Semiconductor device and method for manufacturing the same

Abstract

The present invention discloses a semiconductor device and a method for manufacturing the same. The semiconductor device includes a laser emission structure and a photodetector. The laser emission structure includes an active region that emits a laser beam, a first-type reflector layer located above the active region, and a second-type reflector layer located below the active region; the photodetector is disposed on the laser emission structure and detects the reflected laser beam that is emitted from the active region towards the photodetector and then reflected by the detected object. A cavity is formed in the photodetector. The photodetector includes a third reflector layer that covers the cavity from a side far away from the laser emission structure, and the laser beam is emitted from the third reflector layer. The semiconductor device of the present invention can integrate a vertical cavity surface emitting laser and a photodetector in the vertical direction, enhance the quantum efficiency of the photodetector, enhance the laser gain, and is beneficial to high-power laser output.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor optoelectronic technology, and particularly to a semiconductor device and a method for manufacturing the same. Background Art

[0002] As a semiconductor laser, a vertical cavity surface emitting laser (VCSEL) has the advantages of small size, low power consumption, and easy integration, and is widely used in fields such as three-dimensional sensing, data centers, and optical fiber communication. A vertical cavity surface emitting laser is a semiconductor laser with a new structure that emits laser light perpendicular to the substrate surface. The vertical cavity surface emitting laser can be used in cooperation with a photodetector. The vertical cavity surface emitting laser emits laser light, and the photodetector senses the reflected light beam after the laser light emitted by the vertical cavity surface emitting laser irradiates the object to be detected. In the prior art, the vertical cavity surface emitting laser and the photodetector are independent of each other, which is not conducive to the integration and further miniaturization of the system.

[0003] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes prior art known to those of ordinary skill in the art. Summary of the Invention

[0004] An object of the present invention is to provide a semiconductor device and a method for manufacturing the same, which can integrate a vertical cavity surface emitting laser and a photodetector in the vertical direction, enhance the quantum efficiency of the photodetector, enhance the laser gain, and facilitate high-power laser output.

[0005] To achieve the above object, an embodiment of the present invention provides a semiconductor device, including a laser emission structure and a photodetector. The laser emission structure includes an active region that emits a laser beam, a first type of reflector layer located on the upper side of the active region, and a second type of reflector layer located on the lower side of the active region; the photodetector is disposed on the laser emission structure and detects the reflected laser beam after the laser beam emitted from the active region irradiates the object to be detected in the direction towards the photodetector. A cavity is formed in the photodetector. The photodetector includes a third reflector layer that covers the cavity from the side far away from the laser emission structure, and the laser beam emits from the third reflector layer.

[0006] In one or more embodiments of the present invention, the laser emission structure further includes a first type of contact layer disposed on the side of the first type of reflector layer away from the active region, and the photodetector is disposed on the first type of contact layer.

[0007] In one or more embodiments of the present invention, the vertical projection of the photodetector in the thickness direction of the semiconductor device completely falls within the first type of contact layer, and a first electrode layer is formed on the first type of contact layer outside the photodetector.

[0008] In one or more embodiments of the present invention, the photodetector further includes a first type of semiconductor layer formed on the first type of contact layer, a third type of semiconductor layer formed on a side of the first type of semiconductor layer facing away from the first type of contact layer, a second type of semiconductor layer formed on a side of the third type of semiconductor layer facing away from the first type of semiconductor layer, and a second type of contact layer formed on a side of the second type of semiconductor layer facing away from the third type of semiconductor layer, and a second electrode is formed on the second type of contact layer.

[0009] In one or more embodiments of the present invention, the cavity penetrates through the first type of semiconductor layer, the third type of semiconductor layer, the second type of semiconductor layer, and the second type of contact layer, and the third reflector layer is located on a side of the second type of contact layer facing away from the second type of semiconductor layer and completely covers the cavity.

[0010] In one or more embodiments of the present invention, a substrate is provided on the second type of contact layer, and the third reflector layer is formed on the substrate and located on a side of the substrate facing away from the second type of contact layer.

[0011] In one or more embodiments of the present invention, the substrate is made of a material that does not absorb the lasing wavelength of the laser, preferably a quartz substrate.

