Semiconductor material and semiconductor structure comprising the same

Abstract

A semiconductor material includes a metal, a first metal oxide covering the metal, wherein the first metal oxide is a metal bronze-like oxide, a second metal oxide covering the first metal oxide, and another first metal oxide covering the second metal oxide. A semiconductor structure including the semiconductor material is also provided.

Description

Technical Field

[0001] This application relates to a semiconductor material and a semiconductor structure comprising the aforementioned semiconductor material, and more particularly to a semiconductor material comprising a metallic bronze oxide and a semiconductor structure comprising the aforementioned semiconductor material. Background Technology

[0002] With the development of science and technology, countries around the world have gradually begun to pay attention to the harm of volatile organic compounds (VOCs) to humans. In particular, the European Union and the World Health Organization have begun to promote relevant policies. As a result, sensors are widely used in electronic devices to detect various volatile organic compounds in the environment, such as disinfectants, hand sanitizers, paints, coatings, interior decoration, fumes, and volatile organic compounds generated by industrial activities.

[0003] Existing technologies generally require high-temperature heating to locally heat the sensor (250-450°C) in order to detect gas. However, high temperatures may pose a risk of gas explosion due to volatile organic compounds. Furthermore, the heaters required for high-temperature heating consume the power of the components. In addition, sensors using high-temperature heating methods require additional consideration of heat insulation and heat dissipation components. Therefore, the sensor size needs to be increased, further increasing costs or limiting applications.

[0004] Therefore, although the existing sensors generally meet the requirements, they are not satisfactory in all aspects and still need further improvement. Summary of the Invention

[0005] This application provides a semiconductor material, comprising: a metal; a first metal oxide coating the metal, wherein the first metal oxide is a bronze-type oxide; a second metal oxide coating the first metal oxide; and another first metal oxide coating the second metal oxide.

[0006] In some embodiments, the first metal oxide has a structure as shown in general formula 1: A x M y O z (General Formula 1), wherein A comprises at least one cation, M comprises at least one transition metal ion, a metalloid ion, and a carbon ion, and the values ​​of x, y, and z balance the charge number of General Formula 1, where x is a positive integer between 1 and 12, y is a positive integer between 1 and 6, and z is a positive integer between 1 and 30. In some embodiments, the first metal oxide may also comprise a peroxide.

[0007] In some embodiments, A includes at least one of hydrogen ions, alkali metal ions, alkaline earth metal ions, rare earth metal ions, and ammonium ions, and M includes at least one of tin, titanium, zirconium, cerium, hafnium, molybdenum, tungsten, vanadium, copper, iron, cobalt, nickel, manganese, niobium, tantalum, rhenium, ruthenium, platinum, silicon, boron, germanium, arsenic, and carbon.

[0008] In some embodiments, the first metal oxide and the second metal oxide are semiconductors.

[0009] In some embodiments, the first metal oxide and the second metal oxide are each of type n or type p.

[0010] In some embodiments, the metal includes iron, cobalt, nickel, silver, aluminum, copper, zinc, titanium, zirconium, indium, tin, chromium, manganese, tungsten, molybdenum, the aforementioned alloys, or combinations thereof.

[0011] In some embodiments, the distance between any side of a metal and its opposite side is called the axial length, and the metal has a minimum axial length of 5 nm to 500 nm.

[0012] In some embodiments, the first metal oxide has a first thickness of 1 nm to 20 nm.

[0013] In some embodiments, the second metal oxide has a second thickness of 5 nm to 10 nm.

[0014] In some embodiments, a covalent bond or ionic bond is formed between the first metal oxide and the metal, and a covalent bond or ionic bond is formed between the first metal oxide and the second metal oxide.

[0015] Other embodiments of this application provide a semiconductor structure, including: a substrate; sensing electrodes disposed on the substrate and divided into multiple sensing blocks; and a sensing layer disposed between the sensing blocks, wherein the sensing layer includes multiple semiconductor materials, and in a cross-sectional view, the first metal oxide, the second metal oxide, and the metal of the multiple semiconductor materials are arranged alternately.

[0016] In other embodiments, the semiconductor structure is configured to detect target gases, including reducing gases.

[0017] In other embodiments, the reducing gas includes alcohol and toluene. The sensitivity of the semiconductor structure is positively correlated with the alcohol concentration and negatively correlated with the toluene concentration. The sensitivity is defined as follows: sensitivity = Rg / Ra, where Rg = the resistance of the semiconductor structure under the target gas and Ra = the resistance of the semiconductor structure under dry air.

[0018] In other embodiments, the semiconductor structure further includes an adhesion layer disposed between the sensing layer and the sensing electrode, wherein the adhesion layer is a metallic bronze-based oxide.

[0019] In other embodiments, the distance between any side of the metal of the sensing layer and its opposite side is the axial length and the metal has a minimum axial length, the sensing blocks are spaced apart by a distance, and the ratio of the minimum axial length of the metal to the distance is 1:300 to 1:30000.

[0020] To make the features of this application clear and easy to understand, embodiments are provided below in conjunction with the accompanying drawings for detailed explanation. For other precautions, please refer to the technical field. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0022] Figure 1A This is a cross-sectional view of a semiconductor material according to some embodiments of this application.

[0023] Figure 1B This is a cross-sectional view of another semiconductor material according to some embodiments of this application.

[0024] Figure 1C This is a cross-sectional view of another semiconductor material according to some embodiments of this application.

[0025] Figure 2 This is a top view of a semiconductor structure according to some embodiments of this application.

