Semiconductor composite material, method for preparing the same and use thereof

Abstract

The application discloses a semiconductor composite material and a preparation method and application thereof. The semiconductor composite material comprises a semiconductor substrate, a functional layer and a first metal layer which are stacked in sequence. The functional layer comprises a doped layer. The doped layer comprises a compound AB and a doping element X doped in the compound AB. In the compound AB, A comprises a Zn element, and B comprises at least one element selected from Se, Te and S. The doping element X comprises at least one element selected from B, Al, Ga, In, Tl, Sc, Y, lanthanide series elements and actinide series elements. The functional layer prepared by the application has the characteristics of low work function and high electron concentration, can effectively induce selective collection of electrons, can realize good contact between the semiconductor substrate and the first metal layer, and makes the obtained semiconductor composite material have low contact resistivity, thereby effectively reducing energy loss generated when current passes through a metal-semiconductor interface, and reducing overall energy consumption of a device.

Description

Technical Field

[0001] This invention belongs to the field of electronic technology, and in particular relates to a semiconductor composite material, its preparation method, and its application. Background Technology

[0002] In the field of semiconductor devices, contact resistivity is of paramount importance. Contact resistivity directly affects the power consumption, operating speed, and reliability of devices. Reducing contact resistivity has a significant effect on improving the electrical performance of devices, specifically in the following aspects: First, reducing the resistivity of the metal-semiconductor contact is crucial for reducing device power consumption. During the operation of semiconductor devices, energy loss is inevitable when current passes through the metal-semiconductor interface. By optimizing contact resistivity, this loss can be significantly reduced, thereby reducing the overall power consumption of the device. Second, reducing contact resistivity has a positive effect on accelerating device operation. Especially in high-speed switching applications, lower contact resistance can promote improved charge transfer efficiency, thereby shortening the switching cycle and enhancing the dynamic response characteristics of the device. Third, low contact resistivity is also crucial for enhancing device reliability. High contact resistance can lead to hot spots, triggering thermionic effects and shortening the device's lifespan. Low contact resistance helps reduce thermal damage and ensures the long-term stability of the device.

[0003] In integrated circuit construction, transistors, as the basic building blocks, rely heavily on the low resistivity of their metal-semiconductor contacts for improved switching speed and current drive capability. Specifically, in high-performance processors such as CPUs and GPUs, transistors employing low-contact-resistance technology can achieve higher operating frequencies and lower power consumption, significantly enhancing overall computing performance. In DRAM and SRAM memory cells, low-contact-resistance designs effectively reduce data access latency, increase memory operating speed, and reduce energy consumption. In power devices such as power MOSFETs and IGBTs, the application of low-contact-resistance collectors helps reduce energy loss during switching, improving energy efficiency, which is particularly crucial for fields such as electric vehicles and renewable energy conversion systems. In optoelectronic devices such as LEDs and laser diodes, low-contact-resistance electrodes effectively reduce current injection barriers, improving luminous efficiency and long-term stability. In sensor devices such as photoelectric sensors and pressure sensors, the application of low-contact-resistance electrodes improves signal transmission efficiency and sensitivity, thereby optimizing sensor performance. In the field of solar cells, the design of low-contact-resistance electrodes helps reduce charge recombination losses at the metal-semiconductor interface, improving the photoelectric conversion efficiency of the device. In RF devices such as RF amplifiers and switches, metal-semiconductor contacts with low contact resistance can significantly reduce signal transmission loss and improve RF performance.