[0012] In one or more embodiments of the present invention, the third reflector layer is a DBR layer, wherein the optical thickness A between the surface of the layer structure at the bottom layer facing away from the second type of contact layer and the surface of the first type of contact layer facing away from the first type of semiconductor layer satisfies: (1 / 2)*m*λ, where m is a non-zero natural number and λ is the lasing wavelength of the laser emission structure.

[0013] In one or more embodiments of the present invention, the first type is p-type, the second type is n-type, and the third type is i-type.

[0014] In one or more embodiments of the present invention, the first type is n-type, the second type is p-type, and the third type is i-type.

[0015] In one or more embodiments of the present invention, the second type of reflector layer includes a DBR layer, and the number of periods of the DBR layer is 35 - 50 pairs.

[0016] In one or more embodiments of the present invention, the optical thickness of the active region is (1 / 2 + m)*λ, where λ is the lasing wavelength of the laser emission structure and m is a natural number.

[0017] In one or more embodiments of the present invention, the first type of reflector layer includes a DBR layer, and the number of periods of the DBR layer is 3 - 6 pairs.

[0018] In one or more embodiments of the present invention, the thickness of the first type of contact layer is 50 - 200 nm.

[0019] In one or more embodiments of the present invention, the thickness of the first type of semiconductor layer is 50 - 200 nm.

[0020] In one or more embodiments of the present invention, the thickness of the second type of semiconductor layer is 50 - 200 nm.

[0021] In one or more embodiments of the present invention, the thickness of the third type of semiconductor layer is 500 - 2000 nm.

[0022] In one or more embodiments of the present invention, the thickness of the second type of contact layer is 100 - 200 nm.

[0023] In one or more embodiments of the present invention, the semiconductor device further includes a substrate, the second type of reflector layer is disposed on the substrate, a buffer layer is disposed between the substrate and the second type of reflector layer, and a third electrode electrically connected to the second type of reflector layer is formed on the substrate.

[0024] In one or more embodiments of the present invention, the substrate is a second type of substrate, and the buffer layer is a second type of buffer layer.

[0025] In one or more embodiments of the present invention, the wavelength ranges of the laser emission structure and the photodetector are between 850 nm and 1000 nm, and the lasing wavelength of the laser emission structure is the same as the wavelength of the photodetector.

[0026] Embodiments of the present invention also provide a method for manufacturing a semiconductor device, including:

[0027] Providing a substrate;

[0028] Growing a layer structure constituting a laser emission structure on the substrate, the layer structure including a buffer layer, a second type of reflector layer, an active region, a first type of reflector layer, and a first type of contact layer formed in sequence on the substrate;

[0029] A layer structure constituting a photodetector is grown on the first-type contact layer, and the layer structure includes a first-type semiconductor layer, a third-type semiconductor layer, a second-type semiconductor layer, and a second-type contact layer that are sequentially formed on the first-type contact layer;

[0030] The second-type contact layer, the second-type semiconductor layer, the third-type semiconductor layer, and the first-type semiconductor layer are etched to form an annular platform structure;

[0031] A substrate is disposed on the second-type contact layer;

[0032] A first electrode layer electrically connecting the first-type contact layer is formed on the first-type contact layer, and a second electrode layer electrically connecting the second-type contact layer is formed on the second-type contact layer;

[0033] A third electrode layer electrically connecting the second-type reflector layer is formed on the substrate;

[0034] A third reflector layer is formed on the substrate.

[0035] In one or more embodiments of the present invention, the substrate is made of a material that does not absorb the lasing wavelength of the laser, preferably a quartz substrate. Compared with the prior art, the semiconductor device of the embodiment of the present invention takes into account the performance such as the size and output power of the laser, integrates the detector in the vertical direction, reduces the package size, and has a miniaturized design, and can be applied to a wider range of scenarios.

[0036] The semiconductor device of the embodiment of the present invention can integrate a vertical cavity surface emitting laser and a photodetector in the vertical direction, enhance the quantum efficiency of the photodetector, enhance the laser gain, and is beneficial to high-power laser output.

[0037] The semiconductor device of the embodiment of the present invention reduces the package size of the device, can be widely applied to scenarios such as laser sensing and ranging, increases the cavity length of the active region of the laser emission structure at a lower cost, can effectively improve the laser output power, the reflection characteristics of the first-type reflector layer of the laser emission structure, enhances the reflection ability of the projected light beam, enhances the absorption optical path of the detector, and thereby can effectively increase the absorption efficiency of the photodetector.

