Semiconductor composite material and preparation method and application thereof

Abstract

The invention 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 doping layer comprises a compound AB and a doping element X doped in the compound AB; in the compound AB, A comprises Zn element, and B comprises at least one element of Se, Te or S; the doping element X comprises at least one of B, Al, Ga, In, Tl, Sc, Y, lanthanides or actinides. The functional layer prepared by the method has the characteristics of low work function and high electron concentration at the same time, can effectively induce selective collection of electrons, and can realize good contact between the semiconductor substrate and the first metal layer, so that the obtained semiconductor composite material has low contact resistivity; therefore, the energy loss generated when the current passes through the metal-semiconductor interface is effectively reduced, and the overall energy consumption of the device is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of electronic technology, and in particular relates to a semiconductor composite material and a preparation method and application thereof. Background Art

[0002] In the field of semiconductor devices, the importance of contact resistivity is particularly prominent. Contact resistivity directly affects the power consumption, operating speed and reliability of the device. Reducing the contact resistivity has a significant effect on improving the electrical performance of the device, which is specifically reflected in the following aspects: First, reducing the resistivity of the metal-semiconductor contact point is crucial to reducing the power consumption of the device. During the operation of semiconductor devices, energy loss is inevitable when current passes through the metal-semiconductor interface. By optimizing the contact resistivity, this loss can be significantly reduced, thereby reducing the overall energy consumption of the device. Secondly, the reduction of contact resistivity has a positive effect on speeding up the operation of the device. Especially in high-speed switching application scenarios, lower contact resistance can promote the improvement of charge transfer efficiency, thereby shortening the switching cycle and enhancing the dynamic response characteristics of the device. Furthermore, low contact resistivity is also crucial to enhancing the reliability of the device. Hot spots that may be caused by high contact resistance will trigger the thermal electron effect, thereby shortening the service life of the device. Low contact resistance helps to reduce thermal damage and ensure the long-term stability of the device.

[0003] In the construction of integrated circuits, transistors are the basic building blocks, and the low resistivity characteristics of their metal-semiconductor contacts are crucial to improving switching speed and current driving capabilities. Specifically, in high-performance processors such as CPUs and GPUs, transistors using low contact resistance technology can achieve higher operating frequencies and lower energy consumption, which has a significant effect on improving overall computing performance. In DRAM and SRAM storage cells, low contact resistance design can effectively reduce data access delays, increase memory operation speeds, 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 and improve energy efficiency, which is particularly critical in areas such as electric vehicles and renewable energy conversion systems. In optoelectronic devices such as LEDs and laser diodes, low contact resistance electrodes can effectively reduce current injection barriers and improve the luminous efficiency and long-term stability of the devices. In sensor devices such as photoelectric sensors and pressure sensors, the application of low contact resistance electrodes can improve the efficiency and sensitivity of signal transmission, thereby optimizing the performance of the sensor. In the field of solar cells, the design of low contact resistance electrodes helps reduce charge recombination losses at the metal-semiconductor interface and improve 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 losses and improve RF performance.

[0004] It can be seen that low contact resistivity plays a vital role in the design and application of semiconductor devices. It not only helps to improve the electrical performance of the device, but also effectively reduces energy consumption and enhances the reliability of the device. Therefore, the research and technology development of low contact resistivity semiconductor devices has far-reaching significance for promoting technological progress and market application in the semiconductor industry. For the electron collecting end in the semiconductor device, the surface of the N-type semiconductor substrate is generally highly doped (doping concentration 10 17 ~10 21 cm -3 ) to achieve 10 -6 ~10 -3 mΩ·cm 2 However, for some non-highly doped semiconductor substrates, it is difficult to reduce the contact resistivity to an extremely low level. For example, in conventional medium-doped (1-5×10 15 cm -3 In crystalline silicon, the common transport layer structure cannot have both low work function and sufficient carrier concentration, so the contact resistivity can only reach 10 to 50 mΩ·cm. 2 The best electron-end collection structures currently available, such as LiF / Al or similar systems, in contact with a medium-doped silicon substrate with a textured surface, can only achieve about 1 mΩ·cm 2 Other structures that may achieve lower contact resistance often require more difficult homojunction or heterojunction high doping processes, and it is also difficult to reduce to 1mΩ·cm 2 If the surface is planar or has a modified 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 above-mentioned 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] A second object of the present invention is to provide a method for preparing the semiconductor composite material.

[0007] A third object of the present invention is to provide an electron collecting terminal.