[0004] It is evident that low contact resistivity plays a crucial role in the design and application of semiconductor devices. It not only helps improve the electrical performance of devices but also effectively reduces energy consumption and enhances device reliability. Therefore, research and technological development of low contact resistivity semiconductor devices are of profound significance for promoting technological progress and market applications in the semiconductor industry. For the electron collection terminal in semiconductor devices, high surface doping (doping concentration 10⁻⁶) of the N-type semiconductor substrate is generally employed. 17 ~10 21 cm -3 To achieve 10 -6 ~10 -3 mΩ·cm 2 The contact resistivity is relatively low. However, for some non-heavily doped semiconductor substrates, it is difficult to reduce the contact resistivity to extremely low levels, such as in conventional moderately doped (1–5 × 10⁻⁶) substrates. 15 cm -3 In crystalline silicon, common transport layer structures cannot simultaneously possess both low work function and sufficient carrier concentration, typically limiting contact resistivity to only 10–50 mΩ·cm. 2 One of the best electron-collecting structures currently available, such as LiF / Al or similar systems, achieves a contact strength of approximately 1 mΩ·cm with a textured, moderately doped silicon substrate. 2 Other structures that could potentially achieve low contact resistance often require highly doped homojunction or heterojunction processes, which are more challenging, and it is also difficult to reduce the resistance to 1 mΩ·cm. 2 The following applies. If the surface is flat or has a decorative layer, it is more difficult to achieve low contact resistance. Summary of the Invention

[0005] In order to overcome at least one of the problems existing in the prior art, one of the objectives of the present invention is to provide a semiconductor composite material having a specific structural design and low contact resistivity.

[0006] The second objective of this invention is to provide a method for preparing the above-mentioned semiconductor composite material.

[0007] The third objective of this invention is to provide an electron collection terminal.

[0008] The fourth objective of this invention is to provide a semiconductor device.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A first aspect of the present invention provides a semiconductor composite material comprising a semiconductor substrate, a functional layer, and a first metal layer stacked sequentially; the functional layer includes a doped layer; the doped layer includes a compound AB and a doping element X doped in the compound AB; in the compound AB, A includes Zn, and B includes at least one element selected from Se, Te, or S; the doping element X includes at least one element selected from B, Al, Ga, In, Tl, Sc, Y, a lanthanide element, or an actinide element.

[0011] In the doped layer of this invention, Zn forms a compound AB with at least one of S, Se, or Te. Its conduction band is mainly formed by the hybridization of the 4s electron orbitals of Zn and the 3p, 4p, and 5p orbitals of S, Se, or Te. Due to the characteristics of electron orbitals, the hybridized conduction band inherently has a low electron affinity. Furthermore, if the doping of element X in this invention increases its carrier concentration, thereby reducing its work function, the doped layer can generate sufficient band bending to induce electron transport when in contact with other n-type semiconductor devices. On the other hand, a thinner barrier region is formed at the contact interface, and the tunneling resistance is also low, thus comprehensively reducing the contact resistance.

[0012] Preferably, the compound AB includes ZnSe, ZnTe, ZnS, or ZnSe. x Te y S 1-x-y At least one of (0≤x≤1, 0≤y≤1, 0≤x+y≤1); more preferably, the compound AB includes at least one of ZnSe, ZnTe or ZnS; even more preferably, the compound AB is selected from ZnSe.

[0013] Preferably, the doping element X includes at least one of B, Al, Ga, In, Tl, Sc, or Y; more preferably, the doping element X includes at least one of Al, Ga, In, or Tl; even more preferably, the doping element X is selected from Al.

[0014] In some specific embodiments of the present invention, in compound AB, B further includes the element O. For example, compound AB may be ZnSe. 1-x O x (0≤x≤1), ZnTe 1-x O x (0≤x≤1), ZnS 1-x O x (0≤x≤1), etc.

[0015] Preferably, the compound AB includes ZnSe, ZnTe, ZnS, and ZnSe. x Te y S1-x-y (0≤x≤1, 0≤y≤1, 0≤x+y≤1), ZnSe 1-x O x (0≤x≤1), ZnTe 1-x O x (0≤x≤1) or ZnS 1-x O x At least one of (0≤x≤1); more preferably, the compound AB includes ZnSe, ZnSe 1-x O x (0≤x≤1) or a combination thereof.

[0016] In some specific embodiments of the present invention, the first metal layer may be selected from any one or more metals.

[0017] Preferably, the dopant element X is the same as the element in the first metal layer. Having the same element simplifies the doping process; that is, during the preparation of the first metal layer, the doped layer can be prepared by utilizing the diffusion of the elements of the first metal layer in compound AB, without requiring additional doping steps.