[0038] In the semiconductor device according to the embodiment of the present invention, by integrating a photodetector and a laser emission structure in the vertical direction, and constructing the photodetector into a cavity structure located on the laser emission structure, the surface layer of the photodetector is controlled by a third reflector layer to achieve laser output. The first type of reflector layer at the top of the laser emission structure can reflect the electromagnetic wave transmitted through the photodetector again, effectively increasing the light absorption path of the photodetector. The vacuum cavity in the photodetector is used to realize the characteristic of the external cavity growth of the laser emission structure, reduce the series resistance on the side of the first type of reflector layer of the laser emission structure, and improve the gain of the laser emission structure. Description of the Drawings

[0039] Figure 1 is a three-dimensional structural schematic diagram of a semiconductor device according to an embodiment of the present invention;

[0040] Figure 2 is a cross-sectional structural schematic diagram of a semiconductor device according to an embodiment of the present invention;

[0041] Figure 3 is a schematic flow chart of a manufacturing method of a semiconductor device according to an embodiment of the present invention;

[0042] Figures 4A to 4F is a structural schematic diagram of the process steps of a manufacturing method of a semiconductor device corresponding to an embodiment of the present invention. Detailed Embodiments

[0043] The following will describe in detail the specific embodiments of the present invention with reference to the drawings. However, it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0044] Unless otherwise clearly stated, in the whole specification and claims, the term "comprising" or its variations such as "including" or "having" etc. will be understood to include the stated elements or components, without excluding other elements or other components.

[0045] The present invention provides a semiconductor device, including a laser emission structure and a photodetector. The laser emission structure includes an active region for emitting a laser beam, a first type of reflector layer located on the upper side of the active region, and a second type of reflector layer located on the lower side of the active region; the photodetector is disposed on the laser emission structure and detects the reflected laser beam after the laser beam emitted from the active region towards the photodetector is reflected by the detected object. A cavity is formed in the photodetector. The photodetector includes a third reflector layer covering the cavity from the side far away from the laser emission structure, and the laser beam is emitted from the third reflector layer.

[0046] The present invention integrates a vertical cavity surface emitting laser (laser emission structure) and a photodetector in the vertical direction, enhancing the quantum efficiency of the photodetector, increasing monochromaticity, enhancing laser gain, and facilitating high-power laser output.

[0047] The semiconductor device of the present invention will be elaborated in detail below in conjunction with specific embodiments.

[0048] Figure 1 is a schematic three-dimensional structure diagram of a semiconductor device according to an embodiment of the present invention; Figure 2 is a schematic cross-sectional structure diagram of a semiconductor device according to an embodiment of the present invention. As Figure 1 and Figure 2 shown, the present invention discloses a semiconductor device 10, including a laser emission structure 11 and a photodetector 12. The photodetector 12 is disposed on the laser emission structure 11 for detecting the reflected laser beam after the laser emission structure 11 emits laser to the object to be detected. Among them, a cavity 13 is formed in the photodetector 12. The photodetector 12 includes a third reflector layer 126 covering the cavity 13 from the side away from the laser emission structure 11, and the laser beam is reflected back and forth in the cavity and then emitted from the third reflector layer 126.

[0049] The laser emission structure 11 may include a vertical cavity surface emitting laser (VCSEL), which includes an active region 111 for emitting a laser beam, a first type reflector layer 112 located on the upper side of the active region 111, and a second type reflector layer 113 located on the lower side of the active region 111. It can be understood that the vertical cavity surface emitting laser (VCSEL) belongs to a well-known laser emission structure. Therefore, the following detailed description of the laser emission structure 11, especially the vertical cavity surface emitting laser (VCSEL), does not limit the technical scope of the present invention.

[0050] As Figure 2 shown, the laser emission structure 11 includes: an active region 111, which is a cavity for generating laser resonance; a first type reflector layer 112 located on the upper side of the active region 111, and a second type reflector layer 113 located on the lower side of the active region 111. Among them, the optical thickness of the active region 111 is (1 / 2 + m)*λ, where λ is the lasing wavelength of the laser emission structure and m is a natural number.

