Optical device and method of manufacturing the same

Abstract

The application discloses an optical device and a manufacturing method thereof. The first semiconductor device in the optical device comprises a first semiconductor layer, a first active part, a second semiconductor layer, a first spacer part and a first electric connection part which are arranged in a stack, the second semiconductor layer comprises a first protruding part and a first groove, the first spacer part is arranged in the first groove, two ends of the first electric connection part are connected with the first protruding part and the first spacer part respectively, and the first electric connection part, the first spacer part and the first semiconductor layer enclose a first cavity. The application forms the first cavity between the first electric connection part and the second semiconductor layer, reduces the thickness of the second semiconductor layer corresponding to the first cavity, and makes the first electric connection part and the second semiconductor layer corresponding to the first cavity arranged in a non-contact mode, so that the distance between the first electric connection part and the second semiconductor layer is increased, the parasitic capacitance between the first electric connection part and the second semiconductor layer is reduced, and the sensitivity of the semiconductor device is improved.

Description

Technical Field

[0001] This application relates to the field of optical technology, and in particular to an optical device and a method for manufacturing the same. Background Technology

[0002] Electro-absorption modulated lasers are widely used in telecommunications systems, for example, in high-performance, low-cost optical device modules used in applications such as high-capacity, high-speed optical access networks.

[0003] Current standard high-speed electroabsorption modulated lasers (EMLs) typically include a distributed feedback (DFB) laser and an electroabsorption modulator (EAM). The optical device usually consists of a stacked n-type semiconductor layer, an active layer, a p-type semiconductor layer, and electrode layers positioned on either side of the n-type and p-type semiconductor layers. However, under current high-frequency and high-speed conditions, the parasitic capacitance between the p-type semiconductor layer and the contacting electrode layer in standard high-speed EMLs is excessive, leading to a decrease in the sensitivity of the optical device at high frequencies and reducing its optical performance. Summary of the Invention

[0004] This application provides an optical device and its fabrication method to solve the technical problem of reduced sensitivity in current electroabsorption modulated lasers due to excessive parasitic capacitance.

[0005] To address the above issues, the technical solution provided in this application is as follows:

[0006] This application discloses an optical device, the optical device comprising a first semiconductor device; wherein the first semiconductor device comprises:

[0007] First semiconductor layer;

[0008] A first active portion is disposed on one side of the first semiconductor layer;

[0009] A second semiconductor layer is disposed on the side of the first active portion away from the first semiconductor layer. The second semiconductor layer includes a first protrusion and a first groove disposed on both sides of the first protrusion.

[0010] A first spacer portion is disposed within the first groove, and the first spacer portion and the first protrusion portion are disposed separately; and

[0011] A first electrical connection portion is disposed on the side of the second semiconductor layer away from the first active portion. A first end of the first electrical connection portion is connected to the first protrusion, and a second end of the first electrical connection portion is connected to the first spacer portion.

[0012] The first electrical connection portion, the first spacer portion, and the first semiconductor layer form a first cavity.

[0013] In the optical device of this application, the size of the first cavity in a first direction is greater than or equal to the size of the first protrusion in the first direction, and the first direction is parallel to the direction from the first semiconductor layer to the second semiconductor layer.

[0014] In the optical device of this application, in the direction from the first active portion to the second semiconductor layer, the difference between the thickness of the first spacer portion and the thickness of the first protrusion is less than or equal to a first threshold.

[0015] In the optical device of this application, the optical device includes a second semiconductor device disposed on one side of the first semiconductor device, the second semiconductor device comprising:

[0016] The first semiconductor layer;

[0017] The second active part is disposed on the same layer as the first active part and is insulated from it;

[0018] The second semiconductor layer includes a second protrusion and a second groove disposed on both sides of the second protrusion;

[0019] A second spacer portion is disposed within the second groove, and the second spacer portion and the second protrusion portion are disposed separately; and

[0020] The second electrical connection portion is insulated from the first electrical connection portion. The first end of the second electrical connection portion is connected to the second protrusion, and the second end of the second electrical connection portion is connected to the second spacer portion.

[0021] The second electrical connection portion, the second spacer portion, and the second semiconductor layer form a second cavity, the first cavity and the second cavity are continuously arranged, and the volume of the first cavity is smaller than the volume of the second cavity.

[0022] In the optical device of this application, the contact area between the second electrical connection portion and the second spacer portion is greater than the contact area between the first electrical connection portion and the first spacer portion.

[0023] In the optical device of this application, the second semiconductor layer further includes a first isolation portion disposed between the first protrusion and the second protrusion, wherein the first protrusion is insulated from the second protrusion by the first isolation portion.

[0024] In the optical device of this application, the size of the first cavity in a first direction is larger than the size of the second cavity in the first direction, and the first direction is parallel to the direction from the first semiconductor layer to the second semiconductor layer.

[0025] In the optical device of this application, the minimum distance between the first septum and the first protrusion is smaller than the minimum distance between the second septum and the second protrusion.