[0026] Figure 3A , Figure 3B , Figure 3C According to one embodiment of this application, the diagram illustrates along... Figure 2 A partial cross-sectional view of the A-A' line segment is used to illustrate the various intermediate processes of the semiconductor structure.

[0027] Figure 3D This is an embodiment of the present application, illustrated. Figure 3C Enlarged view of the dashed line portion.

[0028] Figure 4A , Figure 4B , Figure 4C , Figure 4D According to another embodiment of this application, the diagram is drawn along... Figure 2 A partial cross-sectional view of the A-A' line segment is used to illustrate the various intermediate processes of the semiconductor structure.

[0029] Figure 4E According to another embodiment of this application, the diagram is drawn along... Figure 4D Enlarged view of the dashed line portion.

[0030] Figure 5 It is illustrated along some embodiments of this application. Figure 3D or Figure 4E A partial cross-sectional schematic diagram of the semiconductor structure of the B-B' line segment.

[0031] Figure 6A Based on some embodiments of this application, a graph illustrating the resistance of a semiconductor structure to alcohol versus time is shown.

[0032] Figure 6B Based on some embodiments of this application, a scatter plot of the sensitivity and concentration distribution of a semiconductor structure to alcohol is illustrated.

[0033] Figure 7A Based on some embodiments of this application, a graph illustrating the resistance of a semiconductor structure to toluene versus time is shown.

[0034] Figure 7B Based on some embodiments of this application, a scatter plot of the sensitivity and concentration distribution of a semiconductor structure to toluene is illustrated.

[0035] Symbol explanation:

[0036] 10: Substrate

[0037] 20: Sensing electrode

[0038] 20S: Sensing Block

[0039] 30: Insulation layer

[0040] 40: Adhesion layer

[0041] 50: Sensing layer

[0042] 52: Semiconductor Materials

[0043] 52a: Metal

[0044] 52b: First metal oxide

[0045] 52c: Second metal oxide

[0046] 100: Semiconductor Structure

[0047] 200: Semiconductor Structure

[0048] d: diameter

[0049] H: Height

[0050] L: Distance

[0051] s: side length

[0052] t: thickness

[0053] T1: First thickness

[0054] T2: Second thickness

[0055] A-A': line

[0056] B-B': Line Detailed Implementation

[0057] Numerous embodiments or examples are provided below for implementing different elements of the provided subject matter. Specific examples of each element and its configuration are described below to simplify the description of this application. Of course, these are merely examples and are not intended to limit this application. For instance, if the description refers to a first element formed on a second element, it may include embodiments where the first and second elements are in direct contact, or embodiments where an additional element is formed between the first and second elements such that they are not in direct contact. Furthermore, this application may use repeated element symbols in various examples. Such repetition is for the purpose of brevity and clarity, and is not intended to indicate a relationship between the different embodiments and / or configurations discussed.

[0058] Furthermore, spatially relative terms may be used, such as "below," "under," "lower," "above," "higher," etc., to facilitate the description of the relationship between one or more components or features in the diagram. Spatially relative terms are used to include different orientations of the device in use or operation, as well as the orientations described in the diagram. When the device is turned to different orientations (rotated 90 degrees or other orientations), the spatially relative adjectives used will also be interpreted according to the orientation after the turn.

[0059] It should be understood that additional operational steps may be performed before, during, or after the method, and in other embodiments of the method, some operational steps may be replaced or omitted.

[0060] In this text, the terms "about," "approximately," and "substantially" typically indicate a range of 5%, preferably 3%, more preferably 1%, or 2%, or 1%, or 0.5%, within a given value or range. The given quantity is an approximate quantity; that is, even without specific mention of "about," "approximately," or "substantially," the meaning of "about," "approximately," or "substantially" is implied.

[0061] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It is understood that these terms, for example, as defined in a commonly used dictionary, should be interpreted as having a meaning consistent with the relevant art and the background or context of this application, and should not be interpreted in an idealized way.

[0062] Existing technologies generally require localized heating (250-450°C) of the sensor to detect gas. However, high-temperature heating carries drawbacks such as the risk of gas explosion, increased power consumption, and higher costs. To address these issues, this application provides a metal-semiconducting metal oxide (metal-SMOX) as the sensing layer of a semiconductor structure. This allows the semiconductor structure to operate at room temperature and significantly improves its gas selectivity, thus resolving the gas explosion risk and gas discrimination problems associated with high-temperature heating.

[0063] The following provides a detailed description of the semiconductor materials and semiconductors provided in this application. It should be understood that the specific elements and arrangements described below are merely simple and clear descriptions of some embodiments of this application, and are not intended to limit the scope of this application.

[0064] [Semiconductor Materials]

[0065] Figure 1A This is a cross-sectional view of a semiconductor material 52 according to some embodiments of the present application, wherein the semiconductor material 52 may be nanoparticles, nanotubes or nanowires. Figure 1B This is a cross-sectional view of another semiconductor material 52 according to some embodiments of this application, wherein the semiconductor material 52 may be nanoflakes or nanosheets. Figure 1C This is a cross-sectional view of another semiconductor material 52, illustrated according to some embodiments of this application, wherein the semiconductor material 52 may be nanocubes. (Refer to...) Figures 1A to 1C The semiconductor material 52 includes a metal 52a, a first metal oxide 52b, and a second metal oxide 52c. The first metal oxide 52b encapsulates the metal 52a, the second metal oxide 52c encapsulates the first metal oxide 52b, and another first metal oxide 52b encapsulates the second metal oxide 52c. In other words, the metal 52a is embedded in the first metal oxide 52b, the first metal oxide 52b is located between the metal 52a and the second metal oxide 52c, and the second metal oxide 52c is located between the two layers of the first metal oxide 52b.

