DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-10 and 12-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sandhu (US-6,007,408) in view of Xu (US-2010/0279435) and further in view of Chang (US-2004/0072503).
Regarding claim 1, Sandhu (US-6,007,408) discloses a chemical mechanical polishing system (Fig. 2), comprising:
a support (platen 120) to hold a polishing pad (polishing pad 140) (Fig. 2);
a carrier head (wafer carrier 132) to hold a substrate (wafer/substrate 150) against the polishing pad (polishing pad 140) during a polishing process (Fig. 2);
a plurality of sensors (170a-170d) to monitor the temperature of the polishing process (“The polishing machine 110 also has at least one heat sensor 170 (identified only by reference numbers 170(a)-170(c) in FIG. 2) to sense the temperature of a component sensitive to the heat at the pad/substrate interface 160.”) [Sandhu; col. 5, lines 12-16],
the plurality of sensors (170a-170d) including at least a first sensor (substrate heat sensor 170b) positioned in the carrier head to monitor a temperature of the substrate (“a substrate heat sensor 170(b) is connected to the substrate carrier 132 to measure the temperature at the backside of the substrate 150”) [Sandhu; col. 5, lines 23-25] and a second sensor positioned outside the carrier head to monitor a temperature of the polishing pad (“a pad heat sensor 170(a) is embedded into the polishing pad 140 to measure the temperature of the planarizing surface 142 or the planarizing liquid 148”) [Sandhu; col. 5, lines 19-21], but fails to disclose:
a temperature control system to control a temperature of the polishing process;
a controller coupled to the sensor to receive a signal from the sensor and coupled to the temperature control system,
wherein the controller is configured to store data indicating a desired temperature of polishing process and to drive the temperature of the polishing process toward the desired temperature, and wherein the controller comprises a closed-loop control of the temperature control system to drive a measured temperature from the plurality of sensors to the desired temperature.
However, Xu (US-2010/0279435) teaches:
a temperature control system (fluid circulation channels 22 with heating/cooling element 30, and heating/cooling element 108) to control a temperature of the polishing process (Fig. 1);
a controller (“programmed computer or special purpose processor 68”) coupled to a sensor (sensor 66) to receive a signal from the sensor (“An IR sensor 66 located at polishing surface 34 is oriented to sense the temperature of polishing surface 34 adjacent to carrier head 36”) [Xu; paragraph 0029] and coupled to the temperature control system (“programmed computer or special purpose processor 68 can monitor the output of IR sensor 66 and can control pump 24, temperature controller 32, pressure controller 46, and temperature controller 64”) [Xu; paragraph 0029],
wherein the controller (computer/processor 68) is configured to store data indicating a desired temperature (target temperature) of polishing process and to drive the temperature of the polishing process toward the desired temperature (“Computer 68 can set a target temperature of temperature controller 32, then adjusts the power delivered to heating/cooling element 30 to control the temperature of the fluid, e.g., holding it at the target temperature. Thus, the target temperature can be reached, and temperature variations can be reduced.”) [Xu; paragraph 0033] (“The temperature at polishing surface 34 may also be regulated by controlling the temperature of liquid that is delivered to polishing surface 34. Polishing pad 14 may have insulating properties. Therefore, even if the temperature of platen 12 is controlled as described above, it may not provide as much control of the temperature of polishing surface 34 as desired.”) [Xu; paragraph 0034]. Since Xu teaches a temperature control system and controller are an improvement to CMP planarization, which is in the same field of endeavor and pertinent to Sandhu, it therefore would’ve been obvious to one of ordinary skill in the art to incorporate a temperature control system and controller, as taught by Xu, into the CMP device of Sandhu in order to improve planarization of the wafer/substrate (“Applicants have discovered that controlling temperature during CMP can lead to improved planarization, reduced erosion, and reduced dishing. In particular, Applicants have discovered that, for example, in CMP of copper using a slurry with ammonium persulphate (APS) oxidizer, dishing and erosion can depend on the temperature at the surface of a polishing pad and the temperature of the polishing slurry, where dishing is increased with decreasing temperature, whereas erosion is increased with increasing temperature.”) [Xu; paragraph 0006].
