Synchronization between temperature measurement device and radiation sources

1 . A method for measuring temperature of a substrate comprising:

switching one or more sources having response times defined by rise and fall times of less than 100 milliseconds between:

an active state in which the one or more sources heat at least one portion of the substrate, and

an inactive state in which the one or more sources cause substantially no radiation or a negligible amount of radiation to be generated; and

by a temperature measuring device, performing a temperature measurement of the at least one portion of the substrate, wherein the temperature measuring device is synchronized to the switching between the active and inactive states such that:

i) the one or more sources are switched to the inactive state from the active state within the response times and the temperature measurement is started immediately after the one or more sources are switched to the inactive state,

ii) immediately after completion of the temperature measurement, the one or more sources are switched to the active state from the inactive state within the response times, and

iii) the temperature measurement is performed only when the one or more sources are in the inactive state,

thereby preventing radiation from the one or more sources from obscuring the temperature measurement performed by the temperature measuring device,

wherein performing the temperature measurement includes sensing radiation within a measurement wavelength band, wherein the measurement wavelength band is selected to exclude a peak emission wavelength of the one or more sources.

2 . The method of claim 1 , wherein the one or more sources irradiate the substrate during the active state so as to heat the substrate.

3 . The method of claim 1 , wherein the one or more sources includes a plurality of light-emitting diodes or a plurality of laser sources deployed to irradiate the substrate.

4 . The method of claim 1 , wherein the one or more sources includes plasma deployed to bombard the substrate with charged particles during the active state.

5 . The method of claim 1 , wherein the temperature measuring device is synchronized to the switching between the active and inactive states via a synchronization signal corresponding to at least one of: the inactive state, transition from the active state to the inactive state, or transition from the inactive state to the active state.

6 . The method of claim 5 , wherein the synchronization signal is provided by an intensity sensor deployed to sense radiation emitted by the one or more sources.

7 . The method of claim 5 , wherein the synchronization signal is provided by a controller associated with the one or more sources that controls switching of the one or more sources between the active and inactive states.

8 . The method of claim 1 , wherein the temperature measuring device includes a sensor that senses radiation emitted by the sources, and is synchronized to the switching of the one or more sources between the active and inactive states by identifying drops in the emitted radiation corresponding to initiation of the inactive state.

9 . The method of claim 1 , wherein the active state is associated with at least one irradiation time-interval, and wherein each of the at least one irradiation time-interval is a time interval during which the one or more sources emit radiation at an output power or average output power taken over the entirety of the time interval that is sufficiently high so as to heat the substrate, and wherein the inactive state is associated with at least one measurement time-interval, and wherein each of the at least one measurement time-interval is a time interval during which the one or more sources do not emit radiation or emit radiation at an output power that is sufficiently low so as to be negligible to the temperature measuring device.

10 . A system for measuring temperature of a substrate comprising:

one or more sources, having response times defined by rise and fall times of less than 100 milliseconds, deployed in association with the substrate, the one or more sources switchable between: an active state in which the one or more sources heat at least one portion of the substrate, and an inactive state in which the one or more sources cause substantially no radiation or a negligible amount of radiation to be generated;

a controller including at least one processor and configured to switch the one or more sources between the active state and the inactive state; and

a temperature measuring device configured to perform a temperature measurement of the at least one portion of the substrate,

wherein the temperature measuring device and the switching between the active and inactive states are synchronized to each other such that:

i) the one or more sources are switched to the inactive state from the active state by the controller within the response time and the temperature measurement is started immediately after the one or more sources are switched to the inactive state,

ii) immediately after completion of the temperature measurement, the one or more sources are switched to the active state from the inactive state by the controller within the response time, and

iii) the temperature measurement is performed only when the one or more sources are in the inactive state,

thereby preventing radiation from the one or more sources from obscuring the temperature measurement performed by the temperature measuring device,

wherein the temperature measuring device is configured to perform the temperature measurement by sensing radiation within a measurement wavelength band, wherein the measurement wavelength band is selected to exclude a peak emission wavelength of the one or more sources.

11 . The system of claim 10 , wherein the at least one temperature measuring device is synchronized to the switching of the one or more sources via a synchronization signal corresponding to at least one of: the inactive state, transition from the active state to the inactive state, or transition from the inactive state to the active state.

12 . The system of claim 11 , wherein the synchronization signal is provided to the at least one temperature measuring device by the controller.

13 . The system of claim 11 , further comprising: at least one intensity sensor deployed to sense radiation emitted by the one or more sources and configured to provide the synchronization signal to the at least one temperature measuring device.

14 . The system of claim 10 , wherein the at least one temperature measuring device measures radiation and is synchronized to the switching of the one or more sources by identifying drops in the radiation measurement corresponding to initiation of the inactive state.

15 . The system of claim 10 , wherein the one or more sources includes a plurality of light-emitting diodes or a plurality of laser sources.

16 . The system of claim 10 , wherein the active state is associated with at least one irradiation time-interval, and wherein each of the at least one irradiation time-interval is a time interval during which the one or more sources emit radiation at an output power or average output power taken over the entirety of the time interval that is sufficiently high so as to heat the substrate, and wherein the inactive state is associated with at least one measurement time-interval, and wherein each of the at least one measurement time-interval is a time interval during which the one or more sources do not emit radiation or emit radiation at an output power that is sufficiently low so as to be negligible to the temperature measuring device.

17 . A method comprising:

switching one or more radiation sources having response times defined by rise and fall times of less than 100 milliseconds between:

an active state in which the one or more radiation sources irradiate at a substrate so as to heat the substrate, and

an inactive state in which the one or more radiation sources emit substantially no radiation or emit a negligible amount of radiation;

performing by a device:

a first radiation measurement during the inactive state, the first radiation measurement including radiation corresponding to thermal emission by the substrate, and

a second radiation measurement during the active state, the second radiation measurement including radiation corresponding to thermal emission by the substrate and radiation reflected by the substrate in response to radiation emitted by the one or more radiation sources,

wherein the device is synchronized to the switching between the active and inactive states such that:

i) the one or more sources are switched to the inactive state from the active state within the response times and the first radiation measurement is started immediately after the one or more sources are switched to the inactive state,

ii) immediately after completion of the temperature measurement, the one or more sources are switched to the active state from the inactive state within the response times, and

iii) the first radiation measurement is performed only when the one or more sources are in the inactive state,

thereby preventing radiation from the one or more sources from obscuring the radiation measurement performed by the device,

wherein performing the first radiation measurement and the second radiation measurement includes sensing radiation within a measurement wavelength band, wherein the measurement wavelength band is selected to exclude a peak emission wavelength of the one or more radiation sources; and

calculating, based on the first and second radiation measurements, at least one of a reflectivity of the substrate or an emissivity of the substrate.