WO2023152432A1 - Production of a radiation-emitting component from a silicon carbide substrate - Google Patents

Production of a radiation-emitting component from a silicon carbide substrate Download PDF

Info

Publication number
WO2023152432A1
WO2023152432A1 PCT/FR2023/050089 FR2023050089W WO2023152432A1 WO 2023152432 A1 WO2023152432 A1 WO 2023152432A1 FR 2023050089 W FR2023050089 W FR 2023050089W WO 2023152432 A1 WO2023152432 A1 WO 2023152432A1
Authority
WO
WIPO (PCT)
Prior art keywords
substrate
radiation
volume
ion implantation
component
Prior art date
Application number
PCT/FR2023/050089
Other languages
French (fr)
Inventor
Mihai Lazar
Dominique PLANSON
Hervé Morel
Christophe COUTEAU
Original Assignee
Université de Technologie de Troyes
Centre National De La Recherche Scientifique
Institut National Des Sciences Appliquees De Lyon
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Université de Technologie de Troyes, Centre National De La Recherche Scientifique, Institut National Des Sciences Appliquees De Lyon filed Critical Université de Technologie de Troyes
Publication of WO2023152432A1 publication Critical patent/WO2023152432A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/005—Processes
    • H01L33/0054—Processes for devices with an active region comprising only group IV elements
    • H01L33/0058—Processes for devices with an active region comprising only group IV elements comprising amorphous semiconductors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/005—Processes
    • H01L33/0054—Processes for devices with an active region comprising only group IV elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/025—Physical imperfections, e.g. particular concentration or distribution of impurities
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/16—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/34—Materials of the light emitting region containing only elements of Group IV of the Periodic Table
    • H01L33/343—Materials of the light emitting region containing only elements of Group IV of the Periodic Table characterised by the doping materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/005—Processes
    • H01L33/0095—Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/34—Materials of the light emitting region containing only elements of Group IV of the Periodic Table

Definitions

  • This description relates to a method of manufacturing a radiation-emitting component, as well as a component which can be obtained in this way.
  • a radiation-emitting component can be of the color center type, for example to emit single photons, or of the bipolar junction type, such as a light-emitting diode.
  • SiC crystalline silicon carbide
  • SiC silicon carbide
  • advantages which come in particular from the following properties of the material: its chemical inertness, its thermal stability, its thermal conductivity and its wide forbidden band (“gap” in English), in particular in comparison with silicon (Si) which is the semiconductor material most used today in microelectronics.
  • Silicon carbide makes it possible in particular to produce radiation in a controlled manner in the spectral range of visible light, and also around 1.5 pm (micrometre), for example for telecommunication applications.
  • An object of the present invention is therefore to improve the output efficiency of the radiation which is produced within a component based on silicon carbide, towards the outside of this component.
  • this improvement is sought so as to be able to implement it in a reproducible and controlled manner for large series of manufactured components.
  • a first aspect of the invention proposes a process for manufacturing a radiation-emitting component from a substrate of crystalline silicon carbide, this process comprising the following steps:
  • a surface of the substrate determining at least a portion of this surface which is intended to constitute, during use of the component, an exit window towards the outside of the substrate of the radiation which comes from inside the substrate; and 121 while the substrate has a temperature below 200°C (degrees Celsius), implanting ions into the substrate, through the portion of the surface of the substrate which is intended to constitute the exit window of the radiation, with values ion implantation dose and ion implantation energy which are adapted to produce an amorphization of the substrate in a volume located under its surface.
  • an ion implantation which is carried out while the substrate has a temperature greater than 300° C., for example between 300° C. and 600° C. an ion implantation which is carried out while the substrate temperature is below 200°C is more effective in amorphizing the silicon carbide material.
  • This silicon carbide material which is thus amorphized then has a density which is reduced with respect to the crystalline material as it exists before the implantation or outside the volume traversed by the implanted ions.
  • the refractive index of the silicon carbide material is reduced in the portion of material which is intermediate between the surface of the substrate and the ion implantation depth, and this reduction in refractive index produces an effect at least partial antireflection for the radiation which comes from inside the substrate, in particular from the volume of the substrate in which the ions have been implanted, and whose direction of emission crosses the surface of the substrate in the exit window. Thanks to this antireflection effect, the exit of the radiation towards the exterior of the component is favoured, so that the component has a radiation production yield which is improved. In this way, energy consumption by the component is reduced, for an equal amount of radiation which is emitted.
