Semiconductor structure

Abstract

The embodiment of the utility model relates to a semiconductor structure, which comprises an optical bare chip, a first edge coupler and a reflecting layer, the optical die has a top surface and an edge. The first edge coupler is disposed in the optical die and adjacent to the edge of the optical die. The reflective layer is disposed in the optical die and adjacent to the edge of the optical die. The reflective layer is disposed over the first edge coupler and is separated from the first edge coupler.

Description

Technical Field

[0001] The embodiment of the utility model relates to a semiconductor structure. Background Art

[0002] Photonic devices are used in integrated circuits (ICs) to carry signals from one component to another faster than using electrical signals. The electrical signal is converted to an optical signal at one end of a waveguide, the optical signal propagates along the waveguide, and the optical signal is converted back to an electrical signal at the other end of the waveguide. In this way, optical and electrical signaling and processing are combined for signal transmission. Utility Model Content

[0003] An embodiment of the present invention discloses a semiconductor structure, comprising: an optical die having a top surface and an edge; a first edge coupler placed in the optical die and adjacent to the edge of the optical die; and a reflective layer placed in the optical die and adjacent to the edge of the optical die, wherein the reflective layer is placed above the first edge coupler and separated from the first edge coupler.

[0004] An embodiment of the utility model discloses a semiconductor structure, which includes: an optical die; a plurality of edge couplers placed in the optical die, wherein the edge couplers extend in a first direction and are parallel to each other; and a metal layer placed in the optical die, wherein the metal layer extends in a second direction different from the first direction, and the metal layer is separated from the edge couplers in a third direction different from the first direction and the second direction.

[0005] An embodiment of the utility model discloses a method for measuring an optical die, comprising: receiving a substrate including at least a first edge coupler, wherein the first edge coupler is exposed through a first sidewall of a groove; forming a first reflective layer above a second sidewall of the groove, wherein the second sidewall is opposite to the first sidewall; introducing a first incident light into the first reflective layer to form a first reflected light, wherein the first reflected light is guided toward the first edge coupler; and receiving a first measurement result from the first edge coupler. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with standard industry practice, various components are not drawn to scale. In fact, the dimensions of the various components may be arbitrarily increased or reduced for clarity of discussion.

[0007] Figure 1A is a partial top view of a semiconductor structure according to the present disclosure in one or more embodiments; and Figure 1B is along Figure 1A A cross-sectional view taken along line A-A'.

[0008] Figure 2A is a partial top view of a semiconductor structure according to the present disclosure in one or more embodiments; and Figure 2B is along Figure 2A A cross-sectional view taken along line A-A'.

[0009] Figure 3A and Figure 3C is a partial top view of a semiconductor structure according to the present disclosure in one or more embodiments; and Figure 3B is along Figure 3A A cross-sectional view taken along line BB'.

[0010] Figure 4 is a cross-sectional view of one or more embodiments according to the present disclosure.

[0011] Figure 5A is a cross-sectional view of a semiconductor structure according to the present disclosure in one or more embodiments; and Figure 5B yes Figure 5A A cross-sectional view of a semiconductor structure at a stage after a stage.

[0012] Figures 6 to 17 is a cross-sectional view of a semiconductor structure according to the present disclosure in one or more embodiments.

[0013] Fig.18 is a flow chart representing a method for measuring an optical die according to aspects of the present disclosure in one or more embodiments. DETAILED DESCRIPTION

[0014] The following disclosure provides many different embodiments or examples for implementing the different features of the provided theme. The specific examples of the elements and arrangements will be described below to simplify the present disclosure. Of course, this type is only an example and is not intended to be limiting. For example, in the following description, the first member is formed above or on the second member and can include an embodiment in which the first and second members in direct contact are formed, and can also include an embodiment in which an additional member can be formed between the first and second members so that the first and second members may not be in direct contact. In addition, the present disclosure can repeat element symbols and / or letters in various examples. This repetition is for simplification and clarity and does not itself indicate the relationship between the various embodiments and / or configurations discussed.

[0015] Additionally, for ease of description, spatially relative terms such as "below," "beneath," "below," "above," "on," and the like may be used herein to describe the relationship of one element or component to another element or components as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

[0016] As used herein, although terms such as "first", "second", and "third" describe various elements, components, regions, layers, and / or sections, such elements, components, regions, layers, and / or sections should not be limited to such terms. Such terms may be used only to distinguish elements, components, regions, layers, or sections from one another. Unless the context clearly indicates otherwise, terms such as "first", "second", and "third" used herein do not imply a sequence or order.

[0017] Although the numerical ranges and parameters describing the wide range of the present disclosure are approximate values, the numerical values ​​described in the specific examples should be reported as accurately as possible. However, any numerical value inherently contains certain errors that are inevitably caused by the standard deviation found in the corresponding test measurement. In addition, as used herein, the terms "substantially", "about" or "approximately" generally mean within the value or range that can be expected by a person of ordinary skill in the art. Alternatively, the terms "substantially", "about" or "approximately" mean within the acceptable standard error of the mean value considered by a person of ordinary skill in the art. A person of ordinary skill in the art should understand that the acceptable standard error can vary according to different technologies. Except in the operation / working examples or unless otherwise expressly provided, all numerical ranges, amounts, values ​​and percentages disclosed herein (such as the numerical ranges, amounts, values ​​and percentages of the amount of materials, duration, temperature, operating conditions, amount ratios and the like) should be understood to be modified by the terms "substantially", "about" or "approximately" in all examples. Therefore, unless otherwise indicated, the numerical parameters described in the present disclosure and the appended claims are approximate values ​​that can be varied as needed. Finally, each numerical parameter should be interpreted in light of the number of reported significant digits and by applying ordinary rounding techniques. In this article, ranges can be expressed from one endpoint to the other endpoint or between two endpoints. Unless otherwise specified, all ranges disclosed herein include endpoints.

