Systems and methods for filling incisions with index matching fluids

Abstract

The invention relates to a system and method for filling an incision with an index matching liquid. Embodiments of the present disclosure may include a system for filling a cut-out on a wafer with an index matching liquid, the system including a plurality of edge couplers, each edge coupler including a cut-out and a waveguide. Embodiments may also include ribs that suspend the waveguide over the cutout. Embodiments may also include one or more master buckets and one or more monitoring buckets. Embodiments may also include conduits coupling together the plurality of edge couplers, the one or more main buckets, and the one or more monitoring buckets.

Description

Technical Field

[0001] The present disclosure generally relates to on-chip structures for optical fiber array alignment via assisted edge coupler index matching epoxy / oil filling. Background Art

[0002] Various aspects of the present disclosure relate to on-chip structures for optical fiber array alignment via auxiliary edge coupler index matching epoxy / oil filling. Existing solutions for on-chip structures for optical fiber array alignment via auxiliary edge coupler index matching epoxy / oil filling may have various problems. In this regard, existing systems and methods for on-chip structures for optical fiber array alignment via auxiliary edge coupler index matching epoxy / oil filling may be expensive, cumbersome and / or inefficient.

[0003] By comparing these methods with some aspects of the present methods and systems set forth in the remainder of this disclosure with reference to the accompanying figures, limitations and disadvantages of existing systems and methods will become apparent to those skilled in the art. Summary of the invention

[0004] An on-chip structure for fiber array alignment by aiding edge coupler index matching epoxy / oil filling is shown in and / or described in conjunction with at least one of the figures and is more fully set forth in the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1A is a block diagram illustrating a system according to some embodiments of the present disclosure.

[0006] Figure 1B is a 3D diagram of an exemplary edge coupler 110 according to some embodiments of the present disclosure.

[0007] Figure 1C is a top view of an edge coupler 110 according to some embodiments of the present disclosure.

[0008] FIG. 2A to FIG. 2D is an exemplary system according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0009] The following discussion provides various examples of semiconductor devices and methods of manufacturing semiconductor devices. Such examples are non-limiting, and the scope of the appended claims should not be limited to the specific examples disclosed. In the following discussion, the terms "example" and "for example" are non-limiting.

[0010] The drawings illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the present disclosure. In addition, the elements in the drawings are not necessarily drawn to scale. For example, the sizes of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the examples discussed in the present disclosure. The same reference numerals in different drawings represent the same elements.

[0011] The term "or" refers to any one or more items in a list connected by "or". For example, "x or y" means any element in the three-element set {(x), (y), (x, y)}. As another example, "x, y, or z" means any element in the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}.

[0012] The terms “comprises,” “comprising,” “includes” and / or “including” are “open” terms and specify the presence of stated features but do not preclude the presence or addition of one or more other features.

[0013] The terms "first", "second", etc. may be used herein to describe various elements, but these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, for example, a first element discussed in the present disclosure may be referred to as a second element without departing from the teachings of the present disclosure.

[0014] Unless otherwise specified, the term "coupled" may be used to describe two elements that are in direct contact with each other, or to describe two elements that are indirectly connected by one or more other elements. For example, if element A is coupled to element B, element A may be in direct contact with element B or indirectly connected to element B through an intermediate element C. Similarly, the terms "over" or "on" may be used to describe two elements that are in direct contact with each other, or to describe two elements that are indirectly connected by one or more other elements.

[0015] Figure 1A 1 is a block diagram of a system 100 according to various embodiments of the present disclosure. In some embodiments, the system 100 may include a plurality of edge couplers 110, one or more main buckets 120, one or more monitoring buckets 130, and a duct 140. The plurality of edge couplers 110 may include an undercut 112, a waveguide 114, and a rib 116 that suspends the waveguide 114 from the undercut 112. The duct 140 couples the plurality of edge couplers 110, the one or more main buckets 120, and the one or more monitoring buckets 130 together.

[0016] For example, the system 100 may be a photonic integrated circuit (PIC). The edge coupler 110 may be operable to couple a waveguide 114 from the photonic integrated circuit (PIC) / wafer to an external device. An etching process on the wafer, such as in a silicon photonics process, may result in a cut 112 formed below the waveguide 114. The waveguide 114 may be operable to carry an optical signal (e.g., single mode) and may be configured as a single mode optical fiber. In some embodiments, the wafer may be a silicon photonic wafer.

[0017] Figure 1B An exemplary diagram of an edge coupler 110 is shown. Similar reference numerals refer to Figure 1A Similar components in .

[0018] Figure 1C 1 shows a top view of the edge coupler 110. Like reference numerals refer to Figure 1A Similar components in .

