Embodiments of methods for treating dielectric layers are provided herein. In some embodiments, a method of treating a dielectric layer disposed on a substrate supported in a process chamber includes: (a) exposing the dielectric layer to an active radical species formed in a plasma for a first period of time; (b) heating the dielectric layer to a peak temperature of about 900 degrees Celsius to about 1200 degrees Celsius; and (c) maintaining the peak temperature for a second period of time of about 1 second to about 20 seconds.