[0018] Preferably, the first metal layer comprises at least one element selected from Al, Ga, In, Tl, Sc, Y, lanthanides, or actinides; more preferably, the first metal layer comprises at least one element selected from Al, Ga, In, Tl, Sc, or Y; even more preferably, the first metal layer comprises at least one element selected from Al, Ga, In, or Tl; more preferably, the first metal layer is composed of Al.

[0019] Preferably, the semiconductor substrate comprises at least one of silicon, germanium, gallium arsenide, indium phosphide, gallium nitride, silicon carbide, cadmium telluride, cadmium selenide, cadmium telluride selenide, copper indium gallium selenide, copper zinc selenide sulfur, copper indium gallium selenide silver, or organic-inorganic metal halide perovskite materials; more preferably, the semiconductor substrate comprises at least one of silicon, germanium, gallium arsenide, indium phosphide, gallium nitride, silicon carbide, cadmium telluride, cadmium selenide, or cadmium telluride selenide; even more preferably, the semiconductor substrate is selected from silicon; more preferably, the semiconductor substrate is selected from crystalline silicon.

[0020] Preferably, the crystalline silicon is N-type doped crystalline silicon; more preferably, the doping concentration of the N-type doped crystalline silicon is 10. 14～21 cm -3 ; More preferably 10 15～16 cm -3 .

[0021] Preferably, the semiconductor substrate has a modification layer on the surface in contact with the functional layer; the modification layer includes at least one of silicon oxide, aluminum oxide, zinc oxide, zinc aluminum oxide, titanium oxide, magnesium oxide, amorphous silicon, microcrystalline silicon, nanocrystalline silicon, or polycrystalline silicon; more preferably, the modification layer includes at least one of titanium oxide, amorphous silicon, microcrystalline silicon, nanocrystalline silicon, or polycrystalline silicon; even more preferably, the modification layer includes titanium oxide, amorphous silicon, or a combination thereof.

[0022] In some specific embodiments of the present invention, the organic-inorganic metal halide perovskite material can be selected from [(MA)]. x (FA) y (Cs) 1-x-y ][Pb a Sn 1-a ][I b Br 1-b ]3 Where, 0≤x≤1, 0≤y≤1, 0≤x+y≤1, 0≤a≤1, 0≤b≤1.

[0023] Preferably, the thickness of the modification layer is 0.1–10 nm; more preferably, it is 0.5–5 nm.

[0024] Preferably, the thickness of the doped layer is 0.1–100 nm; more preferably 1–10 nm.

[0025] Preferably, the thickness of the first metal layer is 0.001 to 10 μm; more preferably, it is 0.1 to 1 μm.

[0026] Preferably, the functional layer further includes an undoped layer; the undoped layer is disposed between the semiconductor substrate and the doped layer; the undoped layer includes the compound AB.

[0027] In this invention, the compound AB in the undoped layer is the same as the compound AB in the doped layer. The undoped layer in this invention is optional; it is formed when the dopant element X does not form a complete dopant in compound AB.

[0028] In this invention, the thickness of the undoped layer is 0–100 nm; further, the thickness of the undoped layer is 0.1–100 nm; even further, it is 0.1–10 nm.

[0029] In some specific embodiments of the present invention, the doped layer, the undoped layer, and the metal layer may optionally be a single-layer or multi-layer structure.

[0030] Preferably, the semiconductor composite material further includes a second metal layer; the second metal layer is located between the functional layer and the first metal layer; the second metal layer includes at least one element selected from Ca, Mg, Ti, Ba, Ce, Na, Li, K or Cs.

[0031] To prevent excessive diffusion of elements from the first metal layer into the doped layer, which could negatively impact the composite material, such as causing p-type doping and Schottky contacts, a second metal layer is incorporated. This allows for appropriate control of element diffusion in the first metal layer, ensuring that the semiconductor composite material exhibits low contact resistance.

[0032] Preferably, the second metal layer comprises at least one element selected from Ca, Mg, Ti, Ba, or Ce; more preferably, the second metal layer comprises at least one element selected from Ca, Mg, or Ba; and even more preferably, the second metal layer is composed of Mg.