[0066] In some embodiments, metal 52a has a catalytic effect, which can reduce the energy barrier for the reaction of semiconductor materials with target gases (such as volatile organic gases). Metal 52a may be iron (Fe), cobalt (Co), nickel (Ni), silver (Ag), aluminum (Al), copper (Cu), zinc (Zn), titanium (Ti), zirconium (Zr), indium (In), tin (Sn), chromium (Cr), manganese (Mn), tungsten (W), molybdenum (Mo), similar materials, alloys of the foregoing, or combinations thereof.

[0067] In some embodiments, metal 52a may be nanoparticles, nanocubes, nanotubes, nanowires, nanosheets, or nanoplatelets. In this document, the distance between any side of metal 52a and its opposite side is defined as the axial length (in...). Figure 1A , Figure 1B , Figure 1C The diameter d, thickness t, and side length s are respectively represented in the figures, where the shortest axis of metal 52a is from 5 nm to 500 nm, preferably from 6 nm to 300 nm. It should be noted that metal 52a of different shapes can independently have different ranges of diameter d and thickness t. For example, the shortest axis of the nanoparticle is as follows: Figure 1A The diameter d shown is 5nm to 15nm, and the shortest axis length of the nanotube is as follows: Figure 1A The inner diameter d of the nanowire is shown as 5nm to 15nm, and the shortest axis length of the nanowire is as follows. Figure 1A The inner diameter d of the nanosheet is shown to be 40 nm to 60 nm, and the shortest axis length of the nanosheet is as follows. Figure 1B For nanosheets with a thickness t ranging from 30 nm to 50 nm, the shortest axis length is as follows: Figure 1B For thicknesses t ranging from 50 nm to 500 nm, the shortest axis length of the nanocube is as follows: Figure 1C The side length s is shown as 5nm to 15nm.

[0068] According to the inventors' research, in some embodiments, if the shortest axis length is less than 5 nm, fragmentation may occur, making subsequent processes difficult. If the shortest axis length is greater than 500 nm, stable and uniform dispersion may be difficult, which is detrimental to subsequent processes. In some embodiments, if the diameter d of the nanoparticles is less than 5 nm, fragmentation may occur, making subsequent processes difficult. If the diameter d of the nanoparticles is greater than 15 nm, less gas may be adsorbed, resulting in a lower rate of gas sensing and poorer sensitivity.

[0069] For example, metal 52a can be silver nanoparticles, copper nanoparticles, nickel nanoparticles, silver nanowires, copper nanowires, or nickel nanowires.

[0070] The first metal oxide 52b is a highly active metal oxide bronze (MOB) that provides the metal 52a with environmental resistance, such as preventing the metal 52a from being affected by volatile gases and moisture, preventing the metal 52a from oxidizing, and preventing the metal 52a from melting at high temperatures, thereby further preventing an increase in resistance. In some embodiments, the first metal oxide 52b has a structure as shown in general formula 1:

[0071] A x M y O z (General Formula 1)

[0072] Wherein, A includes at least one cation;

[0073] M includes at least one of transition metal ions, metalloid ions, and carbon ions;

[0074] Among them, at least one of A and M is a metal ion;

[0075] The values ​​of x, y, and z balance the charge number in general formula 1, where x is a positive integer between 1 and 12, y is a positive integer between 1 and 6, and z is a positive integer between 1 and 30.

[0076] In some preferred embodiments, A includes at least one selected from hydrogen ions, alkali metal ions, alkaline earth metal ions, rare earth metal ions, and ammonium ions, and M includes at least one selected from tin, titanium, zirconium, cerium, hafnium, molybdenum, tungsten, vanadium, copper, iron, cobalt, nickel, manganese, niobium, tantalum, rhenium, ruthenium, platinum, silicon, boron, germanium, arsenic, and carbon. More preferably, A x M y O z This includes at least one peroxy group to facilitate the formation of a covalent or ionic bond between the first metal oxide 52b and the metal 52a via the peroxy group. For example, A x M y O z It can be HTiO2, HTiO3, HTi2O5, H2Ti2O3, H2Ti2O5, HMoO3, H2MoO3, HMoO4, H2MoO4, HMo2O5, H2Mo2O5, HMo2O6, HMo2O7, H2Mo2O7.

[0077] In some embodiments, the first metal oxide 52b may be an n-type or p-type semiconductor. For example, if M is iron (Fe), titanium (Ti), zirconium (Zr), tin (Sn), tungsten (W), or molybdenum (Mo), then the first metal oxide 52b is an n-type semiconductor; if M is cobalt (Co), nickel (Ni), copper (Cu), or manganese (Mn), then the first metal oxide 52b is a p-type semiconductor.

[0078] In this specification, "-" is used to separate different layers.

[0079] In some embodiments, when a first metal oxide 52b is deposited on metal 52a, the first metal oxide 52b can oxidize the surface of metal 52a to form a metal oxide. Furthermore, the first metal oxide 52b can protect the interior of metal 52a from oxidation, providing metal 52a with environmental resistance, preventing volatile gases from affecting metal 52a and preventing metal 52a from oxidizing. For example, the peroxide group of the first metal oxide 52b can react with metal 52a to form the following structure on the surface of metal 52a:

[0080] A x-m BM y O z-m

[0081] Where A, M, x, y, and z are defined as before;

[0082] B is metal 52a;

[0083] m is the number of oxygen atoms consumed when the first metal oxide 52b oxidizes metal B through its contained peroxy group, where xm is a positive integer not equal to 0 and zm is a positive integer not equal to 0.