[0008] A fourth object of the present invention is to provide a semiconductor device.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[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 in sequence; the functional layer comprises a doping layer; the doping 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 the group consisting of Se, Te, and S; the doping element X comprises at least one selected from the group consisting of B, Al, Ga, In, Tl, Sc, Y, a lanthanide element, and an actinide element.

[0011] In the doping layer of the present invention, Zn and at least one element of S, Se or Te form a compound AB, and its conduction band is mainly formed by the hybridization of the 4s electron orbit of Zn and the 3p, 4p, and 5p orbits of S, Se or Te. Due to the characteristics of the electron orbit, the conduction band formed by hybridization essentially has a lower electron affinity; and, if the present invention increases its carrier concentration by doping with the doping element X, thereby reducing its work function, when the formed doping layer contacts other n-type semiconductor devices, on the one hand, sufficient energy band bending can be generated to induce electron transport, and on the other hand, a thinner barrier region will be formed at the contact interface, and the tunneling resistance is also lower, thereby comprehensively reducing the contact resistance.

[0012] Preferably, the compound AB comprises ZnSe, ZnTe, ZnS or ZnSe x Te y S 1-x-y (0≤x≤1, 0≤y≤1, 0≤x+y≤1); further preferably, the compound AB includes at least one of ZnSe, ZnTe or ZnS; further 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; further preferably, the doping element X includes at least one of Al, Ga, In or Tl; and even more preferably, the doping element X is selected from Al.

[0014] In some specific embodiments of the present invention, in the compound AB, B also includes an O element. For example, the compound AB can 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 comprises ZnSe, ZnTe, ZnS, 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 (0≤x≤1); further 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 can be selected from any one or more metals.

[0017] Preferably, the doping element X is the same as the element of the first metal layer. The same elements can make the doping process simpler, that is, in the process of preparing the first metal layer, the diffusion of the element of the first metal layer in the compound AB can be used to prepare the doped layer without adding an additional doping process.

[0018] Preferably, the first metal layer includes at least one element selected from the group consisting of Al, Ga, In, Tl, Sc, Y, lanthanide or actinide; further preferably, the first metal layer includes at least one element selected from the group consisting of Al, Ga, In, Tl, Sc or Y; even further preferably, the first metal layer includes at least one element selected from the group consisting of Al, Ga, In or Tl; more preferably, the first metal layer is composed of the Al element.

[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; further 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; further 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; further 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 modified layer on the surface in contact with the functional layer; the modified 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; further preferably, the modified layer includes at least one of titanium oxide, amorphous silicon, microcrystalline silicon, nanocrystalline silicon or polycrystalline silicon; even more preferably, the modified layer includes titanium oxide, amorphous silicon or a combination thereof.

[0022] In some 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 ]3Among them, 0≤x≤1, 0≤y≤1, 0≤x+y≤1, 0≤a≤1, 0≤b≤1.

[0023] Preferably, the thickness of the modified layer is 0.1 to 10 nm, and more preferably 0.5 to 5 nm.

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

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

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

[0027] In the present invention, the compound AB in the non-doped layer is the same as the compound AB in the doped layer. The non-doped layer in the present invention is optional, and when the doping element X is not fully doped in the compound AB, a non-doped layer is formed.

[0028] In the present invention, the thickness of the non-doped layer is 0 to 100 nm; further, the thickness of the non-doped layer is 0.1 to 100 nm; further, the thickness of the non-doped layer is 0.1 to 100 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 the group consisting of Ca, Mg, Ti, Ba, Ce, Na, Li, K and Cs.

[0031] In order to prevent the elements of the first metal layer from excessively diffusing into the doping layer, thereby bringing negative effects to the composite material, such as forming p-type doping to produce Schottky contact, a second metal layer is provided to properly control the diffusion of elements of the first metal layer and ensure that the semiconductor composite material has a lower contact resistance.

[0032] Preferably, the second metal layer includes at least one element selected from the group consisting of Ca, Mg, Ti, Ba and Ce; further preferably, the second metal layer includes at least one element selected from the group consisting of Ca, Mg and Ba; and even further preferably, the second metal layer consists of the element Mg.

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

[0034] In order to reduce the diffusion of elements of the second metal layer into the compound AB, the thickness of the second metal layer cannot be too thick. A better effect can be achieved within the above range of the present invention.

[0035] The 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, sequentially preparing a functional layer, a second metal layer and a first metal layer 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, electroplating or chemical vapor deposition; further 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; further preferably, the method for preparing the metal layer is selected from thermal evaporation or electron beam evaporation.