[0051] Exemplarily, the first type reflector layer 112 is a p-type distributed Bragg reflector (DBR) layer, and the number of periods of the p-type distributed Bragg reflector (DBR) layer is 3 - 6 pairs; the second type reflector layer 113 is an n-type distributed Bragg reflector (DBR) layer, and the number of periods of the n-type distributed Bragg reflector (DBR) layer is 35 - 50 pairs. In other examples, the first type can also be n-type and the second type can be p-type.

[0052] The laser emission structure 11 further includes: a first-type contact layer 114 disposed on the side of the first-type reflector layer 112 away from the active region 111. A first electrode layer 115 is formed on the upper surface of the first-type contact layer 114. Exemplarily, the first-type contact layer 114 is a p-type contact layer, and the thickness of the first-type contact layer 114 is 50 - 200 nm. In other examples, the first type may also be n-type, and the second type may be p-type.

[0053] The photodetector 12 is disposed on the first-type contact layer 114, and the vertical projection of the photodetector 12 in the thickness direction of the semiconductor device 10 completely falls within the first-type contact layer 114. The first electrode layer 115 is formed on the first-type contact layer 114 outside the photodetector 12.

[0054] The photodetector 12 includes: a first-type semiconductor layer 121 formed on the first-type contact layer 114, a third-type semiconductor layer 127 formed on the side of the first-type semiconductor layer 121 away from the first-type contact layer 114, a second-type semiconductor layer 122 formed on the side of the third-type semiconductor layer 127 away from the first-type semiconductor layer 121, a second-type contact layer 123 formed on the side of the second-type semiconductor layer 122 away from the third-type semiconductor layer 127, and a second electrode layer 124 formed on the second-type contact layer 123. The cavity 13 of the photodetector 12 is disposed through the first-type semiconductor layer 121, the third-type semiconductor layer 127, the second-type semiconductor layer 122, and the second-type contact layer 123. A substrate 125 is disposed above the second-type contact layer 123, and the second electrode layer 124 is disposed through the substrate 125. A third reflector layer 126 is formed on the substrate 125, and the third reflector layer 126 completely covers the cavity 13 and is located on the side of the substrate 125 away from the second-type contact layer 123.

[0055] The third reflector layer 126 is a distributed Bragg reflector (DBR) layer. Among them, the optical thickness A between the surface of the layer structure at the bottom layer (the layer closest to the substrate 125) away from the substrate 125 and the surface of the first-type contact layer 114 away from the first-type semiconductor layer 121 satisfies: (1 / 2)*m*λ, where m is a non-zero natural number, and λ is the lasing wavelength of the laser emission structure. The reflectivity of the third reflector layer 126 is lower than the reflectivity of the second-type reflector layer 113 to ensure that the laser beam is emitted from the direction of the third reflector layer 126.

[0056] Exemplarily, the substrate 125 is made of a material that does not absorb the lasing wavelength of the laser, preferably a quartz substrate. The first-type semiconductor layer 121 is a p-type InGaAs layer, and the thickness of the first-type semiconductor layer 121 is 50 - 200 nm. The second-type semiconductor layer 122 is an n-type InGaAs layer, and the thickness of the second-type semiconductor layer 122 is 50 - 200 nm. The third-type semiconductor layer 127 is an i-type InGaAs layer, and the thickness of the third-type semiconductor layer 127 is 500 - 2000 nm. The third-type semiconductor layer 127, together with the first-type semiconductor layer 121 and the second-type semiconductor layer 122, forms a PIN junction. Among them, the In component in the InGaAs material is 0.13. The second-type contact layer 123 is an n-type contact layer, and the thickness of the second-type contact layer 123 is 100 - 200 nm. The two materials of the third reflector layer 126 are SiNx / SiO2 materials. In other examples, the first type can also be n-type and the second type can be p-type.