  • the ion implantation which is carried out when the temperature of the substrate is below 200° C. is said to be at room temperature when no heating is intentionally applied to the substrate, or when limited heating is used. Most often, no means of controlling the temperature of the substrate can be used during this so-called implantation at room temperature. But it is also possible to carry out the ion implantation of step 121 while the substrate is cooled using appropriate means. Generally, the temperature of the substrate during step 121 can be higher than 4 K (degree Kelvin).
  • the ion implantation dose and ion implantation energy values can be selected to produce an amorphization of the substrate between its surface and a depth value which is between 0.2 ⁇ m and 1 ⁇ m, measured from the surface of the substrate.
  • these implantation dose and energy values can be adapted with respect to the wavelength of the radiation which will be produced in the substrate during use of the component and intended to exit from the substrate.
  • the amorphization volume, under the surface of the substrate constitutes a layer with an antireflection effect, the thickness of which can be advantageously optimized with respect to the wavelength of the radiation.
  • this radiation which is produced by the component can be visible light or infrared radiation, for example with a wavelength close to 1.5 ⁇ m.
  • the ions that are implanted in step 121 can be selected from among aluminum ions (Al), boron ions (B) and nitrogen ions (N). But other ions also suitable for producing desired dopings can be used alternatively.
  • the ion implantation dose value can be between 10 14 and 10 16 ions per cm 2 (square centimeter), and the ion implantation energy value can be between 20 keV (kiloelectron-volt) and 800 keV.
  • these values are particularly suitable for producing a reduction in refractive index which is sufficient to substantially increase the outward radiation output efficiency of the component.
  • the ions can be implanted in the substrate in step 121, through the portion of its surface which is intended to constitute the exit window. radiation, with a first pair of values for the ion implantation dose and the ion implantation energy, and with a second pair of values for these ion implantation parameters, the first pair of values being adapted to dope at at least a part of a light-emitting diode located in the substrate, at a depth measured from the surface of the substrate which is greater than a thickness of the amorphization volume, this thickness being measured perpendicular to the surface of the substrate, and the second pair of values being adapted to produce the amorphization of the substrate in the volume located under its surface.
  • a combination of ion implantation is particularly advantageous for reducing the manufacturing cost of the light-emitting diode.
  • the implementation with the first pair of values is carried out before that with the second pair
  • the method of the invention may also comprise the following step, which is carried out if necessary after step 121:
  • the heat treatment of this step /3/ can be carried out at atmospheric pressure, under argon (Ar), with a temperature which is between 800° C. and 1900° C., preferably between 1600° C. and 1800° C., for a period which is less than 1 hour. Beyond this duration, this heat treatment could reduce the antireflection effect which is provided by the amorphization of the substrate below the radiation exit window.
  • the heat treatment of step /3/ can be performed during or after an implantation of ions in the substrate which is intended to dope at least part of a light-emitting diode which is situated in this substrate.
  • the latter may be monocrystalline, in particular according to the 3C, 6H or 4H polytype.
  • a second aspect of the invention proposes a radiation-emitting component, which comprises a substrate of crystalline silicon carbide, this substrate having a surface and possessing a first material density value in a volume located under a portion of this surface which is intended to constitute, during use of the component, an exit window towards the exterior of the substrate for radiation coming from the interior of the substrate, this first material density value being lower than a second value density of material which is effective in the substrate at a depth greater than a thickness of the volume corresponding to the first density value, the depth and the thickness being measured perpendicular to the surface of the substrate, the depth being measured from the substrate surface.
  • a quotient of the first material density value to the second material density value may be less than 0.95, preferably less than 0.90 .
  • the silicon carbide substrate may be monocrystalline, at least outside the volume which corresponds to the first density value of the material.
  • Such a component can constitute a colored center emitter, for example for emitting single photons, or a light-emitting diode, located in the substrate. Then, during the use of this component, the radiation is emitted by the colored center or by the light-emitting diode and passes through the output window.
  • the colored center or the light-emitting diode is located below the surface of the substrate at a depth which is greater than or equal to the thickness of the volume corresponding to the first density value of the material.
