A plasma-enhanced chemical vapor deposition (PE-CVD) apparatus includes a chamber including a circumferential pumping channel, a substrate support disposed within the chamber, one or more gas inlets for introducing gas into the chamber, a plasma production device for producing a plasma in the chamber, and an upper and a lower element positioned in the chamber. The upper element is spaced apart from the substrate support to confine the plasma and to define a first circumferential pumping gap, and the upper element acts as a radially inward wall of the circumferential pumping channel. The upper and lower elements are radially spaced apart to define a second circumferential pumping gap which acts as an entrance to the circumferential pumping channel, in which the second circumferential pumping gap is wider than the first circumferential pumping gap.