Optical waveguide structure with waveguide coupler to facilitate off-chip coupling

US9915784B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Russell A. Budd · North Salem, US
• Fuad E. Doany · Katonah, US
• Christopher V. Jahnes · Upper Saddle River, US
• Benjamin G. Lee · Ridgefield, US
• Laurent Schares · Pleasantville, US

Key dates

• Filing date: Aug 6, 2015
• Grant date: Mar 13, 2018
• Expiry date: Aug 6, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B6/2821
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Aspects of the invention are directed to a method for forming an optical waveguide structure. Initially, a base film stack is received with an optical waveguide feature covered by a lower dielectric layer. An etch stop feature is then formed on the lower dielectric layer, and an upper dielectric layer is formed over the etch stop feature. Subsequently, a trench is patterned in the upper dielectric layer and the etch stop feature at least in part by utilizing the etch stop feature as an etch stop. Lastly, a waveguide coupler feature is formed in the trench, at least a portion of the waveguide coupler feature having a refractive index higher than the lower dielectric layer and the upper dielectric layer. The waveguide coupler feature is positioned over at least a portion of the optical waveguide feature but is separated from the optical waveguide feature by a portion of the lower dielectric layer.