The Effect of Plasma Cure Temperature on Spin‐On Glass

The quality of spin‐on glass (SOG) films, which are widely used as interlevel planarization dielectrics, can be improved by curing in gas plasma. The etch rate of SOG films plasma‐cured in oxygen ambient is lower than that of films nitrogen‐cured in a furnace, which is the commonly used SOG curing method. The etch rate decreases with increasing plasma cure temperature. Furthermore, a high‐temperature plasma cure reduces the number of the silanols, which act as adsorption sites of water. However, plasma curing at 400°C promotes hot carrier degradation. There is an optimum plasma curing temperature that can improve film quality with a minimum of hot carrier degradation. That temperature is thought to be around 300°C. The plasma curing process at 300°C can also produce crack‐free SOG films.