  • FIG. 1a is a cross-sectional view of a substrate used to manufacture a light-emitting component, in accordance with the invention
  • FIG. 1b corresponds to [Fig. 1a] for a subsequent step of the method
  • FIG. 1c corresponds to [Fig. 1a] for an even later stage of the process
  • FIG. 1d corresponds to [Fig. 1a] for an even later stage of the process
  • FIG. 2a is a cross-sectional view of a light-emitting component with colored centers, as obtained by a manufacturing method according to the invention.
  • FIG. 2b corresponds to [Fig. 2a] for a photodiode obtained by a manufacturing process according to the invention.
  • a monocrystalline silicon carbide (SiC) substrate 1 for example of polytype 3C, has a surface S.
  • This surface S can be covered with a mask 3, called a hard mask.
  • the hard mask 3 can be of the metal mask type, for example based on nickel (Ni), aluminum (Al) or chromium (Cr).
  • the hard mask 3 can be made of dielectric material, such as silica (SiO2), or of a resin which is resistant to implantation processes and which can be removed completely afterwards.
  • the hard mask 3 can be made of any material suitable for being etched locally.
  • An encapsulating layer 2 can be intermediate between the surface S of the substrate 1 and the hard mask 3.
  • the encapsulating layer 2 is intended to limit or eliminate a sublimation of silicon atoms which would be liable to occur from the surface S of the substrate 1 during heating, but other methods for avoiding such sublimation of the silicon atoms are known, and can be used alternatively.
  • Such an encapsulating layer 2 can be made of graphite carbon (C), for example as obtained by pyrolyzing in situ a layer of photolithographic resin deposited on the surface S of the substrate 1. The pyrolysis treatment of the resin can be carried out at 750°C for 30 minutes under a nitrogen (N2) atmosphere, for example.
  • N2 nitrogen
  • the hard mask 3 is then selectively removed inside a portion W of the surface S, which is intended to constitute an exit window for the radiation of a light-emitting component produced in the substrate 1.
  • Such removal selection of the hard mask 3, inside the window W can be made in one of the ways known to those skilled in the art, for example by optical or electronic lithography then using an etching, wet or plasma process, which is adapted to eliminate the hard mask 3 in each zone where the latter is exposed, that is to say in the window W.
  • a lift-off method can be used alternatively, to obtain the hard mask 3 selectively outside window W on substrate 1 .
  • the configuration which is shown by [Fig. 1 b] is then obtained.
  • the substrate 1 can then be brought into contact with an oxygen plasma (O2) to remove the encapsulating layer 2 in the places where it is no longer covered by the hard mask 3 , as shown by [Fig. 1 C].
  • O2 oxygen plasma
  • an oxygen ion beam etching process or a thermal oxidation treatment can also be used to remove the uncovered portions of the encapsulating layer 2.
  • Ions for example aluminum (Al), boron (B) or nitrogen (N) ions depending on the type of doping desired, are then implanted in the substrate 1, through the opening which was practiced previously in the hard mask 3, and in the encapsulating layer 2 if necessary.
  • ion implantation energy is adopted, so that these ions are finally fixed in a portion V of the substrate 1 which extends from a depth P substantially equal to 0.25 ⁇ m. Then, the substrate 1 is amorphized between its surface S and this depth P, because of the collisions against the carbon and silicon atoms of the substrate 1, of the ions implanted up to their binding sites.
  • this ion implantation is carried out at room temperature, or at a cooling temperature, to promote the amorphization of the substrate 1 from its surface S to the depth P, in line with the window W.
  • the following parameters can be adopted for ion implantation: implantation energy substantially equal to 200 keV, and implanted dose substantially equal to 1.75-10 15 ions per cm 2 .
  • the depth P is substantially equal to 250 nm (nanometer) if aluminum ions are used for the implantation, and the amorphization of the substrate 1 under the window W produces therein a swelling SW of the surface S, as shown in [Fig. 1d].
  • This swelling SW which is of the order of 50 nm at the center of the window W, results from a reduction in the density of the material of the substrate 1 produced by its amorphization. It is substantially equal to 50 nm for the aforementioned implantation conditions.
  • the density of the silicon carbide in the superficial volume VS which is limited by the window W, the surface S and a depth under this surface S which is less than or equal to P, is substantially equal to 0.8 times the density of the silicon carbide of substrate 1 outside this volume VS.