[0026] In the optical device of this application, the optical device includes a third semiconductor device disposed on the side of the first semiconductor device away from the second semiconductor device, the third semiconductor device comprising:

[0027] The first semiconductor layer;

[0028] The third active part is disposed on the same layer as the first active part and the second active part and is insulated therefrom;

[0029] The second semiconductor layer includes a third protrusion and third grooves disposed on both sides of the third protrusion;

[0030] A third spacer portion is disposed within the third groove, and the third spacer portion and the third protrusion portion are disposed separately; and

[0031] The third electrical connection portion is insulated from the first electrical connection portion and the second electrical connection portion. The first end of the third electrical connection portion is connected to the third protrusion, and the second end of the third electrical connection portion is connected to the third spacer portion.

[0032] The third electrical connection portion, the third spacer portion, and the third protrusion portion form a third cavity. The third cavity, the first cavity, and the second cavity are continuously arranged. The contact area between the third electrical connection portion and the third spacer portion is less than or equal to the contact area between the first electrical connection portion and the first spacer portion.

[0033] This application also proposes a method for fabricating an optical device, comprising:

[0034] A stacked structure is provided, comprising a first semiconductor layer, a first active portion, and a second semiconductor layer in a stacked configuration;

[0035] The second semiconductor layer is patterned to form a semiconductor patterned layer including a first protrusion and a first groove disposed on both sides of the first protrusion;

[0036] A first spacer portion is formed in the first groove, and the first spacer portion and the first protrusion portion are disposed separately.

[0037] A first photoresist layer is formed on the semiconductor patterned layer. The first photoresist layer is patterned to remove the photoresist material corresponding to the first protrusion and the first spacer portion.

[0038] A first metal layer and a second photoresist layer are sequentially formed on the stacked structure. The second photoresist layer is patterned to remove the photoresist material in the overlapping area. The overlapping area is the region from the first protrusion to the first spacer.

[0039] A second metal layer is formed in the overlapping area, and the first metal layer outside the overlapping area is removed, so that the second metal layer and the first metal layer in the overlapping area constitute a first electrical connection portion, the first end of the first electrical connection portion is connected to the first protrusion portion, and the second end of the first electrical connection portion is connected to the first spacer portion.

[0040] The remaining first photoresist layer is removed, and the first electrical connection portion, the first spacer portion, and the first semiconductor layer form a first cavity.

[0041] Beneficial effects: By forming a first cavity between the first electrical connection portion and the second semiconductor layer, this application reduces the thickness of the second semiconductor layer corresponding to the first cavity, while ensuring that the first electrical connection portion and the second semiconductor layer corresponding to the first cavity are not in contact, thereby increasing the distance between the first electrical connection portion and the second semiconductor layer, reducing the parasitic capacitance between the first electrical connection portion and the second semiconductor layer, and improving the sensitivity of the semiconductor device. Attached Figure Description

[0042] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0043] Figure 1 This is a cross-sectional view of the first semiconductor device in the optical device of this application;

[0044] Figure 2 This is a top view of the first type of optical device in this application;

[0045] Figure 3 This is a cross-sectional view of the second semiconductor device in the optical device of this application;

[0046] Figure 4 This is a second top view of the optical device of this application;

[0047] Figure 5This is a cross-sectional view of the third semiconductor device in the optical device of this application;

[0048] Figure 6 This is a third top view of the optical device of this application;

[0049] Figure 7 This is a process flow diagram of the first semiconductor device in the optical device of this application;

[0050] Figures 8a to 8h This is a flowchart illustrating the fabrication process steps of the first semiconductor device in the optical device of this application. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0052] Please see Figures 1 to 6 This application proposes an optical device 100, which includes a first semiconductor device 10; wherein the first semiconductor device 10 may include a first semiconductor layer 110, a first active portion 120, a second semiconductor layer 130, a first spacer portion 140, and a first electrical connection portion 150.

[0053] In this embodiment, the first active portion 120 may be disposed on one side of the first semiconductor layer 110.

[0054] In this embodiment, the second semiconductor layer 130 may be disposed on the side of the first active portion 120 away from the first semiconductor layer 110. The second semiconductor layer 130 includes a first protrusion 131 and a first groove 132 disposed on both sides of the first protrusion 131.

[0055] In this embodiment, the first spacer portion 140 may be disposed within the first groove 132, and the first spacer portion 140 and the first protrusion 131 are disposed separately.

[0056] In this embodiment, the first electrical connection portion 150 may be disposed on the side of the second semiconductor layer 130 away from the first active portion 120, the first end of the first electrical connection portion 150 is connected to the first protrusion 131, and the second end of the first electrical connection portion 150 is connected to the first spacer portion 140.

[0057] In this embodiment, the first electrical connection portion 150, the first spacer portion 140, and the first semiconductor layer 110 form a first cavity 160.

