1000 made by Rodel, Inc. layered upon a supporting layer. The polishing belt  12  is rotated by the rollers  20  which drives the polishing belt in the linear motion  22  with respect to the wafer  16 . In one example, a fluid bearing platen  24  supports a section of the polishing belt under the zone where the wafer  16  is applied. The platen  24  can then be used to apply fluid against the under surface of the supporting layer. The applied fluid thus forms a fluid bearing that creates a polishing pressure on the underside of the polishing belt  12  which is applied against the surface of the wafer  16 . Unfortunately, because the polishing rate produced by the fluid bearing typically cannot be controlled very well, the polishing pressure applied by the fluid bearing is non-uniform. Specifically, the temperature of the polishing belt  12  often varies during the polishing process. The polishing belt  12  typically starts off cold and becomes warmer during the wafer polishing. As wafer polishing progresses, the temperature of the polishing belt increases due to the friction between the polishing belt  12 , the slurry, and the wafer  16 . This is extremely problematic because as the temperature of the polishing belt  12  increases, this increases the temperature of the slurry used in the polishing process which then increases the polishing rate of the wafer  16 . In addition, when air is used as the fluid bearing, the air released from the platen  24  is generally extremely cold. This occurs because as the air is outputted from the air output holes in the platen  24 , air expands and therefore becomes colder. Therefore, due to the frictional heat and the cold air from the platen  24 , it is generally very difficult to control the polishing belt temperature. As a result, due to the fact that the prior art polishing system designs do not properly control polishing dynamics, uneven polishing and inconsistent wafer polishing may result thereby decreasing wafer yield and increasing wafer costs.  
           [0010]    In view of the foregoing, there is a need for an apparatus that overcomes the problems of the prior art by having a platen that improves polishing pad temperature control and reduces polishing rate discrepancies.  
         SUMMARY OF THE INVENTION  
         [0011]    Broadly speaking, embodiments of the present invention fill these needs by providing a polishing pad warming system that provides wafer polishing uniformity control during a CMP process by enabling usage of different temperature air in different zones within a platen.  
           [0012]    In one embodiment, a temperature controlling system for use in a chemical mechanical planarization (CMP) system having a linear polishing belt, a carrier capable of applying a substrate over a preparation location over the linear polishing belt is provided. The temperature controlling system includes a platen having a plurality of zones. The temperature controlling system further includes a temperature sensor configured determine a temperature of the linear polishing belt at a location that is after the preparation location. The system also includes a controller for adjusting a flow of temperature conditioned fluid to selected zones of the plurality of zones of the platen in response to output received from the temperature sensor.  
           [0013]    In another embodiment, a temperature controlling system for use in a chemical mechanical planarization (CMP) system having a linear polishing belt, a carrier capable of applying a substrate over a preparation location over the linear polishing belt is provided. The temperature controlling system includes a platen having a plurality of zones. The system also includes a temperature sensor that determines a temperature of the linear polishing belt at a location that is after the preparation location. The system further includes a heating device being positioned before the preparation location and directed toward a surface of the linear polishing belt. The system also includes a controller for adjusting an output from the heating device in response to output received from the temperature sensor.  
           [0014]    A method for heating a polishing pad during chemical mechanical planarization (CMP) is provided. The method includes determining whether a temperature of the polishing pad is substantially equal to a set point temperature. The method also determines if the temperature of the polishing pad is not substantially equal to the set point temperature. If the temperature of the polishing pad is not substantially equal to the set point temperature, the method adjusts at least one of a temperature and a pressure of a heated fluid being outputted from at least one pressure zone of a platen. The adjusting substantially equalizes the temperature of the polishing pad and the set point temperature.  