Neither Sandhu or Xu disclose/teach wherein the controller comprises a closed-loop control of the temperature control system to drive a measured temperature from the plurality of sensors to the desired temperature.
However, Chang (US-2004/0072503) teaches a closed-loop control for a process parameter of a CMP machine (“The closed loop control mode is used to normally maintain the slurry flow rate through the conduit 18 within the specified target rate range after the open loop control mode is used to initially bring the slurry delivery rate up from zero to the specified target rate range.”) [Chang; paragraph 0028]. It, therefore, would’ve been obvious to one of ordinary skill int eh art to use the controller of Xu in a closed-loop control in order to drive the process parameter, which is temperature in Xu, to the desired temperature using feedback (“The closed loop control mode is used to normally maintain the slurry flow rate through the conduit 18 within the specified target rate range after the open loop control mode is used to initially bring the slurry delivery rate up from zero to the specified target rate range.”) [Chang; paragraph 0028] (Fig. 2).
Regarding claim 2, Sandhu, as modified, discloses the system of claim 1, but fails to disclose wherein the first sensor comprises a thermocouple.
However, Xu teaches that a thermocouple is a known technique for measuring temperature (“other known techniques for measuring the temperature of the polishing surface can be employed, e.g. a thermocouple”) [Xu; paragraph 0045]. Since Sandhu teaches that “[a] wide variety of conventional temperature sensors may be used as the heat sensor 170, including those that sense temperature optically, electrically, chemically, etc.” [Sandhu; col. 5, lines 17-19], it therefore would’ve been obvious to use a conventional known measurement device, such as the thermocouple taught by Xu, for the first sensor of Sandhu in order to measure temperatures as desired by Sandhu [Sandhu; col. 5, lines 17-19].
Regarding claim 3, Sandhu, as modified, discloses system of claim 1, wherein the second sensor comprises a thermocouple embedded in or placed on the support (platen 120) (Fig. 2), but fails to disclose wherein the second sensor comprises a thermocouple.
However, Xu teaches wherein the second sensor (a pad heat sensor 170a) comprises a thermocouple (“instead of measuring the temperature of the polishing surface with an IR monitor, other known techniques for measuring the temperature of the polishing surface can be employed, e.g. a thermocouple installed in the platen or embedded in the polishing pad”) [Xu; paragraph 0045]. Since Xu is in the same field of endeavor as Sandhu, it therefore would’ve been an obvious design choice to use the thermocouple of Xu for the first sensor of Sandhu based on considerations such as cost and availability.
Regarding claim 4, Sandhu, as modified, discloses the system of claim 1, wherein Xu further teaches a second sensor (the sensor for monitoring temperature of the pad’s polishing surface) comprises a sensor (“IR sensor 66, computer 68 can monitor the temperature of polishing surface 34”) [Xu; paragraph 0037], positioned above the support (platen 12 of Xu).
Regarding claim 5, Sandhu, as modified, discloses the system of claim 4, wherein the second sensor (IR sensor 66 of Xu, modified into the device of Sandhu) comprises an infrared camera (IR sensor 66, considered to be an infrared device for recording visual signals) (“Using IR sensor 66, computer 68 monitors the temperature of polishing surface 34.”) [Xu; paragraph 0040].
Regarding claim 6, Sandhu, as modified, discloses the system of claim 1, wherein the temperature control system includes a heat exchanger having a fluid passage in the support (“Platen 12 may be made of a thermally conductive material, e.g., aluminum, and can include within its interior an array of fluid circulation channels 22 through which a coolant or heating fluid can be circulated during use.”) [Xu; paragraph 0021].
