Plasma Enhanced (PE) CVD

Plasma Enhanced Chemical Vapor Deposition (PECVD) is utilized to deposit films such as Si, SiO2, Silicon nitride, silicon oxynitride and Silicon carbide at temperatures (200-350C) lower than typical Low Pressure CVD process temperatures.  Plasma assists in the break down of the reactive precursor thereby enabling the process at a lower temperature.  This is useful for deposion over metals such as Al where higher temperatures can not be used.  In the conventional PECVD reactors, the deposition occurs in a parallel plate, capacitively coupled plasma system wherein the substrate sits on the grounded electrode. 

High Density Plasma Enhanced Chemical Vapor Deposition, HDP CVD, occurs in plasma chambers with two power sources, an inductively coupled plasma for source power and a capacitively coupled palsma for bias power. The source power helps in more efficient dissociation of precursors and hence leads to higher plasma density and reaction rate even at lower temperatures.   The bias power, applied to the lower electrode where the substrate is present, helps in ion bombardment which is used effectively to improve the film density and quality as well as bertter fill charactristics for trenches.