Write heads may be formed by reactive ion etching (RIE) a dielectric mask and then reactive ion etching a polymeric underlayer. The first RIE affects the second RIE. The first portion of the first RIE process is performed with a ratio of CF4 to CHF3 between about 1.3 to 2, a gas flow ratio of CF4 to He between 2.2 and about 3, and a ratio of RF source power to RF bias power between about 10 and about 16. The second portion of the first RIE process is performed with a ratio of CF4 to CHF3 between about 0.3 to 0.8, a gas flow ratio of CF4 to He between about 1.2 and about 1.8, and a ratio of RF source power to RF bias between about 22 to 28. With the above parameters, the dielectric mask can be formed with minimized damage on the underlayer.