WO2023005192A1

WO2023005192A1 - Optical antenna and manufacturing method therefor, and optical phased array chip

Info

Publication number: WO2023005192A1
Application number: PCT/CN2022/076391
Authority: WO
Inventors: 吴蓓蓓; 金里; 路侑锡; 冯俊波; 朱继光
Original assignee: 联合微电子中心有限责任公司
Priority date: 2021-07-30
Filing date: 2022-02-16
Publication date: 2023-02-02
Also published as: CN113608197A; CN113608197B

Abstract

Provided are an optical antenna and a manufacturing method therefor, and an optical phased array chip. The optical antenna comprises: a dielectric layer; a plurality of antenna structures, which are located in the dielectric layer and are spaced apart from one another in a first direction, wherein each of the plurality of antenna structures extend in a second direction, which intersects the first direction; and a metal layer, which is located in the dielectric layer and is opposite the plurality of antenna structures, and extends in the second direction, wherein the metal layer has an uneven surface that faces the plurality of antenna structures, such that a first part of light propagated in each of the plurality of antenna structures that is emitted toward the metal layer is reflected by the uneven surface, and interferes with a second part of the light that is emitted away from the metal layer.

Description

Optical antenna, manufacturing method thereof, and optical phased array chip

This application claims the priority of the Chinese patent application with the application number 202110872998.4 and the invention titled "Optical Antenna and Its Manufacturing Method and Optical Phased Array Chip" filed with the China Patent Office on July 30, 2021, the entire contents of which are incorporated by reference incorporated in this application.

technical field

The disclosure relates to the technical field of semiconductors, in particular to an optical antenna, a manufacturing method thereof, and an optical phased array chip.

Background technique

Lidar technology is a high-precision 3D image perception technology, which is widely used in autonomous driving, robots, drones and other fields. Based on the laser radar technology of optical phased array, the phased array is used to realize the steering of the beam in space, so that the pure solid-state two-dimensional beam scanning can be realized. The optical antenna is a key component in the optical phased array. The spot divergence angle and the output light power of the outgoing light emitted from the optical antenna determine the longest distance that the laser radar technology can measure in the ranging application.

Contents of the invention

According to some embodiments of the present disclosure, there is provided an optical antenna, including: a dielectric layer; a plurality of antenna structures located in the dielectric layer and spaced apart from each other in a first direction, each of the plurality of antenna structures an antenna structure extending along a second direction crossing the first direction; and a metal layer located in the dielectric layer opposite to the plurality of antenna structures and extending along the second direction, wherein the The metal layer has an uneven surface facing the plurality of antenna structures, such that a first portion of light propagating in each of the plurality of antenna structures exiting toward the metal layer passes through the uneven surface. The surface reflects and interferes with a second portion of the light that exits away from the metal layer.

According to some embodiments of the present disclosure, an optical phased array chip is provided, including the above-mentioned optical antenna.

According to some embodiments of the present disclosure, there is also provided a method for manufacturing an optical antenna, including: providing a semiconductor-on-insulator substrate, the semiconductor-on-insulator substrate including a first dielectric layer and a semiconductor layer stacked on each other; A patterning process is performed on the semiconductor layer to form a plurality of antenna structures, the plurality of antenna structures are spaced apart from each other in a first direction, and each antenna structure in the plurality of antenna structures is along a direction crossing the first direction. extending in a second direction; and forming a second dielectric layer embedded with a metal layer, the second dielectric layer covering the plurality of antenna structures together with the first dielectric layer, wherein the metal layer has a surface facing the a non-planar surface of the plurality of antenna structures, such that a first portion of light propagating in each of the plurality of antenna structures emitted toward the metal layer is reflected by the non-planar surface and is aligned with the light The second portion of the emitted away from the metal layer interferes.

These and other aspects of the disclosure will be apparent from and will be elucidated with reference to the embodiments described hereinafter.

Description of drawings

Further details, features and advantages of the present disclosure are disclosed in the following description of exemplary embodiments with reference to the accompanying drawings in which:

1A-1C are schematic structural diagrams of an optical antenna 100 according to some embodiments of the present disclosure;

FIG. 2A is a schematic diagram of the far-field amplitude distribution of outgoing light emitted from an optical antenna according to the related art;

2B is a schematic diagram of the far-field amplitude distribution of the outgoing light emitted from the optical antenna according to the related art;

FIG. 2C is a schematic diagram of the far-field amplitude distribution of the outgoing light emitted by the optical antenna 100 according to the present disclosure;

3A-3C are schematic structural diagrams of an optical antenna 300 according to some embodiments of the present disclosure;

4A is a schematic diagram of the far-field amplitude distribution of outgoing light emitted from an optical antenna according to the related art;

4B is a schematic diagram of the far-field amplitude distribution of the outgoing light emitted from the optical antenna according to the related art;

FIG. 4C is a schematic diagram of the far-field amplitude distribution of the outgoing light emitted by the optical antenna 300 according to the present disclosure;

FIG. 5 is a schematic flowchart of a method 500 of manufacturing an optical antenna according to some embodiments of the present disclosure;

6A-6E are schematic cross-sectional structural views of a semiconductor device obtained according to the method 500 of some embodiments of the present disclosure;

FIG. 7 is a flowchart of a process of forming a second dielectric layer embedded with a metal layer in a method 500 according to some embodiments of the present disclosure;

8A-8I are schematic cross-sectional structural views of a semiconductor device obtained according to the method 500 of some embodiments of the present disclosure;

FIG. 9 is a flowchart of a process of forming multiple antenna structures in a method 500 according to some embodiments of the present disclosure; and

FIG. 10 is a flowchart of a process of forming a second dielectric layer embedded with a metal layer in a method 500 according to some embodiments of the present disclosure.

Detailed ways

It will be understood that although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, that these elements, components, regions, layers and/or Sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.