[0038] Preferably, the specific steps of the method for preparing the semiconductor composite material are: preparing compound AB on a semiconductor substrate; then depositing a doping element X on compound AB and diffusing the doping element X into compound AB to form a doping layer; then preparing a first metal layer on the doping layer to obtain the semiconductor composite material.

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

[0040] Preferably, the average deposition rate of the deposited doping element X is More preferably

[0041] After preparing compound AB, doping element X is performed by thermal evaporation, and the heat carried by the evaporated particles can be directly used to cause diffusion, thereby forming a doped layer (AB:X); and by adjusting different deposition rates, different degrees of diffusion can be obtained. When the doping element X is not completely diffused in compound AB, the compound AB near the semiconductor substrate forms an undoped layer; when the doping element X is completely diffused in compound AB, there is no undoped layer.

[0042] Preferably, when the doping element X is the same as the element of the first metal layer, the specific steps of the method for preparing the semiconductor composite material are: preparing compound AB on a semiconductor substrate; then depositing a first metal layer on compound AB, and diffusing part of the metal elements of the first metal layer into compound AB to form a doping layer; the metal elements that have not diffused into compound AB form the first metal layer to obtain the semiconductor composite material.

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

[0044] Preferably, the average deposition rate of the first metal layer is More preferably

[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 method for preparing the semiconductor composite material are: preparing a compound AB on a semiconductor substrate; then depositing a second metal layer on the compound AB; then depositing a first metal layer on the second metal layer, and diffusing part of the metal elements of the first metal layer into the compound AB to form a doping layer; the metal elements that have not diffused into the compound AB form the first metal layer to obtain the semiconductor composite material.

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

[0047] Preferably, the average deposition rate of the second metal layer is More preferably

[0048] The use of a slow thermal evaporation method to deposit the second metal layer can ensure that the metal layer will not diffuse substantially into the compound AB, or the diffusion degree is relatively small.

[0049] The third aspect of the present invention provides an electron collecting end, 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] The 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 collecting end 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 an optoelectronic device, a sensor device, a battery device or a radio frequency device; in some more specific embodiments of the present invention, the semiconductor device includes at least one of a transistor, a light emitting diode (LED), a laser diode, a photoelectric sensor, a pressure sensor, a solar cell, a radio frequency amplifier or a switching device.

[0052] The beneficial effects of the present invention are as follows: the functional layer prepared by the present invention has the characteristics of low work function and high electron concentration at the same time, can effectively induce the selective collection of electrons, can achieve 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 the energy loss generated when the current passes through the metal-semiconductor interface, thereby reducing the overall energy consumption of the device. DETAILED DESCRIPTION

[0053] The content of the present invention is further described in detail below through specific examples. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the principles set forth in the present invention all belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific data exemplified below. The raw materials, reagents or devices used in the following examples and comparative examples, unless otherwise specified, can all be obtained from conventional commercial sources, or can be obtained by existing known methods.

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

[0055] (1) Preparing a thin film layer structure suitable for TLM testing on a substrate, with different spacings between the coating areas;

[0056] (2) Use the four-probe method to test the resistance values ​​at different spacings;

[0057] (3) The contact resistivity is obtained by fitting the resistance value tested using the TLM method.

[0058] Example 1

[0059] This embodiment provides a semiconductor composite material with low contact resistivity, including a semiconductor substrate, an AB:X doping layer, and a first metal layer stacked in sequence; the semiconductor substrate is a medium-doped N-type crystalline silicon wafer with a flat surface, and the doping concentration of the silicon wafer is 3×10 15 cm -3 ; The compound AB is selected as ZnSe; the doping element X is selected as Al; the first metal layer is also selected as Al; the specific preparation steps include:

[0060] (1) Without additional heating of the semiconductor substrate, a ZnSe film was prepared on the semiconductor substrate by thermal evaporation under vacuum conditions. The thickness of the ZnSe film was about 4 nm, and the deposition rate was about

[0061] (2) Using thermal evaporation under vacuum conditions, an Al film was prepared on the ZnSe film. The thickness of the Al film was about 200 nm, and the average deposition rate was about The heat carried by the particles during the evaporation process to prepare the Al film can be used to diffuse to form ZnSe:Al, while the un-diffused 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 0.5 to 0.8 mΩ·cm 2 within the range.

