Light-controlled thyristor based on surface plasmon, manufacturing method and electronic device

Abstract

The embodiment of the present application discloses a light-controlled thyristor based on surface plasmon, a manufacturing method and an electronic device. The light-controlled thyristor includes a light-controlled end; the light-controlled end is provided with a first structure; the first structure is used to make the incident light and the surface plasmon form a resonant coupling effect. The manufacturing method includes: forming a surface at the light-controlled end of the light-controlled thyristor; making a first structure on the surface for making the incident light and the surface plasmon form a resonant coupling effect. The electronic device includes the light-controlled thyristor. The embodiment of the present application can effectively improve the output current and turn-on rate of the light-controlled thyristor, and can make the light source used for the light-controlled thyristor no longer constrained by the ultraviolet band, which can effectively broaden the selectivity of the light source.

Description

Technical Field

[0001] The present application relates to the technical field of light-controlled thyristors, and in particular to a light-controlled thyristor based on surface plasmons, a manufacturing method and an electronic device. Background Art

[0002] Power electronics technology has developed from the birth of the first silicon-based thyristor to the third-generation power electronic devices based on wide-bandgap semiconductor materials such as SiC (silicon carbide), GaN (gallium nitride), and ZnO (zinc oxide), such as MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and IGBT (Insulated Gate Bipolar Transistor), which have emerged in an endless stream; the performance of the devices has become increasingly excellent, and the application fields have become increasingly broad. However, the thyristors that came out in the early days still have an irreplaceable position in some occasions such as high-voltage direct current transmission and motor drive, such as MOSFET, IGBT and other devices.

[0003] At present, various types of thyristors on the market are still mainly silicon-based materials, but because SiC materials are significantly better than Si materials in terms of voltage resistance, high temperature resistance, radiation resistance, high frequency and high speed, SiC-based thyristors have gradually become a research trend. In addition, the triggering methods of thyristors include electrical triggering and optical triggering. Compared with the former, the latter not only ensures the insulation between the main circuit and the control circuit and avoids electromagnetic interference, but also simplifies the device structure, reduces its size and weight, and has a relatively high triggering sensitivity, which meets the requirements of power electronics technology to develop in the direction of high frequency, high sensitivity, high reliability and miniaturization. The only shortcoming is that the light source used for optical triggering is limited. For SiC-based light-controlled thyristors, only when the photon energy is greater than the bandgap width of SiC can it be absorbed and trigger. Only the ultraviolet light band meets this condition. Currently, the ultraviolet light-emitting devices that can be considered include ultraviolet lasers, ultraviolet laser diodes and ultraviolet LEDs. Lasers are large and difficult to integrate; the development of ultraviolet laser diodes themselves is not mature and their performance is still unstable; LEDs have low luminous intensity and low photoelectric conversion efficiency, and the design of current amplification will also make the structure more complicated.

[0004] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present application. It does not necessarily belong to the prior art of the present application. In the absence of clear evidence that the above content has been disclosed on the filing date of the present application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0005] The present application proposes a light-controlled thyristor, a manufacturing method and an electronic device based on surface plasmons, which can effectively improve the output current and turn-on rate of the light-controlled thyristor, and can make the light source used for the light-controlled thyristor no longer restricted by the ultraviolet band, which can effectively broaden the selectivity of the light source.

[0006] In a first aspect, the present application provides a surface plasmon-based light-controlled thyristor, comprising a light-controlled end; the light-controlled end is provided with a first structure; the first structure is used to form a resonant coupling effect between incident light and surface plasmon.

[0007] In some preferred embodiments, the first structure is located at the low-doped side of the PN junction of the photo-control end; or the first structure spans from the low-doped side of the PN junction of the photo-control end to the high-doped side.

[0008] In some preferred embodiments, the first structure is located on the structure with an inclined angle of the light-control end; specific forms of the structure with an inclined angle include an inclined surface, a curved surface and a groove.

[0009] In some preferred embodiments, the first structure is located on the anode base region and / or the cathode base region of the photo-controlled thyristor.

[0010] In some preferred embodiments, the first structure is a metal structure.

[0011] In some preferred embodiments, the first structure is a nanometal structure. In some preferred embodiments, the nanometal structure is a nanometal structure that can perform wave vector compensation on incident light through grating diffraction.

[0012] In some preferred embodiments, the first structure is a metal grating; and the metal grating is a nano-metal grating.

[0013] In some preferred embodiments, the first structure is a periodic or arrayed structure; and the periodic or arrayed structure is a nanometal structure.

