Function-switchable oxide heterojunction photodiode and preparation method thereof

Abstract

The invention relates to the field of semiconductor devices, and discloses a function-switchable oxide heterojunction photodiode and a preparation method thereof, the function-switchable oxide heterojunction photodiode comprises an insulating substrate, an N-type oxide semiconductor and a P-type semiconductor which are arranged in sequence; an II-type energy band contact heterogeneous PN junction is formed on the interface of the P-type semiconductor and the N-type oxide semiconductor; the insulating substrate and the N-type oxide semiconductor are stacked; the P-type semiconductor is locally deposited on the N-type oxide semiconductor; the metal electrode comprises a P-type ohmic electrode and an N-type ohmic electrode, the P-type ohmic electrode is located on the P-type semiconductor, and the N-type ohmic electrode is located on the N-type oxide semiconductor. The P-type semiconductor and the N-type oxide semiconductor are adopted to construct the heterojunction, the characteristic that the natural oxygen vacancy defect energy level in the oxide semiconductor captures or releases carriers under bias voltage is utilized to convert the electrical characteristic of the heterojunction, and photoelectric detection and sensing calculation function switching of the device are achieved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and in particular to a function-switchable oxide heterojunction photodiode and a preparation method thereof. Background Art

[0002] With the emergence of emerging application scenarios such as smart homes, the demand for multifunctional devices is increasing. Traditional photodetectors can only achieve a single detection function. Although they can achieve multifunctionality by interconnecting with other functional devices or packaging them on the same chip, the coupling between modules will increase chip latency, power consumption, and area, which is not conducive to chip integration and miniaturization. In the era of big data, the demand for multifunctional integrated devices is increasing. Traditional multifunctional devices are achieved by interconnecting different functional units such as detectors through external circuits or integrating them on the same chip through packaging technology, which greatly restricts the development of chip integration.

[0003] In recent years, the excellent properties of two-dimensional materials have provided a material basis for the realization of multifunctional devices. By constructing a two-dimensional material heterojunction and applying appropriate excitation, dual functions can be superimposed in a single device, such as ReS2 / WSe2 heterojunction, MoTe2 / MoS2 heterojunction, and graphene / PEIE (polyetherimide) / organic body heterojunction (O-BHJ) multilayer structure heterojunction. The switching between photoelectric detection and other functions can be achieved through gate voltage modulation and wavelength modulation.

[0004] For example, the prior art CN202110550031.4 discloses a composition of silicon carbide, a single-layer graphene, gallium oxide and an electrode, wherein the single-layer graphene is arranged between the silicon carbide and the gallium oxide, and there are two electrodes, both of which are in contact and connected with the single-layer graphene.

[0005] Existing interconnection / integration schemes for different functional units involve coupling issues when interconnecting or integrating discrete devices, leading to delays and other issues that hinder device response speed. Furthermore, the interconnected or integrated chips consume more power and occupy more area, hindering the development of low-power and small-size chips.

[0006] Regarding the reconfigurable device solution of two-dimensional materials. Despite their excellent material properties, the stability and reliability of two-dimensional materials still have much room for improvement. In addition, device preparation methods, such as dry and wet transfer, have problems such as varying degrees of repeatability, uncontrollable interface quality, and low yield, which are not conducive to large-scale production. Summary of the Invention

[0007] The present invention addresses the problems of signal delay, increased power consumption, and uncontrollable, poor uniformity, and low yield in the preparation process of two-dimensional materials caused by the coupling of single-function devices in the prior art, and provides a function-switchable oxide heterojunction photodiode and a preparation method.

[0008] In order to solve the above technical problems, the present invention is solved by the following technical solutions: A function-switchable oxide heterojunction photodiode comprises an insulating substrate, an N-type oxide semiconductor and a P-type semiconductor arranged in sequence; the interface between the P-type semiconductor and the N-type oxide semiconductor forms a type II energy band contact heterojunction. An insulating substrate and an N-type oxide semiconductor are stacked; The P-type semiconductor is locally deposited on the N-type oxide semiconductor; It also includes metal electrodes; the metal electrodes include a P-type ohmic electrode and an N-type ohmic electrode, the P-type ohmic electrode is located on the P-type semiconductor, and the N-type ohmic electrode is located on the N-type oxide semiconductor.