[0019] Typically, the mode field diameter (MFD) of the edge coupler 110 may be about 4 microns, which may result in inefficient fiber coupling. To expand the MFD to about 9 microns for better fiber coupling efficiency and better alignment tolerance with external devices to be connected, one approach may be to fill the cutout 112 of the edge coupler 110 with an index-matched epoxy or oil.

[0020] Accordingly, filling the cutout 112 with an index matching liquid can increase the mode field diameter at the facet of the waveguide. For example, without the index matching liquid, the mode field diameter at the facet of the waveguide 114 can be about 4 microns. In some embodiments, with the index matching liquid, the mode field diameter at the facet of the waveguide 114 can be about 9 microns.

[0021] The process may include making the cutout 112 during wafer fabrication and subsequently filling the cutout 112 with epoxy / oil prior to aligning the PIC with an external device that may be coupled. The epoxy / oil filling process may be very delicate because the cavity of the cutout 112 may be very small and may require high precision tools and / or manual operation. Another issue may be monitoring the epoxy / oil filling process and quality. For example, it may be difficult to determine whether the amount of epoxy / oil present is sufficient to encapsulate the waveguide 114 area of ​​the edge coupler 110.

[0022] Figure 2AAn exemplary system for filling a refractive index matching fluid is shown. In some embodiments, the system 100 may include a plurality of edge couplers 110 (14 are shown and 3 are labeled), one or more main barrels 120, one or more monitoring barrels 130, one or more intermediate monitoring barrels 130a, and a conduit 140. The conduit 140 couples the plurality of edge couplers 110, one or more main barrels 120, the intermediate monitoring barrels 130a, and the one or more monitoring barrels 130 together.

[0023] The conduit 140 may be operable to fill the cavity of the cutout 112 of the edge coupler 110 by forming a communicating vessel with the cutout 112, the main barrel 120, the monitoring barrels 130 and 130a, and the conduit 140. By adding the refractive index matching liquid to the main barrel 120, the refractive index matching liquid may flow from the main barrel 120 through the conduit 140 to fill the cutout 112, the intermediate monitoring barrel 130a, and the monitoring barrel 130 of the edge coupler 110. By adding the refractive index matching liquid to the main barrel 120, the intermediate monitoring barrel 130a, the cutout 112, which are closer to the main barrel 120, will be filled first. The monitoring barrel 130, which is the farthest distance from the main barrel 120, may be filled at the last moment.

[0024] The main barrel 120 can be a cavity operable to add a refractive index matching liquid into the system 100. Specifically, the opening of the main barrel 120 can be selected to be large enough to easily add the refractive index matching liquid into the system 100. In some embodiments, the opening can be a square with a side length of 0.5 mm. In some embodiments, the opening can be a circle with a diameter of 0.5 mm. The opening of the main barrel 120 can be suitable for filling the refractive index matching liquid through an automatic aligner. In some embodiments, the refractive index matching liquid can be oil or epoxy resin.

[0025] Monitoring barrels 130 and 130a can be cavities with openings for monitoring the filling process. The opening of the monitoring barrel 130 can be selected so that the filling level of the system 100 can be verified. Since the opening between the incision 112 and the ribs may be very small, and due to the presence of the ribs 116 and the waveguide 114, by observing from the top opening of the incision 112 below the edge coupler 110, it may be more difficult to directly verify the filling state of the system 100. Therefore, it may be advantageous to use monitoring barrels 130, 130a. The separation distance between at least one of the one or more monitoring barrels 130 and at least one of the one or more main barrels 120 may be greater than the separation distance between any one of the incision 112 and any one of the one or more main barrels 120. In other words, in order to ensure that the filling state of the monitoring barrel 130 can indicate the filling state of the incision 112, the monitoring barrel 120 can be separated from the main barrel 120 for filling by a greater distance than the incision 112. In some embodiments, an intermediate monitoring barrel 130a that can be used to monitor the intermediate filling state accordingly can be provided.

[0026] For filling, it may be advantageous that the plurality of cutouts 112 , the one or more main vats 120 , and the one or more monitoring vats 130 and 130 a , and the conduit 140 may be formed on the same layer of the wafer and / or may have the same depth.

[0027] As will be apparent to those skilled in the art, many different configurations of the system 100 may be envisioned, some of which may be FIG. 2B to FIG. 2D Shown in.

[0028] Figure 2B An exemplary system 100 is shown. Like reference numerals may indicate similar elements to those shown in other figures. Figure 2B In the embodiment, the main tub 120 may be located between the two monitoring tubs 130 , and then when filled, the refractive index matching liquid may flow in two directions, from the main tub 120 to the two monitoring tubs 130 .

[0029] Figure 2C An exemplary system 100 is shown. Like reference numerals may indicate similar elements to those shown in other figures. Figure 2C , the exemplary system 100 may be shown as having multiple master buckets.

