A reactor for depositing an epitaxial layer on a semiconductor wafer contained within the reactor during a chemical vapor deposition process. The reactor comprises a reaction chamber sized and shaped for receiving a semiconductor wafer and an inlet passage in communication with the reaction chamber for delivering reactant gas to the reaction chamber. In addition the reactor includes a susceptor positioned in the reaction chamber for supporting the semiconductor wafer during the chemical vapor deposition process. Further, the reactor comprises an injector including a metering plate generally blocking reactant gas flow through the inlet passage. The plate has a slot extending through the plate totally within a periphery of the plate. The slot is sized for selectively restricting reactant gas flow past the plate thereby to meter reactant gas delivery to the chamber.