           [0015]    In another embodiment, an apparatus for heating a polishing pad during chemical mechanical planarization (CMP) is disclosed. The apparatus includes a platen disposed under the polishing pad. The platen has a platen plate with at least one pressure zone being capable of outputting a heated fluid to an underside portion of the polishing pad. The apparatus also includes an internal manifold coupled to the platen by at least one fluid throughput. The internal manifold is capable of delivering the heated fluid to the at least one pressure zone of the platen by way of the at least one fluid throughput. The apparatus further includes an external manifold coupled to the internal manifold by at least one manifold throughput. The external manifold is capable of delivering the heated fluid to the internal manifold. The apparatus also includes a heater connected to the external manifold by at least one heater throughput. The heater is capable of heating the fluid to one of a plurality of set temperatures and is capable of delivering the heated fluid to the external manifold. The apparatus further includes a controller connected to the internal manifold and a polishing pad temperature sensor. The controller is capable of monitoring a polishing pad temperature and adjusting a delivery of the heated fluid from the internal manifold to the at least one pressure zone to equalize the polishing pad temperature to the set point temperature.  
           [0016]    Because of the advantageous effects of applying controlled fluid pressure of a controlled temperature in various portions of the platen, embodiments of the present invention provide significant improvement in planarization rate consistency. Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:  
         [0018]    [0018]FIG. 1A shows a linear polishing apparatus which is typically utilized in a CMP system.  
         [0019]    [0019]FIG. 1B shows a side view of the linear polishing apparatus.  
         [0020]    [0020]FIG. 2A shows a side view of a chemical mechanical planarization (CMP) system in accordance with an embodiment of the present invention.  
         [0021]    [0021]FIG. 2B shows a side view of a chemical mechanical planarization (CMP) system with a polishing pad heater in accordance with an embodiment of the present invention.  
         [0022]    [0022]FIG. 3 shows a diagram illustrating connections between the internal manifold, the external manifold, and the heater in accordance with one embodiment of the present invention.  
         [0023]    [0023]FIG. 4A shows a close-up overhead view of the platen in accordance with one embodiment of the present invention.  
         [0024]    [0024]FIG. 4B shows a side view of a diametric slice of the platen as shown in FIG. 4A in accordance with one embodiment of the present invention.  
         [0025]    [0025]FIG. 4C shows a platen configuration with concentric temperature zones in accordance with one embodiment of the present invention.  
         [0026]    [0026]FIG. 4D illustrates a platen configuration with horizontal pressure zones in accordance with one embodiment of the present invention.  
         [0027]    [0027]FIG. 4E shows a diagram illustrating a polishing pad heating process in accordance with one embodiment of the present invention.  
         [0028]    [0028]FIG. 5 shows a network diagram illustrating how temperature may be managed through network connections of different components in accordance with one embodiment of the present invention.  
         [0029]    [0029]FIG. 6A is a block diagram of proportional, integral, derivative (PID) controls in controlling a temperature of a zone n (where n is the number of the pressure zone(s) being managed) of the platen in accordance with one embodiment of the present invention.  
         [0030]    [0030]FIG. 6B is a block diagram of proportional, integral, derivative (PID) controls in controlling water temperature delivery by the pre-wet ouput and the post-wet output in accordance with one embodiment of the present invention.  
         [0031]    [0031]FIG. 7 shows a flowchart illustrating a method of heating the polishing pad in accordance with one embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]    An invention is disclosed for a CMP system that provides for polishing uniformity control during a CMP process by controlling polishing pad temperature through utilization of different fluid temperature outputs for different zones of a platen during the CMP process. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order not to unnecessarily obscure the present invention.  
         [0033]    In general, embodiments of the present invention provide a CMP system that has the unique ability to manage polishing rates of a wafer by controlling the temperature of a polishing pad during a CMP process. It should be understood that the CMP system may use any suitable polishing pad structure such as, for example, a linear polishing belt, stainless steel supported polishing belt, etc. The CMP system controls temperature of fluids inputted into the platen to enable different zones within the platen to output the same or different temperatures of fluid onto the polishing pad. The outputting of controlled temperature fluid generates a fluid bearing that enables the polishing pad to be set at certain temperatures. When polishing pad temperatures are properly managed, this creates controlled polishing rates allowing the wafer polishing to be more consistent and efficient. Specifically, a control unit can manage input of heated fluid into different zones of the platen through feedback from a polishing pad temperature sensor thus forming an intelligent feedback loop to obtain controlled polishing pad temperatures. As a result, polishing pressure differences and inconsistencies arising from differing polishing pad temperatures may be managed in a highly regulated manner.  