Spatially relative terms such as "below," "beneath," "lower," "below," "above," "upper," etc. may be used herein for convenience. The description is used to describe the relationship of one element or feature to another element or feature(s) as illustrated in the figures. It will be understood that these 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. For example, if the device in the figures is turned over, elements described as "beneath" or "beneath" other elements or features would then be oriented "beneath" the other elements or features. over the characteristics". Thus, the exemplary terms "below" and "beneath" can encompass both an orientation of above and below. Terms such as "before" or "before" and "after" or "following" may similarly be used, for example, to indicate the order in which light passes through the elements. The device may be oriented otherwise (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It will be further understood that the terms "comprising" and/or "comprising" when used in this specification specify the presence of stated features, integers, steps, operations, elements and/or parts, but do not exclude the presence of one or more The presence or addition of one or more other features, integers, steps, operations, elements, parts and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items, and the phrase "at least one of A and B" means only A, only B, or both A and B.

It will be understood that when an element or layer is referred to as being "on", "connected to", "coupled to" or "adjacent to another element or layer" , it may be directly on, directly connected to, directly coupled to, or directly adjacent to another element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to" or "directly adjacent to" another element or layer , with no intermediate elements or layers present. In no event, however, "on" or "directly on" should be construed as requiring that one layer completely cover the underlying layer.

Embodiments of the disclosure are described herein with reference to schematic illustrations of idealized embodiments (and intermediate structures) of the disclosure. As such, variations from the shapes of the illustrations, for example, as a result of manufacturing techniques and/or tolerances, should be expected. Thus, embodiments of the present disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present disclosure.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted to have meanings consistent with their meanings in the relevant field and/or in the context of this specification, and will not be idealized or overly be construed in a formal sense unless expressly so defined herein.

As used herein, the term "substrate" may refer to the substrate of a diced wafer, or may refer to the substrate of an un-diced wafer. Similarly, the terms chip and die may be used interchangeably unless such interchange would cause a conflict. It should be understood that the term "film" includes layers and should not be construed to indicate vertical or horizontal thickness unless otherwise stated. It should be noted that the thickness of each material layer of the optical antenna shown in the figure is only for illustration and does not represent the actual thickness.

The inventors found that the far-field intensity of the outgoing light emitted by the optical antenna is related to the structure of the optical antenna, and the distribution of the far-field intensity of the outgoing light will affect the combined beam. the size of.

According to one aspect of the present disclosure, an optical antenna is provided. By disposing a metal layer in a dielectric layer, and the metal layer has a non-flat surface facing the antenna structure, the far-field amplitude distribution of the outgoing light emitted by the optical antenna can be optimized. , the output main lobe power and the utilization rate of the output light.

1A is a schematic cross-sectional structure diagram of an optical antenna 100 in a first direction according to some embodiments of the present disclosure, FIG. 1B is a schematic cross-sectional structural diagram of an optical antenna 100 in a second direction, and FIG. 1C is a plane of the antenna structure in the optical antenna 100 Schematic.

The structure of the optical antenna 100 will be described below with reference to FIGS. 1A-1C .

As shown in FIG. 1A and FIG. 1B, the optical antenna 100 includes a dielectric layer 110 and a plurality of antenna structures 120 located in the dielectric layer 110, the plurality of antenna structures 120 are spaced apart from each other in a first direction, and among the plurality of antenna structures 120 Each antenna structure 120 extends along a second direction crossing the first direction.

According to some embodiments, as shown in FIGS. 1A-1C , the first direction is the X direction, the second direction is the Y direction perpendicular to the X direction, and the Z direction is perpendicular to the plane defined by the first direction and the second direction. the third direction.

Continuing to refer to FIG. 1A and FIG. 1B , the optical antenna 100 further includes a metal layer 130 located in the dielectric layer 110 . The metal layer 130 is opposite to the plurality of antenna structures 120 and extends along the second direction.

The metal layer 130 has a non-planar surface facing the plurality of antenna structures 120, so that a first part of the light propagating in each of the plurality of antenna structures 120 that is emitted facing the metal layer 130 is reflected by the non-planar surface and communicates with the A second portion of light exiting away from the metal layer 130 interferes.

As shown in FIG. 1B , the light propagating in the antenna structure 120 includes a first part (shown by arrow B) and a second part (shown by arrow A), wherein the first part faces the metal layer 130 and is emitted by the metal layer The surface of 130 facing the antenna structure 120 is reflected to form reflected light (shown by arrow C).

It should be noted that the term "light propagating in the antenna structure" refers to the light transmitted in the antenna structure along the length direction of the antenna structure, which includes light transmitted from one end of the antenna structure to the other end along the length direction and emitted light and light exiting from the sides of the antenna structure.

According to the optical antenna according to the embodiment of the present disclosure, by disposing a metal layer in the medium layer, and the metal layer has a non-flat surface facing the antenna structure, the first part of light emitted from the antenna structure facing the metal layer is reflected by the non-flat surface Reflected light with multiple directions of propagation is obtained. The reflected light can interfere to varying degrees with the second part of the light emitted from the antenna structure away from the metal layer, so as to optimize the far-field amplitude distribution of the outgoing light emitted through the optical antenna, that is, the outgoing light has a large scanning angle. Higher far-field amplitude. At the same time, it is avoided that the reflected light has a single propagation direction in the XZ plane and interferes with the second part of the light emitted away from the metal layer, and the far-field amplitude distribution of the outgoing light is split (that is, light appears at the center of the scanning area. Intensity loss), so that the outgoing light has a strong light intensity in a large scanning angle range after being combined into a combined beam.

Further, since the metal layer reflects the first part of light emitted towards the metal layer, the reflected light obtained after reflection and the second part of light emitted away from the metal layer have the same or similar propagation direction in the YZ plane, increasing the The outgoing main lobe power of the light emitted from the optical antenna further increases the main lobe power of the outgoing light after it is combined into a combined beam, thereby improving the utilization rate of the outgoing light.

