The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 09, 2007
Filed:
Jul. 27, 2001
Fan Zhong, Fremont, CA (US);
Michael Lennon, Union City, CA (US);
Fan Zhong, Fremont, CA (US);
Michael Lennon, Union City, CA (US);
Lightwave Microsystems Corporation, San Jose, CA (US);
Abstract
A method of depositing a top clad layer for an optical waveguide of a planar lightwave circuit. A GeBPSG top clad layer for an optical waveguide structure of a planar lightwave circuit is fabricated such that the top clad layer comprises doped silica glass, wherein the dopant includes Ge (Germanium), P (Phosphorus), and B (Boron). In depositing a top clad layer for the optical waveguide, three separate doping gasses (e.g., GeH, PH, and BH) are added during the PECVD (plasma enhanced chemical vapor deposition) process to make Ge, P and B doped silica glass (GeBPSG). The ratio of the Ge, P, and B dopants is configured to reduce the formation of crystallization areas within the top clad layer and maintain a constant refractive index within the top clad layer across an anneal temperature range. A thermal anneal process for the top clad layer can be a temperature within a range of 950C to 1050C. The GeBPSG top clad layer reduces the insertion loss of passive arrayed waveguide grating devices and active planar lightwave circuit devices.