Herein disclosed are systems and methods related to semiconductor processing device including a manifold including a bore configured to deliver a gas to a reaction chamber, the manifold including a first block mounted to a second block, the first and second mounted blocks cooperating to at least partially define the bore. A supply channel provides fluid communication between a gas source and the bore, and the supply channel is disposed at least partially in the second block. A metallic seal is disposed about the bore at an interface between the first and second block. Advantageously, the metallic seal improves sealing between the interface between the first block and the second block.