Substrate carrier with array of independently controllable heater elements

Abstract

A substrate carrier is described with an array of independently controllable heater elements. In one example an apparatus includes a substrate carrier to carry a substrate for processing, a plurality of resistive heating elements in the carrier to heat the substrate by heating the carrier, a power supply to supply power to the heating elements, a power controller to provide a control signal, the control signal to control an amount of current applied to each of the heating elements, and a plurality of power interfaces in the carrier each coupled to a heating element to receive the power from the power supply and the control signal from the controller and to modulate the power applied to a respective coupled heating element in response to the control signal.

What is claimed is: 
     
         1 . An apparatus comprising:
 a substrate carrier to carry a substrate for processing;   a plurality of resistive heating elements in the carrier to heat the substrate by heating the carrier;   a power supply to supply power to the heating elements;   a power controller to provide a control signal, the control signal to control an amount of current applied to each of the heating elements; and   a plurality of power interfaces in the carrier each coupled to a heating element to receive the power from the power supply and the control signal from the controller and to modulate the power applied to a respective coupled heating element in response to the control signal.   
     
     
         2 . The apparatus of  claim 1 , wherein the power controller commands an ON state and an OFF state for each heating element by controlling power supplied to each heating element. 
     
     
         3 . The apparatus of  claim 2 , wherein the power supply measures a power supplied to the heating elements when the power controller controls an ON and an OFF state of a heating element to determine a power of the respective heating element. 
     
     
         4 . The apparatus of  claim 1 , further comprising a carrier controller in the carrier coupled to each of the plurality of power interfaces, wherein the power controller provides a digital control signal to the carrier controller and wherein the carrier controller controls the power modulation of the power interface. 
     
     
         5 . The apparatus of  claim 4 , wherein the carrier controller generates a pulse width modulated signal to each power interface and wherein each power interface modulates the received power from the power supply using the received pulse width modulated signal. 
     
     
         6 . The apparatus of  claim 5 , wherein the pulse width modulated signal is an optically modulated signal sent through an optical connection of the carrier and wherein each power interface comprises an opto-isolator coupled to the received pulse width modulated signal and an amplifier and wherein the opto-isolator provides the received pulse width modulated signal to the amplifier to control the amplifier. 
     
     
         7 . The apparatus of  claim 1 , further comprising a fan-out distributor in the carrier to receive the power from the power supply and to distribute the received power to each power interface. 
     
     
         8 . The apparatus of  claim 7 , wherein the power supply is coupled using a single power line to the fan-out distributor in the carrier. 
     
     
         9 . The apparatus of  claim 1 , wherein the power supply measures the voltage and current supplied to the heating elements. 
     
     
         10 . The apparatus of  claim 1 , wherein the carrier is ceramic and the resistive heating elements and the power interfaces are embedded in the ceramic. 
     
     
         11 . A method comprising:
 supplying power to a plurality of heating elements from a common power supply, the heating elements being in a substrate carrier to heat the substrate by heating the carrier, the carrier to carry the substrate during processing;   generating a control signal from a power controller to control an amount of current applied to each of the heating elements;   receiving the power from the power supply at each of a plurality of power interfaces in the carrier each coupled to a heating element;   receiving the control signal at each of the plurality of power interfaces; and   modulating the power applied to a respective coupled heating element by a respective power interface in response to the control signal.   
     
     
         12 . The method of  claim 11 , further comprising receiving instructions at the power controller from a program operating on a terminal to change a power modulation to a heating element of the plurality of heating elements and changing the control signal at the power controller in response to the received instruction. 
     
     
         13 . The method of  claim 11 , further comprising receiving the control signal from the power controller at a carrier controller embedded in the substrate carrier, wherein the control signal is a serial packetized control signal and generating a unique control signal to each heating interface from the carrier controller. 
     
     
         14 . The method of  claim 13  wherein the control signal from the power controller is an optical signal. 
     
     
         15 . The method of  claim 11 , further comprising measuring a voltage of the common power supply;
 measuring a current of the common power supply;   generating a control signal to change a power state of a selected one of the heating elements;   measuring a current of the common power supply after changing the power state;   determining a difference of the first and second current measurement; and   determining a temperature of the selected one of the heating elements using the determined current measurement difference.   
     
     
         16 . A plasma processing chamber comprising:
 a plasma chamber;   a plasma source to generate a plasma containing gas ions in the plasma chamber;   a power supply to supply power;   a power controller to provide a control signal to control heating; and   a substrate carrier to carry a substrate in the chamber for processing, the carrier having a plurality of resistive heating elements to heat the substrate by heating the carrier and a plurality of power interfaces each coupled to a heating element to receive the power from the power supply and the control signal from the controller and to modulate the power applied to a respective coupled heating element in response to the control signal.   
     
     
         17 . The chamber of  claim 16 , further comprising a terminal coupled to the power controller to control the operation of the power interfaces. 
     
     
         18 . The chamber of  claim 16 , wherein the carrier further comprises a fan-out distributor to receive the power from the power supply and distribute the received power to each power interface. 
     
     
         19 . The chamber of  claim 16 , wherein each power interface receives a pulse width modulated signal based on the control signal, the pulse width modulated signal having a duty cycle to modulate the power applied to respective coupled heating element.