NH3 containing plasma nitridation of a layer of a three dimensional structure on a substrate

A method of forming a nitrogen-containing layer, comprising:

• placing a substrate having a first layer disposed thereon on a substrate support of a process chamber, wherein the first layer is a 3-dimensional structure;
• heating the substrate to a first temperature of about 250 degrees Celsius to about 500 degrees Celsius;
• and
• exposing the first layer to an RF plasma formed from a process gas comprising ammonia (NH3) to transform the first layer into the nitrogen-containing layer, wherein the process gas comprises about 0.5% to about 99.5% ammonia (NH3) based on total gas flow and the balance is a noble gas, and wherein the plasma has an ion energy of less than about 8 eV, and wherein an amount of nitrogen incorporated in a top surface of the nitrogen-containing layer is substantially equal to an amount of nitrogen incorporated down a sidewall of the nitrogen-containing layer.