According to some embodiments, the material of the dielectric layer is a dielectric material with a lower refractive index, such as silicon dioxide.

According to some embodiments, the antenna structure is made of a material with a relatively high refractive index, such as silicon.

In some embodiments, materials of the metal layer are materials with high reflectivity such as titanium nitride, aluminum, copper, and gold, which are not limited herein. By setting the material of the metal layer to a material with high reflectivity, the intensity of the reflected light obtained after being reflected by the metal layer is increased, and the output main lobe power of the light emitted from the optical antenna is further improved.

In some embodiments, as shown in FIG. 1A and FIG. 1B , the non-planar surface of the metal layer 130 includes a plurality of concave surfaces 130a juxtaposed along the first direction, wherein each concave surface 130a of the plurality of concave surfaces is arranged along the second direction. direction, and are respectively opposite to each antenna structure 120 in the plurality of antenna structures 120 .

By arranging the non-flat surface of the metal layer as a concave surface opposite to each of the antenna structures in the plurality of antenna structures, for each of the antenna structures in the plurality of antenna structures, the first part of the light emitted towards the metal layer is received by the corresponding concave surface. Reflected light is obtained by reflection, which further improves the light intensity and main lobe power of the combined beam emitted by the optical antenna.

In some embodiments, as shown in FIG. 1A , the concave surface 130a is an arcuate surface.

The concave surface is set as an arcuate surface, so that when the first part of the light propagating in the antenna structure hits the arcuate surface, the cross-section from the antenna structure to the arcuate surface has the same or similar optical path difference. Therefore, when the first part of light is reflected by the metal layer and interferes with the second part of light emitted away from the metal layer, it has the same or similar interference effect at different spatial positions, further improving the far field of the outgoing light emitted by the optical antenna. The optimization effect of amplitude distribution.

It should be understood that the above-mentioned configuration of the concave surface of the non-planar surface of the metal layer as an arc-shaped surface is only exemplary. Those skilled in the art should understand that, in other embodiments, the concave surface 130a may also be configured to have a cross-section in the shape of a "V" or the like, which is not limited here.

In some embodiments, the radius of curvature of the arcuate surface is greater than 314 nm.

In some embodiments, the distance between the metal layer and the plurality of antenna structures is configured such that an optical path difference between the first portion of reflected light and the second portion of light is an integer multiple of a wavelength of the light.

Continuing to refer to FIG. 1B, the optical path difference between the reflected light (shown by arrow C) and the second part (shown by arrow A) obtained after reflection of the first part (shown by arrow B) of the light propagating in the antenna structure 120 is: Integer multiples of the wavelength of light.

By configuring the distance between the metal layer and the plurality of antenna structures such that the optical path difference between the first part of the reflected light and the second part of the light is an integer multiple of the wavelength of the light, the reflected light When the first part interferes with the second part of the light, the interfered light has enhanced light intensity, further improving the optimization effect of the far-field amplitude distribution of the outgoing light emitted through the optical antenna.

In some embodiments, the thickness of the metal layer 130 is greater than or equal to 50 nm.

The structure of each antenna structure in the multiple antenna structures is exemplarily introduced below with reference to FIG. 1C . According to some embodiments, as shown in FIG. 1C , each antenna structure 120 of the plurality of antenna structures 120 includes a body portion 121 extending along a second direction and a plane parallel to a plane defined by the first and second directions. A plurality of protruding portions 122 protrude from the body portion 121 in a direction, and the plurality of protruding portions 122 are periodically arranged along the second direction.

Since the refractive index of the dielectric layer is lower than that of the antenna structure, by arranging a protrusion on the side of the antenna structure (that is, the surface of the body part in the direction perpendicular to the plane defined by the first direction and the second direction) part, the raised part disturbs the light propagating in the antenna structure. Meanwhile, in the embodiments according to the present disclosure, since the metal layer is provided under the antenna structure, and the metal layer has a non-flat surface, the first part of the light propagating in the antenna structure is reflected by the non-flat surface. The reflected light has multiple propagation directions, so as to avoid splitting of the far-field amplitude distribution of the outgoing light emitted through the optical antenna.

2A is a schematic diagram of the far-field amplitude distribution of the outgoing light emitted from the optical antenna adopting the antenna structure of FIG. 1C and not having a metal layer in the dielectric layer according to the related art; FIG. Structure and a schematic diagram of the far-field amplitude distribution of the outgoing light emitted from an optical antenna in which a metal layer with a flat surface is arranged in a dielectric layer; FIG. Schematic representation of the field amplitude distribution.

As shown in Figure 2A, for the optical antenna adopting the antenna structure of Figure 1C and not having a metal layer in the dielectric layer, the far-field amplitude distribution of the outgoing light presents a split shape, so that the central area of the main lobe scanning area (from 0° Start to extend in the direction of both sides) there is a large loss. As shown in Figure 2B, for the optical antenna adopting the antenna structure of Figure 1C and setting a metal layer with a flat surface in the dielectric layer, the far-field amplitude distribution of the outgoing light does not appear to be split, but the far-field amplitude distribution shows In order to have a stronger light intensity in a smaller scanning angle range (concentrated around the scanning angle 0°). As shown in FIG. 2C , for the optical antenna 100 according to the embodiment of the present disclosure, the far-field amplitude of the outgoing light does not appear to be split, and the far-field amplitude distribution shows a strong intensity in a large scanning angle range. light intensity.

3A is a schematic cross-sectional view of an optical antenna 300 in a first direction according to some embodiments of the present disclosure, FIG. 3B is a schematic cross-sectional view of an optical antenna 300 in a second direction, and FIG. 3C is a planar structure of an antenna structure in an optical antenna 300 schematic diagram.