         [0034]    A platen used within the CMP system disclosed herein may include any number of pressure zones within and outside the area of the wafer. Each pressure zone has a plurality of fluid holes that may be utilized to output fluid at different temperatures onto a backside (side opposite the side that polishes the wafer) of the polishing pad thus compensating for polishing pad dynamics inadequacies. It should be understood that the embodiments of the present invention can be utilized for polishing any size wafer such as, for example, 200 mm wafers, 300 mm wafers.  
         [0035]    A fluid as utilized herein may be any type of gas or liquid. Therefore, CMP systems as described below may utilize temperature controlled gas or liquid to control the polishing rate of the wafer. In addition, different temperatures of fluid may be applied at differing pressures over certain pressure zones of the platen. Such a configuration enables extremely flexible wafer polishing rate management.  
         [0036]    [0036]FIG. 2A shows a side view of a chemical mechanical planarization system  100  in accordance with an embodiment of the present invention. In this embodiment, a carrier head  108  may be used to secure and hold a wafer  104  in place during processing. A polishing pad  102  preferably forms a continuous loop around rotating drums  112 . The polishing pad  102  generally moves in a direction  106  at a speed of about 400 feet per minute, however, it should be noted that this speed may vary depending upon the specific CMP operation. As the polishing pad  102  rotates, the carrier  108  may then be used to lower the wafer  104  onto a top surface of the polishing pad  102 .  
         [0037]    A platen  110  may support the polishing pad  102  during the polishing process. The platen  110  may utilize any suitable type of bearing such as a liquid bearing or a gas bearing. Fluid pressure from an internal manifold  114  is inputted through the platen  110  by way of independently controlled pluralities of output holes that may be utilized to provide upward force to the polishing pad  102  to control the polishing pad profile. The fluid pressure from the internal manifold  114  to the platen  110  is supplied through fluid throughput  132 . The fluid throughput  132  may include one or more pathways that may carry fluid from the internal manifold  114  to the platen  110 . The fluid throughput  132  supplies the different platen zones so fluid output out of various zones of the platen  110  may be controlled. Therefore, for any number of separate fluid output zones of the platen  110  that may be controlled, there may exist an equal number of pathways to supply each of those zones from the internal manifold  114 . It should be appreciated that there may be any suitable number of fluid output zones in the platen  110  with any suitable number of corresponding pathways supplying the zone(s).  
         [0038]    The internal manifold  114  receives fluid input from an external manifold  120  through manifold throughput  122 . The manifold throughput  122  may include any suitable number of pathways depending on the number of fluid temperatures desired to be utilized. The pathways that may comprise the manifold throughput  122  may carry fluid of different temperatures or the same temperatures depending on the variety of fluid temperatures desired. In one embodiment, every pathway of the manifold throughput  122  can carry fluid of a different temperature. In such an embodiment, the internal manifold  120  is configured so it can receive fluid of differing temperatures and manage them so different zones of the platen can output any suitable fluids of any suitable temperature desired to be outputted.  