[0033] Preferably, the thickness of the second metal layer is 0.01–20 nm; more preferably 0.1–10 nm; and even more preferably 2–6 nm.

[0034] In order to reduce the diffusion of elements from the second metal layer into compound AB, the thickness of the second metal layer cannot be too thick, and better results can be achieved within the range described above in this invention.

[0035] A second aspect of the present invention provides a method for preparing the semiconductor composite material described in the first aspect of the present invention, comprising the following steps: preparing a functional layer and a first metal layer on a semiconductor substrate to obtain the semiconductor composite material; or, preparing a functional layer, a second metal layer and a first metal layer sequentially on a semiconductor substrate to obtain the semiconductor composite material.

[0036] Preferably, the method for preparing the functional layer includes at least one of thermal evaporation, electron beam evaporation, sublimation, magnetron sputtering, atomic layer deposition, pulsed laser deposition, molecular beam epitaxy, water bath method, hydrothermal reaction method, spin coating method, electroplating method, or chemical vapor deposition method; more preferably, the method for preparing the functional layer is selected from thermal evaporation or electron beam evaporation.

[0037] Preferably, the method for preparing the first metal layer and / or the second metal layer includes at least one of thermal evaporation, electron beam evaporation, magnetron sputtering, pulsed laser deposition, electroplating, or chemical vapor deposition; more preferably, the method for preparing the metal layer is selected from thermal evaporation or electron beam evaporation.

[0038] Preferably, the specific steps of the preparation method of the semiconductor composite material are as follows: preparing compound AB on a semiconductor substrate; depositing dopant element X on compound AB and allowing dopant element X to diffuse into compound AB to form a doped layer; and then preparing a first metal layer on the doped layer to obtain the semiconductor composite material.

[0039] Preferably, the method for depositing dopant element X is selected from thermal evaporation.

[0040] Preferably, the average deposition rate of the dopant element X is: Further preferred

[0041] After preparing compound AB, doping with element X is performed using thermal evaporation. The heat carried by the evaporated particles directly induces diffusion, thus forming a doped layer (AB:X). Furthermore, by adjusting different deposition rates, different degrees of diffusion can be obtained. When doping element X does not completely diffuse in compound AB, an undoped layer forms near the semiconductor substrate; when doping element X completely diffuses in compound AB, no undoped layer exists.

[0042] Preferably, when the doping element X is the same as the element of the first metal layer, the specific steps of the preparation method of the semiconductor composite material are as follows: preparing compound AB on a semiconductor substrate; depositing a first metal layer on compound AB, and allowing some of the metal elements of the first metal layer to diffuse into compound AB to form a doped layer; the metal elements that do not diffuse into compound AB form the first metal layer, thus obtaining the semiconductor composite material.

[0043] Preferably, the method for depositing the first metal layer is selected from the thermal evaporation method.

[0044] Preferably, the average deposition rate of the first metal layer is [value missing]. Further preferred

[0045] Preferably, when the doping element X is the same as the element of the first metal layer, and the semiconductor composite material further includes a second metal layer, the specific steps of the preparation method of the semiconductor composite material are as follows: preparing compound AB on a semiconductor substrate; depositing a second metal layer on compound AB; depositing a first metal layer on the second metal layer, and allowing some of the metal elements of the first metal layer to diffuse into compound AB to form a doped layer; the metal elements that do not diffuse into compound AB form the first metal layer, thus obtaining the semiconductor composite material.

[0046] Preferably, the method for depositing the second metal layer is selected from thermal evaporation.

[0047] Preferably, the average deposition rate of the second metal layer is [value missing]. Further preferred

[0048] By using a slow thermal evaporation method to deposit the second metal layer, it can be ensured that the metal layer will not diffuse into the compound AB, or the degree of diffusion is relatively small.

[0049] A third aspect of the present invention provides an electron collection terminal comprising the semiconductor composite material described in the first aspect of the present invention; or the semiconductor composite material prepared by the preparation method described in the second aspect of the present invention.