[0057] The semiconductor device 10 further includes a substrate 14. The second-type reflector layer 113 is disposed on the substrate 14. A buffer layer 15 is disposed between the substrate 14 and the second-type reflector layer 113. A third electrode 16 electrically connected to the second-type reflector layer 113 is formed on the substrate 14. The types of the substrate 14 and the buffer layer 15 are the same as those of the second-type reflector layer 113. Exemplarily, the material of the substrate 14 is a gallium arsenide substrate, and the material of the buffer layer 15 is a gallium arsenide buffer layer; when the type of the second-type reflector layer 113 is n-type, the substrate 14 is a second-type n-type substrate and the buffer layer 15 is a second-type n-type buffer layer. If the type of the second-type reflector layer 113 is p-type, the substrate 14 is a second-type p-type substrate and the buffer layer 15 is a second-type p-type buffer layer.

[0058] In this embodiment, both the lasing wavelength of the laser emission structure 11 and the wavelength range of the photodetector 12 are between 850 nm and 1000 nm, and the lasing wavelength of the laser emission structure 11 and the wavelength of the photodetector 12 are kept consistent.

[0059] As Figure 3 shown, Figure 3 is a schematic flow chart of a method for manufacturing a semiconductor device according to an embodiment of the present invention; please refer to Figures 4A to 4F the schematic structural diagram of the process steps shown.

[0060] The present invention provides a method for manufacturing a semiconductor device, and the steps thereof include:

[0061] Step 301: Provide a substrate. As Figure 4A shown, provide a second-type substrate 14, and the second-type substrate 14 is preferably an n-type gallium arsenide substrate.

[0062] Step 302: Grow a layer structure that constitutes a laser emission structure on a substrate. The layer structure includes a buffer layer, a second-type reflector layer, an active region, a first-type reflector layer, and a first-type contact layer that are sequentially formed on the substrate. As Figure 4A shown, grow a second-type buffer layer 15, a second-type reflector layer 113, an active region 111, a first-type reflector layer 112, and a first-type contact layer 114 on the second-type substrate 14 in sequence. The thickness of the second-type buffer layer 15 is 200 - 1000 nm, the number of periods of the second-type reflector layer 113 is 35 - 50 pairs, the optical thickness of the active region 111 is (1 / 2 + m)*λ, where λ is the lasing wavelength of the laser emission structure and m is a natural number, the number of periods of the first-type reflector layer 112 is 3 - 6 pairs, and the thickness of the first-type contact layer 114 is 50 - 200 nm.

[0063] Step 303: Grow a layer structure that constitutes a photodetector on the first-type contact layer. The layer structure includes a first-type semiconductor layer, a third-type semiconductor layer, a second-type semiconductor layer, and a second-type contact layer that are sequentially formed on the first-type contact layer. As Figure 4A shown, grow a first-type semiconductor layer 121, a third-type semiconductor layer 127, a second-type semiconductor layer 122, and a second-type contact layer 123 on the first-type contact layer 114 in sequence. The thickness of the first-type semiconductor layer 121 is 50 - 200 nm, and the first-type semiconductor layer 121 is preferably a p-type InGaAs layer. The thickness of the second-type semiconductor layer 122 is 50 - 200 nm, and the second-type semiconductor layer 122 is preferably an n-type InGaAs layer. The thickness of the third-type semiconductor layer 127 is 500 - 2000 nm, and the third-type semiconductor layer 127 is an i-type InGaAs layer. The third-type semiconductor layer 127 and the first-type semiconductor layer 121 and the second-type semiconductor layer 122 together form a PIN junction. Among them, the In component in the InGaAs material is 0.13. The second-type contact layer 123 is an n-type contact layer, and the thickness of the second-type contact layer 123 is 100 - 200 nm.

[0064] Step 304: Etch the second-type contact layer, the second-type semiconductor layer, the third-type semiconductor layer, and the first-type semiconductor layer to form an annular mesa structure. As Figure 4B shown, after masking the grown device, use ICP etching to etch out a hollow region in the middle to form a cavity 13, and at the same time etch the region in the epitaxy to the first-type contact layer 114 to form a mesa region of the photodetector 12.

[0065] Step 305: Set a substrate on the second-type contact layer. As Figure 4CAs shown in the figure, a substrate 125 is disposed on the second-type contact layer 123. The substrate 125 completely covers the cavity 13. The substrate 125 is made of a material that does not absorb the lasing wavelength of the laser, preferably a quartz substrate.

[0066] Step 306: Form a first electrode layer electrically connected to the first-type contact layer on the first-type contact layer and form a second electrode layer electrically connected to the second-type contact layer on the second-type contact layer. As Figure 4D shown in the figure, an opening is formed in the substrate 125, and a second electrode layer 124 electrically connected to the second-type contact layer 123 is formed in the opening. A first electrode layer 115 is disposed on the first-type contact layer 114.

