Nanostructured Titania Coatings for Biological Applications: Fabrication and Characterization - Biological and Biomedical Coatings: Processing and Characterization - page 229

70

60

50

40

30

20

10

0

0 200 400 600 800

Annealing temperature ( º C)

FIGURE 5.27
Relationship between water contact angles and annealing temperature of TiO 2 film fabricated by RF magnetron
sputtering. (From Ye et al., Vacuum , 81, 627-631, 2007. With permission.)

cell adhesion in the first hour. However, the cell proliferation and differentiation behavior
is similar on the nanoscale surface and microscale Ti control.

Chemical Vapor Deposition

Chemical vapor deposition is a chemical process to fabricate pure and high-performance
solid materials. This process is common in the fabrication of functional films. Figure
5.28 depicts the schematic of a CVD apparatus. In a typical CVD process, the substrate
is exposed to one or more volatile precursors that react and/or decompose on the sub-
strate surface to conduct deposition. The volatile by-products are removed by the gas flow
through the reaction chamber. Various monocrystalline, polycrystalline, amorphous, and
epitaxial layers can be produced. The CVD process can be performed at atmospheric pres-
sure and ultrahigh vacuum below 10 -8 Pa. There are many types of CVD processes such
as (Seifried et al. 2000):

• Atmospheric-pressure chemical vapor deposition (APCVD)
• Low-pressure chemical vapor deposition (LPCVD)
• Plasma-assisted (enhanced) chemical vapor deposition (PACVD, PECVD)
• Photochemical vapor deposition (PCVD)
• Laser chemical vapor deposition (LCVD)

Heater

Carrier
gas

Substrate

Source
gas

Heater

FIGURE 5.28
Schematic layout of CVD equipment.