[0063] Example 2

[0064] This embodiment provides a semiconductor composite material with low contact resistivity, including a semiconductor substrate, an AB:X doping layer, and a first metal layer stacked in sequence; the semiconductor substrate is a medium-doped N-type crystalline silicon wafer with a surface texture, and the doping concentration of the silicon wafer is 3×10 15 cm -3 The compound AB is selected as ZnSe; the doping element X is selected as Al; the first metal layer is also selected as Al, and the preparation steps are specifically as follows:

[0065] (1) Without additional heating of the semiconductor substrate, a ZnSe film was prepared on the semiconductor substrate by thermal evaporation under vacuum conditions. The thickness of the ZnSe film was about 5 nm, and the deposition rate was about

[0066] (2) Using thermal evaporation under vacuum conditions, an Al film was prepared on the ZnSe film. The thickness of the Al film was about 200 nm, and the deposition rate was about The heat carried by the particles during the evaporation process to prepare the Al film can be used to diffuse to form ZnSe:Al, while the un-diffused 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] The present embodiment provides a semiconductor composite material with low contact resistivity, comprising a semiconductor substrate, an AB:X doping layer, and a first metal layer stacked in sequence; the semiconductor substrate is a medium-doped N-type crystalline silicon wafer with a textured surface and a TiO2 (1 nm) modified layer, and the doping concentration of the silicon wafer is 3×10 15 cm -3 ; The compound AB is selected as ZnSe; the doping element X is selected as Al; the first metal layer is also selected as Al; the specific preparation steps include:

[0070] (1) Without additional heating of the semiconductor substrate, a ZnSe film was prepared on the semiconductor substrate by thermal evaporation under vacuum conditions. The thickness of the ZnSe film was about 5 nm, and the deposition rate was about

[0071] (2) Using thermal evaporation under vacuum conditions, an Al film was prepared on the ZnSe film. The thickness of the Al film was about 200 nm, and the deposition rate was about The heat carried by the particles during the evaporation process to prepare the Al film can be used to diffuse to form ZnSe:Al, while the un-diffused 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 about 1 mΩ·cm 2 .

[0073] Example 4

[0074] This embodiment provides a semiconductor composite material with low contact resistivity, including a semiconductor substrate, an AB:X doping layer, a second metal layer, and a first metal layer stacked in sequence; the semiconductor substrate is an N-type silicon wafer substrate with an amorphous silicon modification layer coated on the surface, and the doping concentration of the silicon wafer is 3×10 15 cm -3 The compound AB is selected as ZnSe, the doping element X is selected as Al, the second metal layer is selected as Mg, and the first metal layer is selected as Al; the preparation steps include the following:

[0075] (1) Without additional heating of the semiconductor substrate, a ZnSe film was prepared on the semiconductor substrate by thermal evaporation under vacuum conditions. The thickness of the ZnSe film was about 5 nm, and the deposition rate was about

[0076] (2) A metal Mg film was prepared on the ZnSe film by thermal evaporation under vacuum conditions. The thickness of the Mg film was about 6 nm and the deposition rate was about

[0077] (3) Using thermal evaporation under vacuum conditions, an Al film was prepared on the Mg film. The film thickness was 200 nm and the deposition rate was approximately The heat carried by the particles during the evaporation process to prepare the Al film can be used to diffuse to form ZnSe:Al, while the un-diffused Al forms the first metal layer, thereby obtaining the semiconductor composite material of this embodiment.

[0078] In this embodiment, amorphous silicon is added to the surface of the silicon substrate. In order to prevent excessive Al element diffusion into the layer and bring possible negative effects such as the formation of p-type doping to produce Schottky contact, metal Mg is added in this embodiment to properly control the diffusion of Al, and the contact resistivity is reduced to 2mΩ·cm on the non-highly doped silicon wafer with amorphous silicon. 2 .

[0079] Comparative Example 1

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

[0081] Comparative Example 2

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

[0083] Comparative Example 3

[0084] This comparative example provides a semiconductor composite material. The difference between the preparation method and Example 2 is that the ZnSe in step (1) of Example 2 is replaced by ZnO:Li with a thickness of 5 nm, and the 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 difference between the preparation method and Example 2 is that the ZnSe in step (1) of Example 2 is replaced by ZnO:Al, the thickness is 5nm, and the other steps are 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, which is about 60mΩ·cm 2 .

[0087] Comparative Example 5

[0088] This comparative example provides a semiconductor composite material. The difference between the preparation method and Example 2 is that the ZnSe in step (1) of Example 2 is replaced by a low work function metal Ca with a thickness of 20 nm, and the 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 difference between the preparation method and Example 2 is that ZnSe in step (1) of Example 2 is replaced by LiF with a thickness of 2 nm, and the 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 difference between the preparation method and that of Example 3 is that ZnSe in step (1) of Example 3 is replaced by LiF with a thickness of 5 nm, and the 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 difference between the preparation method and that of Example 4 is that ZnSe in step (1) of Example 4 is replaced by LiF with a thickness of 2 nm, the Mg layer is removed, and the 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 to 4 and Comparative Examples 1 to 8 are summarized in Table 1.