[0067] Step 307: Form a third electrode layer electrically connected to the second-type reflector layer on the substrate. As Figure 4E shown in the figure, after thinning the back surface (the side facing away from the second-type buffer layer 15) of the second-type substrate 14 to about 200 - 500 nm, a third electrode layer 16 is disposed on this surface. The third electrode layer 16 serves as an electrode of the laser emission structure.

[0068] Step 308: Form a third reflector layer on the substrate. As Figure 4F shown in the figure, a third reflector layer 126 is disposed on the side of the substrate 125 facing away from the second-type contact layer 123. The third reflector layer 126 includes a DBR layer with a multi-layer structure. When growing the first layer structure, adjust the thickness of the first layer structure to ensure that the surface distance from the lower surface (close to the first-type reflector layer 112) of the first-type contact layer 114 after the growth of the first layer structure satisfies the optical thickness requirement of 0.5*m*λ, where m is a non-zero natural number and λ is the lasing wavelength of the laser emission structure. Since the reflectivity of the second-type reflector layer 113 is close to 100%, the reflectivity of the third reflector layer 126 at the lasing wavelength of the laser emission structure is designed not to be greater than 99% to ensure light emission from the top (the side where the third reflector layer 126 is located) of the semiconductor device 10.

[0069] The semiconductor device and its manufacturing method of the present invention will be introduced below through a specific embodiment.

[0070] First, a 500-nm-thick n-type GaAs buffer layer doped with Si at 2e18 is epitaxially grown on an n-type gallium arsenide substrate using an MOCVD device; then an n-type DBR layer is placed, with 38 periods; then an active region resonator is grown on the n-type DBR layer, and the total thickness meets the requirement of 3 / 2*λ; then 5 periods of p-type DBR layer are placed on the active region; then a 100-nm-thick p-type GaAs contact layer doped with C at 1E19 is grown, and then a 200-nm-thick p-type InGaAs layer doped with C at 5E18, an undoped i-type InGaAs layer with a thickness of 1500 nm, an n-type InGaAs doped with Si at 5E18, and a 200-nm-thick n-type GaAs contact layer doped with Si at 1E19 are successively placed on the p-type GaAs contact layer. The In material component in InGaAs is selected to be 0.13.

[0071] After masking the grown device, the hollow region and the mesa region are etched to the p-type GaAs contact layer using ICP etching. A coating substrate is placed on the top of the mesa region. After opening a hole in the coating substrate, a metal electrode is set on the top. A metal electrode is set on the p-type GaAs contact layer. The back surface of the n-type gallium arsenide substrate is thinned to 200 nm using CMP, and a back surface metal electrode is set.

[0072] SiO2 / SiN is alternately coated on the top coating substrate. x For the material thin film, the thickness of the first layer of SiO2 surface layer to the bottom surface of the p-type DBR meets the 1 / 2*m*λ relationship. Then, the SiNx / SiO2 material is coated in 5 periods of DBR to ensure that the reflectivity of the thin film material on the coating substrate at λ is not higher than 99%. λ is the lasing wavelength of the laser emission structure.

[0073] Compared with the prior art, the semiconductor device according to the embodiment of the present invention takes into account the performance such as the size and output power of the laser while integrating a detector in the vertical direction, reducing the package size, and miniaturizing the design, and has a wider range of applicable scenarios.

[0074] The semiconductor device according to the embodiment of the present invention can integrate a vertical cavity surface emitting laser and a photodetector in the vertical direction, enhance the quantum efficiency of the photodetector, increase the monochromaticity, enhance the laser gain, and is beneficial to high-power laser output.

[0075] The semiconductor device according to the embodiment of the present invention reduces the package size of the device, can be widely applied to scenarios such as laser sensing and ranging, increases the cavity length of the active region of the laser emission structure at a lower cost, can effectively improve the laser output power, the reflection characteristics of the first type of reflector layer of the laser emission structure, enhance the reflection ability of the projected light beam, enhance the absorption optical path of the detector, and thus can effectively increase the absorption efficiency of the photodetector.