[0058] This application reduces the thickness of the second semiconductor layer 130 corresponding to the first cavity 130 by forming a first cavity 160 between the first electrical connection portion 150 and the second semiconductor layer 130. At the same time, it makes the first electrical connection portion 150 and the second semiconductor layer 130 corresponding to the first cavity 160 non-contact, increases the distance between the first electrical connection portion 150 and the second semiconductor layer 130, reduces the parasitic capacitance between the first electrical connection portion 150 and the second semiconductor layer 130, and improves the sensitivity of the semiconductor device.

[0059] It should be noted that the first semiconductor device 10 can be one of a distributed feedback laser, an electroabsorption modulator, and a semiconductor amplifier. The following description will take the first semiconductor device 10 as an electroabsorption modulator as an example.

[0060] It should be noted that the structure of the optical device 100 in this application is not specifically limited, and it is applicable to structures with excessively large parasitic capacitance between the connecting electrodes and the corresponding semiconductor layers. The following embodiments use... Figure 1 The technical solution of this application will be described using the structure in the example.

[0061] The technical solution of this application will now be described in conjunction with specific embodiments.

[0062] Please see Figure 1 and Figure 2 The first semiconductor device 10 may include a substrate 170, a first electrode layer 180 disposed on the substrate 170, a first semiconductor layer 110 disposed on the first electrode layer 180, a first active portion 120 disposed on the first semiconductor layer 110, a second semiconductor layer 130 disposed on the first active portion 120, a first spacer portion 140 disposed in the second semiconductor layer 130, and a first electrical connection portion 150 disposed on the second semiconductor layer 130.

[0063] In this embodiment, the substrate 170 is an insulating substrate, and the specific material is not limited in this application.

[0064] In this embodiment, the first electrode layer 180 includes a first electrode portion 181 and a second electrode portion 182. The first semiconductor layer 110, the first active portion 120, and the second semiconductor layer 130 are all disposed on the first electrode portion 181. The material of the first electrode layer 180 can be one or more of titanium, platinum, gold, or other highly conductive metals.

[0065] In this embodiment, the first semiconductor layer 110 can be an n-type semiconductor layer, the second semiconductor layer 130 can be a p-type semiconductor layer, and the materials of the first semiconductor layer 110 and the second semiconductor layer 130 can include indium phosphide.

[0066] In this embodiment, the first active portion 120 is disposed between the first semiconductor layer 110 and the second semiconductor layer 130. The first active portion 120 may also be a quantum well layer, which may include a multilayer composition of indium gallium arsenide, etc.

[0067] In this embodiment, the dimensions of the first grooves 132 on both sides of the first protrusion 131 may be the same or different, which is not limited here, but can be limited according to specific size requirements.

[0068] In this embodiment, the first electrical connection portion 150 can be another electrode layer of the first semiconductor device 10. The first electrical connection portion 150 is electrically connected to the second electrode portion 182 of the first electrode layer 180 through the gold wire 200. The material of the first electrical connection portion 150 can be the same as the material of the first electrode layer 180.

[0069] In this embodiment, the first electrode layer 180 can be the negative terminal of the first semiconductor device 10, and the first electrical connection portion 150 can be the positive terminal of the first semiconductor device 10.

[0070] In this embodiment, the coefficient of thermal expansion of the substrate 170 needs to match the coefficients of thermal expansion of the first semiconductor layer 110, the second semiconductor layer 130, and the first active portion 120. For example, the coefficient of thermal expansion of indium phosphide is 4.6 ppm / ℃, and the coefficient of thermal expansion of indium gallium arsenide is 5.7 ppm / ℃. Therefore, the coefficient of thermal expansion of the substrate 170 needs to match both of them. For example, the coefficient of thermal expansion of the substrate 170 can be from 4 ppm / ℃ to 6 ppm / ℃.

[0071] In this embodiment, the first spacer portion 140 is made of an insulating material, such as silicon dioxide; the first electrical connection portion 150 is connected to the first protrusion 131 and the first spacer portion 140 respectively. Since the first spacer portion 140 is made of an insulating material, the first electrical connection portion 150 and the first spacer portion 140 are insulated from each other, and the first electrical connection portion 150 is electrically connected to the first active portion 120 only through the first protrusion 131.

[0072] In the optical device 100 of this application, please refer to Figure 1The size of the first cavity 160 in the first direction is greater than or equal to the size of the first protrusion 131 in the first direction, and the first direction is parallel to the direction from the first semiconductor layer 110 to the second semiconductor layer 130.

[0073] In this embodiment, due to the presence of the first cavity 160, the first electrical connection portion 150 is supported only by the first protrusion 131 and the first spacer portion 140, and the middle portion of the first electrical connection portion 150 is not supported. If the dimension of the first cavity 160 in the first direction is smaller than the dimension of the first protrusion 131 in the first direction, the center of gravity of the first electrical connection portion 150 will be located within the first cavity 160, making the first electrical connection portion 150 susceptible to breakage. This application, however, sets the first electrical connection portion 150 in an arch shape, decomposing part of the vertical gravity into horizontal compressive stress, thus reducing the risk of breakage. The risk of breakage of the first electrical connection 150 is reduced, thus improving the stability of the first electrical connection 150. At the same time, in order to reduce the parasitic capacitance between the first electrical connection 150 and the second semiconductor layer 130, the first electrical connection 150 should be as far away from the second semiconductor layer 130 as possible. Therefore, by making the size of the first cavity 160 in the first direction larger than or equal to the size of the first protrusion 131 in the first direction, this application not only ensures the stability of the first electrical connection 150 but also reduces the parasitic capacitance between the first electrical connection 150 and the second semiconductor layer 130, further improving the response capability of the first semiconductor device 10.