[0084] In other words, covalent or ionic bonds are formed between the surface of metal 52a and the first metal oxide 52b. In this paper, A is referred to as... x M y O z -A x-m BM y O z-m The interface between the first metal oxide 52b and the metal 52a is represented, where A x M y O z For the first metal oxide 52b, A x-m BM y O z-m The surface of metal 52a is oxidized by the first metal oxide 52b.

[0085] In some embodiments, the inner first metal oxide 52b has a first thickness T1 of 1 nm to 20 nm, and the thickness of the outer first metal oxide 52b is greater than the first thickness T1 of the inner first metal oxide 52b. According to the inventors' research, in some embodiments, if the first thickness T1 is less than 1 nm, the sensing performance may change, with the overall performance biased towards the sensing performance of the second metal oxide 52c, resulting in poor selectivity for reducing gases. If the first thickness T1 is greater than 20 nm, the resistance of the sensing layer may be too high (>500 MOhms), requiring simultaneous high-temperature heating during operation, making operation at room temperature impossible.

[0086] The second metal oxide 52c is selected from materials that exhibit good activity towards reducing gases, and therefore can be used to sense reducing gases. In some embodiments, the second metal oxide 52c may be an n-type or p-type semiconductor. Preferably, the second metal oxide 52c has the structure shown in the following general formula 2:

[0087] M' i O j (General Formula 2)

[0088] Wherein, M' is the metal that makes the second metal oxide 52c n-type or p-type;

[0089] The values ​​of i and j balance the charge number in general formula 2, where i is a positive integer between 1 and 3, and j is a positive integer between 1 and 10. For example, M' i O j It can be iron oxide nanoparticles (Fe2O3 nanoparticles), zinc oxide nanoparticles (ZnO nanoparticles), titanium oxide nanoparticles (TiO2 nanoparticles), zirconium oxide nanoparticles (ZrO2 nanoparticles), indium oxide nanoparticles (In2O3 nanoparticles), tin oxide nanoparticles (SnO2 nanoparticles), tungsten oxide nanoparticles (WO3 nanoparticles), or molybdenum oxide nanoparticles (MoO3 nanoparticles).

[0090] Specifically, if M' is iron (Fe), zinc (Zn), titanium (Ti), zirconium (Zr), indium (In), tin (Sn), tungsten (W), or molybdenum (Mo), then the second metal oxide 52c is an n-type semiconductor. If M' is cobalt (Co), nickel (Ni), silver (Ag), copper (Cu), chromium (Cr), or manganese (Mn), then the second metal oxide 52c is a p-type semiconductor.

[0091] In some embodiments, for example, the second metal oxide 52c may react with the first metal oxide 52b as shown below:

[0092]

[0093] Where A, M, M', i, j, x, y, and z are defined as before and will not be repeated here, and k is A x M y O z The amount of peroxy group contained therein dehydrates and polymerizes on the surface of the second metal oxide 52c, where xk is a positive integer not equal to 0 and zk is a positive integer not equal to 0. In this paper, A is used as the reference. x-k M y O z-k -M' i O j The interface between the first metal oxide 52b and the second metal oxide 52c is represented, where A x-k M y O z-k For the first metal oxide 52b, M' i O j The first metal oxide 52b and the second metal oxide 52c form covalent or ionic bonds, resulting in a homogeneous or heterogeneous interface between them. Furthermore, either the first metal oxide 52b or the second metal oxide 52c contains adsorbed oxygen species. x M y O z The included peroxy group can provide the first metal oxide 52b or the second metal oxide 52c with more adsorbed oxygen-containing substances than ordinary metal oxides. Due to the presence of adsorbed oxygen-containing substances, it will have a higher affinity for polar compounds in reducing gases, thus distinguishing between polar and non-polar compounds in reducing gases. For example, it can distinguish between alcohol and toluene due to their different affinities. In addition, compared to operation at high temperatures, at room temperature, the first metal oxide 52b or the second metal oxide 52c has more adsorbed oxygen-containing substances, which increases the affinity for reducing gases and results in better reactivity. Therefore, reducing gases can be sensed at room temperature.

[0094] In some embodiments, the second metal oxide 52c has a second thickness T2 of 5 nm to 10 nm. According to the inventors' research, in some embodiments, if the second thickness T2 is less than 5 nm, the sensing performance may change, becoming more biased towards the sensing performance of the first metal oxide 52b, with poorer sensing performance for reducing gases at room temperature. If the second thickness T2 is greater than 10 nm, the sensing performance may change, becoming more biased towards the sensing performance of the second metal oxide 52c, with poorer sensing performance for reducing gases at room temperature.

[0095] In some embodiments, a third metal oxide may optionally be deposited on the second metal oxide 52c (not shown) to adjust the semiconductor material 52 to optimized electrical properties. The definition of the third metal oxide is the same as that of the second metal oxide 52c, and will not be repeated here. The materials of the third metal oxide and the second metal oxide 52c may be the same or different.

