Semiconductor element

Abstract

A semiconductor device includes a first semiconductor structure having a first conductive type and including a first dopant, a second dopant, and a third dopant; a second semiconductor structure having a second conductive type different from the first conductive type; the active structure is located between the first semiconductor structure and the second semiconductor structure; wherein the doping concentration of the first doping is smaller than 3.5 * 10 < 17 > atoms / cm < 3 >, the ratio of the doping concentration of the third doping to the doping concentration of the second doping is larger than 5, and the first semiconductor structure contains aluminum.

Description

Technical Field

[0001] The present invention relates to a semiconductor component, and in particular to an optoelectronic semiconductor component. Background Art

[0002] Semiconductor components are widely used, and the development and research of related materials are also ongoing. For example, III-V semiconductor materials containing group III and group V elements can be applied to various optoelectronic semiconductor components such as light-emitting chips (e.g., light-emitting diodes or laser diodes), light-absorbing chips (photoelectric detectors or solar cells) or non-light-emitting chips (e.g., power components of switches or rectifiers), and can be used in lighting, medical treatment, display, communication, sensing, power supply systems and other fields. With the development of science and technology, there are still many needs for technical research and development of semiconductor components. Although existing semiconductor components generally meet various requirements, they are not satisfactory in all aspects and still need further improvement. Summary of the invention

[0003] A semiconductor element comprises a first semiconductor structure having a first conductivity type and comprising a first doping, a second doping and a third doping; a second semiconductor structure having a second conductivity type different from the first conductivity type; and an active structure located between the first semiconductor structure and the second semiconductor structure; wherein the doping concentration of the first doping is less than 3.5×10 17 atoms / cm 3 , a ratio of a doping concentration of the third doping to a doping concentration of the second doping is greater than 5, and the first semiconductor structure contains aluminum.

[0004] In order to better understand the above and other aspects of the present invention, embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 is a cross-sectional schematic diagram of a semiconductor device according to an embodiment of the present invention;

[0006] Figure 2 is a cross-sectional schematic diagram of a semiconductor stack of a semiconductor element according to an embodiment of the present invention;

[0007] Figure 3 A secondary ion mass spectrometry (SIMS) diagram of a semiconductor device according to an embodiment of the present invention;

[0008] Figure 4 FIG. 4 is a cross-sectional schematic diagram of a laser diode device according to an embodiment of the present invention.

[0009] Explanation of symbols

[0010] 10Semiconductor components

[0011] 100 substrates

[0012] 100a first surface

[0013] 100b Second surface

[0014] 102 upper electrode

[0015] 104 lower electrode

[0016] 106 First protective layer

[0017] 108 Second protection layer

[0018] 110 semiconductor stack

[0019] 111 First semiconductor structure

[0020] 111a First sublayer

[0021] 111b Second sublayer

[0022] 1111 base

[0023] 1112 Ridge

[0024] 112 Second semiconductor structure

[0025] 113 Active Structure

[0026] 114 barrier layer

[0027] 115 contact layer

[0028] 116 first light guide layer

[0029] 117 second optical guide layer

[0030] 2 Laser diode device

[0031] 21 heat sink

[0032] 22a First pin

[0033] 22b Second pin

[0034] 23 Fixed seat

[0035] 231 fixed seats

[0036] 24 laser diode chips

[0037] 27Metal cover

[0038] 271 Glass Window DETAILED DESCRIPTION

[0039] The following disclosure provides many embodiments or examples for implementing different elements of the subject matter provided. Specific examples of each element and its configuration are described below to simplify the description of the embodiments of the present invention. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. For example, if the description mentions that a first element is formed on a second element, it may include an embodiment in which the first and second elements are in direct contact, and it may also include an embodiment in which an additional element is formed between the first and second elements so that they are not in direct contact.

[0040] Furthermore, spatially relative terms such as "under", "below", "lower", "above", "upper" and the like may be used to facilitate describing the relationship between one component or feature and another component or feature in the drawings. Spatially relative terms are used to include different orientations of the device in use or operation, as well as the orientations depicted in the drawings. When the device is turned to a different orientation (rotated 90 degrees or other orientations), the spatially relative adjectives used therein will also be interpreted based on the turned orientation.

