Systems and methods for ESC temperature control
This disclosure relates to a temperature control system that may be used in a plasma processing system that treats microelectronic substrates using plasma. The temperature control system may include a heating array disposed adjacent to the microelectronic substrate and that may selectively generate heat at different portions of the microelectronic substrate. The heating array may include heating modules that selectively generate heat depending upon a breakover voltage of a Silicon Diode for Alternating Current (SIDAC). The amount of heat generated heat may depend upon the resistance of the heating module and the duty cycle of the variable voltage signal.
1. An apparatus, comprising:
a signal generator that generates a power modulation signal;
a heating array coupled to the signal generator, the heating array comprising heating modules that are arranged in parallel, the heating modules comprising a load element and a switch element that are in electrical communication with the signal generator, the load element being in series with the switch element;
a substrate chuck adjacent to the heating array, the substrate chuck comprising a supporting surface for a microelectronic substrate; and
an electrostatic chuck component that can generate an electromagnetic field, the electrostatic chuck component being subjacent to the substrate chuck.
2. The apparatus of claim 1 , wherein at least two of the load elements comprise different resistance values and the switching elements comprise different breakover voltages.
3. The apparatus of claim 1 , wherein the switching elements comprise thyristor devices or bi-directional diodes.
4. The apparatus of claim 1 , wherein the signal generator comprises a voltage component that varies voltage and duty cycle.
5. The apparatus of claim 4 , wherein a first group of heating modules comprises breakover voltages within a first range; and a second group of heating modules comprising breakover voltages within a second range that is different from the first range.
6. The apparatus of claim 1 , wherein the heating array comprises a first group of heating modules comprising breakover voltages within a first range; and a second group of heating modules comprising breakover voltages within a second range that is different from the first range.
7. An apparatus, comprising:
a substrate support surface that can support a microelectronic substrate;
a heating array subjacent to the substrate support surface, the heating array comprising a first parallel arrangement of heating elements, the heating elements comprising a load element connected in series with a bi-directional current component; and
an electrostatic chuck component subjacent to the substrate support surface.
8. The apparatus of claim 7 , wherein the heating array comprises a second parallel arrangement of heating elements that are in series with the first parallel arrangement of heating elements that is in parallel with at least one diode.
9. The apparatus of claim 7 , wherein the bi-directional current components comprise different breakover voltages.
10. The apparatus of claim 9 , wherein the load elements comprise different resistance values.
11. The apparatus of claim 9 , wherein the load elements comprise a common resistance value.
12. The apparatus of claim 9 , wherein the load elements comprise two or more groups of the load elements that have different resistance values.
13. The apparatus of claim 7 , wherein the heating elements comprises two or more groups of the bi-directional current components that have different breakover voltages.
14. The apparatus of claim 7 , wherein the bi-directional current components comprise an electrical element that conducts current flow when a first voltage is applied and prevents current flow through the electrical element when a second voltage is applied.
15. The apparatus of claim 7 , further comprising a single power source coupled to the heating array.
16. A method for treating a substrate, comprising:
receiving a microelectronic substrate on a substrate holder comprising an electrostatic chuck and a parallel arrangement of heating elements comprising a load element in series with a switch element;
applying a chucking voltage to the electrostatic chuck; applying a variable voltage signal to the parallel arrangement to achieve a first temperature profile across the substrate holder; and heating portions of the substrate holder based, at least in part, on the variable voltage and the load elements.
17. The method of claim 16 , wherein the variable voltage signal comprises a bi-polar component.
18. The method of claim 16 , wherein the heating further comprises changing the variable voltage signal to obtain a second temperature profile across the substrate holder.
19. The method of claim 16 , wherein the heating is further based, at least in part, on breakover voltages of the load elements.
20. The method of claim 16 , wherein the heating is further based, at least in part, on a duty cycle of the variable voltage.