[0096] In some embodiments, the method for forming semiconductor material 52 may include the following steps: In the first step of preparation, a mixed solution of a first metal oxide 52b and a metal 52a is prepared. Specifically, 0.1 wt% to 10 wt% of a metal B solution (metal 52a) and 0.01 wt% to 10 wt% of a bronze-like compound A are mixed. x M y O z A solution (first metal oxide 52b) is mixed, wherein 0.1 wt% to 10 wt% of a metal B (52a) solution and 0.01 wt% to 10 wt% of a first metal oxide (52b) solution are mixed to a first mixed solution with a weight percentage of, for example, 10:1 to 1000:1. For example, 4 wt% of a metal B (52a) solution and 0.2 wt% of a first metal oxide (52b) solution are mixed in a 1:1 ratio to obtain the first mixed solution. The metal B solution is preferably 0.5 wt% to 5 wt%, for example, 2 wt% or 4 wt%. Semiconductor material 52 made with 4 wt% metal B solution has lower resistance and better electrical properties, and a faster reaction time compared to semiconductor material 52 made with 2 wt% metal B solution. Metal bronze compound A x M y O z The solution is preferably 0.1 wt% to 2 wt%, for example 0.2 wt%. Furthermore, the aforementioned first mixed solution comprises a core-shell structure of a first metal oxide 52b and a metal 52a, referred to herein as A. x M y O z -A x- m BM y O z-m -B indicates that B is the central layer and A is the central layer.x M y O z As the outermost layer, A x-m BM y O z-m It is located between the central layer B and the outermost layer A x M y O z The oxide layer of the metal. Among them, A, B, M, m, x, y, and z are defined as before and will not be repeated here.

[0097] In the second step of the preparation, a mixed solution of the first metal oxide 52b and the second metal oxide 52c is prepared. Specifically, 0.1 wt% to 20 wt% of the second metal oxide 52c solution is mixed with 0.01 wt% to 10 wt% of a metallic bronze compound A. x M y O z A solution (first metal oxide 52b) is mixed, wherein 0.01 wt% to 10 wt% of the first metal oxide (52b) solution is mixed with 0.1 wt% to 20 wt% of the second metal oxide (52c) solution to a weight percentage of 10:1 to 2000:1, for example, 1 wt% of the first metal oxide (52b) solution and 10 wt% of the second metal oxide (52c) solution are mixed in a 1:1 ratio to obtain a second mixed solution of first metal oxide 52b and second metal oxide 52c. This paper uses A... x-k M y O z-k -M' i O j Indicated. Among them, M' i O j The definitions are the same as before and will not be repeated here. The second metal oxide 52c solution is preferably 0.1 wt% to 10 wt%, for example, 10 wt%. Metal bronze compound A x M y O z The solution is preferably 0.1 wt% to 2 wt%, for example, 1 wt%.

[0098] In the third step of preparation, a sensing solution is made. Specifically, the first mixed solution and the second mixed solution are mixed in an equal volume ratio of 1:1 to obtain the sensing solution.

[0099] The following will provide a detailed explanation of semiconductor structures:

[0100] [Semiconductor Structure]

[0101] Figure 2 This is a top view of a semiconductor structure according to some embodiments of this application. Figures 3A to 3CAccording to the first embodiment of this application, it is along Figure 2 A partial cross-sectional view of line segment A-A' is used to illustrate the various intermediate processes of semiconductor structure 100.

[0102] like Figure 2 and Figure 3A As shown, a sensing electrode 20 is formed on a substrate 10. For example, the substrate 10 may be a polymer substrate, such as containing benzocyclobutene (BCB), epoxy resin, polyimide (PI), polybenzoxazole, or combinations thereof. Furthermore, the substrate 10 may contain elemental semiconductors (e.g., silicon or germanium), compound semiconductors (e.g., silicon carbide, gallium nitride, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, indium antimonide, etc.), or alloy semiconductors (e.g., silicon germanium, gallium arsenide phosphide, aluminum indium phosphide, aluminum gallium arsenide, gallium indium arsenide, gallium indium phosphide, gallium indium arsenide). The substrate 10 may be a semiconductor-on-insulator (SOI) substrate, or a combination thereof, but the embodiments of this application are not limited thereto. The substrate 10 may be a base plate, a buried oxide layer disposed on the base plate, and a semiconductor layer disposed on the buried oxide layer. Alternatively, the substrate 10 may be a semiconductor wafer (e.g., a silicon wafer or other suitable semiconductor wafer).

[0103] The sensing electrode 20 may comprise a conductive material, such as a metal, a metal silicide, a similar material, or a combination thereof, but this embodiment is not limited thereto. For example, the metal may comprise gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), titanium (Ti), chromium (Cr), tungsten (W), aluminum (Al), copper (Cu), a similar material, an alloy thereof, or a combination thereof. Furthermore, the sensing electrode 20 may be formed on the substrate 10 by chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), evaporation, sputtering, electroplating, additive manufacturing (i.e., 3D printing), spin coating, screen printing, other suitable processes, or combinations thereof, but this embodiment is not limited thereto.

[0104] Continue to refer to Figure 2 In some embodiments, the sensing electrode 20 is an interdigital electrode, therefore in Figure 3A In the cross-sectional view, the sensing electrode 20 is divided into multiple sensing blocks 20S.

[0105] Continue to refer to Figure 3B An insulating layer 30 is formed on the substrate 10. Specifically, the insulating layer 30 may be formed on the substrate 10 in the space not occupied by the sensing electrode 20. That is, the insulating layer 30 may be formed between the sensing blocks 20S. The insulating layer 30 may, for example, contain phenylcyclobutene, epoxy resin, polyimide, aluminum nitride, silicon nitride, or other suitable materials, but the embodiments of this application are not limited thereto. In addition, the insulating layer 30 may be deposited on the substrate 10 by techniques such as spin coating, chemical vapor deposition, thermal oxidation, thermal nitriding, multilayer fabrication, and screen printing, but the embodiments of this application are not limited thereto.

[0106] like Figure 3C As shown, in some embodiments, the aforementioned semiconductor material 52 is formed between sensing blocks 20S as a sensing layer 50 to form a semiconductor structure 100, wherein an insulating layer 30 separates the sensing layer 50 from the substrate 10. The sensing layer 50 can be deposited by techniques such as drop casting, spraying, inkjet printing, micro-contact printing, dispensing machine, multilayer fabrication, screen printing, or photolithography.