[0018] Currently, semiconductor packages including both photonic die (called P-die) and electronic die (called E-die) are becoming more and more popular due to their compactness. In addition, optical signaling and processing have been used in more and more applications due to the widespread use of optical fiber related applications for signal transmission.

[0019] For example, the photonic package can be optically coupled to the optical fiber via an edge coupler. In some embodiments, the edge coupler is an optical component that allows optical signals to be coupled between a waveguide and an optical fiber mounted at the edge of the photonic package. In some embodiments, the edge coupler can be continuous with the waveguide and can be formed in the same processing operation as the waveguide.

[0020] In some comparative methods, edge polishing may be applied after die singulation. Such methods are expensive and time-consuming. In addition, in wafer-level measurement or wafer-level testing, various optical fibers and fiber holders may be applied, thereby increasing costs.

[0021] Therefore, the present disclosure provides an optical die having a reflective layer for improving the practicality of wafer-level measurement or wafer-level testing. In some embodiments, during wafer-level measurement or wafer-level testing, the reflective layer reflects incident light to an edge coupler and an angle is formed by the incident light and the reflected light. In such embodiments, the optical fiber providing the incident light can be kept away from the optical die due to the angle, thus reducing the possibility of collision between the optical die and the optical fiber.

[0022] Please refer to Figure 1A and Figure 1B ,in Figure 1A is a partial top view of a semiconductor structure according to the present disclosure in one or more embodiments; and Figure 1B is along Figure 1A 1-1. In some embodiments, the semiconductor structure 10a includes optical dies 100A and 100B. The optical die 100A includes a photonic integrated circuit 102A, and the optical die 100B includes a photonic integrated circuit 102B. The photonic integrated circuits 102A and 102B are formed in a substrate 104. Each of the photonic integrated circuits 102A and 102B converts an electrical signal into an optical signal for transmission along an optical fiber (not shown) and converts an optical signal from an optical fiber into an electrical signal. Therefore, each of the photonic integrated circuits 102A and 102B is responsible for input / output (I / O) of optical signals to / from the optical fiber.

[0023] In some embodiments, the photonic integrated circuits 102A and 102B are formed using a silicon-on-insulator (SoI) substrate. Typically, an SOI substrate includes a layer of semiconductor material, such as silicon, formed on an insulator layer. The insulator layer may be, for example, a buried oxide (BOX) layer or a silicon oxide layer. The insulator layer is disposed on a substrate, typically a silicon or glass substrate. Other substrates, such as multi-layer or gradient substrates, may also be used.

[0024] In some embodiments, although not shown, waveguides may be formed in or over the photonic integrated circuits 102A and 102B. In some embodiments, the waveguides may be silicon waveguides formed by patterning semiconductor material. Patterning semiconductor material may be accomplished using acceptable photolithography and etching techniques. The dimensions of the waveguides may vary depending on the application; therefore, details thereof are omitted for brevity.

[0025] In some embodiments, the optical die 100A includes an edge coupler 110A formed in or above the photonic integrated circuit 102A, and the optical die 100B includes an edge coupler 110B formed in or above the photonic integrated circuit 102B. The edge couplers 110A and 110B allow the waveguide to transmit light to an overlying light source or optical signal source (such as an optical fiber) or receive light from the overlying light source or optical signal source. The edge couplers 110A and 110B can be formed by acceptable photolithography and etching techniques. In an embodiment, the edge couplers 110A and 110B are formed after the waveguides are defined. In some embodiments, the edge couplers 110A and 110B are respectively bidirectional broadband couplers (BC). In some embodiments, the edge couplers 110A and 110B include silicon, silicon nitride, and lithium niobate (LiNbO 3 ), but the present disclosure is not limited thereto.

[0026] Still refer to Figure 1A and Figure 1B , in some embodiments, the edge couplers 110A and 110B extend in the first direction D1, respectively. In some embodiments, the edge couplers 110A and 110B are parallel to each other in the second direction D2. In addition, in some embodiments, the edge couplers 110A and 110B are aligned with each other along the second direction D2, but the present disclosure is not limited thereto. In addition, the edge couplers 110A and 110B are aligned with each other in the third direction D3. In some embodiments, the first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other, but the present disclosure is not limited thereto. In some embodiments, the top surface 112A of the edge coupler 110A is spaced apart from the top surface 106A of the optical die 100A by a distance H1, and the top surface 112B of the edge coupler 110B is spaced apart from the top surface 106B of the optical die 100B by a distance H1. In some embodiments, the distance H1 is between 0.05 microns and about 250 microns, but the present disclosure is not limited thereto. The distance H1 may be modified according to various product designs. In some embodiments, the edge coupler 110A and the edge coupler 110B respectively have the same thickness T1 , and the thickness T1 is between about 100 nanometers and about 1,000 nanometers, but the disclosure is not limited thereto.