[0009] Preferably, the N-type oxide semiconductor is an N-type oxide semiconductor having controllable oxygen defects.

[0010] Preferably, the N-type oxide semiconductor includes zinc oxide ZnO, indium tin oxide ITO, and gallium oxide Ga2O3.

[0011] Preferably, the thickness of the N-type oxide semiconductor is 100 nm to 300 nm.

[0012] Preferably, the insulating substrate is a rigid insulating substrate or a flexible insulating substrate; the insulating substrate includes sapphire Al2O3, iron-doped gallium oxide, mica, and polyimide film.

[0013] Preferably, the P-type semiconductor includes nickel oxide NiO and tin oxide SnO; and the thickness of the P-type semiconductor layer is 30 nm to 80 nm.

[0014] In order to solve the above technical problems, the present invention also provides a method for preparing a function-switchable oxide heterojunction photodiode, which is used to prepare the function-switchable oxide heterojunction photodiode, and the method comprises: Epitaxially growing an N-type oxide semiconductor on the surface of an insulating substrate; locally depositing a P-type semiconductor on the N-type oxide semiconductor; Metal electrodes are prepared on top of the N-type oxide semiconductor and the P-type semiconductor. The metal electrodes include a P-type ohmic electrode and an N-type ohmic electrode. The P-type ohmic electrode is located on the P-type semiconductor, and the N-type ohmic electrode is located on the N-type oxide semiconductor, thereby completing the preparation of the PN heterojunction diode.

[0015] Preferably, the method of epitaxially growing the N-type oxide semiconductor on the insulating substrate includes magnetron sputtering, metal organic chemical vapor deposition MOCVD, hydride vapor phase epitaxy HVPE or plasma enhanced chemical vapor deposition PECVD.

[0016] Preferably, the method of locally depositing the P-type semiconductor on the N-type semiconductor includes metal organic vapor phase epitaxy (MOCVD), electron beam evaporation or magnetron sputtering.

[0017] Preferably, metal electrodes are prepared on top of the N-type oxide semiconductor and the P-type semiconductor, and the methods used to prepare the metal electrodes include magnetron sputtering or electron beam evaporation.

[0018] The present invention has significant technical effects due to the adoption of the above technical solutions: The present invention utilizes the carrier capture and release capabilities of vacancy defect energy levels in oxides to design a heterojunction diode whose photoelectric properties can be switched with an external bias voltage, thereby realizing a multifunctional photoelectric device.

[0019] The present invention uses a P-type semiconductor and an N-type oxide semiconductor to construct a heterojunction, and utilizes the natural oxygen vacancy defect energy level in the oxide semiconductor to capture or release carriers under bias to convert the electrical properties of the heterojunction, thereby realizing the switching of the device's photoelectric detection and sensing functions.

[0020] The oxygen vacancy defects in the N-type oxide semiconductor of the present invention can be controlled by the growth process (oxygen content ratio) to achieve further performance optimization.

[0021] Compared with traditional interconnection or packaging devices, the present invention realizes dual-function integration in a single device, which will be beneficial to the development of chip integration and miniaturization in terms of response speed, power consumption and area.

[0022] The oxide heterojunction of the present invention can realize bias voltage regulation working mode switching, can realize single device dual-function integration, reduce chip area and signal conversion loss, improve collaborative efficiency, and reduce power consumption and cost.

[0023] The oxide heterojunction of the present invention can be directly prepared by silicon-compatible processes such as magnetron sputtering. The surface properties and oxygen vacancies of gallium oxide can be precisely controlled by doping, annealing, and interface modification (such as dry / wet processing). It has excellent interface control capabilities. In addition, the preparation process is mature and stable, with a high yield and good mass production potential.

[0024] The semiconductor process involved in the present invention is compatible with CMOS. Compared with two-dimensional material reconfigurable devices, the preparation process is mature and stable, with a high yield and mass production capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the oxide heterojunction diode of the present invention.

[0026] Figure 2 This is a schematic diagram of the staggered arrangement of the conduction band and the valence band of the present invention.