The structure of the optical antenna 300 will be described below with reference to FIGS. 3A-3C .

As shown in FIG. 3A and FIG. 3B , an optical antenna 300 according to some embodiments of the present disclosure includes a dielectric layer 310 and a plurality of antenna structures 320 located in the dielectric layer 310, and the plurality of antenna structures 320 are spaced apart from each other in a first direction. , and each antenna structure 320 of the plurality of antenna structures 320 extends along a second direction crossing the first direction.

According to some embodiments, as shown in FIGS. 3A-3C , the first direction is the X direction, the second direction is the Y direction perpendicular to the X direction, and the Z direction is perpendicular to the plane defined by the first direction and the second direction. the third direction.

Continuing to refer to FIGS. 3A and 3B , the optical antenna 300 according to an embodiment of the present disclosure further includes a metal layer 330 located in the dielectric layer 310 . The metal layer 330 is opposite to the plurality of antenna structures 320 and extends along the second direction.

The metal layer 330 has an uneven surface facing the plurality of antenna structures 320, so that the first part of the light propagating in each antenna structure 320 in the plurality of antenna structures 320 that is emitted towards the metal layer 330 is reflected by the uneven surface and A second portion of the light that exits away from the metal layer 330 interferes.

In the optical antenna according to an embodiment of the present disclosure, since the metal layer has a non-flat surface facing the antenna structure, the first part of light emitted from the antenna structure facing the metal layer can be reflected by the non-flat surface and away from the metal layer from the antenna structure. The second part of emitted light interferes, thereby optimizing the far-field amplitude distribution of the outgoing light finally emitted through the optical antenna, that is, the outgoing light has a higher far-field amplitude in a larger scanning angle. In this way, after the outgoing light is combined into a combined beam, it has a relatively strong light intensity in a relatively large scanning angle range.

At the same time, since the metal layer is set as a non-planar structure, the first part of light emitted from the antenna structure facing the metal layer is reflected by the non-flat surface, and the reflected light obtained in the XZ plane has multiple propagation directions in the XZ plane, avoiding the single propagation direction of the reflected light. After the same interference occurs with the second part of the light emitted away from the metal layer, the far-field amplitude distribution of the emitted light emitted by the optical antenna is split, that is, the light in the scanning area (for example, at the center position) is avoided. There is a large loss of strength.

In some embodiments, materials of the metal layer are materials with high reflectivity such as titanium nitride, aluminum, copper, and gold, which are not limited herein. By setting the material of the metal layer as a material with high reflectivity, the intensity of the reflected light obtained after being reflected by the metal layer is increased, and the output main lobe power of the light emitted from the optical antenna is further improved.

In some embodiments, as shown in FIG. 3A , the non-planar surface of the metal layer 330 includes a plurality of convex surfaces 330a juxtaposed along the first direction, wherein each convex surface 330a of the plurality of convex surfaces extends along the second direction, And are respectively opposite to each antenna structure 320 in the plurality of antenna structures 320 .

By arranging the non-planar surface of the metal layer as a convex surface opposite to each antenna structure of the plurality of antenna structures, for each antenna structure of the plurality of antenna structures, the first part of light emitted away from the metal layer is received by the corresponding convex surface The reflected light is obtained by the reflection of the optical antenna, which further improves the light intensity and main lobe power of the combined beam emitted by the optical antenna.

In some embodiments, as shown in FIG. 3A , the convex surface 330a is an arcuate surface.

It should be understood that the above-mentioned configuration of the convex surface of the non-flat surface of the metal layer as an arc-shaped surface is only exemplary. Those skilled in the art should understand that, in other embodiments, the convex surface 330a can also be set in other convex shapes, which is not limited here.

In some embodiments, the thickness of the metal layer 330 is greater than or equal to 50 nm.

3A-3C, according to some embodiments, each antenna structure 320 of the plurality of antenna structures 320 includes a first antenna layer 320a and a second antenna layer 320b, the first antenna layer 320a and the second antenna layer 320b They face each other in a direction perpendicular to the plane defined by the first direction and the second direction (ie, the Z direction), wherein the refractive index of the first antenna layer is greater than or equal to that of the second antenna layer.

By arranging the second antenna layer facing the first antenna layer, and the refractive index of the second antenna layer is less than or equal to the refractive index of the first antenna layer, the second antenna layer is opposite to the radiation emitted by the first antenna layer The outgoing light has a slight perturbation, and a longer optical antenna can be obtained, thereby improving the divergence angle of the spot after the light emitted from the optical antenna is combined into a combined beam. At the same time, when the refractive index of the second antenna layer is smaller than that of the first antenna layer, it disturbs the outgoing light emitted by the first antenna layer very slightly, so that in the process of manufacturing the optical antenna, the process The accuracy requirement is lower. That is, under a relatively low process precision, very slight disturbance to the outgoing light emitted by the first antenna layer can still be achieved, so that the reliability and stability of the process for manufacturing the optical antenna can be improved.

According to some embodiments, the dielectric layer is made of a dielectric material with a lower refractive index, such as silicon dioxide; the first antenna layer is made of a material with a high refractive index, such as silicon; the second antenna layer is made of a material with a lower refractive index than Or a material that is equal to the first antenna layer but higher than the dielectric layer, such as silicon nitride, polysilicon, and the like.

In some embodiments, as shown in FIG. 3C , the second antenna layer 320b includes a plurality of grating structures periodically arranged along the second direction.

According to some embodiments, as shown in FIG. 3C , the projection of each of the plurality of grating structures on the first antenna layer 320a exceeds the occupied area of the first antenna layer 320a in the first direction.

According to other embodiments, as shown in FIG. 3A-FIG. 3C, the second antenna can be further weakened by controlling the distance D between the grating structure and the first antenna layer 320a, the width W of the grating structure, and the length L of the grating structure. The antenna layer disturbs the outgoing light emitted by the first antenna layer to control the coupling strength, and further improves the divergence angle of the light spot after the light emitted from the optical antenna is combined into a combined beam.