         [0039]    The external manifold  120  receives heated fluid from a heater  118  by way of a heater throughput  124 . The heater throughput  124  may include any suitable number of pathways depending on the number of different fluid temperatures desired to utilize in the CMP process. It should be understood that the heater  118 , the external manifold  120 , and the internal manifold  114  may manage and transport any type of fluid for utilization in the CMP process such as, for example, air, water, etc. In one embodiment, air may be transported so certain zones of the platen may output differing (or the same) temperatures of air. In addition, a water source  115  may supply heated water to a pre-wet output and a post-wet output of the platen  110 . The water source  115  may supply water that is of any suitable temperature depending on the application desired. In one embodiment, the temperature of the water supplied to the platen  110  by the water source  115  is about 60 degrees C. The water source  115  is connected to the controller  150  which can manage the temperature of the water outputted by the pre-wet output and the post-wet output in conjunction with managing the heated air output from the platen  110 . It should be appreciated that although the controller  150 , the water heater  115 , the platen  110 , the external manifold  120 , and the heater  118  are seen figuratively as being separate components, two or more of the components may be combined to form one component. For example, in one embodiment, the platen  110 , the controller  150 , the internal manifold  114 , and the heater  118  may be combined into one structure. In one embodiment, the internal manifold  114  as shown in FIG. 2A may be located within the confines of the CMP machine. It should be appreciated that the external manifold  120  may be any suitable type of manifold that is outside of the CMP device itself. The external manifold  120 , in one embodiment, may be a facilities manifold outside of the confines of the CMP machine.  
         [0040]    A controller  150  may monitor a temperature of the polishing pad  102  by use of a temperature sensor  160 . It should be appreciated that the controller  150  may be any suitable type of controlling apparatus that can intelligently manage the temperature of the polishing pad  102  through intelligent control of heated fluid output through the various fluid output zones of the platen  110 . Depending on the temperature sensed by the temperature sensor  160 , the controller  150  may manage the amount of fluid output as well as the fluid temperature of the fluid output out of any, some, or all of the air output zones of the platen  110 . It should be understood that the CMP system described herein may utilize any suitable type of platen which may have any suitable number of independently controllable air output zones. The air output zones can therefore apply heated fluid to an underside of the polishing pad  102  to attain the desired polishing pad temperature. Therefore, a feedback loop may between the temperature sensor  160 , the controller  150 , and the internal manifold  114  may be utilized to intelligently control and manage temperature controlled fluid output from independently controlled fluid output zones of the platen  110 .  
         [0041]    It should be appreciated that any suitable type CMP system  100  configuration may be used where heated fluid may be controllably applied to the polishing pad  102 . In one embodiment, the internal manifold  114  may be part of the platen  110 . In another embodiment, there may be a heater directly connected to the internal manifold  114  without using the external manifold  120 . In yet another embodiment, the external manifold  120  may direct fluid into various fluid output zones of the platen  110  without necessitating the existence of the internal manifold  114 . In another embodiment, the heater  118  may provide heated fluid directly to the platen  110  which may have a self enclosed internal manifold. In these various embodiments, the controller  150  manages heated fluid output by controlling the fluid output from whatever suitable apparatus that directs output to the various output zones of the platen  110 .  
         [0042]    In one embodiment, the set point temperature of the polishing pad is below 125 degrees F. It should be understood that the set point temperature may be any suitable temperature depending on the polishing rate desired. If a higher polishing rate is desired, the set point may be a higher temperature. If a lower polishing rate is desired, the set point may be a lower temperature.  
         [0043]    [0043]FIG. 2B shows a side view of a chemical mechanical planarization (CMP) system  100 ′ with a polishing pad heater in accordance with an embodiment of the present invention. In this embodiment, the system  100 ′ includes a polishing pad heater  130  that may be utilized to heat the polishing pad  102 . In one embodiment, the polishing pad heater  130  is disposed above the polishing pad  102  on a trailing edge side of the platen  110 . The polishing pad heater  130  may use any suitable way to heat the polishing pad  102 . In one embodiment, the heater  130  is a radiant heater that is a heat lamp which may heat the polishing pad  102 . A controller  150 ′ may receive input from the temperature sensor  160  and determine an amount of heat outputted by the heater  130  to attain or retain the set point temperature for the polishing pad  102 . In one embodiment, the polishing pad heater  130  may operate at a temperature of up to 250 degrees F. to raise the polishing pad temperature. Therefore, the temperature of the polishing pad  102  may be intelligently controlled by using the heat lamp  130  to heat the polishing pad  102  while the temperature of the polishing pad  102  is monitored by the temperature sensor and the controller  150 ′.  
