Table 7 compares the different CVD schemes. Advantages of CVD include its high growth rates, ability to deposit materials which are hard to evaporate, good reproducibility and growth of epitaxial films. However CVD involves high temperatures, complex processes and toxic and corrosive gasses. Film stoichiometry and density can be monitored by a combination of etch rate comparisons to thermally grown films and ellipsometry to determine the index of refraction of the films. Any dissimilar material deposited on a wafer can cause film stress. This puts a finite limit on the thickness of the film can be deposited before wafer bowing or film cracking occurs.
Having discussed with the film deposition methods such as PVD and CVD now we move on to film modification methods such as diffusion and ion implantation in the next major section.