Multi-plenum showerhead with temperature control

A method for using a showerhead for semiconductor processing operations, the showerhead including:

• a precursor delivery plate with a first side and an opposing second side;
• a radical diffuser plate with a first side and an opposing second side, wherein the second side of the radical diffuser plate faces the first side of the precursor delivery plate;
• a thermal isolator interposed between the precursor delivery plate and the radical diffuser plate;
• and
• a pattern of radical through-holes, wherein:
• each of the radical through-holes passes through the precursor delivery plate, the radical diffuser plate, and the thermal isolator,
• each of the radical through-holes has a hole center axis that is substantially normal to the precursor delivery plate, the radical diffuser plate, and the thermal isolator, and
• each of the radical through-holes maintains a substantially uniform cross-sectional area perpendicular to the hole center axis of the radical through-hole through the precursor delivery plate, the radical diffuser plate, and the thermal isolator,
• the precursor delivery plate includes a pattern of gas delivery holes and one or more internal gas distribution passages,
• each of the gas delivery holes has a hole center axis that is substantially normal to the precursor delivery plate, the radical diffuser plate, and the thermal isolator,
• each of the gas delivery holes is fluidly connected to at least one of the one or more gas distribution passages, and
• each of the gas delivery holes exits the precursor delivery plate on the second side of the precursor delivery plate;
• and
• the method comprising:
• maintaining the precursor delivery plate at a first temperature;
• maintaining the radical diffuser plate at a second temperature;
• providing a first process gas via the gas delivery holes while the diffuser delivery plate is at the first temperature;
• and
• providing a second process gas via the radical through-holes while the radical diffuser plate is at the second temperature.

A reactor for semiconductor processing operations comprising:

• a reaction chamber;
• a wafer support located within the reaction chamber;
• and
• a showerhead including:
• a precursor delivery plate with a first side and an opposing second side;
• a radical diffuser plate with a first side and an opposing second side, wherein the second side of the radical diffuser plate faces the first side of the precursor delivery plate;
• a thermal isolator interposed between the precursor delivery plate and the radical diffuser plate;
• and
• a pattern of radical through-holes, wherein:
• each of the radical through-holes passes through the precursor delivery plate, the radical diffuser plate, and the thermal isolator,
• each of the radical through-holes has a hole center axis that is substantially normal to the precursor delivery plate, the radical diffuser plate, and the thermal isolator,
• each of the radical through-holes maintains a substantially uniform cross-sectional area perpendicular to the hole center axis of the radical through-hole through the precursor delivery plate, the radical diffuser plate, and the thermal isolator,
• the showerhead and the wafer support are configured such that the wafer support is beneath the showerhead within the reaction chamber.

A thermal isolator comprising:

• a first side;
• a second side substantially parallel to, and offset from, the first side;
• a plurality of tubular structures spanning between the first side and the second side, the tubular structures arranged in a distributed pattern across the first side and the second side, wherein:
• the tubular structures substantially prevent fluid flow between volumes within the tubular structures and a volume substantially defined between the first side and the second side.