[0096] Table 1 Structure and performance of Examples 1 to 4 and Comparative Examples 1 to 8

[0097] Surface state 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] It can be seen from Table 1 that, compared with the method in the comparative example, the semiconductor composite material prepared by the method in the embodiment of the present invention has a lower contact resistivity.

[0099] In the present invention, ZnSe:X or ZnTe:X or ZnS:Al or ZnSe with a certain thickness is directly prepared or generated in a subsequent step. x Te y S 1-x-y :X (0≤x≤1, 0≤y≤1, 0≤x+y≤1) layer, because this layer of material has the characteristics of low work function and ~10 15～21 cm -3 The electron concentration can effectively induce the selective collection of electrons, greatly reducing the contact resistivity of the electron collection end, which can reach 10 -9 ~50mΩ·cm 2 Low contact resistivity. In particular, in some non-highly doped semiconductors (carrier concentration is only 1 to 5×10 15 cm -3 ) on the substrate surface may reach 0.1 to 1 mΩ·cm 2 Or even lower.

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

Claims

1. A semiconductor composite material, characterized in that: The invention comprises a semiconductor substrate, a functional layer and a first metal layer which are stacked in sequence; the functional layer comprises a doping layer; the doping 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 the group consisting of Se, Te and S; the doping element X comprises at least one selected from the group consisting of B, Al, Ga, In, Tl, Sc, Y, a lanthanide element and an actinide element.

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 first metal layer includes at least one element of Al, Ga, In, Tl, Sc, Y, lanthanide or actinide; and / or, the semiconductor substrate includes 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 selenium sulfur, copper indium gallium selenide silver or organic-inorganic metal halide perovskite material; And / or, the semiconductor substrate has a modified layer on the surface in contact with the functional layer; the modified 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.

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

4. The semiconductor composite material according to claim 1, characterized in that The functional layer further includes a non-doped layer; the non-doped layer is disposed between the semiconductor substrate and the doped layer; and the non-doped layer includes the compound AB.

5. The semiconductor composite material according to claim 1, characterized in that: The semiconductor composite material also 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 of Ca, Mg, Ti, Ba, Ce, Na, Li, K or Cs; and / or the thickness of the second metal layer is 0.01 to 20 nm.

6. A method for preparing a semiconductor composite material according to any one of claims 1 to 5, characterized in that: The following steps are involved: Sequentially preparing a functional layer and a first metal layer on a semiconductor substrate to obtain the semiconductor composite material; or That is, a functional layer, a second metal layer and a first metal layer are sequentially prepared on a semiconductor substrate to obtain the semiconductor composite material.

7. The preparation method according to claim 6, characterized in that: 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, hydrothermal reaction, spin coating, electroplating or chemical vapor deposition; 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.

8. The preparation method according to claim 7, characterized in that: The specific steps of the method for preparing the semiconductor composite material are: preparing compound AB on a semiconductor substrate; then depositing a doping element X on compound AB and diffusing the doping element X into compound AB to form a doping layer; then preparing a first metal layer on the doping layer to obtain the semiconductor composite material; Alternatively, when the doping element X is the same as the element of the first metal layer, the specific steps of the method for preparing the semiconductor composite material are: preparing a compound AB on a semiconductor substrate; then depositing a first metal layer on the compound AB, and diffusing part of the metal element of the first metal layer into the compound AB to form a doping layer; The metal elements that are not diffused into the compound AB form a first metal layer to obtain the semiconductor composite material; Alternatively, 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 method for preparing the semiconductor composite material are: preparing a compound AB on a semiconductor substrate; then depositing a second metal layer on the compound AB; then depositing a first metal layer on the second metal layer, and diffusing part of the metal elements of the first metal layer into the compound AB to form a doping layer; The metal elements that are not diffused into the compound AB form a first metal layer to obtain the semiconductor composite material.

9. An electron collection terminal, characterized in that: The semiconductor composite material comprises the semiconductor composite material described in any one of claims 1 to 5; or the semiconductor composite material prepared by the preparation method described in any one of claims 6 to 8.

10. A semiconductor device, characterized in that: It comprises the semiconductor composite material as described in any one of claims 1 to 5; or the semiconductor composite material prepared by the preparation method as described in any one of claims 6 to 8; or the electron collecting end as described in claim 9.