Diamond like carbon coating of substrate housings
View Patent ↗Embodiments of the invention include articles comprising a diamond like carbon coating or doped diamond like carbon coating on one or more surfaces of a plastic substrate or a plastic enclosure. Embodiments of the DLC or doped DLC coatings reduce the gas permeation of the coated plastic or thermoplastic to hydrogen or helium compared to the permeability of the plastic alone. The DLC or doped DLC coatings coating provides a surface resistivity of from about 10 7 to about 10 14 ohm/square and have a transmittance that range from about 0% to about 70% less than the transmittance of the underlying plastic substrate in the range of about 300 nm to about 1100 nm. The DLC coated plastic can be used in environmental enclosures for protecting environmentally sensitive substrates such as semiconductor wafers and reticles.
1. An article comprising:
a thermoplastic and an adherent diamond like carbon coating on one or more surfaces of said thermoplastic, the adherent diamond like carbon coating being a doped diamond like carbon that further comprises 8.1 atomic percent or more of oxygen and 9.7 atomic percent or less of nitrogen, said adherent diamond like carbon coating has a permeability coefficient for helium gas that is at least 10 times less than the permeability coefficient for helium of said thermoplastic, the diamond like carbon coating has a surface resistivity of from about 10 7 to about 10 14 ohm/square and said adherent diamond like carbon coating has a transmittance that is 0% to 70% less than the transmittance of said thermoplastic to light in the range of 300 nm to 1100 nm.
2. The article of claim 1 where the article is an enclosure for environmentally sensitive substrates that comprises at least a portion of a carrier from the group consisting of: a carrier for wafers; a carrier for flat panel displays; and a carrier for lithographic reticles.
3. The article of claim 1 where the surface resistivity of the adherent diamond like carbon coating provides a surface resistivity in the range of 10 8 ohm per square to 10 12 ohm per square.
4. The article of claim 1 where the surface resistivity of the adherent diamond like carbon coating provides a surface resistivity in the range of 10 9 ohm per square to 10 12 ohm per square.
5. The article of claim 1 where the adherent diamond like carbon coating has a variation of surface resistivity that is less than 10 2 ohm per square.
6. The article of claim 1 where the adherent diamond like carbon coating has a variation of surface resistivity that is less than 10 1 ohm per square.
7. The article of claim 1 where the adherent diamond like carbon coating has an XPS spectra that has a carbon peak, an oxygen peak, and a nitrogen peak.
8. The article of claim 7 where the XPS spectrum of said adherent diamond like carbon coating includes a carbon peak at about 284 eV, an oxygen peak at about 532 eV, and a nitrogen peak at about 399 eV.
9. The article of claim 1 where the adherent diamond like carbon coating is further treated by a plasma, a reactive gas containing plasma, or corona discharge, an oxygen containing plasma, to form a hydrophilic adherent diamond like carbon coating.
10. The article of claim 1 where the article is a substrate carrier.