Loss monitoring in photonic circuit fabrication
AssigneeJuniper Networks, Inc.
InventorsErik Johan Norberg, Rui Liang, Benjamin M. Curtin, Jared Bauters
Life of this patent
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Abstract
Optical fabrication monitor structures can be included in a design fabricated on a wafer from a mask or fabrication reticle. A first set of components can be formed in an initial fabrication cycle, where the first set includes functional components and monitor structures. A second set of components can be formed by subsequent fabrication processes that can potentially cause errors or damage to the first set of components. The monitor structures can be implemented during fabrication (e.g., in a cleanroom) to detect fabrication errors without pulling or scrapping the wafer.
Claims20
A method for measuring optical component errors during fabrication of a photonic integrated circuit, the method comprising:
- fabricating, on a silicon layer of the photonic integrated circuit, a plurality of optical components using an initial fabrication cycle in a fabrication environment, the plurality of optical components including functional optical components to process light in the photonic integrated circuit and fabrication waveguide monitor structures to measure damage to one or more regions of the photonic integrated circuit that are susceptible to damage caused by a subsequent fabrication cycle process to form the photonic integrated circuit;
- fabricating, in another layer of the photonic integrated circuit, a plurality of additional optical components using the subsequent fabrication cycle in the fabrication environment, the plurality of additional optical components being included in the one or more regions that are susceptible to damage from the subsequent fabrication cycle;
- and
- identifying, in the fabrication environment, damage to the one or more regions of the silicon layer caused by the subsequent fabrication cycle, the damage measured from light propagating through one of the fabrication wave guide monitor structures formed from the initial fabrication cycle.
A photonic integrated circuit on a wafer that includes one or more fabrication waveguide monitor structures, the wafer comprising:
- a photonic integrated circuit comprising a plurality of optical components formed in a silicon layer of the wafer using an initial fabrication cycle in a fabrication environment, the plurality of optical components including functional silicon optical components to process light in the photonic integrated circuit and fabrication waveguide monitor structures to measure damage to one or more regions in the wafer that are susceptible to damage caused by a subsequent fabrication process to form a plurality of additional optical components in the photonic integrated circuit, wherein the plurality of additional optical components are formed in an additional layer of the photonic integrated circuit using the subsequent fabrication cycle in the fabrication environment, the plurality of additional optical components being included in the one or more regions that are susceptible to damage from the subsequent fabrication cycle;
- and
- an excess region that is external to the photonic integrated circuit, the excess region separated from the photonic integrated circuit by singulating the wafer, at least one of the fabrication wave guide monitor structures being formed, using the initial fabrication cycle, in the photonic integrated circuit and the excess region such that the photonic integrated circuit comprises a partial portion of the at least one of the fabrication waveguide monitor structures, the fabrication waveguide monitor structures including a waveguide to propagate light through the one or more regions to identify damage caused by the subsequent fabrication cycle.
Dependencies are inferred from the claim text.