Implementations of the present disclosure provide methods for processing substrates in a processing chamber. In one implementation, the method includes (a) depositing a dielectric layer on a first substrate at a first chamber pressure using a first high-frequency RF power, (b) depositing sequentially a dielectric layer on N substrates subsequent to the first substrate at a second chamber pressure, wherein N is an integral number of 5 to 10, and wherein depositing each substrate of N substrates comprises using a second high-frequency RF power that has a power density of about 0.21 W/cm2 to about 0.35 W/cm2 lower than that of the first high-frequency RF power, (c) performing a chamber cleaning process without the presence of a substrate, and (d) repeating (a) to (c).