US Patent 11437249 Showerhead device for semiconductor processing system

To create constant partial pressures of the by-products and residence time of the gas molecules across the wafer, a dual showerhead reactor can be used. A dual showerhead structure can achieve spatially uniform partial pressures, residence times and temperatures for the etchant and for the by-products, thus leading to uniform etch rates across the wafer. The system can include differential pumping to the reactor.