[0041] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meanings as understood by those of ordinary skill in the art to which the present invention belongs. It should be understood that these terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the background or context of the relevant technology and the present invention, and should not be interpreted in an idealized or overly formal manner unless specifically defined in the embodiments of the present invention.

[0042] The composition, dopant and defects of each layer included in the semiconductor device of the present invention can be analyzed by any suitable method, such as secondary ion mass spectrometer (SIMS), transmission electron microscopy (TEM) or scanning electron microscope (SEM); the thickness of each layer can also be analyzed by any suitable method, such as transmission electron microscopy or scanning electron microscope.

[0043] The semiconductor device of the present invention may include a light emitting chip (e.g., a light emitting diode or a laser diode), a light absorbing chip (e.g., a photodetector or a solar cell), or a non-light emitting chip (e.g., a power element of a switch or a rectifier). The laser diode may be an edge emitting laser diode (EEL). In the various schematic diagrams and exemplary embodiments described below, similar reference numerals are used to represent similar elements.

[0044] Figure 1 1 is a cross-sectional schematic diagram of a semiconductor device 10 according to an embodiment of the present invention. The semiconductor device 10 comprises a substrate 100, a semiconductor stack 110 located on the substrate 100, an upper electrode 102 and a lower electrode 104, wherein the upper electrode 102 is located on the semiconductor stack 110 and the lower electrode 104 is located below the substrate 100. The substrate 100 has a first surface 100a and a second surface 100b opposite to the first surface 100a. The semiconductor stack 110 comprises a second semiconductor structure 112, an active structure 113 and a first semiconductor structure 111 sequentially stacked on the first surface 100a along the direction of the Z axis. The semiconductor device 10 may further optionally comprise a first protective layer 106 covering the semiconductor stack 110 and located below the upper electrode 102, and a second protective layer 108 located between the first protective layer 106 and the upper electrode 102.

[0045] Figure 2 1 is a cross-sectional schematic diagram of a semiconductor stack 110 of a semiconductor device 10 according to an embodiment of the present invention. The semiconductor stack 110 includes a first semiconductor structure 111, a second semiconductor structure 112, and an active structure 113 located between the first semiconductor structure 111 and the second semiconductor structure 112. The first semiconductor structure 111 has a first conductivity type, and the second semiconductor structure 112 has a second conductivity type different from the first conductivity type. For example, the first semiconductor structure 111 is p-type and the second semiconductor structure 112 is n-type, or the first semiconductor structure 111 is n-type and the second semiconductor structure 112 is p-type. Thus, the first semiconductor structure 111 and the second semiconductor structure 112 can provide holes and electrons or electrons and holes, respectively, to combine with the active structure 113 and emit light.

[0046] The first semiconductor structure 111 contains aluminum (Al) and includes a first doping, a second doping, and a third doping. The atomic weight of the second doping is less than the atomic weight of the first doping and the atomic weight of the third doping, and the atomic weight of the third doping is greater than the atomic weight of the first doping. In this embodiment, the first doping and the third doping can make the same semiconductor material have different conductivity types, for example: the doping concentration is 1×10 18 atoms / cm 3 The first doping and doping concentration above are 1×10 18 atoms / cm 3The third doping mentioned above can make the semiconductor material form n-type and p-type, or p-type and n-type. In this embodiment, the concentration of the third doping is greater than the concentration of the second doping, and the concentration of the second doping is greater than the concentration of the first doping; because the doping concentration of the third doping in the first semiconductor structure 111 is greater than the doping concentration of the first doping, the conductivity type of the first semiconductor structure 111 is determined by the third doping. In other words, the third doping makes the first semiconductor structure 111 have the first conductivity type. The third doping is intentional doping when growing the first semiconductor structure 111, while the first doping and the second doping are unintentional doping when growing the first semiconductor structure 111, but are inevitable doping caused by the deposition of specific elements on the epitaxial wafer during the crystal growth process. The third doping can be, for example, elements such as magnesium (Mg) or zinc (Zn). In this embodiment, the first doping is carbon (C), the second doping is hydrogen (H), and the third doping is magnesium (Mg). The material of the first semiconductor structure 111 in this embodiment is a compound containing nitrogen and aluminum, such as aluminum gallium nitride (AlGaN).

