One implementation provides a method including providing a substrate into a processing chamber through a loading port, rotating the substrate clockwise, providing a gas mixture into a processing region through an inject insert comprising a first, second, and third sets of inject inlets, wherein the first set of inject inlets creates an inner zone inside the processing region, the second set of inject inlets creates a middle zone radially outward of the inner zone, and the third set of inject inlets creates an outer zone radially outward the middle zone, the gas mixture is provided by flowing the gas mixture through the first and second sets of inject inlets, and inject inlets of the third set of inject inlets that are away from the loading port, while blocking flow of the gas mixture into inject inlets of the third set of inject inlets that are closer to the loading port.