  • This reduction in density causes a reduction in the luminous refractive index of the material of the substrate 1 in the volume VS.
  • This volume with a reduced luminous refractive index value will then produce an at least partial anti-reflection effect, for radiation coming from the fixing zone of the implanted ions.
  • the residual part of the hard mask 3, outside the window W, is then removed, again by wet etching, then a heat treatment is applied to the substrate to activate the doping constituted by the implanted ions.
  • the substrate 1 can be brought to a temperature substantially equal to 1700° C. for 30 minutes, at atmospheric pressure under argon (Ar).
  • Ar argon
  • the implantation of the ions can be carried out in two distinct stages, to differentiate the functions of amorphization of the silicon carbide material in the volume VS, and of doping in a volume V which is located on a side opposite the surface S with respect to the volume VS.
  • the volume V is located under the volume VS in the substrate 1, the volume VS then being called the surface volume.
  • the superficial volume VS is essentially dedicated to producing the antireflection effect to promote the exit of the radiation, and the volume V is dedicated to producing the radiation.
  • the implantation of the ions in the volume V can be carried out with a first pair of values for the ion implantation dose and the ion implantation energy in order to dope the substrate 1 in the volume V, then a second pair of values for these implantation parameters in order to amorphize the silicon carbide material in the surface volume VS.
  • the depth P then corresponds to an upper limit of the volume V, in the direction of the surface S of the substrate 1.
  • the values for amorphizing the substrate 1 in the surface volume VS can be 10 15 ions per cm 2 for the dose d implantation, and 100 keV for the implantation energy, and those for creating the doping in the volume V can be 10 14 ions per cm 2 and 200 keV.
  • FIG. 2a is a cross-sectional view of a component with color centers, for producing single photons. These colored centers, produced by the doping, are located in the volume V and denoted CC, and part of the photons they emit are oriented towards the window W.
  • the superficial volume VS in which the refractive index of the material of the substrate 1 is reduced according to the invention, reduces a reflection of these photons on the surface S, internal to the substrate 1.
  • R designates the radiation which is constituted by the photons which leave through the window W.
  • FIG. 2a also shows two photons R' which are produced by the color centers CC while being directed outside the window W, and which are reflected towards the interior of the substrate 1 by the surface S.
  • FIG. 2b is a cross-sectional view of a photodiode fabricated by the method of the invention.
  • the single-crystal silicon carbide substrate 1 which is used may be originally N-type doped, and the doping which is carried out to create the surface volume VS may be of the P-type, like the volume V.
  • the lower limit of the volume V, denoted J in the figure, is the photodiode junction.
  • the component may be completed by a rear electrode 4 and an upper electrode 5.
  • the upper electrode 5 may be formed in a manner known to those skilled in the art, on the swelling SW of the surface S.
  • a current is injected between the two electrodes 4 and 5, with a direct electrical bias of the photodiode, radiation R is emitted by the junction J, part of which leaves the substrate 1 through the window W.
  • this part of the radiation which is produced by the photodiode and which emerges from the substrate 1 is increased thanks to the invention.
  • a component manufactured in accordance with the invention may be of a type other than a single photon emitter or a photodiode.
  • any numerical values that have been quoted are for illustrative purposes only, and may be changed depending on the particular application.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Ceramic Products (AREA)
  • Led Devices (AREA)

Abstract

The invention relates to a method for producing a radiation-emitting component (R) from a crystalline silicon carbide substrate (1), comprising the implantation of ions at ambient temperature into said substrate. The implantation produces an amorphization of the substrate in a volume (VS) that is located below the surface (S) of said substrate. This results in a local decrease in the density of the substrate, which improves an output of the radiation (R) from the interior of the substrate. The component may be a single-photon emitter based on color centers (CC), or a light-emitting diode.