[0076] In the semiconductor device according to the embodiment of the present invention, by integrating a photodetector and a laser emission structure in the vertical direction, and configuring the photodetector into a cavity structure located on the laser emission structure, the surface layer of the photodetector is controlled by a third reflector layer to achieve laser output. The first type of reflector layer at the top of the laser emission structure can reflect the electromagnetic wave transmitted through the photodetector again, effectively increasing the optical absorption path of the photodetector, utilizing the vacuum cavity in the photodetector to achieve the characteristics of an external cavity growth of the laser emission structure, reducing the series resistance on the side of the first type of reflector layer of the laser emission structure, and improving the gain of the laser emission structure.

[0077] All aspects, embodiments, features and examples of the present invention should be considered illustrative in all respects and are not intended to limit the present invention. The scope of the present invention is only defined by the claims. Without departing from the spirit and scope of the claimed invention, those skilled in the art will understand other embodiments, modifications and uses.

[0078] In this application, the use of headings and sections does not mean to limit the present invention; each section can be applied to any aspect, embodiment or feature of the present invention.

[0079] Throughout this application, where a composition is described as having, comprising or including a specific component or where a process is described as having, comprising or including a specific process step, it is contemplated that the compositions of the teachings of the present invention also consist essentially of or consist of the recited components, and the processes of the teachings of the present invention also consist essentially of or consist of the recited process steps or groups of process steps.

[0080] In this application, where an element or component is referred to as being included in and / or selected from the recited list of elements or components, it is understood that the element or component can be any of the recited elements or components and can optionally be from a group consisting of two or more of the recited elements or components. In addition, it is understood that, without departing from the spirit and scope of the teachings of the present invention, the elements and / or features of the compositions, devices or methods described herein can be combined in various ways whether explicitly stated or implicitly stated herein.

[0081] Unless specifically stated otherwise, the use of the terms "comprising" and "having" should generally be understood as open-ended and non-limiting.

[0082] Unless specifically stated otherwise, the use of the singular herein includes the plural (and vice versa). In addition, unless the context clearly dictates otherwise, the singular forms "a" and "the" include the plural forms. Additionally, where the use of the term "about" is before a magnitude, unless specifically stated otherwise, the teachings of the present invention also include the specific magnitude itself.

[0083] It should be understood that the order of the steps or the order of performing a particular action is not of great importance as long as the teachings of the present invention remain operable. In addition, two or more steps or actions may be performed simultaneously.

[0084] It should be understood that the various figures and descriptions of the present invention have been simplified to illustrate elements relevant to a clear understanding of the present invention, and other elements have been eliminated for the purpose of clarity. However, those skilled in the art will recognize that these and other elements may be desirable. However, since such elements are well known in the art and since they do not contribute to a better understanding of the present invention, no discussion of such elements is provided herein. It should be understood that the figures are presented for illustrative purposes and not as construction diagrams. The details omitted and the modifications or alternative embodiments are within the scope of those skilled in the art.

[0085] It can be understood that in a particular aspect of the present invention, a single component may be replaced by a plurality of components and a plurality of components may be replaced by a single component to provide an element or structure or to perform one or several given functions. This substitution is considered to be within the scope of the present invention except where such substitution will not operate to practice a particular embodiment of the present invention.

[0086] Although the present invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions and / or additions can be made and elements of the embodiments can be replaced with substantially equivalent ones without departing from the spirit and scope of the present invention. Additionally, many modifications can be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, the present invention is not intended to be limited to the particular embodiments disclosed for carrying out the present invention, but is intended to cover all embodiments falling within the scope of the appended claims. Furthermore, unless specifically stated, any use of the terms first, second, etc. does not denote any order or importance, but the terms first, second, etc. are used to distinguish one element from another.

Claims

1. A semiconductor device, characterized in that, Comprising: A laser emission structure, including an active region that emits a laser beam, a first-type reflector layer located on the upper side of the active region, and a second-type reflector layer located on the lower side of the active region; A photodetector, disposed on the laser emission structure and detecting a reflected laser beam that is emitted from the active region towards the photodetector and reflected by an object to be detected. A cavity is formed in the photodetector. The photodetector includes a third reflector layer that covers the cavity from a side far away from the laser emission structure. The laser beam emits from the third reflector layer.