[0027] It should be noted that the optical dies 100A and 100B may further include elements such as back-end-of-line (BEOL) interconnect structures, redistribution structures, connection pads, and external contacts. In addition, other optical elements such as grating couplers may be formed in the optical dies 100A and 100B; however, for the sake of brevity, the details thereof are omitted.

[0028] In some embodiments, the trench 113 may be formed in the substrate 104. In some embodiments, the sidewalls of the trench 113 may be referred to as the edge of the optical die 100A and the edge of the optical die 100B, but the present disclosure is not limited thereto. Figure 1A and Figure 1B , the edge couplers 110A and 110B are exposed through the sidewalls of the groove 113. In some embodiments, the edge coupler 110A is considered to be adjacent to the edge of the optical die 100A, and the edge coupler 110B is considered to be adjacent to the edge of the optical die 100B. Light can enter the edge couplers 110A and 110B through the groove 113. In some embodiments, the width W of the groove 113 (which is also referred to as the distance between the end of the edge coupler 110A and the end of the edge coupler 110B) is between about 50 microns and about 1,000 microns, but the present disclosure is not limited thereto. In some embodiments, as long as the edge couplers 110A and 110B are exposed, the depth of the groove 113 can vary depending on the application; therefore, for the sake of brevity, its details are omitted. In addition, the substrate 104 can be exposed through the bottom of the groove 113, but the present disclosure is not limited thereto.

[0029] refer to Figure 2A and Figure 2B In some embodiments, the reflective layers 120A and 120B are formed at opposite sidewalls of the trench 113. The reflective layers 120A and 120B may include a metal layer. For example, the reflective layers 120A and 120B may include gallium nitride (GaN), aluminum (Al), copper (Cu), and silver (Ag), but the present disclosure is not limited thereto. In some embodiments, the formation of the reflective layers 120A and 120B may be accomplished using acceptable photolithography and etching techniques, and the details thereof are omitted for brevity.

[0030] In addition, the reflective layers 120A and 120B are respectively placed above the edge couplers 110A and 110B. For example, the reflective layer 120A is placed above the edge coupler 110A, and the reflective layer 120B is placed above the edge coupler 110B. In addition, the reflective layer 120A is separated from the edge coupler 110A, and the reflective layer 120B is separated from the edge coupler 110B. Figure 2AAs shown in FIG. 1 , the reflective layers 120A and 120B extend in the second direction D2, respectively. In such an embodiment, the extending directions of the reflective layers 120A and 120B are perpendicular to the extending directions of the edge couplers 110A and 110B, as seen from a plan view.

[0031] In some embodiments, the top surface 122A of the reflective layer 120A is flush with the top surface 106A of the optical die 100A, and the top surface of the reflective layer 120B is flush with the top surface 106B of the optical die 100B. Figure 2B However, Ref. Figure 5A In some embodiments, the top surface 122A of the light reflecting layer 120A is spaced apart from the top surface 106A of the optical die 100A by a distance H2, and the top surface 122B of the light reflecting layer 120B is spaced apart from the top surface 106B of the optical die 100B by a distance H2. The distance H2 is between about 0 micrometers and about 50 micrometers, but the present disclosure is not limited thereto.

[0032] refer to Figure 2B and Figure 3A , the reflective layer 120A has a side surface 124A exposed through the side wall of the trench 113 and parallel to the side wall of the trench 113, and the reflective layer 120B has a side surface 124B exposed through the side wall of the trench 113 and parallel to the side wall of the trench 113. In addition, the length L of the reflective layers 120A and 120B is measured along the side surfaces 124A and 124B in the third direction D3. In some embodiments, the length L is between about 0.1 micrometers and about 100 micrometers, but the present disclosure is not limited thereto. In some embodiments, the thickness of each of the reflective layers 120A and 120B is between about 1 nanometer and about 50 micrometers, but the present disclosure is not limited thereto.

[0033] In some embodiments, the side surface 124A of the reflective layer 120A is parallel to the side surface 114A of the edge coupler 110A, and the side surface 124B of the reflective layer 120B is parallel to the side surface 114B of the edge coupler 110B, such as Figure 2B and Figure 5A However, the present disclosure is not limited thereto.

[0034] refer to Figure 4 In some embodiments, the reflective layer 120A may be embedded in the optical die 100A, and the reflective layer 120B may be embedded in the optical die 100B. For example, in the semiconductor structure 10b, the side surface 124A of the reflective layer 120A is flush with the side surface 114A of the edge coupler 110A, and the side surface 124B of the reflective layer 120B is flush with the side surface 114B of the edge coupler 110B.

[0035] In some comparative embodiments, wafer-level measurement or wafer-level testing may be performed on the semiconductor structures 10a, 10b, and 11. In such comparative embodiments, an optical fiber is inserted into the groove 113 so that an optical signal can be introduced into the edge couplers 110A and 110B. However, because the top surfaces 112A and 112B of the edge couplers 110A and 110B are separated from the top surfaces 106A and 106B of the optical dies 100A and 100B, the optical fiber must be inserted into the groove 113 at a certain tilt angle. In addition, an optical fiber holder is applied to provide the tilt angle. Even under this condition, an undesirable collision may occur between the optical fiber and the optical dies 100A and 100B or between the optical fiber holder and the optical dies 100A and 100B.