[0074] In this embodiment, when the first electrical connection portion 150 is formed using a metal material with good toughness, the size of the first cavity 160 in the first direction can be smaller than the size of the first protrusion 131 in the first direction, while ensuring that the parasitic capacitance between the first electrical connection portion 150 and the second semiconductor layer 130 is within the allowable range of the semiconductor device.

[0075] In the optical device 100 of this application, please refer to Figure 1 In the direction from the first active portion 120 to the second semiconductor layer 130, the difference between the thickness of the first spacer portion 140 and the thickness of the first protrusion 131 is less than or equal to a first threshold.

[0076] In this embodiment, the first electrical connection portion 150 can be formed by electroplating. During the electroplating process, the metal film layers formed in the electroplating area are all of equal thickness. Therefore, if the difference between the thickness of the first protrusion 131 and the thickness of the first spacer portion 140 is large, it will result in a large step difference between the two contact ends of the first electrical connection portion 150, affecting the stability of the first electrical connection portion 150.

[0077] In this embodiment, the first threshold can be 1 micrometer.

[0078] In this embodiment, the thickness of the first spacer portion 140 can be equal to the thickness of the first protrusion portion 131.

[0079] Please see Figure 1 and Figure 2 The depth of the first groove 132 can be the same as the thickness of the second semiconductor layer 130, that is, the second semiconductor layer 130 corresponding to the first groove 132 is hollowed out, and the first active part 120 is exposed in the first groove 132. Therefore, the first semiconductor device 10 of this application also includes a whole thin film insulating layer 190 disposed on the second semiconductor layer 130.

[0080] In this embodiment, the material of the thin film insulating layer 190 can be the same as the material of the first spacer portion 140.

[0081] In this embodiment, the thin film insulating layer 190 covers the inner wall of the first groove 132 and the surface of the second semiconductor layer 130 away from the first active portion 120; in addition, the thin film insulating layer 190 corresponding to the first end of the first electrical connection portion 150 is etched so that the first end of the first electrical connection can be electrically connected to the first protrusion 131; the thin film insulating layer 190 corresponding to the second end of the first electrical connection can also be etched so that there is a step difference between the thin film insulating layer 190 near the gold wire 200 and the first spacer portion 140.

[0082] In this embodiment, the thin film insulating layer 190 corresponding to the second end of the first electrical connection portion 150 can also be retained, and can be set according to the process and the thickness of the first spacer portion 140.

[0083] In this embodiment, the shapes of the first grooves 132 on both sides of the first protrusion 131 may be different, for example... Figure 2 As shown in the structure, the first groove 132 on the side closer to the gold wire 200 also has a groove for placing the first spacer portion 140, while the first groove 132 on the side away from the gold wire 200 does not have a corresponding structure.

[0084] In the optical device 100 of this application, please refer to Figure 3 and Figure 4 The optical device 100 includes a second semiconductor device 20 disposed on one side of the first semiconductor device 10, and the second semiconductor device 20 may be a distributed feedback laser.

[0085] In this embodiment, the second semiconductor device 20 includes a stacked structure of the substrate 170, the second electrode layer 280, the first semiconductor layer 110, the second active portion 220, the second semiconductor layer 130, the second spacer portion 240, and the second electrical connection portion 250. The film layer in the stacked structure can be formed in the same process as the corresponding film layer in the first semiconductor device 10, and the substrate 170, the first semiconductor layer 110, and the second semiconductor layer 130 can be shared.

[0086] In this embodiment, the second active portion 220 may be disposed on the same layer as the first active portion 120 and insulated from it; the second semiconductor layer 130 may include a second protrusion 231 and a second groove 232 disposed on both sides of the second protrusion 231; the second spacer portion 240 may be disposed in the second groove 232, and the second spacer portion 240 and the second protrusion 231 are disposed separately; the second electrical connection portion 250 is insulated from the first electrical connection portion 150, the first end of the second electrical connection portion 250 is connected to the second protrusion 231, and the second end of the second electrical connection portion 250 is connected to the second spacer portion 240.

[0087] In this embodiment, the second electrical connection portion 250, the second spacer portion 240, and the second semiconductor layer 130 form a second cavity 260, and the first cavity 160 and the second cavity 260 can be arranged continuously or discontinuously.

