A method includes receiving a workpiece that includes a substrate, a first dielectric layer over the substrate, and an optical layer over the dielectric layer; patterning the optical layer to form a first waveguide and a grating coupler; forming a first opening in the substrate that exposes the first dielectric layer, wherein at least a portion of the first opening is directly over the grating coupler; depositing a metal layer in the first opening; and depositing a second dielectric layer over the metal layer.

A method includes receiving a workpiece that includes a substrate, a first dielectric layer over the substrate, and an optical layer over the dielectric layer; patterning the optical layer to form a first waveguide and a grating coupler; forming a first opening in the substrate that exposes the first dielectric layer, wherein at least a portion of the first opening is directly over the grating coupler; depositing a metal layer in the first opening; and depositing a second dielectric layer over the metal layer.

Disclosed is a system and method for communication using an efficient fiber-to-chip grating coupler with a high coupling efficiency. In one embodiment, a method for communication, includes: transmitting optical signals between a semiconductor photonic die on a substrate and an optical fiber array attached to the substrate using at least one corresponding grating coupler on the semiconductor photonic die, wherein the at least one grating coupler each comprises a plurality of coupling gratings, a waveguide, a cladding layer, a first reflection layer and a second reflection layer, wherein the plurality of coupling gratings each comprises at least one step in a first lateral direction and extends in a second lateral direction, wherein the first and second lateral directions are parallel to a surface of the substrate and perpendicular to each other in a grating plane, wherein the first reflection layers are configured such that the plurality of coupling gratings is disposed between the first reflection layer and the cladding layer, wherein the second reflection layer are configured such that the cladding layer is disposed between the second reflection layer and the waveguide.

A method and system for generating a physical layout for a grating coupler integrated in a photonically-enabled circuit are disclosed herein. In some embodiments, the method receives a parametrized wavelength, a parametrized first refractive index, a parametrized second refractive index, a parametrized taper length, a parametrized width, a parametrized grating length, and a parametrized incident angle of the optical beam incident onto the grating coupler and generates a physical layout for the grating coupler based on the received parametrized inputs, the generating of the physical layout is according to a predefined model, and outputs the physical layout of the grating coupler for manufacturing under a semiconductor fabrication process.

An apparatus for testing a wafer or chip comprising a photonic integrated circuit comprises: an electrical signal interface module comprising an array of movable conducting structures; a photonic signal interface module attached to the electrical signal interface module, the photonic signal interface module comprising one or more optical fiber interfaces, and a first set of grating couplers arranged over at least a first plane of the photonic signal interface module; and one or more electrical signal connections between the electrical signal interface module and the photonic signal interface module.

An apparatus for testing a wafer or chip comprising a photonic integrated circuit comprises: an electrical signal interface module comprising an array of movable conducting structures; a photonic signal interface module attached to the electrical signal interface module, the photonic signal interface module comprising one or more optical fiber interfaces, and a first set of grating couplers arranged over at least a first plane of the photonic signal interface module; and one or more electrical signal connections between the electrical signal interface module and the photonic signal interface module.

A grating structure, a diffraction optical waveguide, and a display device are disclosed. The grating line of the grating structure has a cross-sectional profile with a narrow top and a wide bottom, wherein the cross-sectional profile comprises six feature points, and the six feature points respectively have coordinates (0, 0), (L2, H2), (L3, H3), (L4, H4), (L5, H5) and (L6, 0) in a cross section, and satisfy following relationships: H.sub.drop=min(H4,H5)?max(H3,H2)>50 nm; 0.1<(L5?L4)/(L3?L2); L3>0.34T; and 0.05T<L5?L4<0.32T. By controlling the parameters of these feature points, the cross-sectional profile can be adjusted, and thus significantly improving the optical effect (comprising diffraction efficiency and uniformity) that the grating structure can achieve, and at the same time increasing degrees of freedom in grating design and optical effect regulation.

A method of forming a semiconductor structure includes: providing an initial substrate having a first region and a second region; forming a first substrate on the initial substrate; forming a first insulating layer on the first substrate; forming a second substrate on the first insulating layer; removing the second substrate in the second region to form a second insulating layer on the first insulating layer in the second region; and forming a plurality of passive devices on the second insulating layer in the second region and forming a plurality of active devices on the second substrate in the first region.

A method of forming a semiconductor structure includes: providing an initial substrate having a first region and a second region; forming a first substrate on the initial substrate; forming a first insulating layer on the first substrate; forming a second substrate on the first insulating layer; removing the second substrate in the second region to form a second insulating layer on the first insulating layer in the second region; and forming a plurality of passive devices on the second insulating layer in the second region and forming a plurality of active devices on the second substrate in the first region.

A package structure comprises photonic dies and an interposer structure. Each photonic die includes a dielectric layer and a first grating coupler embedded in the dielectric layer. The interposer structure is disposed below the photonic dies. The interposer structure includes an oxide layer and a second grating coupler embedded in the oxide layer. The photonic dies are optically coupled through the first grating couplers of the photonic dies and the second grating coupler of the interposer structure.