Method of coating substrate and coated article

• US 20010016262A1
• Filed: 01/04/2001
• Published: 08/23/2001
• Est. Priority Date: 01/07/2000
• Status: Abandoned Application

• Current Assignee: Nippon Sheet Glass Company Limited
• Original Assignee: Nippon Sheet Glass Company Limited
• Inventors: Toyoshima, Takayuki, Anzaki, Toshiaki
• Application Number:
  US09/753,620
• Publication Number:
  US 20010016262A1
• Time in Patent Office: Days
• US Class Current: 428/428
• CPC Class Codes: C03C 17/002 for flat glass, e.g. float glass
• CPC Class Codes: C03C 17/225 Nitrides
• CPC Class Codes: C03C 17/245 by deposition from the vapour phase
• CPC Class Codes: C23C 14/027 Graded interfaces
• CPC Class Codes: C23C 14/0676 Oxynitrides
• CPC Class Codes: Y10T 428/31598 Next to silicon-containing [silicone, cement, etc.] layer

Abstract

A silicon target material is sputtered in a vacuum chamber having a controlled vacuum atmosphere in a reactive sputtering gas containing oxygen and nitrogen while varying the composition of the sputtering gas during the sputtering to thereby form a coating having a refractive index gradient due to a composition gradient in the thickness direction thereof on the substrate. The coating reduces the surface reflectance of glass to one-twentieth in a wavelength region of from 450 to 650 nm.

Claims

1. A method of coating a substrate comprising sputtering a target material in a vacuum chamber having a controlled vacuum atmosphere to form a coating comprising said target material, wherein the composition of a sputtering gas introduced into said vacuum chamber is varied during the sputtering to form a coating having a composition gradient in the thickness direction thereof on said substrate.

2. The method of coating a substrate according to

claim 1

, wherein said target material is silicon or a silicon compound, and said sputtering gas is a mixed gas of argon, oxygen and nitrogen.

3. The method of coating a substrate according to

claim 2

, wherein the ratio of oxygen and nitrogen of said mixed gas is varied.

4. The method of coating a substrate according to

claim 1

, wherein the composition of said sputtering gas is varied according to the reflectance or the transmittance of the substrate while being coated.

5. An article comprising a substrate and a coating which is obtained by the method according to

claim 1

and has a smaller refractive index in the part farther from the substrate than in the part nearer to the substrate.

6. The article according to

claim 5

, wherein said coating comprises silicon, nitrogen and oxygen and has a nitrogen content decreased and an oxygen content increased in the thickness direction thereof from the substrate side toward the surface thereof.

7. The article according to

claim 6

, which has a reflectance of 0.2% or less for visible light incident on the coating side.