[0027] Figure 3-1 Schematic diagram of applying reverse bias in the present invention. Figure 3-2 It is a schematic diagram of applying forward bias in the present invention.

[0028] Figure 4 -a is a schematic diagram of cleaning and drying the substrate for preparing an oxide heterojunction diode according to the present invention.

[0029] Figure 4 -b is a schematic diagram of depositing N-type oxide semiconductor gallium oxide to prepare an oxide heterojunction diode according to the present invention.

[0030] Figure 4 -c is a schematic diagram of depositing P-type semiconductor nickel oxide to prepare an oxide heterojunction diode according to the present invention.

[0031] Figure 4 -d is a schematic diagram of the glue coating for preparing oxide heterojunction diodes according to the present invention.

[0032] Figure 4 -e is a schematic diagram of exposure and development of the oxide heterojunction diode prepared according to the present invention.

[0033] Figure 4 -f is a schematic diagram of depositing an N-type ohmic electrode for preparing an oxide heterojunction diode according to the present invention.

[0034] Figure 4 -g is a schematic diagram of the debonding process for preparing an oxide heterojunction diode according to the present invention.

[0035] Figure 4 -h is a schematic diagram of the glue coating for preparing oxide heterojunction diodes according to the present invention.

[0036] Figure 4 -i is a schematic diagram of exposure and development of an oxide heterojunction diode prepared according to the present invention.

[0037] Figure 4 -j is a schematic diagram of depositing a P-type ohmic electrode for preparing an oxide heterojunction diode according to the present invention.

[0038] Figure 4 -k is a schematic diagram of the debonding process for preparing an oxide heterojunction diode according to the present invention.

[0039] Among them, 1 is a substrate, 2 is an N-type oxide semiconductor, 3 is a P-type semiconductor, 4 is a metal electrode, 5 is a photoresist, 41 is a P-type ohmic contact electrode, and 42 is an N-type ohmic contact electrode. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0041] Example 1

[0042] An oxide heterojunction diode with switchable photoelectric detection and sensing functions comprises a substrate, an N-type oxide semiconductor, a P-type semiconductor and a metal electrode.

[0043] An N-type oxide semiconductor is arranged on a substrate; a P-type semiconductor covers the N-type oxide semiconductor; the P-type semiconductor and the N-type oxide semiconductor are in contact to form a PN junction; and electrodes are arranged on the P-type semiconductor and the N-type oxide semiconductor.

[0044] The substrate provides mechanical support, lattice matching conditions required for growth, and electrical insulation for the N-type oxide semiconductor; N-type oxide semiconductors have defect energy levels introduced by natural oxygen vacancies. These defect energy levels are located 1.0-1.3 eV below the conduction band and act as trap states or intermediate states to capture photogenerated electrons, forming retention states that support changes in the electrical properties of the heterojunction. The oxygen vacancy defect energy level in N-type oxide semiconductors can be controlled by growth process / interface modification process; The P-type semiconductor and the N-type oxide semiconductor form a type II band contact heterojunction to maximize the separation, transport and collection of photogenerated carriers; The electrodes form ohmic contacts with the P-type semiconductor and the N-type oxide semiconductor, respectively, without introducing additional resistance.

[0045] exist Figure 1 A heterojunction diode based on oxide semiconductor is designed in the present invention. The heterojunction diode based on oxide semiconductor adopts a heterojunction constructed by a P-type semiconductor and an N-type oxide semiconductor.

[0046] Figure 2 Among them, E V is the top energy level of the valence band, E C is the conduction band bottom energy level, E F The Fermi level is the same as the Fermi level. The heterojunction formed by the P-type semiconductor and the N-type oxide semiconductor forms a type II band contact. The conduction bands and valence bands of the P-type semiconductor and the N-type oxide semiconductor are staggered. Electrons in the N-type oxide semiconductor are depleted and migrate to the P-type semiconductor, while holes in the P-type semiconductor are depleted and migrate to the N-type semiconductor. Electrons and holes are physically isolated from each other on either side of the heterojunction, effectively reducing the probability of carrier recombination and improving the lifetime of photogenerated carriers. Simultaneously, the resulting built-in electric field accelerates the separation of photogenerated carriers, improving photocurrent collection efficiency. Natural oxygen vacancies in the N-type oxide semiconductor form defect levels. These defect levels can trap or release carriers, resulting in different electrical properties at the heterojunction surface. By applying an external bias to the heterojunction, the relative dominance of the built-in electric field and defect levels in carrier transport can be manipulated to achieve different device operating modes.