         [0044]    [0044]FIG. 3 shows a diagram  180  illustrating connections between the internal manifold  114 , the external manifold  120 , and the heater  118  in accordance with one embodiment of the present invention. In one embodiment, fluids of four different temperatures are utilized. Fluids such as clean dry air, deionized water, etc. may be utilized in the described apparatus herein. In one embodiment, air may heated by the heater  118  and transported to the platen  110  through the external manifold  120  and the internal manifold  114 . In another embodiment, a combination of air and water may be heated by the heater  118  and transported through the external manifold  120  and the internal manifold  114 . In yet another embodiment, water may be heated by the heater  118  and transported to the platen  110  through the external manifold  120  and the internal manifold  114 . It should be appreciated that the heater  118  may output any suitable number of different fluid temperatures to the external manifold  120  which may in turn supply the any suitable corresponding number of different fluid temperatures to the internal manifold  114 .  
         [0045]    In one embodiment, the internal manifold  114  has an electronic pressure (EP) regulator to control fluid flow to the platen  110 . In this way, the internal manifold  114  may control fluid pressure to the platen  110  and supply any suitable temperature fluid to any suitable fluid output zone of the platen  110 . In one embodiment, the heater  118  may output fluids with temperatures of 50 degrees F., 60 degrees F., 70 degrees F., and 80 degrees F. through tubes  124   a ,  124   b ,  124   c , and  124   d  respectively. Preferably, the temperatures of 125 degrees F. and below are utilized. The tubes  124   a ,  124   b ,  124   c , and  124   d  may, in one embodiment, define the heater throughput  124 . The external manifold  120  may then output the fluid inputs from the tubes  124   a ,  124   b ,  124   c , and  124   d  to the internal manifold  114  through tubes  122   a ,  122   b ,  122   c , and  122   d  respectively. In one embodiment, the tubes  122   a ,  122   b ,  122   c , and  122   d  may define the manifold throughput  122 . The internal manifold  114  may then, through management from the controller  150 , control fluid temperature and pressure outputs to, in one embodiment, six different fluid output zones of the platen  110  through tubes  132   a ,  132   b ,  132   c ,  132   d ,  132   e , and  132   f  which may define, in one embodiment, fluid throughput  132 . It should be appreciated that the heater  118  may be any suitable type of heater that can heat the desired volume of fluid to a desired temperature. In one embodiment, the heater  118  may be a 40 kW heater that supplies fluids with temperatures of up to a 125 degrees F.  
         [0046]    [0046]FIG. 4A shows a close-up overhead view of the platen  110  in accordance with one embodiment of the present invention. Although an exemplary platen configuration is shown with certain pressure sub-zones, any suitable platen with any suitable number and configuration of fluid pressure zones may be utilized within the system  100  described above in reference to FIG. 2A. For example, fluid pressure zones as those describe in U.S. patent application Ser. No. 09/823,722 entitled “APPARATUS FOR CONTROLLING LEADING EDGE AND TRAILING EDGE POLISHING”, and U.S. patent application Ser. No. 10/029,958 entitled “APPARATUS FOR EDGE POLISHING UNIFORMITY CONTROL” may be utilized. These patent applications are hereby incorporated by reference.  
         [0047]    In one embodiment, a peripheral fluid output zone  204   a  includes different annular sub-zones that include varying sizes of concentric air pressure zones. It should be appreciated that the peripheral zone  204   a , as well as a central zone  204   b , may have any number of sub-zones such as, for example,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 ,  10 , etc. It should also be understood that the peripheral zone  204   a  and the central zone  204   b  may have any type of sub-zones such as, for example, circular sub-zones, semicircular sub-zones, etc. In one embodiment, the peripheral zone  204   a  has 5 sub-zones including annular sub-zones  204   a - 1 ,  204   a - 2 ,  204   a - 3 ,  204   a - 4 , and  204   a - 5 , and the central zone  204   b  has one zone with no sub-zones. Each of the sub-zones may be separately controlled so that the air flow rate through the separate sub-zones may be varied to optimize the CMP operation. By individually controlling the air flow rates through the separate sub-zones, variations in pressure can be generated at different diameters on the wafer including areas inside and outside of the wafer circumference. Thus, the plurality of sub-zones within the peripheral zone  204   a  and the central zone  204   b  therefore allow management of temperature and fine tuning of the pressure applied on different areas of the polishing pad  102 . This pressure and temperature variation may be used to vary the polishing rates of different parts of a wafer because, as is well known in those skilled in the art, the amount of polishing that occurs on a portion of a wafer is a function of the pressure being applied on the corresponding portion of the polishing pad and a function of the temperature of the polishing pad  102  during polishing. Therefore, more or less sub-zones may be utilized depending the polishing profile requirements. It should also be appreciated that none, one, or more air pressure sub-zones may have a larger circumference than a wafer being polished.  
