Apparatus, systems, and methods for temperature control of substrates using embedded fiber optics and epoxy optical diffusers
Substrate temperature control apparatus and electronic device manufacturing systems provide pixelated light-based heating to a substrate in a process chamber. A substrate holder in the process chamber may include a baseplate. The baseplate has a top surface that may have a plurality of cavities and a plurality of grooves connected to the cavities. Optical fibers may be received in the grooves such that each cavity has a respective optical fiber terminating therein to transfer light thereto. Some or all of the cavities may have an epoxy optical diffuser disposed therein to diffuse light provided by the optical fiber. A ceramic plate upon which a substrate may be placed may be bonded to the baseplate. A thermal spreader plate may optionally be provided between the baseplate and the ceramic plate. Methods of controlling temperature across a substrate holder in an electronic device manufacturing system are also provided, as are other aspects.
1. A substrate holder, comprising:
a baseplate comprising:
a plurality of cavities formed in a top surface of the baseplate, each cavity of the plurality of cavaties having an opening on the top surface;
a plurality of feedthrough holes extending from a back surface of the baseplate to the top surface of the baseplate; and
a plurality of optical fiber bundles, each optical fiber bundle of the plurality of optical fiber bundles having a plurality of optical fibers, wherein at least a lengthwise portion of each one of the plurality of optical fiber bundles is disposed in a corresponding feedthrough hole, and each one of the plurality of optical fibers terminates in a respective one of the plurality of cavities and is configured to transmit light thereto.
2. The substrate holder of claim 1 , further comprising a plurality of grooves formed in the top surface of the baseplate, wherein each one of the plurality of grooves is connected to one of the plurality of feedthrough holes, and, wherein each one of the plurality of cavities is connected to one of the plurality of grooves.
3. The substrate holder of claim 1 , further comprising an optical diffuser disposed in at least some of the plurality of cavities.
4. The substrate holder of claim 3 , wherein the optical diffuser comprises diffusing particles suspended therein.
5. The substrate holder of claim 3 , wherein the optical diffuser comprises a diffusing particle located near an output end of an optical fiber of the plurality of optical fibers.
6. The substrate holder of claim 1 , further comprising a ceramic plate coupled to the top surface of the baseplate via an elastomer bond disposed therebetween, the ceramic plate comprising an infrared absorbent coating adjacent each one of the plurality of cavities.
7. The substrate holder of claim 1 , further comprising:
a thermal spreader plate coupled to the top surface of the baseplate via a first elastomer bond disposed there between; and
a ceramic plate coupled to the thermal spreader plate via a second elastomer bond disposed therebetween.
8. The substrate holder of claim 1 , wherein at least some of the plurality of cavities are electro-polished, gold plated, or both.
9. The substrate holder of claim 2 , wherein some of the plurality of optical fibers are pre-bent to conform to some of the plurality of grooves.