Regarding claim 7, Sandhu, as modified, discloses the system of claim 1, comprising an in-situ monitoring system (“a preferred embodiment of the present invention determines the endpoint in-situ and in real-time without removing the substrate from the polishing pad and without stopping the polishing process”) [Sandhu; col. 7, lines 48-51] configured to generate a signal that depends on an amount of material on the substrate (“The polishing machine also has a substrate carrier that may be positioned over the planarizing surface of the polishing pad, and at least one sensor that monitors a characteristic of a polishing component that is influenced by the type of material being removed from the substrate. In a preferred embodiment, the sensor is preferably a heat sensor that measures the temperature of a polishing component sensitive to heat at the front side of the substrate, such as the planarizing surface of the polishing pad, the back side of the substrate, or the CMP byproducts produced by polishing the substrate.”) [Sandhu; col. 2, line 63 - col. 3, line 6], and wherein the controller (as modified into Sandhu by Xu) is configured to store data indicating a desired temperature of polishing process as a function of the signal (“Computer 68 can set a target temperature of temperature controller 32, then adjusts the power delivered to heating/cooling element 30 to control the temperature of the fluid, e.g., holding it at the target temperature. Thus, the target temperature can be reached, and temperature variations can be reduced.”) [Xu; paragraph 0033] (“The temperature at polishing surface 34 may also be regulated by controlling the temperature of liquid that is delivered to polishing surface 34. Polishing pad 14 may have insulating properties. Therefore, even if the temperature of platen 12 is controlled as described above, it may not provide as much control of the temperature of polishing surface 34 as desired.”) [Xu; paragraph 0034].
Regarding claim 8, Sandhu, as modified, discloses the system of claim 7, wherein the in-situ monitoring system is configured to detect exposure of an underlying layer of the substrate during the polishing process (“After the cover layer is at least partially removed from the substrate and a portion of the underlying layer engages the polishing medium, the heat between the substrate and the polishing medium changes to within a second heat range because the chemical reaction between the underlying layer and the polishing medium is different than that of the cover layer. The heat may also change when the underlying layer engages the polishing medium because the coefficient of friction between the underlying layer and the polishing medium may also be different than that of the cover layer. The heat sensors sense the change in heat from the first heat range to the second heat range, and CMP processing is preferably stopped when the sensed heat is within the second heat range.”) (emphasis added) [Sandhu; col. 3, lines 22-35].
Regarding claim 9, Sandhu, as modified, discloses the system of claim 8, wherein the function comprises a step function (i.e. a function that increases or decreases abruptly from one value to another) that is discontinuous (i.e. changes) upon changes of exposure of the underlying layer of substrate (“After the cover layer is at least partially removed from the substrate and a portion of the underlying layer engages the polishing medium, the heat between the substrate and the polishing medium changes to within a second heat range because the chemical reaction between the underlying layer and the polishing medium is different than that of the cover layer. The heat may also change when the underlying layer engages the polishing medium because the coefficient of friction between the underlying layer and the polishing medium may also be different than that of the cover layer. The heat sensors sense the change in heat from the first heat range to the second heat range, and CMP processing is preferably stopped when the sensed heat is within the second heat range.”) (emphasis added) [Sandhu; col. 3, lines 22-35].
Regarding claim 10, Sandhu, as modified, discloses the system of claim 7, wherein the in-situ monitoring system is configured to generate a signal having a value representative of a thickness of a layer or of an amount removed during the polishing process (measures temperature, which is representative of a changing thickness and/or amount of material removed) (“The endpoint is preferably determined by monitoring the temperature of the polishing component and stopping the removal of material from the substrate when the temperature changes from a first temperature corresponding to heat H.sub.1 to a second temperature corresponding to heat H.sub.2. Accordingly, the second temperature of the polishing component preferably provides a predetermined temperature at which CMP processing is stopped.”) [Sandhu; col. 3, lines 22-35].
Regarding claim 12, Sandhu, as modified, discloses a method of chemical mechanical polishing, comprising:
holding a substrate (wafer 150) against a polishing pad (polishing pad 140) (Fig. 2);
monitoring a temperature of the polishing process with a plurality of sensors (170a-170d) (“The polishing machine 110 also has at least one heat sensor 170 (identified only by reference numbers 170(a)-170(c) in FIG. 2) to sense the temperature of a component sensitive to the heat at the pad/substrate interface 160.”) [Sandhu; col. 5, lines 12-15],
the plurality of sensors (170a-170d) including at least a first sensor (substrate heat sensor 170b) positioned in the carrier head to monitor a temperature of the substrate (“a substrate heat sensor 170(b) is connected to the substrate carrier 132 to measure the temperature at the backside of the substrate 150”) [Sandhu; col. 5, lines 23-25] and a second sensor (a pad heat sensor 170(a)) positioned outside the carrier head (wafer carrier 132) (Fig. 2) to monitor a temperature of the polishing pad (“a pad heat sensor 170(a) is embedded into the polishing pad 140 to measure the temperature of the planarizing surface 142 or the planarizing liquid 148”) [Sandhu; col. 5, lines 19-21], but fails to disclose;
storing data indicating a desired temperature of polishing process; and
performing closed-loop control to drive a measured temperature from the plurality of sensors to the desired temperature.