[0107] Figure 3D The illustration is based on the first embodiment of this application. Figure 3C An enlarged view of the dotted line portion. (See image below.) Figure 3D As shown, the sensing layer 50 is located between the sensing blocks 20S and has multiple semiconductor materials 52, wherein in the cross-sectional view ( Figure 5 In the semiconductor material 52, the first metal oxide 52b, the second metal oxide 52c, and the metal 52a are arranged alternately. The second metal oxide 52c is adjacent to the first metal oxide 52b and does not contact the metal 52a. For simplicity, only a portion of the semiconductor material 52 is shown in the figure as an example, but its quantity and arrangement are not intended to limit this application. Furthermore, the sensing layer 50 has a height H of 100nm to 500μm and a length L of 10μm to 1000μm, meaning that the sensing blocks 20S are spaced apart by a distance L. The shortest axis of the semiconductor material 52 is (… Figures 1A to 1C The ratio of the diameter d, thickness t or side length s shown to the distance L is 1:20 to 1:200000, preferably 1:300 to 1:40000.

[0108] According to the inventors' research, in some embodiments, if the height H of the sensing layer 50 is less than 100 nm, the semiconductor material 52 cannot be vertically overlapped along the direction of height H, which may result in a large electrical error. If the height H is greater than 500 μm, the sensing effect may be poor. In some embodiments, if the length L is less than 10 μm, the rate of change may be small. If the length L is greater than 1000 μm, the resistance value may be too large, making the sensor difficult to implement. In some embodiments, if the ratio of the shortest axis length to the distance L is less than 1:20, the rate of change may be small. If the ratio of the shortest axis length to the distance L is greater than 1:200000, the resistance value may be too large, making the sensor difficult to implement.

[0109] The target gas detected by the semiconductor structure 100 may include volatile organic compounds (VOCs) gas, preferably reducing gases, such as alcohol, isopropanol, acetone, and toluene.

[0110] This application uses a core-shell structure of metal and metal oxide as a semiconductor material 52 in the sensing layer 50 of a semiconductor structure 100. The semiconductor material 52 has a first metal oxide 52b coating the metal to protect the metal 52a from volatile organic gases and prevent internal oxidation of the metal 52a. Furthermore, the first metal oxide 52b can form covalent or ionic bonds with the second metal oxide 52c that coats it. Since the first metal oxide 52b and the second metal oxide 52c form a junction, there is a tradeoff effect at the junction for reducing and oxidizing molecules, thus enabling the identification of reducing gases. Furthermore, the second metal oxide 52c contains metallic bronze compounds, which have more adsorbed oxygen species than ordinary metal oxides. This results in the second metal oxide 52c having different affinities for different polar gases. Therefore, there is a secondary trade-off effect for polar and nonpolar molecules, with better affinity for polar gases, thus further improving the distinguishability. For example, the second metal oxide 52c has different affinities for polar alcohol and nonpolar toluene, and the sensitivity to alcohol and toluene is positively correlated with the concentration trend, while the sensitivity to toluene is negatively correlated with the concentration trend. Therefore, it has significant distinguishability when the target gas contains both alcohol and toluene. Furthermore, since the sensing layer 50 of this application uses the semiconductor material 52 mentioned above, and this semiconductor material 52 has more adsorbed oxygen species than general metal oxides, it has a higher affinity for polar gases at room temperature, while having a lower affinity for non-polar gases. Therefore, the semiconductor structure 100 of this application can be used to identify and measure polar and non-polar reducing gases at room temperature and pressure.

[0111] Figure 4A , Figure 4B , Figure 4C , Figure 4D According to the second embodiment of this application, it is along Figure 2 A partial cross-sectional view of line segment A-A' is used to illustrate the various intermediate processes of semiconductor structure 200. Figure 4E The illustration is based on a second embodiment of this application. Figure 4D The enlarged view of the dashed section is used to illustrate the various intermediate processes of the semiconductor structure 200. The main difference between the second embodiment and the first embodiment is that the semiconductor structure 200 has an adhesion layer 40.

[0112] Figures 4A to 4B The steps are the same as those in the first embodiment. Figures 3A to 3B The steps are the same and will not be repeated here. Continue to refer to... Figure 4CIn some embodiments, before forming the sensing layer 50, the adhesion layer 40 is first formed on the insulating layer 30 and positioned between the sensing blocks 20S. For example... Figure 4C As shown, the adhesion layer 40 can be formed on the sidewalls of each sensing block 20S. Since the adhesion layer 40 is a highly active metallic bronze-based compound, it can serve as the sensing layer 50 formed subsequently (see reference). Figure 4D The adhesion promoter facilitates the adhesion between the sensing layer 50 and the sensing block 20S and the insulating layer 30. Furthermore, the adhesion layer 40 can be compliantly formed on the insulating layer 30 and the sidewalls of the sensing block 20S via a deposition process. Examples of deposition processes include chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), evaporation, sputtering, electroplating, additive manufacturing (i.e., 3D printing), screen printing, other suitable processes, or combinations thereof.

[0113] like Figure 4D As shown, the sensing layer 50 is formed on the adhesion layer 40. That is, the sensing layer 50 is disposed between the sensing blocks 20S and the substrate 10 through the adhesion layer 40.

[0114] Figure 4E This is an embodiment of the present application, illustrated. Figure 4D An enlarged view of the dotted line portion. (See image below.) Figure 4E As shown, the sensing layer 50 is located between the sensing blocks 20S and has multiple semiconductor materials 52, wherein in the cross-sectional view ( Figure 5 In the first metal oxide 52b, the second metal oxide 52c and the metal 52a are arranged alternately.