[0036] Reference and comparison methods Figure 3A , Figure 3B , Figure 4 and Figure 5B , in wafer-level measurement or wafer-level testing according to the present disclosure, the optical fiber 130 is separated from the groove 113. For example, the optical fiber or optical fiber array 130 held by the optical fiber holder 132 can be close to the groove 113 and can be held above the optical die 100B, but the distance H3 between the optical fiber 130 and the top surface 106B of the optical die 100B is maintained. In some embodiments, a sensor 134 can be used on the bottom of the optical fiber holder 132 to measure the distance H3 between the optical fiber 130 and the top surface 106B of the optical die 100B. In some embodiments, the incident light L I The incident light L is introduced from the optical fiber 130 to the reflective layer 120A. I The light L is reflected by the reflective layer 120A to form a reflected light L R .like Figure 3B , Figure 4 and Figure 5B As shown in FIG. 1 , in some embodiments, the side surface 124A formed on the reflective layer 120A and the incident light L I The angle A1 between the side surface 124A of the reflective layer 120A and the reflected light L R The angle A2 between the reflected light L and the reflected light L may be between about 1° and about 89°. It should be understood that the angle A1 is equal to the angle A2. R The optical signal reaches the edge coupler 110B and is introduced into the optical die 100B through the edge coupler 110B. In such embodiments, a measurement signal or a test result is obtained in the optical die 100B.

[0037] refer to Figure 3CIn some embodiments, after performing wafer-level measurement or wafer-level testing on edge coupler 110B of optical die 100B, the same measurement or testing may be performed on edge coupler 110A of optical die 100A. In such embodiments, fiber holder 132 may be close to trench 113 and may be held above optical die 100A, but distance H3 is maintained between optical fiber 130 and top surface 106A of optical die 100A. Incident light L I The incident light L is introduced from the optical fiber 130 to the reflective layer 120B. I The light L is reflected by the reflective layer 120B to form a reflected light L R In such embodiments, the reflected light L R The edge coupler 110A is reached and introduced into the optical die 100A through the edge coupler 110A. In such an embodiment, a measurement signal or a test result is obtained in the optical die 100A. It should be understood that this mechanism is similar to Figure 3B Therefore, for the sake of brevity, repeated diagrams are omitted.

[0038] In some embodiments, the reflective layers 120A and 120B may have various configurations to improve the reflection of the optical signal. Figure 6 and Figure 7 In some embodiments, each of the reflective layers 120A and 120B may have a concave surface. In some embodiments, the radius of curvature of the concave surface of the reflective layers 120A and 120B may be greater than about 1 micron. In some embodiments, the radius may be between about 1 micron and infinity.

[0039] Also refer to Figure 6 and Figure 7 , wafer-level measurement or wafer-level testing may be performed on the semiconductor structures 12a and 12b. For example, wafer-level testing may be performed on the edge coupler 110A of the optical die 100A and the edge coupler 110B of the optical die 100B, respectively. For example, the optical fiber 130 held by the optical fiber holder 132 may be close to the groove 113 and may be held above the optical die 100B, but the distance H3 is maintained between the optical fiber 130 and the top surface 106B of the second optical die 100B. In some embodiments, the incident light L I The incident light L is introduced from the optical fiber 130 to the reflective layer 120A. I The light L is reflected by the reflective layer 120A to form a reflected light L R .like Figure 6 and Figure 7 As shown in FIG. 1 , in some embodiments, the angle θ1 is formed at the incident light L I With reflected light L R and the angle θ1 may be between about 2° and about 178°. In such embodiments, the reflected light L RThe optical die 100B is introduced into the optical die 100B through the edge coupler 110B. In such embodiments, a measurement signal or test result is obtained in the optical die 100B. As mentioned above, the same measurement or test can be performed on the edge coupler 110A; therefore, the details thereof are omitted for brevity.

[0040] In some embodiments, the groove 113 may have various configurations to improve the reflection of the optical signal. Figure 8 and Fig. 9 In some embodiments, the groove 113 may have a different Figure 7 . For example, the sidewall of the trench 113 (which is referred to as the edge of the optical die 100A and the edge of the optical die 100B) may have two portions. In some embodiments, the sidewall of the trench 113 has a first portion 115-1 and a second portion 115-2. The second portion 115-2 is coupled to the first portion 115-1 and the bottom of the trench 113. Angle A3 is formed by the first portion 115-1 and the second portion 115-2 of the sidewall of the trench 113. In some embodiments, angle A3 is between about 2° and about 178°.

[0041] refer to Figure 8 and Fig. 9 In some embodiments, the first portion 115 - 1 of the sidewall of the trench 113 is parallel to a horizontal line ( Figure 8 and Fig. 9 In some embodiments, the second portion 115-2 of the sidewall of the trench 113 forms an angle A4 with the horizontal line, and the angle A5 is between about 1° and about 89°. In some embodiments, the angle A4 is equal to the angle A5. In some alternative embodiments, the angle A4 and the angle A5 are different from each other.

[0042] Still refer to Figure 8 and Fig. 9, the reflective layers 120A and 120B are placed above the first portion 115-1 of the sidewall of the trench 113; therefore, the reflective layers 120A and 120B are inclined with the first portion 115-1 of the sidewall of the trench 113. In such embodiments, the side surface 114A of the edge coupler 110A and the side surface 114B of the edge coupler 110B are exposed through the second portion 115-2 of the sidewall of the trench 113, and therefore, the side surfaces 114A and 114B of the edge couplers 110A and 110B are inclined with the second portion 115-2 of the sidewall of the trench 113. Therefore, the side surface 114A of the edge coupler 110A forms an angle with the side surface 124A of the reflective layer 120A, and the angle is an obtuse angle. The side surface 114B of the edge coupler 110B forms an angle with the side surface 124B of the reflective layer 120B, and the angle is an obtuse angle.