However, Xu (US-2010/0279435) teaches:
Storing data indiciating a desired temperature o fa polishing process; and performing control to drive a measured temperature from a plurality of sensor to the desired temperature (“programmed computer or special purpose processor 68 can monitor the output of IR sensor 66 and can control pump 24, temperature controller 32, pressure controller 46, and temperature controller 64”) [Xu; paragraph 0029] (“Computer 68 can set a target temperature of temperature controller 32, then adjusts the power delivered to heating/cooling element 30 to control the temperature of the fluid, e.g., holding it at the target temperature. Thus, the target temperature can be reached, and temperature variations can be reduced.”) [Xu; paragraph 0033] (“The temperature at polishing surface 34 may also be regulated by controlling the temperature of liquid that is delivered to polishing surface 34. Polishing pad 14 may have insulating properties. Therefore, even if the temperature of platen 12 is controlled as described above, it may not provide as much control of the temperature of polishing surface 34 as desired.”) [Xu; paragraph 0034]. Since Xu teaches temperature control provides an improvement to CMP planarization, which is in the same field of endeavor and pertinent to Sandhu, it therefore would’ve been obvious to one of ordinary skill in the art to incorporate temperature control, as taught by Xu, into the CMP device of Sandhu in order to improve planarization of the wafer/substrate (“Applicants have discovered that controlling temperature during CMP can lead to improved planarization, reduced erosion, and reduced dishing. In particular, Applicants have discovered that, for example, in CMP of copper using a slurry with ammonium persulphate (APS) oxidizer, dishing and erosion can depend on the temperature at the surface of a polishing pad and the temperature of the polishing slurry, where dishing is increased with decreasing temperature, whereas erosion is increased with increasing temperature.”) [Xu; paragraph 0006].
Neither Sandhu or Xu disclose/teach wherein the controller comprises a closed-loop control of the temperature control system to drive a measured temperature from the plurality of sensors to the desired temperature.
However, Chang (US-2004/0072503) teaches a closed-loop control for a process parameter of a CMP machine (“The closed loop control mode is used to normally maintain the slurry flow rate through the conduit 18 within the specified target rate range after the open loop control mode is used to initially bring the slurry delivery rate up from zero to the specified target rate range.”) [Chang; paragraph 0028]. It, therefore, would’ve been obvious to one of ordinary skill int eh art to use the controller of Xu in a closed-loop control in order to drive the process parameter, which is temperature in Xu, to the desired temperature using feedback (“The closed loop control mode is used to normally maintain the slurry flow rate through the conduit 18 within the specified target rate range after the open loop control mode is used to initially bring the slurry delivery rate up from zero to the specified target rate range.”) [Chang; paragraph 0028] (Fig. 2).
Regarding claim 13, Sandhu, as modified, discloses the method of claim 12, but fails to disclose wherein the first sensor comprises a thermocouple.
However, Xu teaches that a thermocouple is a known technique for measuring temperature (“other known techniques for measuring the temperature of the polishing surface can be employed, e.g. a thermocouple”) [Xu; paragraph 0045]. Since Sandhu teaches that “[a] wide variety of conventional temperature sensors may be used as the heat sensor 170, including those that sense temperature optically, electrically, chemically, etc.” [Sandhu; col. 5, lines 17-19], it therefore would’ve been obvious to use a conventional known measurement device, such as the thermocouple taught by Xu, for the first sensor of Sandhu in order to measure temperatures as desired by Sandhu [Sandhu; col. 5, lines 17-19].
Regarding claim 14, Sandhu, as modified, discloses the method of claim 12, wherein the second sensor comprises a thermocouple embedded in or placed on the support (platen 120) (Fig. 2), but fails to disclose wherein the second sensor comprises a thermocouple.