[0014] In some preferred embodiments, the specific forms of the periodic or arrayed structure include a metal film structure with a hole array, a metal particle array structure, a metal nanowire array structure, and a metal nanorod array structure.

[0015] In some preferred embodiments, the material of the metal structure includes at least one of silver, gold, copper, aluminum, iron, titanium, platinum and chromium.

[0016] In some preferred embodiments, the photo-controlled thyristor includes SiC-based photo-controlled thyristor and Si-based photo-controlled thyristor.

[0017] In some preferred embodiments, the specific forms of the light-controlled thyristor include NPNP structure light-controlled thyristor and PNPN structure light-controlled thyristor.

[0018] In a second aspect, the present application provides a method for manufacturing a light-controlled thyristor based on surface plasmons: forming a surface at a light-controlled end of the light-controlled thyristor; and manufacturing a first structure on the surface for causing incident light to form a resonant coupling effect with the surface plasmons.

[0019] In a third aspect, the present application provides an electronic device comprising the above-mentioned light-controlled thyristor.

[0020] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0021] The light-controlled end is provided with a first structure, and the resonant coupling effect between the incident light and the surface plasmon of the first structure can enhance the light absorption capacity and light response sensitivity of the light-controlled end, and can further increase the photocurrent, thereby effectively improving the output current and opening rate of the light-controlled thyristor, without the need for additional current amplification design. The above-mentioned effect is no longer directly related to the incident light energy, but is also closely related to the incident angle and the structural parameters of the first structure. As long as the structural parameters of the first structure are reasonably designed within a certain range, the light source used for the light-controlled thyristor is no longer constrained by the ultraviolet band, which can effectively broaden the selectivity of the light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of a surface plasmon-based light-controlled thyristor according to a first embodiment of the present application;

[0023] Figure 2 This is a schematic diagram of the interaction between light and surface plasmon according to the first embodiment of the present application;

[0024] Figure 3 A local enlarged view of the electric field component generated by the surface plasmon oscillation of the first embodiment of the present application;

[0025] Figure 4 This is an enlarged view of the local structure of the metal film with hole array applied to the light-controlled SiC thyristor according to the second embodiment of the present application;

[0026] Figure 5 Schematic diagram of the structure of a surface plasmon-based light-controlled thyristor according to the third embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the embodiments of the present application clearer, the following Figures 1 to 5It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing or for circuit connection.

[0029] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0031] First embodiment

[0032] This embodiment explores the application of surface plasmon in the field of light-controlled thyristors, and provides a light-controlled thyristor based on surface plasmon under the premise that the light intensity and light source wavelength of the light-controlled end of the prior art are limited. The light-controlled thyristor of this embodiment is a SiC-based light-controlled thyristor.

[0033] This embodiment applies surface plasmon to SiC-based light-controlled thyristor.

[0034] refer to Figure 1 The light-controlled thyristor of this embodiment includes an N+ substrate 1, a P-cathode base region 2, an N anode base region 3, a P+ injection region 4, an anode metal 5, a cathode metal 6, a space charge region 8 of a reverse biased PN junction, and a light-controlled terminal 100. The doping concentration of the P-cathode base region 2 is lower than 3. The light-controlled terminal 100 is provided with a first structure 7.

[0035] The method for manufacturing the surface plasmon-based light-controlled thyristor of this embodiment is described. A surface 200 is formed by etching the most basic N+P-NP+ four-layer structure of the light-controlled thyristor; for example, the surface 200 is formed by two etching processes. A first structure 7 is manufactured on the surface 200.

[0036] The first structure 7 can enhance the light absorption capacity and light response sensitivity of the light-controlled end 100 through surface plasmons. That is to say, the first structure 7 of this embodiment is a structure in which light and surface plasmon resonant coupling occurs on the surface when irradiated with light. Surface plasmon (SP) is a localized collective oscillation mode of electrons existing between the interfaces of two materials (whose dielectric constants are of opposite signs) under the action of an external field, forming an electromagnetic wave transmitted along the interface. When the frequency of the external field matches the frequency of the electron oscillation, surface plasmon resonance will be caused, generating a greatly enhanced electric field, which decays exponentially in the direction perpendicular to the interface, and the penetration depth in the two materials is extremely small, about the sub-wavelength order. In addition, the specific material of the first structure 7 can be determined according to the characteristic requirements of the light-controlled thyristor. Metals such as silver, gold, copper, aluminum, iron, titanium, platinum and chromium can be used as a material for making the first structure 7 because they are rich in free electrons; that is to say, the first structure 7 of this embodiment is a metal structure. Nanoscale metal structures such as metal films, metal particles, metal gratings, metal nanowires and metal nanorods can all be used as the first structure 7; that is, the first structure 7 of this embodiment is a nanometal structure.