[0088] In this embodiment, the volume of the first cavity 160 is smaller than the volume of the second cavity 260; to ensure the performance of the distributed feedback laser, the distributed feedback laser and the electroabsorption modulator differ in design size, with the distributed feedback laser occupying a larger size in the optical device 100 than the electroabsorption modulator. Figure 3 In the structure, the projected area of ​​the first electrical connection portion 150 on the substrate 170 is smaller than the projected area of ​​the second electrical connection portion 250 on the substrate 170, and the corresponding volume of the first cavity 160 is also smaller than the volume of the second cavity 260.

[0089] In the optical device 100 of this application, please refer to Figure 3 and Figure 4 The contact area between the second electrical connection portion 250 and the second spacer portion 240 is greater than the contact area between the first electrical connection portion 150 and the first spacer portion 140.

[0090] In this embodiment, in order to ensure that the forces borne by both ends of the second electrical connection portion 250 are the same, the contact area between the second electrical connection portion 250 and the second spacer portion 240 needs to match the overlap area between the second electrical connection portion 250 and the second protrusion 231. Since the projected area of ​​the first electrical connection portion 150 on the substrate 170 is smaller than the projected area of ​​the second electrical connection portion 250 on the substrate 170, the contact area between the second electrical connection portion 250 and the second spacer portion 240 needs to be larger than the contact area between the first electrical connection portion 150 and the first spacer portion 140 to improve the stability of the second electrical connection portion 250.

[0091] In the optical device 100 of this application, please refer to Figure 3 and Figure 4 The second semiconductor layer 130 may further include a first isolation portion 133 disposed between the first protrusion 131 and the second protrusion 231, wherein the first protrusion 131 is insulated from the second protrusion 231 by the first isolation portion 133.

[0092] In this embodiment, the first isolation portion 133 can be a hollow portion, that is, equivalent to a cavity being provided between the first protrusion 131 and the second protrusion 231, and the first protrusion 131 and the second protrusion 231 being air-isolated; or, the first isolation portion 133 can be an insulating material to isolate the first protrusion 131 and the second protrusion 231, and avoid interference between the p-contact terminals in the first semiconductor device 10 and the second semiconductor device 20.

[0093] Under the existing high-frequency and high-speed operating conditions, since the distributed feedback laser is controlled by an electro-absorption modulator, the device effect of the electro-absorption modulator will directly affect the device effect of the entire optical device. Therefore, the parasitic capacitance generated at the p-contact has a greater impact on the device effect of the electro-absorption modulator than on the device effect of the distributed feedback laser.

[0094] In the optical device 100 of this application, please refer to Figure 3 and Figure 4 The dimension y1 of the first cavity 160 in the first direction is greater than the dimension y2 of the second cavity 260 in the first direction, and the first direction is parallel to the direction from the first semiconductor layer 110 to the second semiconductor layer 130. That is, the distance y1 between the first electrical connection portion 150 and the corresponding region of the second semiconductor layer 130 is greater than the distance y2 between the second electrical connection portion 250 and the corresponding region of the second semiconductor layer 130, further reducing the parasitic capacitance between the first electrical connection portion 150 and the corresponding region of the second semiconductor layer 130, and improving the response capability of the first semiconductor device 10.

[0095] In the optical device 100 of this application, the minimum distance x1 between the first spacer portion 140 and the first protrusion 131 can be smaller than the minimum distance x2 between the second spacer portion 240 and the second protrusion 231. Since both ends of the first electrical connection portion 150 are connected to the first spacer portion 140 and the first protrusion 131 respectively, the reduction in the minimum distance x1 between the first spacer portion 140 and the first protrusion 131 is equivalent to reducing the size of the first electrical connection portion 150 in that direction, thereby reducing the relative area between the first electrical connection portion 150 and the corresponding area of ​​the second semiconductor layer 130, that is, reducing the parasitic capacitance between the first electrical connection portion 150 and the corresponding area of ​​the second semiconductor layer 130, and improving the response capability of the first semiconductor device 10.

[0096] In the optical device 100 of this application, please refer to Figure 5 and Figure 6 The optical device 100 includes a third semiconductor device 30 disposed on the side of the first semiconductor device 10 away from the second semiconductor device 20, and the third semiconductor device 30 may be a semiconductor amplifier.

[0097] In this embodiment, the third semiconductor device 30 includes a stacked structure of the substrate 170, the third electrode layer 380, the first semiconductor layer 110, the third active portion 320, the second semiconductor layer 130, the third spacer portion 340, and the third electrical connection portion 350. The film layer in the stacked structure can be formed in the same process as the corresponding film layer in the first semiconductor device 10 and the second semiconductor device 20, and the substrate 170, the first semiconductor layer 110, and the second semiconductor layer 130 can be shared.

[0098] In this embodiment, the third active portion 320 is disposed on the same layer as the first active portion 120 and the second active portion 220 and is insulated therefrom; the second semiconductor layer 130 may include a third protrusion 331 and a third groove 332 disposed on both sides of the third protrusion 331; the third spacer portion 340 may be disposed in the third groove 332, and the third spacer portion 340 and the third protrusion 331 are disposed separately; the third electrical connection portion 350 is insulated from the first electrical connection portion 150 and the second electrical connection portion 250, the first end of the third electrical connection portion 350 is connected to the third protrusion 331, and the second end of the third electrical connection portion 350 is connected to the third spacer portion 340.