[0047] The first working mode is detection mode. Figure 3-1 Among them, E V is the top energy level of the valence band, E C is the bottom energy level of the conduction band, hv is the photon energy, E L It is a defect energy level; when a reverse bias is applied, the depletion region is further widened, the photoresponse is enhanced, and the increased electric field promotes the efficient separation, transport and collection of photogenerated carriers, thereby improving the response speed of the device and thus exhibiting the photodetection function.

[0048] The second working mode is the sensing and computing mode. Figure 3-2 Among them, E V is the top energy level of the valence band, E C is the bottom energy level of the conduction band, hv is the photon energy, E L When a forward bias is applied, the built-in electric field in the heterojunction is weakened, reducing the barrier height and facilitating carrier injection. In this state, defects such as oxygen vacancies in the N-type oxide semiconductor dominate the capture and release of carriers, significantly enhancing the persistent photoconductivity effect, presenting multi-level conduction states with long retention times, thus enabling photoelectric sensing and computing.

[0049] The thickness of the N-type semiconductor layer is 100 to 300nm to ensure the quality and photon absorption efficiency of the gallium oxide film; the thickness of the P-type semiconductor layer is 30 to 80nm to reduce the extinction rate while ensuring the quality of the material.

[0050] Example 2

[0051] Based on Example 1, this embodiment provides a method for manufacturing an oxide heterojunction diode with switchable photodetection and sensing functions, including: Step 1: Clean the insulating substrate A 400 μm thick sapphire Al2O3 substrate was placed in acetone, isopropanol and deionized water for ultrasonic cleaning for 10 minutes respectively. After cleaning, the substrate was dried by nitrogen purge. Figure 4 -a.

[0052] Step 2: Deposit N-type gallium oxide Using RF magnetron sputtering, under the conditions of 100W sputtering power, pure argon (60sccm) deposition atmosphere and 8mTorr pressure, a high-purity (99.99%) gallium oxide target was used to grow N-type gallium oxide 2 with a thickness of 180 nm on a sapphire Al2O3 substrate 1, as shown in Figure 2. Figure 4 -b.

[0053] Step 3: Depositing P-type nickel oxide Using magnetron sputtering, under the conditions of 90W RF power, oxygen (20sccm) and argon (40sccm) mixed atmosphere and 6mTorr pressure, a 50nm thick layer of P-type nickel oxide 3 was grown on N-type gallium oxide 2 using a high-purity (99.99%) nickel oxide target, as shown in Figure 2. Figure 4 -c.

[0054] Step 4: Forming Metal Electrodes Spin-coat the photoresist, develop it after UV exposure to form a mask, use the electron beam evaporation process to deposit the Ti / Au stacked metal electrode, and remove the excess photoresist and metal through the stripping process, and anneal it in nitrogen at 470℃ to form an ohmic electrode, such as Figure 4 -d, Figure 4 -e, Figure 4 -f and Figure 4 -g.

[0055] Step 5: Forming Metal Electrodes Same as step 4, Ni / Au stacked metal is deposited as ohmic electrode by photolithography and electron beam evaporation process. Figure 4 -h, Figure 4 -i, Figure 4 -j and Figure 4 -k.

[0056] Example 3

[0057] Based on Example 1, this embodiment provides a method for manufacturing an oxide heterojunction diode with switchable photodetection and sensing functions, including: Step 1: Clean the insulating substrate The C-surface sapphire substrate was sequentially placed in acetone, isopropanol and deionized water for ultrasonic cleaning for 10 minutes respectively, and the substrate was dried by nitrogen purge after cleaning.

[0058] Step 2: Deposit N-type gallium oxide Using RF magnetron sputtering, a high-purity (99.99%) gallium oxide target was used for deposition for 60 minutes at a sputtering power of 200W, an Ar / O2 (95sccm / 5sccm) deposition atmosphere and a pressure of 0.7Pa. N-type gallium oxide with a thickness of 120nm was grown on the substrate, and then annealed at 800°C in air.