[0047] In one embodiment, the doping concentration of the first dopant in the first semiconductor structure 111 can be less than 3.5×10 17 atoms / cm 3 The ratio of the doping concentration of the third doping to the doping concentration of the second doping is greater than 5, for example, 5 to 10, so that the semiconductor device 10 has a higher output power. In this embodiment, the ratio of the doping concentration of the third doping to the doping concentration of the first doping in the first semiconductor structure 111 is 25 to 100.

[0048] like Figure 1 , Figure 2 As shown, in this embodiment, the first semiconductor structure 111 includes a first sub-layer 111 a and a second sub-layer 111 b , and the first sub-layer 111 a is closer to the active structure 113 than the second sub-layer 111 b . Figure 3 : is a secondary ion mass spectrometry (SIMS) diagram of a semiconductor device 10 according to an embodiment of the present invention. The first doping is carbon (C), the second doping is hydrogen (H), and the third doping is magnesium (Mg). Figure 3 As shown, the ratio of the doping concentration of the third doping to the doping concentration of the second doping of the first semiconductor structure 111 is about 5.6, and the doping concentration of the first doping is about 2.8×10 17 atoms / cm 3。 A ratio of the doping concentration of the third doping to the doping concentration of the first doping of the first semiconductor structure 111 is approximately 62.5.

[0049] It can be observed from the SIMS graph that the doping concentration of the third doping in the first sub-layer 111a is less than the doping concentration of the third doping in the second sub-layer 111b, thereby reducing the degree to which the first semiconductor structure 111 absorbs the light emitted by the active structure 113, thereby obtaining a semiconductor element 10 with high output efficiency. In this embodiment, the doping concentration of the second doping in the first sub-layer 111a is also less than the doping concentration of the second doping in the second sub-layer 111b; the doping concentration of the first doping in the first sub-layer 111a is substantially the same as the doping concentration of the first doping in the second sub-layer 111b.

[0050] The second semiconductor structure 112 includes a first doping, a second doping and a fourth doping. The fourth doping makes the second semiconductor structure 112 have a second conductivity type. The fourth doping and the first doping with sufficient doping concentration can make the same semiconductor material have the same conductivity type. For example, the doping concentration is 1×10 18 atoms / cm 3 The first doping and doping concentration above are 1×10 18 atoms / cm 3 The above fourth doping can make the semiconductor material form n-type or p-type. In this embodiment, the doping concentration of the fourth doping in the second semiconductor structure 112 is greater than the doping concentration of the second doping, and the doping concentration of the fourth doping is greater than the doping concentration of the first doping, and the doping concentration of the first doping can be greater than or equal to the doping concentration of the second doping. The fourth doping is intentional doping when growing the second semiconductor structure 112, while the first doping and the second doping are unintentional doping when growing the second semiconductor structure 112, but are inevitable doping caused by the deposition of specific elements on the epitaxial chip during the crystal growth process. The fourth doping can be, for example, elements such as silicon (Si) or carbon (C). In this embodiment, in this embodiment, the first doping is carbon (C), the second doping is hydrogen (H), the third doping is magnesium (Mg), and the fourth doping is silicon (Si). The material of the second semiconductor structure 112 is a compound containing nitrogen and aluminum, such as aluminum gallium nitride (AlGaN).

