Package structure, semiconductor device and method of fabricating the same

A package structure, comprising:

• a photonic die comprising conductive posts, an optical coupler, and a polymer layer covering the conductive posts and the optical coupler;
• an optical connector element disposed over the photonic die, wherein the optical connector element comprises:
• an optical via arranged in alignment with the optical coupler;
• a polymeric cladding layer covering sidewalls of the optical via;
• and
• a base structure surrounding the optical via and the polymeric cladding layer;
• a redistribution layer, electrically connected to the conductive posts of the photonic die.

A method of fabricating a semiconductor device, comprising:

• forming an optical connector element, comprising:
• providing a base structure;
• etching the base structure to form an opening;
• forming an oxide layer in the opening;
• forming a cladding layer in the opening;
• forming a first polymer via in the opening, wherein the first polymer via is surrounded by the cladding layer, and a refractive index of the cladding layer is different than a refractive index of the first polymer via, and the oxide layer surrounds the cladding layer and the first polymer via;
• performing a planarization process on a first surface of the base structure to reveal a first end of the first polymer via;
• reducing a thickness of the base structure from a second surface of the base structure to reveal a second end of the first polymer via, wherein the first polymer via passes through the base structure from the first surface to the second surface, and the oxide layer extends from the first surface to the second surface, wherein the first surface is opposite to the second surface;
• disposing the optical connector element over an optical coupler, wherein the optical coupler receives optical signals from the first polymer via.