Fig. 4A is a schematic diagram of the far-field amplitude distribution of outgoing light emitted from an optical antenna that adopts an antenna structure including a first antenna layer and a second antenna layer and does not set a metal layer in a dielectric layer according to the related art, and Fig. 4B is a schematic diagram according to the related art The technology adopts an antenna structure including a first antenna layer and a second antenna layer and a schematic diagram of the far-field amplitude distribution of the outgoing light emitted from an optical antenna in which a metal layer with a flat surface is arranged in the dielectric layer. FIG. 4C is a schematic diagram according to the present disclosure A schematic diagram of the far-field amplitude distribution of the outgoing light emitted from the optical antenna 300 of the embodiment.

As shown in Figure 4A, for an optical antenna that adopts an antenna structure including the first antenna layer and the second antenna layer and does not set a metal layer in the dielectric layer, the outgoing light has a larger light intensity in a smaller scanning angle range . As shown in Figure 4B, for an optical antenna with an antenna structure including the first antenna layer and the second antenna layer and a metal layer with a flat surface in the dielectric layer, the outgoing light has a larger scanning angle range. The light intensity is high, but it is split, so that there is a large loss in the central area of the main lobe scanning area (extending from 0° to both sides). As shown in FIG. 4C , for the optical antenna 300 according to the embodiment of the present disclosure, the far-field amplitude of the outgoing light does not appear to be split, and the far-field amplitude distribution shows a strong intensity in a large scanning angle range. light intensity.

It will be appreciated that, in some embodiments, certain features of optical antenna 100 described above with respect to FIGS. 1A-1C and certain features of optical antenna 300 described with respect to FIGS. 3A-3C may be used without conflict. Combine with each other. For example, the antenna structure 120 in the optical antenna 100 can be replaced with the antenna structure 320 in the optical antenna 300 . For another example, the metal layer 130 in the optical antenna 100 may be replaced by the metal layer 330 in the optical antenna 300 .

According to another aspect of the present disclosure, there is also provided an optical phased array chip, including the above-mentioned optical antenna.

According to another aspect of the present disclosure, there is provided a method of manufacturing an optical antenna. The optical antenna manufactured by the manufacturing method is provided with a metal layer in a dielectric layer, and the metal layer has a non-flat surface facing the antenna structure, which can be optimized The far-field amplitude distribution of the outgoing light emitted by the optical antenna, the main lobe power of the outgoing light, and the utilization rate of the outgoing light. Meanwhile, the method of manufacturing an optical antenna according to the present disclosure may integrate a MEMS manufacturing process.

FIG. 5 shows a flowchart of a method 500 of manufacturing an optical antenna according to some embodiments of the present disclosure. 6A-6E illustrate schematic cross-sectional structures of a semiconductor device obtained using the method 500 according to some embodiments. FIG. 7 shows a flowchart of the process of forming the second dielectric layer embedded with the metal layer in the method 500 according to some embodiments.

As shown in FIG. 5, method 500 includes:

Step S510: providing a semiconductor-on-insulator substrate, the semiconductor-on-insulator substrate comprising a first dielectric layer and a semiconductor layer stacked on each other;

Step S520: At least by performing a patterning process on the semiconductor layer, forming a plurality of antenna structures, the plurality of antenna structures are spaced apart from each other in a first direction, and each antenna structure in the plurality of antenna structures is along extending in a second direction intersecting the first direction; and

Step S530: forming a second dielectric layer embedded with a metal layer, the second dielectric layer covers the multiple antenna structures together with the first dielectric layer, wherein the metal layer has a a non-planar surface of the structure such that a first portion of light propagating in each of the plurality of antenna structures exiting towards the metal layer is reflected by the non-planar surface of light and away from the light The second part of light emitted by the metal layer interferes.

In step S510 , as shown in FIG. 6A , a semiconductor-on-insulator substrate 600 is provided, wherein the semiconductor substrate 600 includes a first dielectric layer 620 and a semiconductor layer 630 stacked on the dielectric layer. In some embodiments, the semiconductor substrate 600 further includes a supporting substrate layer 610 , wherein the first dielectric layer 620 and the semiconductor layer 630 are sequentially stacked on the substrate layer 610 .

According to some embodiments, the semiconductor-on-insulator substrate includes a silicon-on-insulator substrate, such as an SOI chip or an SOG chip, or the like.

It should be understood that the semiconductor-on-insulator substrate may be a semiconductor substrate on which chips or devices are formed, or a semiconductor substrate on which no chips are formed, which is not limited herein.

In some embodiments, in step S520, at least by performing a patterning process on the semiconductor layer 630 on the semiconductor substrate 600, a plurality of antenna structures are formed, and the plurality of antenna structures have the optical structure described in conjunction with FIGS. Structure of multiple antenna structures in an antenna. Wherein, the plurality of antenna structures are spaced apart from each other in a first direction, each of the plurality of antenna structures extends along a second direction perpendicular to the first direction, and each of the plurality of antenna structures The antenna structure includes a body portion extending along a second direction and a plurality of protruding portions protruding from the body portion in a direction parallel to a plane defined by the first and second directions, the plurality of protruding portions extending along the The second direction is arranged periodically.

In some embodiments, as shown in FIG. 6B , a plurality of antenna structures 630 a are formed by performing a patterning process on the semiconductor layer 630 . The patterning process includes photolithography, etching process, etc., which are well known to those skilled in the art and will not be repeated here.

According to some embodiments, as shown in FIG. 7, in step S530, forming the second dielectric layer embedded with the metal layer includes:

Step S710: forming a first covering layer covering the first dielectric layer and the plurality of antenna structures, and a plurality of parts of the first covering layer opposite to the plurality of antenna structures protrude upward;

Step S720: forming the metal layer at least partially covering the first covering layer; and

Step S730: forming a second covering layer covering the metal layer, wherein the first covering layer and the second covering layer form the second dielectric layer.