[0050] A fourth aspect of the present invention provides a semiconductor device comprising the semiconductor composite material described in the first aspect of the present invention; or the semiconductor composite material prepared by the preparation method described in the second aspect of the present invention; or the electron collection terminal described in the third aspect of the present invention.

[0051] In some specific embodiments of the present invention, the semiconductor device includes at least one of optoelectronic devices, sensor devices, battery devices, or radio frequency devices; in some more specific embodiments of the present invention, the semiconductor device includes at least one of transistors, light-emitting diodes (LEDs), laser diodes, photoelectric sensors, pressure sensors, solar cells, radio frequency amplifiers, or switching devices.

[0052] The beneficial effects of this invention are: the functional layer prepared by this invention has the characteristics of low work function and high electron concentration, which can effectively induce selective collection of electrons, achieve good contact between the semiconductor substrate and the first metal layer, and make the obtained semiconductor composite material have low contact resistivity, thereby effectively reducing the energy loss generated when current passes through the metal-semiconductor interface, thereby reducing the overall energy consumption of the device. Detailed Implementation

[0053] The following specific embodiments further illustrate the content of the present invention in detail. It should also be understood that the following embodiments are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the principles described herein are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not intended to be limited to the specific data in the examples below. Unless otherwise specified, the raw materials, reagents, or apparatus used in the following embodiments and comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0054] In the following examples and comparative examples, the test data were obtained by the TLM method, and the main process is as follows:

[0055] (1) A thin film layer structure suitable for TLM testing is prepared on a substrate, with different spacing between the coated areas;

[0056] (2) The resistance values ​​at different spacings were tested using the four-probe method;

[0057] (3) The contact resistivity is obtained by fitting the resistance value of the test according to the TLM method.

[0058] Example 1

[0059] This embodiment provides a semiconductor composite material with low contact resistivity, comprising a semiconductor substrate, a doped layer AB:X, and a first metal layer stacked sequentially; the semiconductor substrate is a moderately doped N-type silicon wafer with a flat surface and a doping concentration of 3×10⁻⁶. 15 cm -3 The compound AB is chosen as ZnSe; the dopant element X is chosen as Al; the first metal layer is also chosen as Al; the specific preparation steps include the following:

[0060] (1) Without additional heating of the semiconductor substrate, a ZnSe thin film is prepared on the semiconductor substrate using thermal evaporation under vacuum conditions. The thickness of the ZnSe thin film is approximately 4 nm, and the deposition rate is approximately [missing information].

[0061] (2) An Al film was prepared on a ZnSe film using thermal evaporation under vacuum conditions. The thickness of the Al film was approximately 200 nm, and the average deposition rate was approximately [missing information]. The heat carried by the particles during the evaporation preparation of Al thin films can be used to diffuse and form ZnSe:Al, while the undiffused Al forms the first metal layer, thereby obtaining the semiconductor composite material of this embodiment.

[0062] The contact resistivity of the semiconductor composite material obtained in this embodiment is between 0.5 and 0.8 mΩ·cm. 2 Within the range.

[0063] Example 2

[0064] This embodiment provides a semiconductor composite material with low contact resistivity, comprising a semiconductor substrate, a doped layer AB:X, and a first metal layer stacked sequentially; the semiconductor substrate is a moderately doped N-type silicon wafer with a textured surface, and the doping concentration of the silicon wafer is 3×10⁻⁶. 15 cm -3 The compound AB is chosen as ZnSe; the dopant element X is chosen as Al; the first metal layer is also chosen as Al, and the specific preparation steps include the following:

[0065] (1) Without additional heating of the semiconductor substrate, a ZnSe thin film is prepared on the semiconductor substrate using thermal evaporation under vacuum conditions. The thickness of the ZnSe thin film is approximately 5 nm, and the deposition rate is approximately [missing information].

[0066] (2) An Al film was prepared on a ZnSe film using thermal evaporation under vacuum conditions. The thickness of the Al film was approximately 200 nm, and the deposition rate was approximately [missing information]. The heat carried by the particles during the evaporation preparation of Al thin films can be used to diffuse and form ZnSe:Al, while the undiffused Al forms the first metal layer, thereby obtaining the semiconductor composite material of this embodiment.