2. The semiconductor device according to claim 1, wherein, The laser emission structure further includes a first-type contact layer disposed on a side of the first-type reflector layer far away from the active region, and the photodetector is disposed on the first-type contact layer.

3. The semiconductor device according to claim 2, characterized in that, A vertical projection of the photodetector in the thickness direction of the semiconductor device completely falls within the first-type contact layer, and a first electrode layer is formed on the first-type contact layer outside the photodetector.

4. The semiconductor device according to claim 3, wherein The photodetector further includes a first-type semiconductor layer formed on the first-type contact layer, a third-type semiconductor layer formed on a side of the first-type semiconductor layer facing away from the first-type contact layer, a second-type semiconductor layer formed on a side of the third-type semiconductor layer facing away from the first-type semiconductor layer, and a second-type contact layer formed on a side of the second-type semiconductor layer facing away from the third-type semiconductor layer. A second electrode is formed on the second-type contact layer.

5. The semiconductor device according to claim 4, wherein, The cavity penetrates through the first-type semiconductor layer, the third-type semiconductor layer, the second-type semiconductor layer, and the second-type contact layer. The third reflector layer is located on a side of the second-type contact layer facing away from the second-type semiconductor layer and completely covers the cavity.

6. The semiconductor device according to claim 5, characterized in that, A substrate is disposed on the second-type contact layer. The third reflector layer is formed on the substrate and is located on a side of the substrate facing away from the second-type contact layer.

7. The semiconductor device according to claim 5, wherein, The third reflector layer is a DBR layer. Among them, the optical thickness A between the surface of the layer structure at the bottom layer facing away from the second-type contact layer and the surface of the first-type contact layer facing away from the first-type semiconductor layer satisfies: (1 / 2)*m*λ, where m is a non-zero natural number and λ is the lasing wavelength of the laser emission structure.

8. The semiconductor device according to any one of claims 5, characterized in that, The first type is p-type, the second type is n-type, and the third type is i-type; or The first type is n-type, the second type is p-type, and the third type is i-type.

9. The semiconductor device according to any one of claims 5, wherein The second-type reflector layer includes a DBR layer, and the number of periods of the DBR layer is 35 - 50 pairs; and / or The optical thickness of the active region is (1 / 2 + m)*λ, where λ is the lasing wavelength of the laser emission structure and m is a natural number; and / or The first-type reflector layer includes a DBR layer, and the number of periods of the DBR layer is 3 - 6 pairs; and / or The thickness of the first-type contact layer is 50 - 200 nm; and / or The thickness of the first-type semiconductor layer is 50 - 200 nm; and / or The thickness of the second type of semiconductor layer is 50 - 200 nm; and / or The thickness of the third type of semiconductor layer is 500 - 2000 nm; and / or The thickness of the second type of contact layer is 100 - 200 nm.

10. The semiconductor device according to claim 1, wherein, The semiconductor device further includes a substrate, the second type of reflector layer is disposed on the substrate, a buffer layer is disposed between the substrate and the second type of reflector layer, and a third electrode electrically connecting the second type of reflector layer is formed on the substrate.

11. The semiconductor device according to claim 10, wherein, The substrate is a second type of substrate, and the buffer layer is a second type of buffer layer.

12. A method for manufacturing a semiconductor device, characterized in that, Comprising: Providing a substrate; Growing a layer structure constituting a laser emission structure on the substrate, the layer structure including a buffer layer, a second type of reflector layer, an active region, a first type of reflector layer, and a first type of contact layer formed in sequence on the substrate; Growing a layer structure constituting a photodetector on the first type of contact layer, the layer structure including a first type of semiconductor layer, a third type of semiconductor layer, a second type of semiconductor layer, and a second type of contact layer formed in sequence on the first type of contact layer; Etching the second type of contact layer, the second type of semiconductor layer, the third type of semiconductor layer, and the first type of semiconductor layer to form an annular platform structure; Disposing a substrate on the second type of contact layer; Forming a first electrode layer electrically connecting the first type of contact layer on the first type of contact layer and forming a second electrode layer electrically connecting the second type of contact layer on the second type of contact layer; Forming a third electrode layer electrically connecting the second type of reflector layer on the substrate; Forming a third reflector layer on the substrate.

Images