[0037] According to the above, in this embodiment, the light-controlled end 100 is provided with a first structure 7, and the resonant coupling effect between the incident light and the surface plasmon of the first structure 7 can enhance the light absorption ability and light response sensitivity of the light-controlled end 100, and can further increase the photocurrent, thereby effectively improving the output current and opening rate of the light-controlled thyristor without the need for additional current amplification design.

[0038] Example, reference Figure 1, the first structure 7 is a metal grating, specifically a nano-metal grating. The surface 200 is a structure with an inclined angle formed by an etching process, specifically an inclined plane. A layer of nano-scale metal grating is made on the etched inclined plane, wherein the thickness of the metal grating is within the range of tens of nanometers, thereby forming the first structure 7. The grating period Λ is comparable to the wavelength of the incident light. Among them, the N+ substrate 1 and the P+ injection region 4 are used for the injection of electrons and holes respectively; when the anode metal 5 and the cathode metal are forward biased, the PN junction between the P-cathode base region 2 and the N anode base region 3 is reverse biased; the nano-metal grating as the first structure 7 is located within the inclined range of the space charge region 8 of the PN junction reversely biased at the photocontrol end 100, and the strong attenuation electric field generated by its surface plasmon is used to accelerate the reverse drift of electrons and holes in the space charge region 8 of the reverse biased PN junction, thereby quickly forming a photocurrent.

[0039] Figure 2 The waveform 9 in FIG. 1 shows the surface plasmon oscillation of the metal part of a single grating period (the specific number of oscillation periods is related to the light incident angle, the light wavelength and the structural parameters of the first structure 7). When the incident light with a frequency of ω is incident on the first structure 7, i.e., the nanometal grating, at an incident angle θ, since the structural parameters and the incident angle of the first structure 7 are reasonably designed, when the wave vector matching is satisfied, i.e., the When (where k sp is the surface plasmon wave vector, m is the diffraction order, and c is the speed of light), the incident light couples with the waveform 9 to produce resonance, that is, the photons of the incident light resonate with the free electrons on the metal surface; specifically, the incident light passes through the nano-metal grating, and the nano-metal grating achieves wave vector compensation for the incident light through grating diffraction, which can excite the plasmons on the surface of the metal structure to resonate; in this way, the light absorption capacity of the light-control end 100 can be significantly enhanced, and the photocurrent can be increased.

[0040] also, Figure 3 It is shown that waveform 9 generates a strong attenuated electric field E in the downward direction perpendicular to the surface. The electric field E acts in the space charge region 8 of the reverse biased PN junction, and the depth of action is related to parameters such as the grating period, duty cycle, thickness, etc. The electric field E can accelerate the drift of holes in the P-cathode base region 2 and electrons in the N-anode base region 3, so that the SiC-based light-controlled thyristor can be turned on quickly.

[0041] Since wave vector matching is not only related to the incident light frequency ω (or wavelength), but also to the incident angle θ and metal grating structure parameters such as grating period Λ, the light source is no longer limited to the ultraviolet band, thereby broadening the selectivity of the light source.

[0042] In other embodiments, the light-controlled thyristor is a Si-based light-controlled thyristor or other light-triggered thyristors.

[0043] In other embodiments, the light-controlled thyristor is a PNPN structure light-controlled thyristor with a P-type doped substrate.

[0044] In other embodiments, the first structure 7 is disposed on the reversely inclined surface of the light-control end 100 .

[0045] Second embodiment

[0046] The principle of this embodiment is basically the same as that of the first embodiment. The difference between this embodiment and the first embodiment is that in this embodiment, reference Figure 4 , the first structure 7 is a periodic or array structure, specifically a metal film with a hole array, the film thickness is in the range of tens of nanometers, and the hole diameter is between tens and hundreds of nanometers, that is, the periodic or array structure is a nano-metal structure with a hole array; in addition, the first structure 7 is only placed on the low-doped side slope of the space charge region 8 of the reverse-biased PN junction. In this way, since the strong attenuation field of the surface plasmon in the vertical surface direction directly acts on the space charge region 8 of the reverse-biased PN junction of the photo-controlled end 100, the drift of electrons and holes can be accelerated, thereby forming a photocurrent in a very short time, which can further improve the opening speed of the photo-controlled thyristor, and achieve dual optimization of output current and sensitivity.

[0047] In other embodiments, the first structure 7 is located on the anode base region and / or cathode base region of the photo-controlled thyristor; illustratively, the first structure 7 spans from the low-doped side of the PN junction of the photo-controlled terminal 100 to the high-doped side of the junction.