[0043] refer to Figure 8 In some embodiments, the reflective layer 120A may be embedded in the optical die 100A, and the reflective layer 120B may be embedded in the optical die 100B. For example, in the semiconductor structure 10b, the side surface 124A of the reflective layer 120A and the side surface 124B of the reflective layer 120B are flush with the first portion 115 - 12 of the sidewall of the trench 113 .

[0044] Wafer-level measurements or wafer-level tests may be performed on the semiconductor structures 13a and 13b. For example, wafer-level tests may be performed on the edge couplers 110A and 110B of the optical die 100A and the optical die 100B, respectively. In some embodiments, the optical fiber 130 held by the optical fiber holder 132 may be close to the groove 113 and may be held above the optical die 100B, but the distance H3 is maintained between the optical fiber 130 and the top surface 106B of the optical die 100B. In some embodiments, the incident light L I The incident light L is introduced from the optical fiber 130 to the reflective layer 120A. I The light L is reflected by the reflective layer 120A to form a reflected light L R .like Figure 8 and Fig. 9 As shown in FIG. 1 , in some embodiments, the side surface 124A formed on the reflective layer 120A and the incident light L I The angle A1 between the side surface 124A of the reflective layer 120A and the reflected light L may be between about 1° and about 89°. R and angle A2 may be between about 1° and about 89°. It should be understood that angle A1 is equal to angle A2. In such embodiments, the reflected light L RThe optical die 100B is introduced into the optical die 100B through the edge coupler 110B. In such embodiments, a measurement signal or test result is obtained in the optical die 100B. As mentioned above, the same measurement or test can be performed on the edge coupler 110A; therefore, the details thereof are omitted for brevity.

[0045] In the above-described embodiment, the groove 113 may have a symmetrical configuration, and the reflective layers 120A and 120B are symmetrically placed. However, in other embodiments, the groove 113 may have an asymmetrical configuration to improve reflection. Fig.10 and Fig.11 In some embodiments, semiconductor structures 14a and 14b are provided that include an optical die 100 and an edge coupler 110. The edge coupler 110 is exposed through an asymmetric trench 117. In some embodiments, the edge coupler 110 can be referred to as being adjacent to and exposed through an edge of the optical die 100. Fig.10 and Fig.11 , the asymmetric groove 117 may have a first sidewall 119a and a second sidewall 119b opposite to each other. The first sidewall 119a may be a substantially straight sidewall, and the edge coupler 110 is exposed through the straight first sidewall 119a. The second sidewall 119b may be a meandering sidewall. In some embodiments, the meandering second sidewall 119b may include at least three portions 119b-1, 119b-2, and 119b-3, wherein portion 119b-2 couples portion 119b-1 to portion 119b-3. In addition, portion 119b-2 is referred to as a light receiving portion. In such embodiments, a reflective layer 120 is placed above the light receiving portion 119b-2. In some embodiments, the light receiving portion 119b-2 is tilted so that the reflective layer 120 forms an angle θ with a normal perpendicular to the bottom of the groove 117. m ,like Fig.10 and Fig.11 In some embodiments, the angle θ m Between about 1° and about 45°, but the disclosure is not limited thereto.

[0046] refer to Fig.11 In some embodiments, the reflective layer 120 may be embedded in the optical die 100 .

[0047] Wafer-level measurements or wafer-level tests may be performed on the edge couplers 110 of the optical die 100 of the semiconductor structures 14a and 14b. For example, the optical fiber 130 held by the fiber holder 132 may be close to the asymmetric trench 117 and may be held above the optical die 100, but the distance H3 is maintained between the optical fiber 130 and the top surface 106 of the optical die 100. In some embodiments, the incident light L I The incident light L is introduced from the optical fiber 130 to the reflective layer 120.I The light L is reflected by the reflective layer 120 to form a reflected light L R .like Fig.10 and Fig.11 As shown in the figure, the reflected light L R The optical signal reaches the edge coupler 110 and is introduced into the optical die 100 through the edge coupler 110. In such an embodiment, a measurement signal or a test result is obtained in the optical die 100.

[0048] In some embodiments, the reflective layers 120A and 120B can be used to improve wafer-level measurement or wafer-level testing of various edge couplers. For example, semiconductor structures 15a to 15c including optical dies 100A and 100B that are different from each other are provided. Fig.12 , the optical die 100A may include a multi-layer edge coupler 110A, while the optical die 100B may include a single-layer edge coupler 110B. In other words, the edge coupler 110A is different from the edge coupler 110B. The reflective layers 120A and 120B may be placed over the sidewalls of the trench 113. As mentioned above, the reflective layer 120A may be adjacent to the edge of the optical die 100A and the reflective layer 120B may be adjacent to the edge of the optical die 100B. The arrangement of the reflective layers 120A and 120B may be similar to that mentioned above and Fig.13 and Fig.14 The arrangement described in ; therefore, for the sake of brevity, its details are omitted.