In step S710, as shown in FIG. 6C, a first covering layer 621 covering the first dielectric layer 620 and the plurality of antenna structures 620a is formed. Since the surfaces of the plurality of antenna structures 620a are higher than the surface of the first dielectric layer 620, the portions of the first covering layer 620 opposite to the plurality of antenna structures 620a protrude upward. In some embodiments, the first cover layer 621 is made of the same material layer as the first dielectric layer. According to some embodiments, the first dielectric layer 620 is a silicon oxide layer, and the first covering layer 621 is a silicon oxide layer. According to some embodiments, the method of forming the first capping layer 621 includes but not limited to chemical vapor deposition, physical vapor deposition, etc., which are not limited here.

In step S720 , as shown in FIG. 6D , a metal layer 640 covering the first covering layer 621 is formed. According to some embodiments, the metal layer 640 is made of materials with high reflectivity such as titanium nitride, aluminum, copper and gold. According to some embodiments, the method of forming the metal layer 640 includes but not limited to sputtering deposition, etc., which is not limited here.

In step S730 , as shown in FIG. 6E , a second covering layer 622 covering the metal layer 640 is formed. In some embodiments, the second covering layer 622 is made of the same material layer as the first covering layer 621 and the first dielectric layer, so that the second dielectric layer formed by the first covering layer 621 and the second covering layer 622 is identical to the first The dielectric layer 620 covers the antenna structure 620a together. According to some embodiments, the first dielectric layer 620 is a silicon oxide layer, the first covering layer 621 is a silicon oxide layer, and the second covering layer 622 is a silicon oxide layer. According to some embodiments, the method of forming the second capping layer 622 includes but is not limited to forming a second capping material layer by a deposition process, and performing a planarization process on the second capping material layer by a grinding process to form the second capping layer 624 . According to some embodiments, the deposition process includes, but is not limited to, chemical chemical vapor deposition, physical vapor deposition, etc., without limitation here. According to some embodiments, grinding processes include but are not limited to chemical mechanical grinding and the like.

According to some embodiments, after step S530 is completed, it further includes providing a semiconductor substrate with devices formed thereon, by releasing the supporting substrate layer 610 after bonding the semiconductor substrate with devices formed thereon to the surface of the second dielectric layer , to complete the fabrication of the optical antenna.

8A-8I illustrate schematic cross-sectional structural views of a semiconductor device obtained using the method 500 according to some embodiments. FIG. 9 shows a flowchart of the process of forming multiple antenna structures in method 500 according to some embodiments. FIG. 10 shows a flowchart of the process of forming the second dielectric layer embedded with the metal layer in the method 500 according to some embodiments.

In step S510 , as shown in FIG. 8A , a semiconductor-on-insulator substrate 800 is provided, wherein the semiconductor substrate 800 includes a first dielectric layer 820 and a semiconductor layer 830 stacked on the dielectric layer. In some embodiments, the semiconductor substrate 800 further includes a supporting substrate layer 810 , wherein the first dielectric layer 820 and the semiconductor layer 830 are sequentially stacked on the substrate layer 810 .

According to some embodiments, the semiconductor-on-insulator substrate includes a silicon-on-insulator substrate, such as an SOI substrate or an SOG substrate, or the like.

In some embodiments, in step S520, at least by performing a patterning process on the semiconductor layer 830 on the semiconductor substrate 800, a plurality of antenna structures are formed, and the plurality of antenna structures have the optical structure described in conjunction with FIGS. 3A-3C. Structure of multiple antenna structures in an antenna. Wherein, each antenna structure in the plurality of antenna structures includes a first antenna layer and a second antenna layer.

The step S520 of forming the plurality of antenna structures is shown in FIG. 9 . Referring to FIG. 9, step S520 includes:

Step S910: forming a plurality of first antenna layers spaced apart from each other in the first direction by performing a patterning process on the semiconductor layer;

Step S920: forming a first covering layer covering the first dielectric layer and the plurality of first antenna layers; and

Step S930: forming a plurality of second antenna layers on the first cover layer, each second antenna layer is connected to each first antenna layer in a direction perpendicular to the plane defined by the first direction and the second direction The layers are facing each other, and the refractive index of the first antenna layer is greater than or equal to the refractive index of the second antenna layer.

In step S910 , as shown in FIG. 8B , a plurality of first antenna layers 830 a spaced apart from each other in a first direction are formed by performing a patterning process on the semiconductor layer 830 . The patterning process includes photolithography, etching process, etc., which are well known to those skilled in the art and will not be repeated here.

In step S920, as shown in FIG. 8C, a first covering layer 821 covering the first dielectric layer 820 and the plurality of first antenna layers 830a is formed. In some embodiments, the first covering layer 821 and the first dielectric layer 820 use the same material layer. According to some embodiments, the first dielectric layer 820 is a silicon oxide layer, and the first covering layer 821 is a silicon oxide layer. According to some embodiments, the method of forming the first capping layer 821 includes, but is not limited to, forming a first capping material layer by a deposition process, and performing a planarization process on the first capping material layer by a grinding process to form the first capping layer 821. According to some embodiments, the deposition process includes, but is not limited to, chemical chemical vapor deposition, physical vapor deposition, etc., without limitation here. According to some embodiments, grinding processes include but are not limited to chemical mechanical grinding and the like.

In step S930, as shown in FIG. 8D, a plurality of second antenna layers 831 are formed on the first cover layer 821, and each second antenna layer 831 is in a direction perpendicular to the plane defined by the first direction and the second direction. Opposite to each first antenna layer 821 , the refractive index of the first antenna layer 830 a is greater than or equal to the refractive index of the second antenna layer 831 .

