Germanium silicon oxynitride high index films for planar waveguides

• US 6,408,125 B1
• Filed: 11/10/1999
• Issued: 06/18/2002
• Est. Priority Date: 11/10/1999
• Status: Expired due to Term

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Bellman, Robert Alan, Sachenik, Paul Arthur, Grandi, Thomas Paul, Akwani, Ikerionwu Asiegbu
• Primary Examiner(s): Ullah, Akm E.
• Application Number:
  US09/437,677
• Time in Patent Office: 951 Days
• Field of Search: 423/325, 423/385, 428/336, 428/432, 428/469, 257/396, 257/611, 385/142, 385/147, 437/24, 437/26, 437/27
• US Class Current: 385/142
• CPC Class Codes: C01B 21/0821 Oxynitrides of metals, boron or silicon
• CPC Class Codes: C01P 2006/32 Thermal properties
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C03B 19/1453 Thermal after-treatment of the shaped article, e.g. dehydrating, consolidating, sintering
• CPC Class Codes: C03B 2201/24 doped with nitrogen, e.g. silicon oxy-nitride glasses
• CPC Class Codes: C03B 2201/31 doped with germanium
• CPC Class Codes: C03B 32/00 Thermal after-treatment of glass products not provided for in groups C03B19/00 , C03B25/00 - C03B31/00 or C03B37/00, e.g. crystallisation, eliminating gas inclusions or other impurities; Hot-pressing vitrified, non-porous, shaped glass products
• CPC Class Codes: C03C 2201/24 containing nitrogen, e.g. silicon oxy-nitride glasses
• CPC Class Codes: C03C 2201/31 containing germanium
• CPC Class Codes: C03C 3/045 Silicon oxycarbide, oxynitride or oxycarbonitride glasses
• CPC Class Codes: C03C 3/111 containing nitrogen
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A composition represented by the formula Si_1−xGe_xO_2(1−y)N_1.33y, wherein x is from about 0.05 to about 0.6 and y is from about 0.14 to about 0.74 exhibits properties highly suited for use in fabricating waveguides for liquid crystal based optical devices. In particular, the compositions have an index of refraction of from about 1.6 to about 1.8 for light at a wavelength of 1550 nm, and/or a coefficient of thermal expansion of from about 2.5×10⁻⁶° C.⁻¹ to about 5.0×10⁻⁶° C.⁻¹. The compositions also have inherently low hydrogen content, and a high hydrogen permeability which allows better hydrogen removal by thermal annealing to provide a material which exhibits low optical losses and better etching properties than alternative materials.

Claims

1. A composition represented by the formula Si₁₋

xGe_xO<sub>2(1−

y)</sub>N_1.33y, wherein x is from about 0.05 to about 0.6 and y is from about 0.14 to about 0.74.

2. The composition of claim 1, wherein the composition has an index of refraction of from about 1.6 to about 1.8 for light at a wavelength of 1550 nm.

3. The composition of claim 1, wherein the composition has a coefficient of thermal expansion of from about 2.5×

10<sup>−

6</sup>°

C.<sup>−

1</sup> to about 5.0×

10<sup>−

6</sup>°

C.<sup>−

1</sup>.

4. The composition of claim 2, wherein the composition has a coefficient of thermal expansion of from about 2.5×

10<sup>−

6</sup>°

C.<sup>−

1</sup> to about 5.0×

10<sup>−

6</sup>°

C.<sup>−

1</sup>.

5. A composition of germanium silicon oxynitride having an index of refraction of from about 1.6 to about 1.8 for light at a wavelength of 1550 nm.

6. The composition of claim 5, wherein the composition has a coefficient of thermal expansion of from about 2.5×

10<sup>−

6</sup>°

C.<sup>−

1</sup> to about 5.0×

10<sup>−

6</sup>°

C.<sup>−

1</sup>.

7. A germanium silicon oxynitride film deposited on a silicon substrate, the germanium silicon oxynitride film having an index of refraction of from about 1.6 to about 1.8 for light at a wavelength of 1550 nm, and a coefficient of thermal expansion of from about 2.5×

10<sup>−

6</sup>°

C.<sup>−

1</sup> to about 5.0×

10<sup>−

6</sup>°

C.<sup>−

1</sup>.

8. A germanium silicon oxynitride film deposited on a silicon substrate, the germanium silicon oxynitride film represented by the formula Si₁₋

xGe_xO<sub>2(1−

y)</sub>N_1.33y, wherein x is from about 0.05 to about 0.6 and y is from about 0.14 to about 0.74.