Description

Description Description
Titre : FABRICATION D’UN COMPOSANT EMETTEUR DE RAYONNEMENT A PARTIR D’UN SUBSTRAT DE CARBURE DE SILICIUM Title: MANUFACTURING OF A RADIATION EMITTING COMPONENT FROM A SILICON CARBIDE SUBSTRATE
Domaine technique Technical area
[0001] La présente description concerne un procédé de fabrication d’un composant émetteur de rayonnement, ainsi qu’un composant qui peut être obtenu de cette manière. De façon générale, un tel composant émetteur de rayonnement peut être du type à centres colorés, par exemple pour émettre des photons uniques, ou du type à jonction bipolaire, tel qu’une diode électroluminescente. This description relates to a method of manufacturing a radiation-emitting component, as well as a component which can be obtained in this way. Generally, such a radiation-emitting component can be of the color center type, for example to emit single photons, or of the bipolar junction type, such as a light-emitting diode.
Technique antérieure Prior technique
[0002] L’utilisation de carbure de silicium (SiC) cristallin pour produire des composants émetteurs de rayonnement présente de nombreux avantages, qui proviennent en particulier des propriétés suivantes du matériau : son inertie chimique, sa stabilité thermique, sa conductivité thermique et sa large bande interdite («gap» en anglais), notamment en comparaison du silicium (Si) qui est le matériau semiconducteur le plus utilisé aujourd’hui en microélectronique. Le carbure de silicium permet en particulier de produire de façon contrôlée du rayonnement dans l’intervalle spectral de la lumière visible, et aussi autour de 1 ,5 pm (micromètre), par exemple pour des applications de télécommunication. [0002] The use of crystalline silicon carbide (SiC) to produce radiation-emitting components has many advantages, which come in particular from the following properties of the material: its chemical inertness, its thermal stability, its thermal conductivity and its wide forbidden band (“gap” in English), in particular in comparison with silicon (Si) which is the semiconductor material most used today in microelectronics. Silicon carbide makes it possible in particular to produce radiation in a controlled manner in the spectral range of visible light, and also around 1.5 pm (micrometre), for example for telecommunication applications.
[0003] L’efficacité d’extraction du rayonnement qui est produit à l’intérieur du composant en carbure de silicium, éventuellement dopé intentionnellement, vers l’extérieur de ce composant afin que le rayonnement puisse être utilisé pour l’application voulue, est alors un enjeu majeur. En effet, une extraction du rayonnement qui est plus efficace permet de réduire une consommation énergétique du composant à quantité égale de rayonnement qui est utilisable. En outre, il est essentiel de pouvoir produire en série des composants dont l’efficacité d’émission est contrôlée et reproductible. [0003] The extraction efficiency of the radiation which is produced inside the silicon carbide component, optionally doped intentionally, towards the outside of this component so that the radiation can be used for the desired application, is then a major issue. Indeed, an extraction of the radiation which is more efficient makes it possible to reduce the energy consumption of the component for an equal quantity of radiation which is usable. In addition, it is essential to be able to mass-produce components whose emission efficiency is controlled and reproducible.
Problème technique [0004] Un but de la présente invention est donc d’améliorer l’efficacité de sortie du rayonnement qui est produit au sein d’un composant à base de carbure de silicium, vers l’extérieur de ce composant. En particulier, cette amélioration est recherchée de façon à pouvoir la mettre en œuvre de façon reproductible et contrôlée pour des séries importantes de composants fabriqués. Technical problem [0004] An object of the present invention is therefore to improve the output efficiency of the radiation which is produced within a component based on silicon carbide, towards the outside of this component. In particular, this improvement is sought so as to be able to implement it in a reproducible and controlled manner for large series of manufactured components.
Résumé de l’invention Summary of the Invention
[0005] Pour atteindre ce but ou un autre, un premier aspect de l’invention propose un procédé de fabrication d’un composant émetteur de rayonnement à partir d’un substrat de carbure de silicium cristallin, ce procédé comprenant les étapes suivantes : To achieve this goal or another, a first aspect of the invention proposes a process for manufacturing a radiation-emitting component from a substrate of crystalline silicon carbide, this process comprising the following steps:
/1/ dans une surface du substrat, déterminer au moins une portion de cette surface qui est destinée à constituer, lors d’une utilisation du composant, une fenêtre de sortie vers l’extérieur du substrat du rayonnement qui provient de l’intérieur du substrat ; et 121 pendant que le substrat possède une température inférieure à 200°C (degré Celsius), implanter des ions dans le substrat, à travers la portion de la surface du substrat qui est destinée à constituer la fenêtre de sortie du rayonnement, avec des valeurs de dose d’implantation ionique et d’énergie d’implantation ionique qui sont adaptées pour produire une amorphisation du substrat dans un volume situé sous sa surface. /1/ in a surface of the substrate, determining at least a portion of this surface which is intended to constitute, during use of the component, an exit window towards the outside of the substrate of the radiation which comes from inside the substrate; and 121 while the substrate has a temperature below 200°C (degrees Celsius), implanting ions into the substrate, through the portion of the surface of the substrate which is intended to constitute the exit window of the radiation, with values ion implantation dose and ion implantation energy which are adapted to produce an amorphization of the substrate in a volume located under its surface.
