Planarization processes and applications III. As-deposited and annealed film properties

Although germanosilicates with and without boron and phosphorus dopants hav e been shown to planarize over steps at temperatures below 800 degrees C, o ther properties of the films, such as water solubility, electrical conducti vity, and mechanical stress, are also concerns with these materials. This s tudy examines these film properties for undoped and boron- and/or phosphoru s-doped germanosilicate glasses deposited by plasma-enhanced chemical vapor deposition. Water solubility resistance was improved for most film composi tions after anneals in argon, steam, forming gas, or two-step anneals in ar gon and steam or argon and forming gas. Electrical leakage and breakdown be havior was also found to improve in steam anneals and even further in two-s tep argon-steam anneals but leakage increased following forming gas anneals , Mechanical stress was found to generally increase in magnitude following argon anneals, but stress levels were reduced again to near as-deposited va lues following a subsequent steam anneal. For the greatest improvement in p roperties, a two-step anneal, first in argon and subsequently in steam, is recommended. (C) 2000 The Electrochemical Society. S0013-4651(99)07-098-6. All rights reserved.