Low loss optical waveguide device
View Patent ↗A method for forming optical devices on-planar substrates, as well as optical devices formed by the method are described. The method uses a linear injection APCVD process to form optical waveguide devices on planar substrates. The method is performed at approximately atmospheric pressure. According to the method, a wafer with a lower cladding layer already formed by either CVD or oxidation is placed on a conveyer, which may include a heating element. The heated wafer is transported underneath a linear injector such that the chemicals from the linear injector react on the wafer surface to form a core layer. After the core layer is formed, photoresist is spun on the surface of the wafer, and then standard lithography is used to pattern the optical devices. Next, reactive ion etching (RIE) is used to form waveguide lines. The remaining photoresist is then removed. An upper cladding layer is formed to substantially cover the core regions. The upper cladding layer may be formed in a manner similar to that used to form the core layer. The refractive index of the upper cladding layer is generally the same as that of the lower cladding layer. The refractive index of the core layer is generally 0.2% to 2% greater than that of the upper and lower cladding layers.
1. A method for producing an optical waveguide device, comprising:
providing a wafer comprising a wafer material positioned on a conveyer, said wafer providing a lower cladding material;
providing a linear injector positioned to transport a layer formation material onto an exposure area, such that when said wafer is conveyed through said exposure area said layer formation material can form a layer on said wafer;
forming a core layer on said lower cladding material by conveying said wafer on said conveyer through said exposure area while said linear injector transports a core layer formation material and a dopant source for the core layer formation material onto said exposure area at approximately atmospheric pressure;
forming a core by etching said core layer; and
forming an upper cladding layer on said core region by conveying said wafer on said conveyer through said exposure area while said linear injector transports an upper cladding layer formation material onto said exposure area at approximately atmospheric pressure, such that said upper cladding layer substantially covers said core.
2. The method of claim 1 wherein the lower cladding material is a lower cladding layer on said wafer.
3. The method of claim 1 wherein the lower cladding material is the wafer material.
4. The method of claim 1 , further comprising the step of heating the wafer.
5. The method of claim 1 , wherein the core layer formation material includes TEOS.
6. The method of claim 1 , wherein the core layer formation material includes TEPo.
7. The method of claim 1 , wherein the core layer formation material includes TMPi.
8. The method of claim 1 , wherein the core layer formation material includes TMOG.
9. The method of claim 1 , wherein the core layer formation material includes an oxidizing agent.
10. The method of claim 1 , wherein the upper cladding layer formation material includes TEOS.
11. The method of claim 1 , wherein the upper cladding layer formation material includes TMPi.
12. The method of claim 1 , wherein the upper cladding layer formation material includes TEPo.
13. The method of claim 1 , wherein the upper cladding layer formation material includes TEB.
14. The method of claim 1 , wherein the upper cladding layer formation material includes TMB.
15. The method of claim 1 , wherein the upper cladding layer formation material includes an oxidizing agent.
16. The method of claim 1 wherein the dopant source is selected from a group consisting of: B 2 O 3 , P 2 O 5 , GeO 2 , and TiO 2 .
17. The method of claim 1 wherein said linear injector transports a dopant source for the upper cladding layer formation material onto said exposure area along with the upper cladding layer formation material.