[0099] In this embodiment, the third electrical connection portion 350, the third spacer portion 340, and the third protrusion form a third cavity 360, and the third cavity 360 is arranged continuously or discontinuously with the first cavity 160 and the second cavity 260.

[0100] In this embodiment, the contact area between the third electrical connection portion 350 and the third spacer portion 340 is less than or equal to the contact area between the first electrical connection portion 150 and the first spacer portion 140.

[0101] In this embodiment, please refer to Figure 5 and Figure 6 The second semiconductor layer 130 may further include a second isolation portion 134 disposed between the first protrusion 131 and the third protrusion 331, wherein the first protrusion 131 is insulated from the third protrusion 331 by the second isolation portion 134.

[0102] In this embodiment, the second isolation portion 134 can be a hollow portion, that is, equivalent to a cavity being provided between the first protrusion 131 and the third protrusion 331, and the first protrusion 131 and the third protrusion 331 being air-isolated; or, the second isolation portion 134 can be an insulating material to isolate the first protrusion 131 and the third protrusion 331, thereby avoiding interference between the p-contact terminals in the first semiconductor device 10 and the third semiconductor device 30.

[0103] In this embodiment, the first isolation portion 133 and the second isolation portion 134 can be made of the same material.

[0104] In this embodiment, the dimension y1 of the first cavity 160 in the first direction can be greater than or equal to the dimension y3 of the third cavity 360 in the first direction.

[0105] In this embodiment, the minimum distance x1 between the first spacer portion 140 and the first protrusion 131 can be less than or equal to the minimum distance x3 between the third spacer portion 240 and the third protrusion 331.

[0106] This application reduces the thickness of the second semiconductor layer 130 corresponding to the cavity by forming a cavity between the electrical connection portion of at least one of the distributed feedback laser, the electroabsorption modulator, and the semiconductor amplifier and the second semiconductor layer 130. At the same time, by making the electrical connection portion non-contact with the second semiconductor layer 130 corresponding to the cavity, the distance between the electrical connection portion and the second semiconductor layer 130 is increased, the parasitic capacitance between the electrical connection portion and the second semiconductor layer 130 is reduced, and the sensitivity of the semiconductor device is improved.

[0107] Please see Figure 7This application also proposes a method for manufacturing an optical device 100, which includes:

[0108] S10, a stacked structure is provided consisting of a first semiconductor layer 110, a first active portion 120, and a second semiconductor layer 130.

[0109] In this step, please refer to Figure 8a In the stacked structure, the first semiconductor layer 110 can be an n-type semiconductor layer, and the second semiconductor layer 130 can be a p-type semiconductor layer. The materials of the first semiconductor layer 110 and the second semiconductor layer 130 can include indium phosphide. The first active part 120 can be disposed between the first semiconductor layer 110 and the second semiconductor layer 130. The first active part 120 can also be a quantum well layer, which can include a multilayer composition of indium gallium arsenide, etc.

[0110] S20, the second semiconductor layer 130 is patterned to form a semiconductor patterned layer including a first protrusion 131 and a first groove 132 disposed on both sides of the first protrusion 131;

[0111] In this step, please refer to Figure 8b The second semiconductor layer 130 can be formed by processes such as coating photoresist, exposing the photoresist, developing, etching the second semiconductor layer 130, and stripping the patterned photoresist to create a semiconductor pattern layer including a first protrusion 131 and first grooves 132 disposed on both sides of the first protrusion 131. The semiconductor material corresponding to the first groove 132 can be completely or partially etched. Figure 8b The structure in the image is completely etched.

[0112] S30, a first spacer portion 140 is formed in the first groove 132, and the first spacer portion 140 and the first protrusion 131 are separately disposed;

[0113] In this step, please refer to Figure 8b A whole layer of spacer material is formed on the second semiconductor layer 130. After patterning, the spacer material located in the first groove 132 and close to the second electrode 182 is retained to form the first spacer 140. The spacer material can be an insulating material such as silicon dioxide.

[0114] Following this step, the process may further include forming a thin film insulating layer 190 on the stacked structure to protect the second semiconductor layer 130, wherein the thickness of the thin film insulating layer 190 is much smaller than the thickness of the first spacer portion 140.

[0115] S40, a first photoresist layer 210 is formed on the semiconductor patterned layer. The first photoresist layer 210 is patterned to remove the photoresist material corresponding to the first protrusion 131 and the first spacer portion 140.

[0116] In this step, please refer to Figure 8c The first photoresist layer 210 undergoes an exposure and development process to remove the photoresist material corresponding to the first protrusion 131 and the first septum portion 140, thereby exposing the first protrusion 131 and the first septum portion 140.

[0117] S50, a first metal layer 220 and a second photoresist layer 230 are sequentially formed on the stacked structure. The second photoresist layer 230 is patterned and the photoresist material in the overlapping area AA is removed. The overlapping area AA is the area from the first protrusion 131 to the first spacer 140.