[0067] The contact resistivity of the semiconductor composite material obtained in this embodiment is less than 0.2 mΩ·cm. 2 .

[0068] Example 3

[0069] This embodiment provides a semiconductor composite material with low contact resistivity, comprising a semiconductor substrate, a doped layer AB:X, and a first metal layer stacked sequentially; the semiconductor substrate is a moderately doped N-type silicon wafer with a textured surface and a TiO2 (1nm) modification layer, the doping concentration of the silicon wafer being 3×10⁻⁶. 15 cm -3 The compound AB is chosen as ZnSe; the dopant element X is chosen as Al; the first metal layer is also chosen as Al; the specific preparation steps include the following:

[0070] (1) Without additional heating of the semiconductor substrate, a ZnSe thin film is prepared on the semiconductor substrate using thermal evaporation under vacuum conditions. The thickness of the ZnSe thin film is approximately 5 nm, and the deposition rate is approximately [missing information].

[0071] (2) An Al film was prepared on a ZnSe film using thermal evaporation under vacuum conditions. The thickness of the Al film was approximately 200 nm, and the deposition rate was approximately [missing information]. The heat carried by the particles during the evaporation preparation of Al thin films can be used to diffuse and form ZnSe:Al, while the undiffused Al forms the first metal layer, thereby obtaining the semiconductor composite material of this embodiment.

[0072] The contact resistivity of the semiconductor composite material obtained in this embodiment is approximately 1 mΩ·cm. 2 .

[0073] Example 4

[0074] This embodiment provides a semiconductor composite material with low contact resistivity, comprising a semiconductor substrate, a doped layer AB:X, a second metal layer, and a first metal layer stacked sequentially; the semiconductor substrate is an N-type silicon wafer substrate with an amorphous silicon modification layer deposited on its surface, and the doping concentration of the silicon wafer is 3×10⁻⁶. 15 cm -3 The compound AB is chosen as ZnSe, the dopant element X is chosen as Al, the second metal layer is chosen as Mg, and the first metal layer is chosen as Al; the specific preparation steps include the following:

[0075] (1) Without additional heating of the semiconductor substrate, a ZnSe thin film is prepared on the semiconductor substrate using thermal evaporation under vacuum conditions. The thickness of the ZnSe thin film is approximately 5 nm, and the deposition rate is approximately [missing information].

[0076] (2) A metallic Mg film was prepared on a ZnSe film using thermal evaporation under vacuum conditions. The thickness of the Mg film was approximately 6 nm, and the deposition rate was approximately [missing information].

[0077] (3) An Al film with a thickness of 200 nm was prepared on a Mg film using thermal evaporation under vacuum conditions, and the deposition rate was approximately [missing information]. The heat carried by the particles during the evaporation preparation of Al thin films can be used to diffuse and form ZnSe:Al, while the undiffused Al forms the first metal layer, thereby obtaining the semiconductor composite material of this embodiment.

[0078] In this embodiment, amorphous silicon was added to the surface of the silicon substrate. To prevent excessive Al diffusion into this layer and its potential negative impacts, such as the formation of p-type doping and Schottky contacts, Mg metal was added in this embodiment to appropriately control Al diffusion. This reduced the contact resistivity to 2 mΩ·cm on the undoped silicon wafer with amorphous silicon. 2 .

[0079] Comparative Example 1

[0080] This comparative example provides a semiconductor composite material. The preparation method differs from Example 1 in that ZnSe in step (1) of Example 1 is replaced with ZnO:Al, and the thickness is 5 nm; all other steps are the same. The contact resistivity of the semiconductor composite material obtained in this comparative example is 150–200 mΩ·cm. 2 .

[0081] Comparative Example 2

[0082] This comparative example provides a semiconductor composite material. The preparation method differs from Example 1 in that ZnSe in step (1) of Example 1 is replaced with LiF, and the thickness is 2 nm; all other steps are the same. The contact resistivity of the semiconductor composite material obtained in this comparative example is 3–5 mΩ·cm. 2 .