[0051] like Figure 2As shown, in the present embodiment, the semiconductor stack 110 further selectively includes a barrier layer 114 located between the first semiconductor structure 111 and the active structure 113, and a contact layer 115 located on the second sublayer 111b of the first semiconductor structure 111. The band gap of the barrier layer 114 is greater than the band gap of the first semiconductor structure 111, and thus can be used to suppress the overflow of carriers (e.g., electrons, holes). In the present embodiment, the barrier layer 114 contains aluminum. The aluminum of the first semiconductor structure 111 has a first atomic percentage, and the aluminum of the barrier layer 114 has a second atomic percentage greater than the first atomic percentage, thereby making the barrier layer 114 have a higher band gap. The first atomic percentage is, for example, 3% to 8%, and the second atomic percentage is, for example, 10% to 25%. The above atomic percentage refers to the proportion of the number of atoms of a certain element in the same group of elements in a compound. For example, the chemical formula of aluminum gallium nitride can be expressed as Al X Ga Y N, Al and Ga are elements of the same group, so X+Y=1, where = is the atomic percentage of aluminum. In this embodiment, the barrier layer 114 is located between the first sublayer 111a and the active structure 113, and the barrier layer 114 includes a third doping, and the doping concentration of the third doping in the barrier layer 114 is greater than the doping concentration of the third doping in the first sublayer 111a. The doping concentration of the third doping in the barrier layer 114 is less than the doping concentration of the third doping in the second sublayer 111b, as shown in FIG. Figure 3 Specifically, in the manufacturing process design, when the doping concentration of the third doping in the barrier layer 114 is greater than the doping concentration of the third doping in the first sub-layer 111a, it can be ensured that there is enough third doping in the first sub-layer 111a, so that the first sub-layer 111a can provide an appropriate amount of carriers (such as electrons or holes) to enhance the performance of the semiconductor device 10. The material of the barrier layer 114 in this embodiment is a compound containing nitrogen and aluminum, and the barrier layer 114 and the first semiconductor structure 111 are compounds having the same elements, such as aluminum gallium nitride (AlGaN).

[0052] In this embodiment, the contact layer 115 also has a third doping, and the doping concentration of the third doping of the contact layer 115 is greater than the doping concentration of the third doping in the first semiconductor structure 111, thereby making the contact resistance between the semiconductor stack 110 and the upper electrode 102 lower. In one embodiment, the doping concentration of the third doping of the contact layer 115 is greater than 1×10 20 atoms / cm 3 The doping concentration of the third doping in the first semiconductor structure 111 is between 5×10 17 atoms / cm 3 With 5×10 19 atoms / cm 3However, the embodiments of the present invention are not limited thereto.

[0053] In the present invention, the doping concentration is in the thickness direction (such as Figure 1 Since the above-mentioned layers (e.g., the first semiconductor structure 111, the first sublayer 111a, the second sublayer 111b, the barrier layer 114, the contact layer 115, the second semiconductor structure 112, etc.) are layered structures with a certain thickness, different thickness positions of the same layer may have different doping concentrations, and the change of the doping concentration may be intentional (e.g., introducing different flow rates of gas epitaxial sources during the epitaxial process) or unintentional (e.g., unavoidable factors during the epitaxial process).

[0054] like Figure 2 As shown, the semiconductor stack 110 may further selectively include a first light-guiding layer 116 located between the first semiconductor structure 111 and the active structure 113, and / or a second light-guiding layer 117 located between the second semiconductor structure 112 and the active structure 113. In this embodiment, the first light-guiding layer 116 is located between the barrier layer 114 and the active structure 113. The refractive index of the first light-guiding layer 116 and the second light-guiding layer 117 is smaller than the refractive index of the active structure 113, so they can be used to confine the light generated from the active structure 113.

[0055] The first semiconductor structure 111, the second semiconductor structure 112, the barrier layer 114, the contact layer 115, the first optical guide layer 116 and the second optical guide layer 117 are nitride-based semiconductors, such as those of the general formula In x Al y Ga 1-x-y N (0≤x, 0≤y, 0≤x+y≤1). The active structure 113 may be a group III-V binary compound semiconductor (e.g., gallium arsenide (GaAs), indium phosphide (InP), gallium phosphide (GaP), gallium nitride (GaN)), a group III-V multi-element compound semiconductor (e.g., aluminum gallium arsenide (AlGaAs), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), aluminum indium gallium nitride (AlInGaN), gallium arsenide phosphide (GaAsP), aluminum gallium indium phosphide (AlGaInP), aluminum indium gallium arsenide (AlInGaAs)), or a group II-VI binary compound semiconductor (e.g., cadmium selenide (CdSe), cadmium sulfide (CdS), zinc selenide (ZnSe)).