         [0048]    The platen  110  also includes a pre-wet output  232  and a post-wet output  230 . The pre-wet output  232  is a line of output holes disposed in an area which encounters the polishing pad  120  before the platen plate  202  when the polishing pad is moving in the direction  106 . The post-wet output  230  is a line of output holes disposed in an area which encounters the polishing pad  102  after the platen plate  202  when the polishing pad is moving in the direction  106 . The pre-wet output  232  and the post-wet output  230  delivers fluid to an area above the platen  230  so a back surface of the polishing pad  102  may be cleaned and lubricated during the CMP process.  
         [0049]    [0049]FIG. 4B shows a side view of a diametric slice of the platen  110  as shown in FIG. 4A in accordance with one embodiment of the present invention. The platen includes a platen plate  202 , mounting plate  228 , and a platen cover  222 . In this embodiment, annular recesses  206   a ,  206   b ,  206   c ,  206   d ,  206   e , and  206   f  that are capable of outputting air are defined within the platen plate  202 . It should be understood that any number or configuration of recesses that may output fluid can be utilized depending on the configuration and number of fluid pressure zones desired. For example, in another embodiment the recesses may be semicircular instead of annular, or in yet another embodiment, both annular and semicircular shaped recesses may be used. The annular recesses  206   a ,  206   b ,  206   c ,  206   d , and  206   e  are configured to receive fluid from at least one fluid input port formed therein and to supply the annular sub-zones  204   a - 1 ,  204   a - 2 ,  204   a - 3 ,  204   a - 4 , and  204   a - 5  respectively with fluid so  5  distinct zones of fluid pressure may be created over the peripheral zone  204   a . The annular recess  206   f  is configured to supply fluid to a central portion of the platen so fluid pressure may be created over the central zone  204   b . The platen plate  202  may optionally include an end point detection hole  224  which may be utilized for CMP end point detection operations. In addition, an air/water pre-wet line  236  and an air/water post-wet line  238  are defined to form circle through the inside of the platen plate. The air/water pre-wet line  236  may have the pre-wet output  232  to a surface of the platen plate  202 . The air/water pre-wet line  238  may have the post-wet output  230  to the surface of the platen plate  202 . By injecting water through the line  236  and/or the line  238 , the surface of the platen plate  202  may be wetted before commencing CMP operations.  
         [0050]    The platen plate  202  is configured to be attached onto the mounting plate  228 . The mounting plate  228  is configured to receive fluid from the internal manifold  114  (as shown in FIG. 2A) through mounting plate fluid inputs  234  and to provide the fluid to the annular recesses  206   a ,  206   b ,  206   c ,  206   d ,  206   e ,  206   f , and  206   g  within the platen plate  202 . The platen cover  222  may couple the outside edges of the platen plate  202  and the mounting plate  228  together to keep the platen plate  202  and the mounting plate  228  as a cohesive unit.  
         [0051]    Therefore, in operation, air is inputted through inputs  234  and channeled through the mounting plate  228  to fluid input ports feeding the annular recesses  206   a ,  206   b ,  206   c ,  206   d ,  206   e ,  206   f , and  206   g . The fluid pressure then forces fluid out to zones  204   a - 1 ,  204   a - 2 ,  204   a - 3 ,  204   a - 4 ,  204   a - 5 , and  204   b.    