According to some embodiments, the method of forming a plurality of second antenna layers 831 on the first capping layer 821 includes, but is not limited to, forming a second antenna material layer by a deposition process, and performing a planarization process on the second antenna material layer by a grinding process. A plurality of second antenna layers 831 are then formed through a patterning process. According to some embodiments, the deposition process includes, but is not limited to, chemical chemical vapor deposition, physical vapor deposition, etc., without limitation here. According to some embodiments, the polishing process includes but not limited to chemical mechanical polishing, etc., which is not limited here. According to some embodiments, the patterning process includes photolithography, etching processes, and the like.

In some embodiments, in the above step S520, by controlling the distance between the plurality of second antenna layers 831 and the first antenna layer 830a, the width and length of each second antenna layer 831 in the plurality of second antenna layers 831 , can control the coupling strength between multiple second antenna layers 831, improve the disturbance of the second antenna layer to the outgoing light emitted by the first antenna layer, and further improve the light emitted from the optical antenna after being combined into a combined beam. Spot divergence angle.

The step S530 of forming the second dielectric layer embedded with the metal layer is shown in FIG. 10 . Referring to Figure 10, step S530 includes:

Step S1010: forming a second covering layer covering the first covering layer and the plurality of second antenna layers;

Step S1020: Perform a patterning process on the second cover layer to form a plurality of ridges spaced from each other in the first direction, and every two adjacent ridges in the plurality of ridges are located on the on both sides of a respective second antenna layer of the plurality of second antenna layers;

Step S1030: forming a third covering layer on the patterned second covering layer, the third covering layer comprising a plurality of protrusions corresponding to the plurality of ridges respectively correspond;

Step S1040: forming the metal layer at least partially covering the third covering layer; and

Step S1050: forming a fourth covering layer covering the metal layer, wherein the first covering layer, the second covering layer, the third covering layer and the fourth covering layer form the second medium layer.

In step S1010 , as shown in FIG. 8E , a second covering layer 822 covering the first covering layer 821 and the plurality of second antenna layers 831 is formed. In some embodiments, the second covering layer 822 is made of the same material layer as the first covering layer 821 and the first dielectric layer 820 . According to some embodiments, the first dielectric layer 820 is a silicon oxide layer, the first covering layer 821 is a silicon oxide layer, and the second covering layer 822 is a silicon oxide layer. According to some embodiments, the method of forming the second covering layer 822 includes but not limited to forming the second covering material layer by using a deposition process, and performing a planarization process on the second covering material layer by a grinding process to form the second covering layer 822 . According to some embodiments, the deposition process includes, but is not limited to, chemical chemical vapor deposition, physical vapor deposition, etc., without limitation here. According to some embodiments, the polishing process includes but not limited to chemical mechanical polishing, etc., which is not limited here.

In step S1020 , as shown in FIG. 8F , a patterning process is performed on the second covering layer 822 to form a plurality of ridges 822 a spaced apart from each other in the first direction. Every two adjacent ridge bars 822 a of the plurality of ridge bars 822 a are located on both sides of a corresponding one of the second antenna layers 831 of the plurality of second antenna layers 831 .

In step S1030, as shown in FIG. 8G, a third covering layer 823 is formed on the patterned second covering layer 822. The third covering layer 823 includes a plurality of protrusions, and the plurality of protrusions are respectively connected to a plurality of Ridge 822a corresponds. Since the surface of the plurality of ridges 822a is higher than the surface of other areas of the second covering layer 822, the parts opposite to the plurality of ridges 822a protrude upward to form a protrusion, so that the third covering layer 823 is opposite to the plurality of antenna structures 820a. Multiple sections are recessed downwards. In some embodiments, the third covering layer 823 is made of the same material layer as the second covering layer 822 , the first covering layer 821 and the first dielectric layer 820 . According to some embodiments, the first dielectric layer 820 is a silicon oxide layer, the first covering layer 821 is a silicon oxide layer, the second covering layer 822 is a silicon oxide layer, and the third covering layer 823 is a silicon oxide layer. According to some embodiments, the method of forming the third covering layer 823 includes but not limited to chemical chemical vapor deposition, physical vapor deposition, etc., which is not limited here.

In step S1040 , as shown in FIG. 8H , a metal layer 840 at least partially covering the third covering layer 823 is formed. According to some embodiments, the metal layer 840 is made of materials with high reflectivity such as titanium nitride, aluminum, copper and gold. According to some embodiments, the method of forming the metal layer 840 includes but not limited to sputtering deposition, etc., which is not limited here.

In step S1050 , as shown in FIG. 8I , a fourth covering layer 824 covering the metal layer 840 is formed. In some embodiments, the fourth covering layer 824 uses the same material layer as the third covering layer 823, the second covering layer 822, the first covering layer 821 and the first dielectric layer 820, so that the fourth covering layer 824 and the third covering layer 824 The second dielectric layer jointly formed by the covering layer 823 , the second covering layer 822 , and the first covering layer 821 covers the antenna structure (including the first antenna layer 830 a and the second antenna layer 831 ) together with the first dielectric layer 820 . According to some embodiments, the first dielectric layer 820 is a silicon oxide layer, the first covering layer 821 is a silicon oxide layer, the second covering layer 822 is a silicon oxide layer, the third covering layer 823 is a silicon oxide layer, and the fourth covering layer 824 for the silicon oxide layer. According to some embodiments, the method of forming the fourth covering layer 824 includes but not limited to forming the fourth covering material layer by deposition process, and performing planarization process on the fourth covering material layer by grinding process to form the fourth covering layer 824 . According to some embodiments, the deposition process includes, but is not limited to, chemical chemical vapor deposition, physical vapor deposition, etc., without limitation here. According to some embodiments, the polishing process includes but not limited to chemical mechanical polishing, etc., which is not limited here.