[0115] Figure 5 It is illustrated along some embodiments of this application. Figure 3D The semiconductor structure 100 along the B-B' segment or Figure 4E The schematic diagram shows a partial cross-sectional view of the semiconductor structure 200 of the B-B' line segment. It should be noted that, for the sake of simplification, only a portion of the metal 52a, the first metal oxide 52b, and the second metal oxide 52c are shown in the diagram as examples. For clarity, the cross-section of the B-B' line segment is enlarged, but its quantity, proportion, and arrangement are not intended to limit this application.

[0116] like Figure 5 As shown, in some embodiments, the semiconductor material 52 of the sensing layer 50 is disposed between the sensing blocks 20S. The second metal oxide 52c in the semiconductor material 52 is adjacent to the first metal oxide 52b, and the second metal oxide 52c is not in contact with the metal 52a. The first metal oxide 52b and the second metal oxide 52c are semiconductors, and the first metal oxide 52b and the second metal oxide 52c can each be independently n-type or p-type. Therefore, the first metal oxide 52b and the second metal oxide 52c can both be n-type or both be p-type. Alternatively, the first metal oxide 52b and the second metal oxide 52c can be n-type and p-type, or p-type and n-type, respectively, so that the sensing layer 50 has an alternating arrangement of n-type and p-type on the B-B' cross-section. Preferably, the first metal oxide 52b (HTiO2, HTiO3, HTi2O5, H2Ti2O3, H2Ti2O5, HMoO3, H2MoO3, HMoO4, H2MoO4, HMo2O5, H2Mo2O5, HMo2O6, HMo2O7, H2Mo2O7) and the second metal oxide 52c are iron oxide nanoparticles (Fe2O3 nanoparticles), zinc oxide nanoparticles (ZnO nanoparticles), titanium oxide nanoparticles (TiO2 nanoparticles), zirconium oxide nanoparticles (ZrO2 nanoparticles), indium oxide nanoparticles (In2O3 nanoparticles), tin oxide nanoparticles (SnO2 nanoparticles), tungsten oxide nanoparticles (WO3 nanoparticles), and molybdenum oxide nanoparticles (MoO3 nanoparticles), which is beneficial for regulating the adsorbed oxygen species to adjust the affinity of polar / nonpolar gases.

[0117] [Measurement of resistance versus time curve]

[0118] Figure 6A This is a resistance-time curve of the semiconductor structure to alcohol according to an embodiment of this application. The measurement method involves sequentially introducing target gases—alcohol—of different concentrations into the semiconductor structure of this embodiment and measuring the resistance-time curve of the semiconductor structure. Figure 6A As shown, specifically, during the interval of 2-6 minutes with dry air, a target ambient gas with an alcohol concentration of 50-5050 ppm is introduced for 1-5 minutes each time. The alcohol ambient gas is as follows: Figure 6AAs shown in the dashed graph representing alcohol gas concentrations of 50ppm, 220ppm, 490ppm, 1000ppm, 3000ppm, and 5050ppm, the resistance value measured by the semiconductor structure in this embodiment increases with increasing alcohol concentration.

[0119] Figure 7A The image shows the resistance-time curve of the semiconductor structure to toluene in an embodiment of this application. The measurement method involves introducing a target gas—toluene—at a concentration of 50-5050 ppm into the semiconductor structure of this embodiment and measuring the resistance-time curve of the semiconductor structure. Figure 7A As shown, during the interval of 2-6 minutes with dry air, a target ambient gas with a toluene concentration of 300-3000 ppm is introduced for 1-5 minutes. The toluene ambient gas is as follows: Figure 7A The dashed line diagram shows the ranges of toluene gas concentrations of 300ppm, 600ppm, 2000ppm, 2500ppm, and 3000ppm. The resistance value measured by the semiconductor structure in this embodiment decreases as the toluene concentration increases.

[0120] [Measurement Sensitivity vs. Concentration Scatter Plot]

[0121] Figure 6B This is a graph showing the relationship between the sensitivity of the semiconductor structure and the alcohol concentration in an embodiment of this application. First, the resistance of the semiconductor structure in dry air is measured. Then, the resistance values ​​of the semiconductor structure at different concentrations of target gas, previously measured, are substituted into Equation 1 to obtain the sensitivity of the semiconductor structure to the target gas. Finally, a graph showing the relationship between the sensitivity and the concentration of the target gas is obtained:

[0122] Sensitivity = Rg / Ra (Equation 1)

[0123] Rg = Resistance of the semiconductor structure under the target gas.

[0124] Ra = the resistance of a semiconductor structure in dry air.

[0125] like Figure 6B As shown, the sensitivity of the semiconductor structure in this embodiment increases with increasing alcohol concentration; therefore, the sensitivity of the semiconductor structure is positively correlated with alcohol concentration. Conversely, the relationship between the sensitivity of the semiconductor structure in this embodiment and toluene concentration is shown in the graph below. Figure 7B As shown, the sensitivity of the semiconductor structure decreases as the toluene concentration increases, therefore the sensitivity of the semiconductor structure is negatively correlated with the toluene concentration.

[0126] Table 1 shows the relationship between the sensitivity and concentration of the semiconductor structure in the embodiments of this application and Comparative Examples 1-6 for the target gas (alcohol, toluene).

