Showerhead assembly with recursive gas channels

A process chamber, comprising:

• a chamber body defining an interior volume therein;
• a substrate support disposed in the interior volume to support a substrate;
• and
• a showerhead assembly disposed in the interior volume opposite the substrate support, wherein the showerhead assembly comprises:
• a chill plate comprising a gas plate and a cooling plate having an aluminum-silicon foil interlayer disposed therebetween for diffusion bonding the gas plate to the cooling plate;
• and
• a heater plate comprising a first plate, a second plate, and a third plate, wherein an aluminum-silicon foil interlayer is disposed between the first plate and the cooling plate for diffusion bonding the first plate to the cooling plate, wherein an aluminum-silicon foil interlayer is disposed between the first plate and the second plate for diffusion bonding the first plate to the second plate, and wherein an aluminum-silicon foil interlayer is disposed between the second plate and the third plate for diffusion bonding the second plate to the third plate.

A method of manufacture for a showerhead assembly for use in a substrate processing chamber, comprising:

• providing an aluminum-silicon foil interlayer between a gas plate of a chill plate and a cooling plate of the chill plate and diffusion bonding the gas plate to the cooling plate;
• providing an aluminum-silicon foil interlayer between a first plate of a heater plate and the cooling plate and diffusion bonding the first plate to the cooling plate;
• providing an aluminum-silicon foil interlayer between the first plate and a second plate of the heater plate and diffusion bonding the first plate to the second plate;
• and
• providing an aluminum-silicon foil interlayer between the second plate and a third plate of the heater plate and diffusion bonding the second plate to the third plate.