Thermal processing system with supplemental resistive heater and shielded optical pyrometry

A thermal processing system for processing a semiconductor substrate within a range of processing temperatures, the processing system including an improved temperature control system for determining thermal characteristics of the substrate based upon light intensity within a given range of wavelengths, the temperature control system comprising:

• a shield comprising a material substantially nontransmissive to light within the given range of wavelengths at the processing temperatures;
• the shield having a surface positioned relative to the substrate such that a cavity is formed between the substrate and the surface of the shield;
• the shield and the substrate substantially preventing extrinsic light within the given range of wavelengths from reflecting into the cavity;
• a first optical sensor disposed for sampling the intensity of light in the cavity within the given range of wavelengths and for producing an output representative of said intensity;
• wherein the shield forms an aperture and the first optical sensor samples the intensity of the light in the cavity through the aperture;
• the shield comprises at least two pieces, including a rotating piece and a non-rotating piece;
• the rotating piece supports the substrate and rotates the substrate during processing;
• and
• the non-rotating piece forms the aperture for the first optical sensor;
• further comprising an elevational actuator coupled to the non-rotating piece such that raising and lowering the elevational actuator causes the non-rotating piece to be raised and lowered.

A thermal processing system for processing a semiconductor substrate comprising:

• a processing chamber wherein light is radiated into the processing chamber;
• a first surface of the substrate exposed to the processing chamber for processing;
• a shield having an interior surface positioned relative to a second surface of the substrate such that a shielded region is formed between the second surface of the substrate and the interior surface of the shield;
• the shield absorbing heat and emitting substantial thermal radiation within the shielded region;
• wherein the shield provides thermal insulation for maintaining substantial temperature uniformity of the substrate during processing;
• and
• an optical sensor disposed to sample the intensity of light emitted in the shielded region within a given range of wavelengths;
• wherein the shield and the substrate substantially prevent the light in the processing chamber from interfering with the intensity of the emitted light sampled by the optical sensor.

A thermal processing system for processing a semiconductor substrate at a processing temperature comprising:

• a processing chamber;
• a thermally conducive support for the semiconductor substrate in the processing chamber, the support providing thermal insulation for the substrate;
• a lamp system for providing radiant energy to the substrate in the processing chamber;
• and
• a resistive peripheral heater adjacent to the support;
• wherein the peripheral heater heats the support to enhance the thermal insulation provided by the support at the periphery of the substrate for maintaining substantial temperature uniformity of the substrate during processing.

A thermal processing system for processing a semiconductor substrate at a processing temperature comprising:

• a processing chamber within which the substrate is placed for processing;
• a lamp system for providing radiant energy to the processing chamber;
• a radiation shield forming a cavity adjacent to the substrate, the shield absorbing heat and emitting substantial thermal radiation within the cavity;
• and
• a supplemental resistive heater to heat the shield;
• wherein the supplemental resistive heater and the shield provide thermal insulation for maintaining substantial temperature uniformity of the substrate during processing.