[0127] [Table 1]

[0128] gas This application Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Alcohol rise decline decline decline decline decline decline Toluene decline decline decline decline decline decline decline Distinguishing yes no no no no no no

[0129] Comparative Examples 1-6 in Table 1 are commercially available sensors. The models of Comparative Examples 1-6 are, respectively, the MQ-2 and MQ-3 manufactured by Hanwei Electronics Co., Ltd. which use coil heating, the TGS2620 manufactured by Figaro Technology Co., Ltd. which uses a heater, the CCS801 manufactured by Austria Microelectronics Co., Ltd., the TGS8100 manufactured by Figaro Technology Co., Ltd., the CCS811 manufactured by Austria Microelectronics Co., Ltd., and the ASMLVP2 manufactured by Austria Microelectronics Co., Ltd. which use a heater made of microelectromechanical systems.

[0130] As can be seen from the results in Table 1, this application uses the following... Figure 1A The core-shell structure of metal and metal oxide shown is used as a semiconductor material in the sensing layer of a semiconductor structure. Because the semiconductor material has a first metal oxide coating the metal, it protects the metal from volatile organic gases and prevents metal oxidation. Furthermore, the first metal oxide can form covalent or ionic bonds with the second metal oxide, providing a semiconductor interface between the two oxides. Since the second metal oxide contains bronze-like compounds, it has more adsorbed oxygen species than ordinary metal oxides. Therefore, the second metal oxide of the semiconductor material has different affinities for different polar gases, resulting in different affinities for alcohol and toluene, both reducing gases. Consequently, the sensitivity increases and decreases with increasing concentrations of alcohol and toluene, respectively, thus demonstrating discriminative power. In contrast, the sensitivity of Comparative Examples 1-6 only increases or decreases with increasing concentrations of alcohol and toluene, therefore lacking discriminative power.

[0131] Furthermore, this application uses, as Figure 1A The core-shell structure of metal and metal oxide shown is used as a semiconductor material in the sensing layer of a semiconductor structure. Because this semiconductor material has a high affinity for reducing gases and a low energy barrier, it can be used to measure reducing gases at room temperature and pressure, avoiding the risk of gas explosion caused by heating, reducing power consumption, and lowering costs. In contrast, Comparative Examples 1-6 all require high-temperature heating (250-450°C) to locally heat the semiconductor structure for measurement, which carries the disadvantages of gas explosion risk, increased power consumption, and increased costs.

[0132] The features of several embodiments have been summarized above to enable those skilled in the art to better understand the viewpoints of the embodiments described herein. Those skilled in the art should understand that other processes and structures can be easily designed or modified based on the embodiments described herein to achieve the same purpose and / or advantages as the embodiments described herein. Those skilled in the art should also understand that such equivalent structures do not depart from the spirit and scope of this application, and various changes, substitutions, and replacements can be made without departing from the spirit and scope of this application. Therefore, the scope of protection of this application shall be determined by the claims.

Claims

1. A semiconductor material, characterized in that, include: The metal is iron, cobalt, nickel, silver, aluminum, copper, zinc, titanium, zirconium, indium, tin, chromium, manganese, tungsten, molybdenum, or an alloy of iron, cobalt, nickel, silver, aluminum, copper, zinc, titanium, zirconium, indium, tin, chromium, manganese, tungsten, and molybdenum, or a combination of iron, cobalt, nickel, silver, aluminum, copper, zinc, titanium, zirconium, indium, tin, chromium, manganese, tungsten, and molybdenum; A first metal oxide, coating the metal, wherein the first metal oxide is a bronze-type oxide containing a peroxide, and the first metal oxide has a structure as shown in general formula 1: AxMyOz (General Formula 1) Wherein, A includes at least one of hydrogen ions, alkali metal ions, alkaline earth metal ions, rare earth metal ions, and ammonium ions. M includes at least one of tin, titanium, zirconium, cerium, hafnium, molybdenum, tungsten, vanadium, copper, iron, cobalt, nickel, manganese, niobium, tantalum, rhenium, ruthenium, platinum, silicon, boron, germanium, arsenic and carbon; The values ​​of x, y, and z balance the charge number in general formula 1, where x is a positive integer between 1 and 12, y is a positive integer between 1 and 6, and z is a positive integer between 1 and 30. A second metal oxide, coating the first metal oxide, is used to sense reducing gases; and Another first metal oxide coats the second metal oxide.

2. The semiconductor material as described in claim 1, characterized in that, The first metal oxide and the second metal oxide are semiconductors.

3. The semiconductor material as described in claim 1, characterized in that, The distance between any side of the metal and its opposite side is the axial length, and the metal has a minimum axial length of 5 nm to 500 nm.

4. The semiconductor material as described in claim 1, characterized in that, The first metal oxide has a first thickness of 1 nm to 20 nm.

5. The semiconductor material as described in claim 1, characterized in that, The second metal oxide has a second thickness of 5 nm to 10 nm.

6. A semiconductor structure, characterized in that, include: substrate; Sensing electrodes are disposed on the substrate and are divided into multiple sensing blocks; and A sensing layer is disposed between the plurality of sensing blocks, wherein the sensing layer comprises a plurality of semiconductor materials as described in any one of claims 1 to 5, and in the cross-sectional view, the first metal oxide, the second metal oxide, and the metal of the plurality of semiconductor materials are arranged alternately.

7. The semiconductor structure as described in claim 6, characterized in that, Including: An adhesion layer is disposed between the sensing layer and the sensing electrode, wherein the adhesion layer is a metallic bronze oxide.

8. The semiconductor structure as described in claim 6, characterized in that, The metal of the sensing layer has an axial length between any side of it and its opposite side, and the metal has a shortest axial length. The sensing blocks are spaced apart by a distance, and the ratio of the shortest axial length of the metal to the distance is 1:20 to 1:200000.

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