[0049] In some embodiments, wafer-level measurement or wafer-level testing is performed on the semiconductor structures 15a to 15c. According to the present disclosure, the optical fiber 130 is separated from the groove 113. For example, the optical fiber 130 held by the optical fiber holder 132 can be close to the groove 113 and can be held above the optical die 100B, and the distance H3 between the optical fiber 130 and the top surface 106B of the optical die 100B is maintained. In some embodiments, a sensor 134 can be used on the bottom of the optical fiber holder 132 to measure the distance H3 between the optical fiber 130 and the top surface 106B of the optical die 100B. In some embodiments, the incident light L I The incident light L is introduced from the optical fiber 130 to the reflective layer 120A. I The light L is reflected by the reflective layer 120A to form a reflected light L R .like Fig.12 As shown in FIG. 1 , in some embodiments, the side surface 124A formed on the reflective layer 120A and the incident light L I The angle A1 between the side surface 124A of the reflective layer 120A and the reflected light L may be between about 1° and about 89°. R and angle A2 may be between about 1° and about 89°. It should be understood that angle A1 is equal to angle A2. In such embodiments, the reflected light L RThe optical signal reaches the edge coupler 110B and is introduced into the optical die 100B through the edge coupler 110B. In such embodiments, a measurement signal or a test result is obtained in the optical die 100B.

[0050] In some embodiments, after performing wafer-level measurement or wafer-level testing on edge coupler 110B, the same measurement or testing may be performed on edge coupler 110A. In such embodiments, fiber holder 132 may be close to groove 113 and may be held above optical die 100A, and a distance is maintained between optical fiber 130 and top surface 106A of first optical die 100A. In such embodiments, the distance between top surface 106A of optical die 100A and optical fiber 130 may be different from distance H3, but the present disclosure is not limited thereto. Incident light L I The incident light L is introduced from the optical fiber 130 to the reflective layer 120B. I The light L is reflected by the reflective layer 120B to form a reflected light L R In such embodiments, the reflected light L R Arrives at edge coupler 110A and is introduced into optical die 100A through edge coupler 110A. In such embodiments, a measurement signal or test result is obtained in optical die 100A. It should be understood that this mechanism is similar to the configuration on reflective layer 120A; therefore, repeated drawings are omitted for brevity.

[0051] refer to Fig.15 In some embodiments, a semiconductor structure 16 including a plurality of edge couplers 110A and a plurality of edge couplers 110B is provided. The edge coupler 110A may belong to one optical die. In other embodiments, depending on the product design, the edge coupler 110A may belong to more than one optical die. In some embodiments, the edge coupler 110B may belong to another optical die. In other embodiments, depending on the product design, the edge coupler 110B may belong to more than one optical die. The number of edge couplers 110A may be equal to the number of edge couplers 110B. However, in some alternative embodiments, the number of edge couplers 110A is different from the number of edge couplers 110B.

[0052] like Fig.15, edge couplers 110A and 110B extend in a first direction D1 and are parallel to each other in a second direction D2. In some embodiments, the width of each edge coupler 110A is equal to the width of each edge coupler 110B. The distance between adjacent edge couplers 110A is equal to the distance between adjacent edge couplers 110B. In addition, semiconductor structure 16 includes a trench 113 that exposes the ends of each edge coupler 110A and 110B. In some embodiments, edge coupler 110A is placed at one side of trench 113 and edge coupler 110B is placed at the opposite side of trench 113, such as Fig.15 In some embodiments, each of the edge couplers 110A may be aligned with one of the edge couplers 110B in the second direction D2. In other embodiments, the edge coupler 110A may be offset from the edge coupler 110B in the second direction D2, such as Fig.15 An offset distance H4 may be measured between a central axis CA of edge coupler 110A and a central axis CB of edge coupler 110B, wherein the offset distance H4 is between 0 and approximately 1,000 microns.

[0053] refer to Fig.15 In some embodiments, the reflective layers 120A and 120B may be placed above the sidewalls of the trench 113. The reflective layers 120A and 120B extend in the second direction D2, respectively. In such embodiments, from a plan view, the extending direction of the reflective layers 120A and 120B may be perpendicular to the extending direction of the edge couplers 110A and 110B. The arrangement of the reflective layers 120A and 120B may be similar to the above-mentioned and Figure 5A and Figures 6 to 9 therefore, the details are omitted for the sake of brevity.

[0054] In some embodiments, wafer-level measurement or wafer-level testing is performed on the semiconductor structure 16. According to the present disclosure, the optical fiber 130a is separated from the groove 113. For example, the optical fiber 130a held by the optical fiber holder 132a can approach the groove 113, and a vertical distance H3 is maintained between the optical fiber 130a and the opening of the groove 113. The configuration of light introduction, light reflection, and light reception is similar to the above configuration; therefore, for the sake of brevity, its details are omitted. Therefore, a measurement signal or a test result of the edge coupler 110B is obtained. In some embodiments, the optical fiber 130b held by the optical fiber holder 132b is used to perform wafer-level measurement on the edge coupler 110A. The configuration of light introduction, light reflection, and light reception is similar to the above configuration; therefore, for the sake of brevity, its details are omitted. Therefore, a measurement signal or a test result of the edge coupler 110A is obtained. In some embodiments, the measurement of the edge coupler 110A can be performed before or after the measurement of the edge coupler 110B. In some alternative embodiments, due to the offset arrangement, the measurements of edge coupler 110A are performed simultaneously with the measurements of edge coupler 110B, such as Fig.15 As shown in .