[0056] Please refer to Figure 1 and Figure 2In order to increase the ratio of the fundamental mode to the lateral mode of the emitted light, the first semiconductor structure 111 further includes a base 1111 and a ridge 1112 protruding from the base 1111. In one embodiment, the ridge 1112 is formed by removing part of the second sublayer 111b and part of the first sublayer 111a by yellow light development and etching after forming the first semiconductor structure 111, and the unremoved part of the second sublayer 111b and part of the first sublayer 111a constitute the ridge 1112. The semiconductor element 10 of this embodiment is a laser element, and the active structure 113 has two corresponding end faces (not shown), and the two end faces constitute a resonant cavity. The light emitted from the active structure 113 resonates back and forth between the two end faces and generates laser light. The laser light can be visible light or invisible light, for example: blue light with a wavelength of 400nm to 500nm.

[0057] The contact layer 115 is disposed on the ridge 1111 of the first semiconductor structure 111, and the upper electrode 102 covers the ridge 1111 and is electrically connected to the first semiconductor structure 111. The first protective layer 106 is used to protect the sidewalls of the semiconductor stack 110, and the first protective layer 106 extends to cover the upper surface of the base 1111, two opposite sides of the ridge 1112, a portion of the upper surface of the contact layer 115, and a portion of the first surface 100a of the substrate 100. The second protective layer 108 is located between the first protective layer 106 and the upper electrode 102, so that the second protective layer 108 can strengthen the isolation between the first semiconductor structure 111 and the upper electrode 102 to prevent electrical connection between the two.

[0058] In some embodiments, the substrate 100 is, for example, a silicon substrate, a nitride-based semiconductor substrate, a silicon carbide substrate, or a gallium arsenide substrate. In one embodiment, the substrate 100 may be further processed by patterning, for example, the substrate 100 may be patterned to form a rough surface, but is not limited thereto. In detail, the first surface 100a and the second surface 100b of the substrate 100 of the present embodiment have different roughnesses, the second surface 100b has a roughened structure and the roughness is greater than the first surface 100a, the substrate 100 is connected to the semiconductor stack 110 with the first surface 100a, and is connected to the lower electrode 104 with the second surface 100b. The roughened structure can increase the adhesion between the substrate 100 and the lower electrode 104. In one embodiment, the substrate 100 contains a semiconductor material containing nitrogen, such as gallium nitride (GaN) or other suitable materials. The upper surface 100a of the substrate 100 includes the (0001) plane, the (000-1) plane, the (10-10) plane, the (11-20) plane, the (10-14) plane, the (10-15) plane, and the (11-24) plane, and the (0001) plane is preferably used as the epitaxial growth plane of the semiconductor stack 110. The thickness of the substrate 100 may be between 50 μm and 500 μm.

[0059] In addition, a transparent conductive layer (not shown) may be selectively disposed on the contact layer 115 to more evenly distribute the current in the semiconductor device 10. The transparent conductive layer covers a portion of the first protective layer 106. The material of the transparent conductive layer may be indium tin oxide (ITO), indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc tin oxide (ZTO), gallium zinc oxide (GZO), zinc oxide (ZnO), indium cerium oxide (ICO), indium tungsten oxide (IWO), indium titanium oxide (ITiO), indium zinc oxide (IZO), indium gallium oxide (IGO), gallium aluminum zinc oxide (GAZO), or a combination of the above materials, or a transparent metal layer (e.g., aluminum, nickel, gold with a thickness of less than 500 angstroms).