[0118] In this step, please refer to Figure 8e The first metal layer 220 is deposited in its entirety, and the second photoresist layer 230 undergoes exposure and development processes to remove the photoresist material in the overlapping area AA, so that the first metal layer 220 in the overlapping area AA is exposed.

[0119] S60, a second metal layer 240 is formed in the overlapping area AA, and the first metal layer 220 outside the overlapping area AA is removed, so that the second metal layer 240 and the first metal layer 220 in the overlapping area AA constitute a first electrical connection portion 150, the first end of the first electrical connection portion 150 is connected to the first protrusion 131, and the second end of the first electrical connection portion 150 is connected to the first spacer portion 140;

[0120] In this step, please refer to Figure 8f First, a second metal layer 240 can be formed in the overlapping area AA using processes such as electroplating. The thickness of the second metal layer 240 is much greater than the thickness of the first metal layer 220. Second, the photoresist material outside the overlapping area AA can be removed to expose the first metal layer 220 outside the overlapping area AA. Finally, the exposed first metal layer 220 and second metal layer 240 are etched using an etching process. After the first metal layer 220 outside the overlapping area AA is removed, the etching of the second metal layer 240 is stopped, so that the second metal layer 240 and the first metal layer 220 in the overlapping area AA form a first electrical connection portion 150.

[0121] S70, the remaining first photoresist layer 210 is removed, and the first electrical connection portion 150, the first spacer portion 140 and the first semiconductor layer 110 form a first cavity 160.

[0122] In this step, please refer to Figure 8g The remaining first photoresist layer 210 is removed using a photoresist stripping solution, so that a first cavity 160 is formed between the first electrical connection portion 150 and the corresponding region of the second semiconductor layer 130.

[0123] S80, a first electrode portion 181 is formed on the side of the first semiconductor layer 110 opposite to the second semiconductor layer 130, and a first electrode portion 181 and a second electrode portion 182 are simultaneously formed on the substrate 170. The first electrode portion 181 on the substrate and the first electrode portion 181 on the stacked structure are aligned and bonded to bond the stacked structure and the substrate 170, thereby electrically connecting the first electrode portion 181 and the second electrode portion 182. A gold wire 200 is provided between the first electrical connection portion 150 and the second electrode portion 182 to electrically connect the first electrical connection portion 150 and the second electrode portion 182, thereby forming an attachment. Figure 8h The structure.

[0124] In this step, because Figure 8h The figure shows a cross-sectional view. The first electrode portion 181 and the second electrode portion 182 are separated, but from the top view, the first electrode portion 181 and the second electrode portion 182 are electrically connected.

[0125] In this embodiment, when the process of the first semiconductor device 10 is completed, the processes of the second semiconductor device 20 and the third semiconductor device 30 can be carried out simultaneously. The specific processes and structures can refer to the process and structure of the first semiconductor device 10.

[0126] Finally, due to the appendix Figures 8a to 8h The process shown in the diagram only illustrates the fabrication process for one semiconductor device. However, in actual wafer fabrication, multiple semiconductor devices are typically fabricated simultaneously. Therefore, this wafer structure is diced to form multiple semiconductor devices, and the substrate 170 is bonded to the corresponding semiconductor devices to form an attached structure. Figure 8g The structure in.

[0127] In this embodiment, the coefficient of thermal expansion of the substrate 170 needs to match the coefficients of thermal expansion of the first semiconductor layer 110, the second semiconductor layer 130, and the first active portion 120. For example, the coefficient of thermal expansion of indium phosphide in the first or second semiconductor layer is 4.6 ppm / ℃, and the coefficient of thermal expansion of indium gallium arsenide in the first active portion is 5.7 ppm / ℃. Therefore, the coefficient of thermal expansion of the substrate 170 needs to match both of them. For example, the coefficient of thermal expansion of the substrate 170 can be from 4 ppm / ℃ to 6 ppm / ℃.

[0128] This application discloses an optical device and its fabrication method. The first semiconductor device in the optical device includes a first semiconductor layer, a first active portion, a second semiconductor layer, a first spacer portion, and a first electrical connection portion stacked together. The second semiconductor layer includes a first protrusion and a first groove. The first spacer portion is disposed in the first groove. The two ends of the first electrical connection portion are respectively connected to the first protrusion and the first spacer portion. The first electrical connection portion, the first spacer portion, and the first semiconductor layer form a first cavity. By forming a first cavity between the first electrical connection portion and the second semiconductor layer, this application reduces the thickness of the second semiconductor layer corresponding to the first cavity. At the same time, it makes the first electrical connection portion and the second semiconductor layer corresponding to the first cavity non-contact, increases the distance between the first electrical connection portion and the second semiconductor layer, reduces the parasitic capacitance between the first electrical connection portion and the second semiconductor layer, and improves the sensitivity of the semiconductor device.