[0055] refer to Fig.16 In some embodiments, the optical fibers may be placed to form an optical fiber array 140 held by an array holder 142. In such embodiments, measurements may be performed on edge coupler 110B by optical fiber array 140 while measurements may be performed on edge coupler 110A by optical fiber 130. In alternative embodiments, measurements on edge coupler 110A may be performed by optical fiber array 140 while measurements on edge coupler 110B are performed by optical fiber 130, further increasing efficiency. In some embodiments, although not shown, measurements on both edge couplers 110A and 110B may be performed by optical fiber array 140.

[0056] refer to Fig.17 In some embodiments, to further improve the measurement efficiency or test efficiency, at least the alignment mark 150 may be placed above the top surface 106A or 106B. Therefore, the optical fiber 130 or the optical fiber array 140 may be aligned with the alignment mark 150, thereby accurately introducing light into the reflective layer 120A or 120B.

[0057] Please refer to Fig.18, wherein a flow chart representing a method 20 for measuring an optical die is provided. Although the disclosed method 20 is illustrated and described herein as a series of actions or operations, it should be understood that the order of the illustrated actions or operations should not be interpreted as intended to be limiting. For example, in addition to the operations illustrated and / or described herein, some operations may be performed in a different order and / or simultaneously with other actions or operations. In addition, not all illustrated operations may be required to implement one or more aspects or embodiments of the present invention. Furthermore, one or more of the operations described herein may be implemented in one or more separate operations and / or stages.

[0058] In operation 201, a substrate is received. In some embodiments, the substrate includes at least an edge coupler, and the edge coupler is exposed through a first sidewall of a trench. In some embodiments, a semiconductor structure 10a, 10b, 11, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, or 16 including a substrate 104 is received. Figure 1A and Figure 1B , substrate 104 may include edge couplers 110, 110A, and / or 110B. In addition, edge couplers 110, 110A, and / or 110B are exposed through the sidewalls of trenches 113 or 117. In some embodiments, edge coupler 110 is considered to be adjacent to an edge of optical die 100. In other embodiments, edge coupler 110A is adjacent to an edge of optical die 100A, and edge coupler 110B is adjacent to an edge of optical die 100B.

[0059] In operation 202, a first reflective layer is formed on a second sidewall of the trench. Figures 2A to 17 , for example, the reflective layer 120 or 120A is formed on the first sidewall of the trench 113 .

[0060] In some embodiments, in operation 202, a second reflective layer may be formed on the first sidewall of the trench. Figures 2A to 17 , in such embodiments, reflective layer 120B is formed over the sidewall opposite to where reflective layer 120A is placed. In some embodiments, reflective layers 120A and 120B are formed simultaneously. As mentioned above, reflective layer 120A is placed over and separated from edge coupler 110A, and reflective layer 120B is placed over and separated from edge coupler 110B. The configuration and arrangement of reflective layers 120 and 120A are similar to those described above; therefore, details thereof are omitted for brevity.

[0061] In operation 203, first incident light is introduced into a first reflective layer to form first reflected light, wherein the first reflected light is guided toward a first edge coupler. Figures 3A to 17 , incident light LI The incident light L is introduced from the optical fiber 130 or the optical fiber array 140. I The light L is reflected by the reflective layer 120 or 120A to form a reflected light L R , where the reflected light L R The optical fiber 130 or optical fiber array 140 is vertically and directly placed above the edge coupler 110 or 110B to be tested.

[0062] In some embodiments, in operation 203, the second incident light is introduced into the reflective layer 120B to form a second reflected light, wherein the second reflected light is guided toward the edge coupler 110A, such as Figure 3C In some embodiments, the measurements performed on edge coupler 110A and edge coupler 110B may be performed sequentially. In other embodiments, the measurements performed on edge coupler 110A and edge coupler 110B may be performed simultaneously, such as Fig.15 and Fig.16 As shown in .

[0063] In operation 204, a first measurement result is received from the first edge coupler. As mentioned above, the reflected light L R Enter the edge coupler 110 or 110B to be tested, and thereby convert the optical signal into an electrical signal and thus receive a measurement or test result from this edge coupler.

[0064] In some embodiments, in operation 204 , a second measurement is received from edge coupler 110A.

[0065] Embodiments of the present disclosure provide an optical die with a reflective layer for improving the practicality of wafer-level measurement or wafer-level test facilities. The reflective layer helps to reflect incident light to an edge coupler and an angle is formed by the incident light and the reflected light. In such embodiments, the optical fiber providing the incident light can be kept away from the optical die due to the angle, thus reducing the possibility of collision between the optical die and the optical fiber.

[0066] In some embodiments, a semiconductor structure is provided. The semiconductor structure includes an optical die, a first edge coupler, and a reflective layer. The optical die has a top surface and an edge. The first edge coupling is placed in the optical die and adjacent to the edge of the optical die. The reflective layer is placed in the optical die and adjacent to the edge of the optical die. The reflective layer is placed above the first edge coupler and separated from the first edge coupler.

[0067] In some embodiments, a semiconductor structure is provided. The semiconductor structure includes an optical die, a plurality of edge couplers placed in the optical die, and a metal layer placed in the optical die. The edge couplers extend in a first direction and are parallel to each other. The metal layer extends in a second direction different from the first direction. The metal layer is separated from the edge couplers in a third direction different from the first and second directions.

