Periphery purge shutter and flow control systems and methods

A method for operating a chemical vapor deposition (CVD) system, the method comprising:

• providing a wafer carrier having an upper surface;
• mounting the wafer carrier on a susceptor;
• rotating the susceptor about an axis;
• providing a precursor gas to the upper surface via an injector block such that at least a portion of the precursor gas is deposited at the upper surface;
• providing a purge gas at an inner periphery purge inlet arranged between the injector block and an upper shutter that extends radially about the axis, thereby causing a peripheral gas flow along a radially inner edge of the upper shutter;
• and
• providing a lower shutter, arranged radially outward from the upper shutter from the axis, such that an un-deposited portion of the precursor gas as well as the purge gas provided at the inner periphery purge inlet both flow out of the reactor chamber via a gap defined between the upper shutter and the lower shutter.