[0030] Figure 2D An exemplary system 100 is shown. Like reference numerals may indicate similar elements to those shown in other figures. Figure 2D , the exemplary system 100 may be shown having an alternative catheter 140 shape.

[0031] The present disclosure includes references to certain examples, however, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present disclosure. In addition, modifications may be made to the disclosed examples without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the disclosed examples, but the present disclosure will include all examples falling within the scope of the appended claims.

Claims

1. A system for filling a cutout with a refractive index matching fluid on a wafer or a photonic integrated circuit (PIC), the system comprising: A plurality of edge couplers, each of the edge couplers comprising: incision; waveguide, where A rib suspends the waveguide over the cutout; One or more master barrels; One or more monitoring buckets; and A conduit is provided to couple the plurality of edge couplers, the one or more main barrels, and the one or more monitoring barrels together.

2. The system according to claim 1, wherein: The refractive index matching liquid is oil or epoxy resin.

3. The system according to claim 1, wherein: The one or more main barrels include an opening for adding the index matching fluid to the system.

4. The system according to claim 3, wherein: The opening is a square with a side length of 0.5 mm.

5. The system according to claim 3, wherein: The opening is circular with a diameter of 0.5 mm.

6. The system according to claim 3, wherein: The opening is suitable for being filled with the index matching fluid by an automated station.

7. The system according to claim 1, wherein: The one or more monitoring buckets include openings for monitoring the progress of the filling.

8. The system according to claim 1, wherein: A separation distance between at least one of the one or more monitoring barrels and at least one of the one or more main barrels is greater than a separation distance between any one of the cutouts and any one of the one or more main barrels.

9. The system according to claim 1, wherein: The plurality of cutouts, the one or more main barrels, and the one or more monitoring barrels are formed on a same layer of the wafer.

10. The system according to claim 1, wherein: The plurality of cutouts, the one or more main barrels, and the one or more monitoring barrels have the same depth.

11. The system according to claim 1, wherein: The coupling through the conduit forms a communicating container from the plurality of edge couplers, the one or more main barrels, and the one or more monitoring barrels.

12. The system of claim 1, wherein: The filling of the cutout with the index matching fluid increases the mode field diameter at the facets of the waveguide.

13. The system of claim 1, wherein: Without the index matching fluid, the mode field diameter at the facets of the waveguide is approximately 4 microns.

14. The system of claim 1, wherein: When the index matching fluid is used, the mode field diameter at the facets of the waveguide is approximately 9 microns.

15. The system of claim 1, wherein: A photonic integrated circuit comprises the system.

16. The system of claim 1, wherein: The wafer is a silicon photonic wafer.

17. A method for filling a cutout on a wafer or a photonic integrated circuit (PIC) with a refractive index matching fluid, the method comprising: filling a plurality of cutouts, each of the cutouts being associated with an edge coupler, each of the edge couplers comprising: incision; waveguide, where A rib suspends the waveguide over the cutout; adding the refractive index matching fluid to one or more master barrels; monitoring a filling status using one or more monitoring buckets; and The index matching fluid is dispensed using a conduit, wherein the conduit couples the plurality of edge couplers, the one or more main barrels, and the one or more monitoring barrels together.

18. The method according to claim 16, wherein: The refractive index matching liquid is oil or epoxy resin.

19. The method according to claim 16, wherein: The one or more main barrels include an opening for adding the index matching fluid to the system.

20. The method according to claim 19, wherein: The opening is a square with a side length of 0.5 mm.

21. The method according to claim 19, wherein: The opening is circular with a diameter of 0.5 mm.

22. The method according to claim 19, wherein: The opening is suitable for being filled with the index matching fluid by an automated station.

23. The method according to claim 16, wherein: The monitoring includes observing the one or more monitoring bucket fill levels.

24. The method according to claim 16, comprising: A separation distance between at least one of the one or more monitoring barrels and at least one of the one or more main barrels is selected to be greater than the separation distance between any one of the cutouts and any one of the one or more main barrels.

25. The method of claim 16, comprising: The plurality of cutouts, the one or more main barrels, and the one or more monitoring barrels are formed on the same layer of the wafer.

26. The method of claim 17, comprising: The plurality of cutouts, the one or more main barrels, and the one or more monitoring barrels are formed to have the same depth.

27. The method of claim 17, comprising: The plurality of edge couplers, the one or more main barrels, and the one or more monitoring barrels are coupled through the conduit to form a communicating container.

28. The method of claim 17, comprising: The mode field diameter at the facets of the waveguide is increased by filling the cutouts with the index matching fluid.

29. The method of claim 17, comprising: In the absence of the index matching fluid, a mode field diameter of 4 microns was obtained at the facets of the waveguide.

30. The method of claim 17, comprising: In the case of using the index matching liquid, the mode field diameter obtained at the facets of the waveguide was 9 microns.

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