According to some embodiments, after step S530 is completed, the semiconductor substrate in which the devices are formed is bonded to the surface of the second dielectric layer, and then the supporting substrate layer 810 is released to complete the manufacture of the optical antenna.

While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative and exemplary and not restrictive; the disclosure is not limited to the disclosed Example. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps not listed, the indefinite article "a" or "an" does not exclude a plurality, and the term "plurality" means two or more . The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

An optical antenna comprising:

medium layer;

a plurality of antenna structures located in the dielectric layer and spaced apart from each other in a first direction, each antenna structure of the plurality of antenna structures extending along a second direction intersecting the first direction; and

a metal layer located in the dielectric layer opposite to the plurality of antenna structures and extending along the second direction,

Wherein, the metal layer has an uneven surface facing the plurality of antenna structures, so that the first part of the light propagating in each antenna structure of the plurality of antenna structures that is emitted toward the metal layer passes through the The non-planar surface reflects and interferes with a second portion of the light that exits away from the metal layer.
The optical antenna of claim 1, wherein said non-planar surface of said metal layer has a configuration selected from the group consisting of:

The non-flat surface includes a plurality of concave surfaces juxtaposed along the first direction, wherein each concave surface of the plurality of concave surfaces extends along the second direction and is respectively connected to the antenna structures of the plurality of antenna structures. the respective antenna structures are opposite; and

The uneven surface includes a plurality of convex surfaces juxtaposed along the first direction, wherein each convex surface of the plurality of convex surfaces extends along the second direction and is respectively connected to each of the plurality of antennas The antenna structure is relative.
The optical antenna according to claim 2, wherein each of the plurality of concave surfaces and each of the plurality of convex surfaces is an arcuate surface.
The optical antenna as claimed in claim 3, wherein the curvature radius of the arc surface is larger than 314nm.
The optical antenna of claim 1 , wherein the distance between the metal layer and the plurality of antenna structures is configured such that the reflected first portion of the light is separated from the second portion of the light. The optical path difference between the two parts is an integer multiple of the wavelength of the light.
The optical antenna of claim 1, wherein each antenna structure of said plurality of antenna structures includes a body portion extending along said second direction and extending parallel to said first direction and said second direction. A plurality of protruding portions protruding from the body portion in the direction of the defined plane, the plurality of protruding portions being periodically arranged along the second direction.
The optical antenna of claim 1, wherein each of said plurality of antenna structures includes a first antenna layer and a second antenna layer, said first antenna layer and said second antenna layer being perpendicular to are opposite to each other in the direction of the plane defined by the first direction and the second direction, wherein the refractive index of the first antenna layer is greater than or equal to the refractive index of the second antenna layer.
The optical antenna of claim 7, wherein the second antenna layer comprises a plurality of grating structures periodically arranged along the second direction.
The optical antenna of claim 8, wherein a projection of each of said plurality of grating structures onto said first antenna layer exceeds an occupancy of said first antenna layer in said first direction. area.
The optical antenna according to any one of claims 1 to 9, wherein the metal layer comprises at least one selected from the group consisting of titanium nitride, aluminum, copper and gold.
The optical antenna according to any one of claims 1 to 9, wherein the thickness of the metal layer is greater than or equal to 50 nm.
An optical phased array chip, comprising the optical antenna according to any one of claims 1-11.
A method of manufacturing an optical antenna, comprising:

providing a semiconductor-on-insulator substrate comprising a first dielectric layer and a semiconductor layer stacked on each other;

At least by performing a patterning process on the semiconductor layer, a plurality of antenna structures are formed, the plurality of antenna structures are spaced apart from each other in a first direction, each of the plurality of antenna structures is along the extending in a second direction intersecting the first direction; and

forming a second dielectric layer embedded with a metal layer, the second dielectric layer covers the plurality of antenna structures together with the first dielectric layer, wherein the metal layer has a non-conductive layer facing the plurality of antenna structures a flat surface such that a first portion of light propagating in each of the plurality of antenna structures exiting toward the metal layer is reflected by the non-flat surface and is aligned with the light away from the metal layer The second part ejected interferes.
The method according to claim 13, wherein said forming the second dielectric layer embedded with the metal layer comprises:

forming a first covering layer covering the first dielectric layer and the plurality of antenna structures, and a plurality of portions of the first covering layer opposite to the plurality of antenna structures protrude upward;

forming the metal layer at least partially covering the first cover layer; and

A second covering layer covering the metal layer is formed, wherein the first covering layer and the second covering layer form the second dielectric layer.
The method of claim 13, wherein each antenna structure of the plurality of antenna structures comprises a first antenna layer and a second antenna layer,

Wherein, said forming multiple antenna structures includes:

forming a plurality of first antenna layers spaced apart from each other in the first direction by performing a patterning process on the semiconductor layer;

forming a first covering layer covering the first dielectric layer and the plurality of first antenna layers; and

A plurality of second antenna layers are formed on the first cover layer, and each second antenna layer faces each first antenna layer in a direction perpendicular to a plane defined by the first direction and the second direction , the refractive index of the first antenna layer is greater than or equal to the refractive index of the second antenna layer, and

Wherein, said forming the second dielectric layer embedded with the metal layer includes:

forming a second covering layer covering the first covering layer and the plurality of second antenna layers;

performing a patterning process on the second cover layer to form a plurality of ridges spaced apart from each other in the first direction, and every two adjacent ridges in the plurality of ridges are located at the plurality of first on both sides of a corresponding second antenna layer of the two antenna layers;

forming a third covering layer on the patterned second covering layer, the third covering layer comprising a plurality of protrusions corresponding to the plurality of ridges respectively;

forming the metal layer at least partially covering the third cover layer; and

A fourth covering layer covering the metal layer is formed, wherein the first covering layer, the second covering layer, the third covering layer and the fourth covering layer form the second dielectric layer.