         [0052]    [0052]FIG. 4C shows a platen configuration  340  with concentric temperature zones in accordance with one embodiment of the present invention. In this embodiment, the platen configuration  340  includes a plurality of concentric pressure zones  342 ,  344 ,  346 ,  348 , and a center pressure zone  350 . Each of the pressure zones  342 ,  344 ,  346 ,  348 , and  350  may output different temperatures of fluid or the same temperature of fluid or any suitable combination of temperature fluids.  
         [0053]    [0053]FIG. 4D illustrates a platen configuration  360  with horizontal pressure zones in accordance with one embodiment of the present invention. In this embodiment, the platen configuration  360  includes horizontal temperature zones  362 ,  364 ,  366 ,  368 , and  370 . Each of the horizontal temperature zones may output different temperatures of fluid or the same temperature of fluid or any suitable combination of temperature fluids.  
         [0054]    [0054]FIG. 4E shows a diagram  380  illustrating a polishing pad heating process in accordance with one embodiment of the present invention. In this embodiment, the carrier head  108  holding the wafer  104  is pressed down onto the polishing pad  102  moving in the direction  106 . In this embodiment, the platen  110  is shown applying heated air to an underside of the polishing pad  102  from a variety of pressure zones. Also, the pre-wet output  232  and the post-wet output  230  are shown to be applying heated water to the underside of the polishing pad  102 . At this time, the heat temperature sensor  160  is detecting the temperature of the polishing pad  102  and through a feedback loop, the controller  150  (as shown in FIG. 2A) is monitoring and adjusting the heated fluid applied by the platen  110  and also adjusting the heated water delivered from pre-wet  232  and the post-wet output  230 . In addition, the heater  130  may be disposed above the polishing pad  102  and heat the polishing pad to a set temperature. The heater  130  may be optionally used as shown in FIG. 2B or in addition to using heated air through the platen to heat the polishing pad  102 .  
         [0055]    [0055]FIG. 5 shows a network diagram  400  illustrating how temperature may be managed through network connections of different components in accordance with one embodiment of the present invention. The control diagram shows a touch screen  402  connected to a scheduler  404  which is then connected to an Internet switch  406 . The Internet switch  406  is connected to a cluster controller  408  and a temperature controller  410 . In one embodiment, the touch screen  402  enables a user to set fluid zones pressure, fluid zones temperature, hot water output and also monitor current fluid zones as well as hot water temperature. The scheduler  404  manages the sending and receiving of data between the touch screen  402  and the internet switch  406 . The internet switch  406  directs data sent on the network to the intended locations. The cluster controller  408  manages nodes within the network and assists in the process of resource allocation within the network. The temperature controller  150  can receive a request to set air zones temperature and hot water set point. The temperature controller  150  also may perform proportional, integral, derivative (PID) control (PID control is described in further detail in reference to FIGS. 6A and 6B) for all air zones and hot water temperature. The temperature controller  410  may also transmit current zone temperature and hot water per request synchronously. The temperature controller  410  is any suitable type of controller that is configurable to receive the inputs described above, execute proportional, integral, derivative (PID) control signals (as described in further detail in reference to FIG. 6A), and produce the outputs to control the various controllable devices (e.g., internal manifold). In one embodiment, the temperature controller  410  can be a programmable logic controller (PLC) such as is available from Siemens or any other supplier of suitable PLCs. Alternatively, the controller  410  can be any type of generic computing system such as a personal computer.  
         [0056]    [0056]FIG. 6A is a block diagram  500  of proportional, integral, derivative (PID) controls in controlling a temperature of a zone n (where n is the number of the pressure zone(s) being managed) of the platen  110  in accordance with one embodiment of the present invention. It should be appreciated that the PID control described herein may be used to control and manage temperature of any of the pressure zones on the platen  110 . In one embodiment, zones  1 ,  2 ,  3 ,  4 ,  5 , and  6  may correspond to the annular sub-zones  204   a - 1 ,  204   a - 2 ,  204   a - 3 ,  204   a - 4 ,  204   a - 5 , and the central zone  204   b  respectively.  