[0129] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0130] The foregoing has provided a detailed description of an optical device and its manufacturing method according to the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An optical device, characterized in that, The optical device includes a first semiconductor device; wherein the first semiconductor device includes: First semiconductor layer; A first active portion is disposed on one side of the first semiconductor layer; A second semiconductor layer is disposed on the side of the first active portion away from the first semiconductor layer. The second semiconductor layer includes a first protrusion and a first groove disposed on both sides of the first protrusion. A first spacer portion is disposed within the first groove, and the first spacer portion and the first protrusion portion are disposed separately; and A first electrical connection portion is disposed on the side of the second semiconductor layer away from the first active portion. A first end of the first electrical connection portion is connected to the first protrusion, and a second end of the first electrical connection portion is connected to the first spacer portion. The first electrical connection portion, the first spacer portion, and the first semiconductor layer form a first cavity.

2. The optical device according to claim 1, characterized in that, The size of the first cavity in the first direction is greater than or equal to the size of the first protrusion in the first direction, and the first direction is parallel to the direction from the first semiconductor layer to the second semiconductor layer.

3. The optical device according to claim 1, characterized in that, In the direction from the first active portion to the second semiconductor layer, the difference between the thickness of the first spacer portion and the thickness of the first protrusion is less than or equal to a first threshold.

4. The optical device according to any one of claims 1 to 3, characterized in that, The optical device includes a second semiconductor device disposed on one side of the first semiconductor device, the second semiconductor device comprising: The first semiconductor layer; The second active part is disposed on the same layer as the first active part and is insulated from it; The second semiconductor layer includes a second protrusion and a second groove disposed on both sides of the second protrusion; A second spacer portion is disposed within the second groove, and the second spacer portion and the second protrusion portion are disposed separately; and The second electrical connection portion is insulated from the first electrical connection portion. The first end of the second electrical connection portion is connected to the second protrusion, and the second end of the second electrical connection portion is connected to the second spacer portion. The second electrical connection portion, the second spacer portion, and the second semiconductor layer form a second cavity. The first cavity and the second cavity are arranged continuously or discontinuously, and the volume of the first cavity is smaller than the volume of the second cavity.

5. The optical device according to claim 4, characterized in that, The contact area between the second electrical connection portion and the second spacer portion is greater than the contact area between the first electrical connection portion and the first spacer portion.

6. The optical device according to claim 4, characterized in that, The second semiconductor layer further includes a first isolation portion disposed between the first protrusion and the second protrusion, wherein the first protrusion is insulated from the second protrusion by the first isolation portion.

7. The optical device according to claim 4, characterized in that, The size of the first cavity in the first direction is larger than the size of the second cavity in the first direction, and the first direction is parallel to the direction from the first semiconductor layer to the second semiconductor layer.

8. The optical device according to claim 4, characterized in that, The minimum distance between the first septum and the first protrusion is less than the minimum distance between the second septum and the second protrusion.

9. The optical device according to claim 4, characterized in that, The optical device includes a third semiconductor device disposed on the side of the first semiconductor device away from the second semiconductor device, the third semiconductor device comprising: The first semiconductor layer; The third active part is disposed on the same layer as the first active part and the second active part and is insulated therefrom; The second semiconductor layer includes a third protrusion and third grooves disposed on both sides of the third protrusion; A third spacer portion is disposed within the third groove, and the third spacer portion and the third protrusion portion are disposed separately; and The third electrical connection portion is insulated from the first electrical connection portion and the second electrical connection portion. The first end of the third electrical connection portion is connected to the third protrusion, and the second end of the third electrical connection portion is connected to the third spacer portion. The third electrical connection portion, the third spacer portion, and the third protrusion portion form a third cavity. The third cavity, the first cavity, and the second cavity are continuously arranged. The contact area between the third electrical connection portion and the third spacer portion is less than or equal to the contact area between the first electrical connection portion and the first spacer portion.

10. A method for manufacturing an optical device, characterized in that, include: A stacked structure is provided, comprising a first semiconductor layer, a first active portion, and a second semiconductor layer in a stacked configuration; The second semiconductor layer is patterned to form a semiconductor patterned layer including a first protrusion and a first groove disposed on both sides of the first protrusion; A first spacer portion is formed in the first groove, and the first spacer portion and the first protrusion portion are disposed separately. A first photoresist layer is formed on the semiconductor patterned layer. The first photoresist layer is patterned to remove the photoresist material corresponding to the first protrusion and the first spacer portion. A first metal layer and a second photoresist layer are sequentially formed on the stacked structure. The second photoresist layer is patterned to remove the photoresist material in the overlapping area. The overlapping area is the region from the first protrusion to the first spacer. A second metal layer is formed in the overlapping area, and the first metal layer outside the overlapping area is removed, so that the second metal layer and the first metal layer in the overlapping area constitute a first electrical connection portion, the first end of the first electrical connection portion is connected to the first protrusion portion, and the second end of the first electrical connection portion is connected to the first spacer portion. The remaining first photoresist layer is removed, and the first electrical connection portion, the first spacer portion, and the first semiconductor layer form a first cavity.

Images