[0060] In some embodiments, the material of the upper electrode 102 may include chromium (Cr), aluminum (Al), palladium (Pd), platinum (Pt), nickel (Ni), gold (Au), titanium (Ti), tungsten (W), any combination thereof, or other suitable conductive materials. The material of the lower electrode 104 may include palladium (Pd), chromium (Cr), titanium (Ti), aluminum (Al), gold (Au), platinum (Pt), any combination thereof, or other suitable conductive materials, and may also be a composite material formed by multiple conductive materials.

[0061] The first protective layer 106 and / or the second protective layer 108 include oxides, nitrides, oxynitrides of silicon (Si), zirconium (Zr), aluminum (Al), or tantalum (Ta), or a single layer of the aforementioned materials or a multilayer of any two or more of the aforementioned materials. The thickness of the first protective layer 106 and / or the second protective layer 108 is not particularly limited, as long as the thickness can reduce or prevent the externally injected current from directly flowing from the upper electrode 102 to the semiconductor stack 110 and can protect the semiconductor stack 110.

[0062] Figure 4 2 is a cross-sectional schematic diagram of a laser diode device 2 according to an embodiment of the present invention. The laser diode device 2 includes a heat sink 21, a first pin 22a and a second pin 22b, a fixing base 23, a primary fixing base 231, a laser diode chip 24, and a metal cover 27. The first pin 22a and the second pin 22b are disposed on the back of the heat sink 21. The fixing base 23 is protrudingly disposed on the surface of the heat sink 21 and is connected to the second pin 22b of the ground (GND). The secondary fixing base 231 is disposed on the inner side of the fixing base 23 and provides a connection for the laser diode chip 24. The metal cover 27 also includes a glass window 271 disposed on its top surface, and the bottom edge of the metal cover 27 is connected to the top of the heat sink 21. The laser diode chip 24 may include a semiconductor element 10 according to an embodiment of the present invention, but the present invention is not limited thereto.

[0063] In summary, although the present invention is disclosed in conjunction with the above embodiments, it is not intended to limit the present invention. A person skilled in the art in the art to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be based on the definition of the attached claims.

Claims

1. A semiconductor device comprising: A first semiconductor structure having a first conductivity type and comprising a first doping, a second doping and a third doping; A second semiconductor structure having a second conductivity type different from the first conductivity type; as well as An active structure located between the first semiconductor structure and the second semiconductor structure; The doping concentration of the first doping is less than 3.5×10 17 atoms / cm 3 , a ratio of the doping concentration of the third doping to the doping concentration of the second doping is greater than 5, and the first semiconductor structure contains aluminum.

2. The semiconductor device according to claim 1, wherein The first semiconductor structure has a first sublayer and a second sublayer. The first sublayer is closer to the active structure than the second sublayer, and the third doping concentration in the first sublayer is less than the third doping concentration in the second sublayer.

3. The semiconductor element according to claim 1 or 2, wherein: A ratio of a doping concentration of the third doping to a doping concentration of the first doping in the first semiconductor structure is 25 to 100.

4. The semiconductor element according to claim 1 or 2, wherein: The invention also comprises a barrier layer located between the first semiconductor structure and the active structure, wherein the barrier layer comprises aluminum, and the aluminum in the first semiconductor structure has a first atomic percentage, and the aluminum in the barrier layer has a second atomic percentage greater than the first atomic percentage.

5. The semiconductor device according to claim 2, wherein: The invention also comprises a barrier layer located between the first sub-layer and the active structure, the barrier layer comprises the third doping, and the concentration of the third doping in the barrier layer is greater than the concentration of the third doping in the first sub-layer.

6. The semiconductor device according to claim 1 or 2, wherein: The first dopant is carbon.

7. The semiconductor device according to claim 1 or 2, wherein: The second doping is hydrogen.

8. The semiconductor device according to claim 1 or 2, wherein: The third doping is magnesium. 9 . The semiconductor device as claimed in claim 1 , further comprising an upper electrode, wherein the first semiconductor structure comprises a ridge and the upper electrode covers the ridge.

10. The semiconductor device according to claim 1 or 2, wherein: The semiconductor light emitting element is a laser element.

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