However, Xu teaches wherein the second sensor (a pad heat sensor 170a) comprises a thermocouple (“instead of measuring the temperature of the polishing surface with an IR monitor, other known techniques for measuring the temperature of the polishing surface can be employed, e.g. a thermocouple installed in the platen or embedded in the polishing pad”) [Xu; paragraph 0045]. Since Xu is in the same field of endeavor as Sandhu, it therefore would’ve been an obvious design choice to use the thermocouple of Xu for the first sensor of Sandhu based on considerations such as cost and availability.
Regarding claim 15, Sandhu, as modified, discloses the system of claim 12, wherein Xu further teaches a second sensor (the sensor for monitoring temperature of the pad’s polishing surface) comprises a sensor (“IR sensor 66, computer 68 can monitor the temperature of polishing surface 34”) [Xu; paragraph 0037], positioned above the support (platen 12 of Xu).
Regarding claim 16, Sandhu, as modified, discloses the method of claim 15, wherein the second sensor (IR sensor 66 of Xu, modified into the device of Sandhu) comprises an infrared camera (IR sensor 66, considered to be an infrared device for recording visual signals) (“Using IR sensor 66, computer 68 monitors the temperature of polishing surface 34.”) [Xu; paragraph 0040].
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sandhu (US-6,007,408) in view of Xu (US-2010/0279435) and further in view of Chang (US-2004/0072503) and Roover (US-2006/0106479).
Regarding claim 11, Sandhu, as modified, discloses the system of claim 10, but fails to disclose wherein the function comprises a continuous function that is continuous across changes in the thickness of the layer of the substrate or the amount removed.
However, Roover (US-2006/0106479) teaches linear models are what most multivariable feedback control design techniques are based on (“Because most multivariable feedback control design techniques are based on linear models, linear models must be derived from the dynamic, possibly non-linear, CMP sub-models (see FIG. 2) that describe the linear CMP behavior at a specific operating point (a selection of constant input values). The continuous linear models take on the form: d x .function. ( t ) d t = Ax .times. ( t ) + Bu .times. ( t ) , y .function. ( t ) = Cx .times. ( t ) + Du .times. ( t ) , ( 15 ) ##EQU11## where x(t) denotes the vector of state variables, u(t) denotes the vector of input variables (actuators), and y(t) denotes the vector of output variables (sensors), and A, B, C, and D are the state-space matrices of appropriate size. In discrete time, Equation (15) translates to: x(k+1)=Ax(k)+Bu(k), (16) y(k)=Cx(k)+Du(k), where k denotes the current (discrete) time sample t.sub.k=k.DELTA.T, while t.sub.k denotes current time at sample k and .DELTA.T denotes the sampling time of the model of Equation (16), i.e. the time-interval of discretization. For the CMP pressure model, Equations (15) and (16) are formed by Equations (11-13). The thickness at each node on the wafer, h,(k), i=-N . . . N, form the state vector x(k), the pressures p.sub.j, j=1 . . . n, form the input vector u(k), and the average measured thickness in each zone, h.sub.j.sup.avg, j=1 . . . n, form the output vector y(k).”) [Roover; paragraph 0070]. Since Sandhu teaches the function comprises a function that is across changes in the thickness of the layer of the substrate or the amount removed (measures temperature, which is representative of a changing thickness and/or amount of material removed) (“The endpoint is preferably determined by monitoring the temperature of the polishing component and stopping the removal of material from the substrate when the temperature changes from a first temperature corresponding to heat H.sub.1 to a second temperature corresponding to heat H.sub.2. Accordingly, the second temperature of the polishing component preferably provides a predetermined temperature at which CMP processing is stopped.”) [Sandhu; col. 3, lines 22-35], and since Roover teaches that continuous linear models/functions are what such control design technique would be based on, it therefore would’ve been obvious to one of ordinary skill in the art to use a continuous function, as taught by Roover, in order to provide feedback control for the device of Sandhu, as modified [Roover; paragraph 0070].
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US-20050048875 are pertinent to claim 1.
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/JOEL D CRANDALL/Examiner, Art Unit 3723
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