[0083] Comparative Example 3

[0084] This comparative example provides a semiconductor composite material. The preparation method differs from Example 2 in that ZnSe in step (1) of Example 2 is replaced with ZnO:Li, and the thickness is 5 nm; all other steps are the same. The contact resistivity of the semiconductor composite material obtained in this comparative example is 100 mΩ·cm. 2 .

[0085] Comparative Example 4

[0086] This comparative example provides a semiconductor composite material. The preparation method differs from Example 2 in that ZnSe in step (1) of Example 2 is replaced with ZnO:Al, and the thickness is 5 nm, while the other steps remain the same. Although ZnO:Al is similar to ZnSe:Al, the contact resistivity of the semiconductor composite material obtained in this comparative example is much greater than that of ZnSe:Al, approximately 60 mΩ·cm. 2 .

[0087] Comparative Example 5

[0088] This comparative example provides a semiconductor composite material. The preparation method differs from Example 2 in that ZnSe in step (1) of Example 2 is replaced with a low work function metal, Ca, and the thickness is 20 nm. All other steps are the same. The contact resistivity of the semiconductor composite material obtained in this comparative example is 56 mΩ·cm. 2 .

[0089] Comparative Example 6

[0090] This comparative example provides a semiconductor composite material. The preparation method differs from Example 2 in that ZnSe in step (1) of Example 2 is replaced with LiF, and the thickness is 2 nm; all other steps are the same. The contact resistivity of the semiconductor composite material obtained in this comparative example is 2.2 mΩ·cm. 2 .

[0091] Comparative Example 7

[0092] This comparative example provides a semiconductor composite material. The preparation method differs from Example 3 in that ZnSe in step (1) of Example 3 is replaced with LiF, and the thickness is 5 nm; all other steps are the same. The contact resistivity of the semiconductor composite material obtained in this comparative example is 5 mΩ·cm. 2 .

[0093] Comparative Example 8

[0094] This comparative example provides a semiconductor composite material. The preparation method differs from Example 4 in that ZnSe in step (1) of Example 4 is replaced with LiF, the thickness is 2 nm, and the Mg layer is removed; all other steps are the same. The contact resistivity of the semiconductor composite material obtained in this comparative example is 11 mΩ·cm. 2 .

[0095] The structures and properties of Examples 1-4 and Comparative Examples 1-8 are summarized in Table 1.

[0096] Table 1 shows the structure and performance of Examples 1-4 and Comparative Examples 1-8.

[0097] Surface condition Modification layer Transport layer structure <![CDATA[Contact resistivity (mΩ·cm 2 )]]> Example 1 flat / ZnSe:Al / Al 0.5～0.8 Example 2 suede / ZnSe:Al / Al <0.2 Example 3 suede <![CDATA[TiO2]]> ZnSe:Al / Al 1 Example 4 suede a-Si:H ZnSe:Al / Mg / Al 2 Comparative Example 1 flat / ZnO:Al / Al 150～200 Comparative Example 2 flat / LiF / Al 3～5 Comparative Example 3 suede / ZnO:Li / Al 100 Comparative Example 4 suede / ZnO:Al / Al 60 Comparative Example 5 suede / Ca / Al 56 Comparative Example 6 suede / LiF / Al 2.2 Comparative Example 7 suede <![CDATA[TiO2]]> LiF / Al 5 Comparative Example 8 suede a-Si:H LiF / Al 11

[0098] As can be seen from Table 1, compared with the method in the comparative example, the semiconductor composite material prepared by the method in this embodiment of the invention has a lower contact resistivity.

[0099] In this invention, ZnSe:X, ZnTe:X, ZnS:Al, or ZnSe of a certain thickness are prepared directly or generated in subsequent steps. x Te y S 1-x-y Layer X (0≤x≤1, 0≤y≤1, 0≤x+y≤1), due to the material of this layer simultaneously possessing the characteristics of low work function and ~10 15～21 cm -3 The high electron concentration effectively induces selective electron collection, significantly reducing the contact resistivity at the electron collection end to 10⁻⁶. -9 ~50mΩ·cm 2 Low contact resistivity. In particular, in some undoped semiconductors (carrier concentration only 1–5 × 10⁻⁶), this is particularly true. 15 cm -3 The surface osmotic pressure can reach 0.1–1 mΩ·cm. 2 Or even lower.