[0068] In some embodiments, a method for measuring an optical die is provided. The method includes the following operations. A substrate is received. The substrate includes at least a first edge coupler. The first edge coupler is exposed through a first sidewall of a groove. A first reflective layer is formed above a second sidewall of the groove. The second sidewall is opposite to the first sidewall. A first incident light is introduced into the first reflective layer to form a first reflected light, wherein the first reflected light is directed toward the first edge coupler. A first measurement result is received from the first edge coupler.

[0069] The features of several embodiments have been summarized above so that those skilled in the art can better understand aspects of the present disclosure. Those skilled in the art will appreciate that they can readily use the present disclosure as a basis for designing or modifying other processes and structures for implementing the same purposes and / or achieving the same advantages of the embodiments introduced herein. Those skilled in the art will also recognize that such equivalent constructions should not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and modifications to the present disclosure without departing from the spirit and scope of the present disclosure.

[0070] Explanation of symbols

[0071] 10a: Semiconductor structure

[0072] 10b: Semiconductor Structure

[0073] 11: Semiconductor structure

[0074] 12a: Semiconductor Structure

[0075] 12b: Semiconductor Structure

[0076] 13a: Semiconductor Structure

[0077] 13b: Semiconductor structure

[0078] 14a: Semiconductor Structure

[0079] 14b: Semiconductor Structure

[0080] 15a to 15c: Semiconductor Structure

[0081] 16: Semiconductor structure

[0082] 20: Methods

[0083] 100: Optical bare die

[0084] 100A: Optical Bare Die

[0085] 100B: Optical Bare Die

[0086] 102A: Photonic Integrated Circuits

[0087] 102B: Photonic Integrated Circuits

[0088] 104: Substrate

[0089] 106: Top

[0090] 106A: Top surface

[0091] 106B: Top surface

[0092] 110:Edge Coupler

[0093] 110A:Edge Coupler

[0094] 110B:Edge Coupler

[0095] 112A: Top surface

[0096] 112B: Top surface

[0097] 113: Groove

[0098] 114A: Side surface

[0099] 114B: Side surface

[0100] 115-1: Part 1

[0101] 115-2: Part 2

[0102] 117: Asymmetric groove

[0103] 119a: first side wall

[0104] 119b: Second side wall

[0105] 119b-1: Partial

[0106] 119b-2: Light receiving part

[0107] 119b-3: Partial

[0108] 120: Reflection layer

[0109] 120A: Reflective layer

[0110] 120B: Reflective layer

[0111] 122A: Top surface

[0112] 122B: Top surface

[0113] 124A: Side surface

[0114] 124B: Side surface

[0115] 130: Fiber Optic

[0116] 130a: Fiber Optic

[0117] 130b: Fiber Optic

[0118] 132: Fiber Optic Seat

[0119] 132a: Fiber Optic Seat

[0120] 132b: Fiber Optic Seat

[0121] 134: Sensor

[0122] 140:Fiber Array

[0123] 142: Array seat

[0124] 150: Alignment mark

[0125] 201: Operation

[0126] 202: Operation

[0127] 203: Operation

[0128] 204: Operation

[0129] A1:Angle

[0130] A2: Angle

[0131] A3: Angle

[0132] A4: Angle

[0133] A5: Angle

[0134] CA: Central Axis

[0135] CB: Center axis

[0136] D1: First direction

[0137] D2: Second direction

[0138] D3: Third direction

[0139] H1: Distance

[0140] H2: Distance

[0141] H3: Distance

[0142] H4: Offset distance

[0143] L: Length

[0144] L I :Incident Light

[0145] L R :Reflected Light

[0146] T1: Thickness

[0147] W: Width

[0148] θ 1 : Angle

[0149] θ m :angle.

Claims

1. A semiconductor structure, characterized in that It includes: an optical die having a top surface and an edge; an edge coupler placed in the optical die and adjacent to the edge of the optical die; and A reflective layer is placed in the optical die and adjacent to the edge of the optical die, wherein the reflective layer is placed over and separated from the edge coupler.

2. The semiconductor structure according to claim 1, characterized in that From a plan view, an extending direction of the reflective layer is perpendicular to an extending direction of the edge coupler.

3. The semiconductor structure according to claim 1, characterized in that A top surface of the edge coupler is spaced a first distance from the top surface of the optical die, and a top surface of the reflective layer is spaced a second distance from the top surface of the optical die.

4. The semiconductor structure according to claim 1, characterized in that The reflective layer is embedded in the optical die.

5. The semiconductor structure according to claim 1, characterized in that A side surface of the edge coupler and a side surface of the reflective layer are parallel to each other.

6. The semiconductor structure according to claim 1, characterized in that A side surface of the edge coupler forms an angle with a side surface of the reflective layer, and the angle is an obtuse angle.

7. The semiconductor structure according to claim 1, characterized in that A side surface of the reflective layer includes a concave surface.

8. A semiconductor structure, characterized in that It includes: Optical die; a plurality of edge couplers disposed in the optical die, wherein the edge couplers extend in a first direction parallel to each other; and A metal layer is disposed in the optical die, wherein the metal layer extends in a second direction different from the first direction, and the metal layer is separated from the edge coupler in a third direction different from the first direction and the second direction.

9. The semiconductor structure according to claim 8, characterized in that The edge coupler is a broadband coupler.

10. The semiconductor structure according to claim 8, characterized in that The metal layer includes gallium nitride (GaN), aluminum (Al), copper (Cu), and silver (Ag).

Images