[0048] In other embodiments, the periodic or arrayed structure may also be a metal particle array structure, a metal nanowire array structure, and a metal nanorod array structure.

[0049] Third embodiment

[0050] The principle of this embodiment is basically the same as that of the first embodiment. The difference between this embodiment and the first embodiment is that in this embodiment, reference Figure 5 , the surface 200 is a curved surface or a groove structure with a certain inclination angle; in addition, the first structure 7 is an array of nano-scale metal particles, wherein the particle diameter is about tens of nanometers.

[0051] Fourth embodiment

[0052] This embodiment provides an electronic device, which includes the above-mentioned light-controlled thyristor.

[0053] In the embodiment of the present application, a nanometer-scale metal structure is introduced into the photo-controlled end 100 of the photo-controlled thyristor, and the specific position is on the anode base region or / and the cathode base region. By etching a bevel, a curved surface or a groove, a periodic / array nanostructure of a metal film with a hole array or a metal particle array or a metal grating as the first structure 7 is prepared on the etched surface; when the incident light passes through the metal structure, the metal structure realizes wave vector compensation of the incident light through grating diffraction, which can excite the plasmon on the surface of the metal structure to produce resonance, which can enhance the light absorption of the photo-controlled end 100, thereby increasing the photocurrent, and can also make the generated enhancement field act on the space charge region 8 of the reverse biased PN junction to accelerate the drift of electrons and holes, thereby accelerating the formation of photocurrent. This effect is no longer directly related to the incident light energy, but also closely related to the incident angle and the structural parameters of the nanometal. As long as the structural parameters of the nanometal are reasonably designed within a certain range, the light source used for the photo-controlled thyristor is no longer constrained by the ultraviolet band, which can effectively broaden the selectivity of the light source.

[0054] The above content is a further detailed description of the present application in combination with specific / preferred implementation methods, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, without departing from the concept of the present application, they can also make several substitutions or modifications to the described implementation methods, and these substitutions or modifications should be deemed to belong to the protection scope of the present application.

Claims

1. A light-controlled thyristor based on surface plasmon, characterized in that: The invention comprises a light-controlled end; the light-controlled end is provided with a first structure; the first structure is used to make the incident light and the surface plasmon form a resonant coupling effect, thereby improving the output current and the opening rate of the light-controlled thyristor; wherein the first structure is located on a structure with an inclined angle in the space charge region of the reverse-biased PN junction of the light-controlled end, and the strong attenuation electric field generated by the surface plasmon is used to accelerate the reverse drift of electrons and holes in the space charge region of the reverse-biased PN junction, thereby quickly forming a photocurrent; the first structure is a nano-metal grating, wherein the structural parameters of the nano-metal grating and the frequency and incident angle of the incident light are designed to meet ,in, is the surface plasmon wave vector, ω is the frequency of the incident light, m ​​is the diffraction order, c is the speed of light, The grating period is such that the photons of the incident light resonate with the free electrons on the metal surface. The incident light passes through the nano-metal grating, and the nano-metal grating realizes wave vector compensation for the incident light through grating diffraction.

2. The light-controlled thyristor according to claim 1, characterized in that: The first structure is located at the low-doping side of the PN junction of the light-control end; or the first structure crosses the junction from the low-doping side of the PN junction of the light-control end to the high-doping side.

3. The light-controlled thyristor according to claim 1, characterized in that: Specific forms of the structure with an inclined angle include a slope, a curved surface and a groove.

4. The light-controlled thyristor according to claim 1, characterized in that: The first structure is located on the anode base region and / or the cathode base region of the photo-controlled thyristor.

5. The light-controlled thyristor according to claim 1, characterized in that: The first structure is a metal structure; the metal structure is a nanometal structure; the material of the metal structure includes at least one of silver, gold, copper, aluminum, iron, titanium, platinum and chromium; the metal structure is a metal structure that can compensate the wave vector of incident light by diffraction.

6. The light-controlled thyristor according to claim 1, characterized in that: The light-controlled thyristor includes a SiC-based light-controlled thyristor and a Si-based light-controlled thyristor; the specific forms of the light-controlled thyristor include a NPNP-structured light-controlled thyristor and a PNPN-structured light-controlled thyristor.

7. A method for manufacturing a light-controlled thyristor according to any one of claims 1 to 6, characterized in that: A surface is formed at the photo-controlled end of the photo-controlled thyristor; a first structure for causing incident light to form a resonant coupling effect with surface plasmons is manufactured on the surface.

8. An electronic device, characterized in that: The method comprises the light-controlled thyristor according to any one of claims 1 to 6.

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