[0100] In summary, the functional layer prepared by this invention has both low work function and high electron concentration, which can effectively induce selective electron collection and achieve good contact between the semiconductor substrate and the first metal layer. This results in a semiconductor composite material with low contact resistivity, thereby effectively reducing the energy loss generated when current passes through the metal-semiconductor interface and thus reducing the overall energy consumption of the device.

Claims

1. A semiconductor composite material with low contact resistivity, characterized in that, The device comprises a semiconductor substrate, a functional layer, and a first metal layer stacked sequentially. The functional layer includes a doped layer. The doped layer includes a compound AB and a dopant element X doped in the compound AB. In the compound AB, A includes Zn, and B includes Se and / or Te. The dopant element X includes at least one of Al, Ga, In, Tl, Sc, Y, a lanthanide element, or an actinide element. The doping element X is the same as the element in the first metal layer; during the preparation of the first metal layer, the doping layer is prepared by the diffusion of the element in the first metal layer in compound AB. The functional layer further includes an undoped layer; the undoped layer is disposed between the semiconductor substrate and the doped layer; the undoped layer includes the compound AB; The semiconductor composite material further includes a second metal layer; the second metal layer is located between the functional layer and the first metal layer.

2. The semiconductor composite material according to claim 1, characterized in that, In the compound AB, B also includes the element O; And / or, the semiconductor substrate comprises at least one of silicon, germanium, gallium arsenide, indium phosphide, gallium nitride, silicon carbide, cadmium telluride, cadmium selenide, cadmium telluride selenide, copper indium gallium selenide, copper zinc selenide sulfur, copper indium gallium selenide silver, or organic-inorganic metal halide perovskite materials; And / or, the semiconductor substrate has a modification layer on the surface in contact with the functional layer; the modification layer includes at least one of aluminum oxide, zinc oxide, zinc aluminum oxide, titanium oxide, magnesium oxide, amorphous silicon, microcrystalline silicon, nanocrystalline silicon, or polycrystalline silicon.

3. The semiconductor composite material according to claim 1, characterized in that, The thickness of the doped layer is 0.1~100 nm; And / or, the thickness of the first metal layer is 0.001~10μm.

4. The semiconductor composite material according to claim 1, characterized in that, The second metal layer includes at least one element selected from Ca, Mg, Ti, Ba, Ce, Na, Li, K, or Cs; And / or, the thickness of the second metal layer is 0.01~20nm.

5. A method for preparing a semiconductor composite material as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Compound AB was prepared on a semiconductor substrate; A second metal layer is then deposited on compound AB; then a first metal layer is deposited on the second metal layer, and some of the metal elements in the first metal layer diffuse into compound AB to form a functional layer including a doped layer; the metal elements that do not diffuse into compound AB form the first metal layer, thus obtaining the semiconductor composite material.

6. The preparation method according to claim 5, characterized in that, The method for preparing the functional layer includes at least one of the following: thermal evaporation, electron beam evaporation, sublimation, magnetron sputtering, atomic layer deposition, pulsed laser deposition, molecular beam epitaxy, water bath method, hydrothermal reaction method, spin coating method, electroplating method, or chemical vapor deposition method. And / or, the method for preparing the first metal layer and / or the second metal layer includes at least one of thermal evaporation, electron beam evaporation, magnetron sputtering, pulsed laser deposition, electroplating, or chemical vapor deposition.

7. An electron collection terminal, characterized in that, The semiconductor composite material includes the semiconductor composite material according to any one of claims 1 to 4; or the semiconductor composite material obtained by the preparation method according to any one of claims 5 to 6.

8. A semiconductor device, characterized in that, It includes the semiconductor composite material according to any one of claims 1 to 4; or the semiconductor composite material prepared by the preparation method according to any one of claims 5 to 6; or the electron collection terminal according to claim 7.