         [0057]    Although the PID controls are described in relation to controlling the temperature of zone n of the platen  110 , the same principles are applicable to controlling any other control variable such as controlling the flow of the fluid with a particular temperature. A desired set point, such as a desired temperature of the n pressure zone may be set. The n air zone may be any one of the fluid zones located within the platen  110  where the fluid output may be independently controlled. Therefore, the block diagram  500  may be utilized to control the temperature of the fluid output in any fluid output zone. A desired set point, such as a desired temperature of a particular air zone is applied to an input  502 . The proportional, integral, derivative variables Kp, Ki, Kd are extracted from the signal to the input  502 . Each of the PID variables are applied to corresponding PID calculations  504   a ,  504   b ,  504   c  to produce a control signal  510 . For example, the control signal output may be a zone  1  air temperature control signal. The control signal  510  is then applied to a control output heater power and the process (e.g., zone  1  temperature control signal applied to the control input of the first zone temperature). The process also receives and utilizes a signal for the particular zone being managed from the electronic pressure (EP) regulator. A feedback signal  512  is fed back to the input  502  to provide an error control/feedback. If the set point applied to the input  502  is the desired air temperature is the desired air temperature of air zone  1 , then the feedback signal  512  may be a detected air temperature from the air zone  1  such as from a temperature sensor. In such a fashion, all zones of the platen  110  may be controlled and managed in an intelligent manner so the temperature of the polishing pad may be substantially equalized to the set point temperature.  
         [0058]    [0058]FIG. 6B is a block diagram  560  of proportional, integral, derivative (PID) controls in controlling water temperature delivery by the pre-wet ouput and the post-wet output in accordance with one embodiment of the present invention. The PID controls described in the block diagram  560  are in relation to controlling the temperature and output of heated water through the pre-wet output and the post-wet output. A desired set point, such as a desired temperature of the heated water may be set. The heated water may be transported to the platen  110  and delivered to a top surface of the platen from the pre-wet output and/or the post-wet output. A desired set point, such as a desired temperature of water is applied to an input  562 . The proportional, integral, derivative variables Kp, Ki, Kd are extracted from the signal to the input  562 . Each of the PID variables are applied to corresponding PID calculations  564   a ,  564   b ,  564   c  to produce a control signal  566 . For example, the control signal output may be a pre-wet heated water control signal. The control signal  566  is then applied to a control ouput heater power and the process (e.g., pre-wet heated water control signal applied to the control input of the polishing pad temperature). A feedback signal  568  is fed back to the input  562  to provide an error control/feedback. In one embodiment, if the set point applied to the input  562  is the desired water temperature is the desired water temperature from the pre-wet output, then the feedback signal  568  may be a detected water temperature from the pre-wet output such as from the temperature sensor.  
         [0059]    [0059]FIG. 7 shows a flowchart  600  illustrating a method of heating the polishing pad  102  in accordance with one embodiment of the present invention. The method begins with operation  602  which determines a temperature of a polishing pad. In this operation, the controller may receive a signal from a heat sensor indicating the temperature of the polishing pad. After operation  602 , the method moves to operation  604  which establishes whether the polishing pad is at a set temperature (also known as set point temperature). In operation  604 , the controller compares the polishing pad temperature with the set point temperature. If the polishing pad is not at the set temperature, the method moves to operation  606  which adjusts temperature of the polishing pad to the set temperature by varying temperature(s) and/or pressure(s) of the fluid(s) being outputted from various pressure zones of a platen, and by varying temperature of water being delivered from a pre-wet output and/or a post-wet output.  
         [0060]    Therefore, through intelligent management and control of the temperature(s) of fluids being outputted from the platen, the polishing pad temperature may in turn be managed to provide optimal wafer polishing rates. In addition, through the control of the polishing pad temperatures, polishing rates may be customized depending on the polishing rates desired. Therefore, the CMP system described herein enables optimized wafer polishing operations.  
         [0061]    Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.