Fabrication of a high temperature showerhead

Methods of manufacturing a semiconductor processing chamber showerheads may include forming a melted aluminum alloy composition, cooling the melted aluminum alloy composition at a rate of at least 103 K/sec to form solid aluminum alloy particles, and forming a core region of a showerhead from the solid aluminum alloy particles. The core region of the showerhead may include an inner core region and an outer core region that may be coupled together. The inner core region may define a plurality of apertures. The outer core region may define a channel that receives a heating element. The methods may include coating the core region with one of aluminum or aluminum oxide and joining a peripheral edge of the outer core region with an inner edge of a metallic annular liner. The metallic annular liner may have a lower thermal conductivity than the core region of the showerhead.