[0059] Step 3: Depositing P-type nickel oxide Using magnetron sputtering, a 50 nm thick layer of P-type nickel oxide was grown on N-type gallium oxide using a high-purity (99.99%) nickel oxide target under 200W RF power, a mixed atmosphere of oxygen (35sccm) and argon (35sccm) and a pressure of 0.6Pa.

[0060] Step 4: Forming Metal Electrodes The photoresist is spin-coated and developed after UV exposure to form a mask. The Ti / Au stacked metal electrode is deposited using an electron beam evaporation process. The excess photoresist and metal are removed through a stripping process, and the ohmic electrode is formed by annealing in nitrogen.

[0061] Step 5: Forming Metal Electrodes Similar to step 4, a Ni / Au stacked metal is deposited as an ohmic electrode through photolithography and electron beam evaporation processes.

Claims

1. A function-switchable oxide heterojunction photodiode comprising an insulating substrate, an N-type oxide semiconductor, and a P-type semiconductor arranged in sequence; characterized in that: The interface between the P-type semiconductor and the N-type oxide semiconductor forms a type II band contact heterojunction; An insulating substrate and an N-type oxide semiconductor are stacked; The P-type semiconductor is locally deposited on the N-type oxide semiconductor; It also includes metal electrodes; the metal electrodes include a P-type ohmic electrode and an N-type ohmic electrode, the P-type ohmic electrode is located on the P-type semiconductor, and the N-type ohmic electrode is located on the N-type oxide semiconductor.

2. The function-switchable oxide heterojunction photodiode according to claim 1, characterized in that: N-type oxide semiconductors are N-type oxide semiconductors with controllable oxygen vacancies.

3. The function-switchable oxide heterojunction photodiode according to claim 1, characterized in that: N-type oxide semiconductors include zinc oxide ZnO, indium tin oxide ITO, and gallium oxide Ga2O3.

4. The function-switchable oxide heterojunction photodiode according to claim 1, characterized in that: The thickness of the N-type oxide semiconductor is 100 nm to 300 nm.

5. The function-switchable oxide heterojunction photodiode according to claim 1, characterized in that: The insulating substrate is a rigid insulating substrate or a flexible insulating substrate; the insulating substrate includes sapphire Al2O3, iron-doped gallium oxide, mica, and polyimide film.

6. The function-switchable oxide heterojunction photodiode according to claim 1, characterized in that: The P-type semiconductor includes nickel oxide NiO and tin oxide SnO; the thickness of the P-type semiconductor layer is 30nm to 80nm.

7. A method for preparing a function-switchable oxide heterojunction photodiode, characterized in that: A method for preparing a function-switchable oxide heterojunction photodiode according to any one of claims 1 to 6, comprising: Epitaxially growing an N-type oxide semiconductor on the surface of an insulating substrate; Locally depositing a P-type semiconductor on an N-type semiconductor; Metal electrodes are prepared on top of the N-type oxide semiconductor and the P-type semiconductor. The metal electrodes include a P-type ohmic electrode and an N-type ohmic electrode. The P-type ohmic electrode is located on the P-type semiconductor, and the N-type ohmic electrode is located on the N-type oxide semiconductor. The preparation of the PN heterojunction diode is completed.

8. The method for preparing a function-switchable oxide heterojunction photodiode according to claim 7, wherein: Methods for epitaxially growing an N-type oxide semiconductor on an insulating substrate include magnetron sputtering, metal organic chemical vapor deposition (MOCVD), hydride vapor phase epitaxy (HVPE), or plasma enhanced chemical vapor deposition (PECVD).

9. The method for preparing a function-switchable oxide heterojunction photodiode according to claim 7, wherein: Methods for locally depositing a P-type semiconductor on an N-type semiconductor include metal organic vapor phase epitaxy (MOCVD), electron beam evaporation, or magnetron sputtering.

10. The method for preparing a function-switchable oxide heterojunction photodiode according to claim 7, wherein: Metal electrodes are prepared on top of the N-type oxide semiconductor and the P-type semiconductor. The methods used to prepare the metal electrodes include magnetron sputtering or electron beam evaporation.

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