[0006] En effet, les inventeurs ont découvert que contrairement à une implantation ionique qui est effectuée pendant que le substrat possède une température supérieure à 300°C, par exemple comprise entre 300°C et 600°C, une implantation ionique qui est effectuée pendant que la température du substrat est inférieure à 200°C est plus efficace pour amorphiser le matériau de carbure de silicium. Ce matériau de carbure de silicium qui est ainsi amorphisé possède alors une densité qui est réduite par rapport au matériau cristallin tel qu’existant avant l’implantation ou en dehors du volume traversé par les ions implantés. Pour cette raison, l’indice de réfraction du matériau de carbure de silicium est réduit dans la portion de matériau qui est intermédiaire entre la surface du substrat et la profondeur d’implantation des ions, et cette réduction d’indice de réfraction produit un effet antireflet au moins partiel pour le rayonnement qui provient de l’intérieur du substrat, notamment du volume du substrat dans lequel les ions ont été implantés, et dont la direction d’émission traverse la surface du substrat dans la fenêtre de sortie. Grâce à cet effet antireflet, la sortie du rayonnement vers l’extérieur du composant est favorisée, si bien que le composant présente un rendement de production de rayonnement qui est amélioré. De cette façon, une consommation d’énergie par le composant est réduite, à quantité égale de rayonnement qui est émise. [0006] Indeed, the inventors have discovered that unlike an ion implantation which is carried out while the substrate has a temperature greater than 300° C., for example between 300° C. and 600° C., an ion implantation which is carried out while the substrate temperature is below 200°C is more effective in amorphizing the silicon carbide material. This silicon carbide material which is thus amorphized then has a density which is reduced with respect to the crystalline material as it exists before the implantation or outside the volume traversed by the implanted ions. For this reason, the refractive index of the silicon carbide material is reduced in the portion of material which is intermediate between the surface of the substrate and the ion implantation depth, and this reduction in refractive index produces an effect at least partial antireflection for the radiation which comes from inside the substrate, in particular from the volume of the substrate in which the ions have been implanted, and whose direction of emission crosses the surface of the substrate in the exit window. Thanks to this antireflection effect, the exit of the radiation towards the exterior of the component is favoured, so that the component has a radiation production yield which is improved. In this way, energy consumption by the component is reduced, for an equal amount of radiation which is emitted.
[0007] La réduction de la densité du substrat dans le volume d’amorphisation peut produire un gonflement de celui-ci qui apparaît au niveau de sa surface. Ce gonflement constitue alors une preuve de la réduction de la densité du matériau de carbure de silicium qu’a produite l’implantation ionique. Dans ce cas, les valeurs de profondeur dans le substrat qui sont citées dans la suite sont mesurées à partir de la surface du substrat telle que résultant du gonflement. [0007] Reducing the density of the substrate in the amorphization volume can produce swelling of the latter which appears at its surface. This swelling then constitutes evidence of the reduction in the density of the silicon carbide material produced by the ion implantation. In this case, the values of depth in the substrate which are quoted below are measured from the surface of the substrate as resulting from the swelling.
[0008] Dans le jargon de l’Homme du métier, l’implantation ionique qui est effectuée alors que la température du substrat est inférieure à 200°C, est dite à température ambiante lorsqu’aucun chauffage n’est appliqué intentionnellement au substrat, ou lorsqu’un chauffage limité est utilisé. Le plus souvent, aucun moyen de contrôle de la température du substrat peut n’être utilisé pendant cette implantation dite à température ambiante. Mais il est aussi possible de réaliser l’implantation ionique de l’étape 121 pendant que le substrat est refroidi en utilisant des moyens appropriés. De façon générale, la température du substrat pendant l’étape 121 peut être supérieure à 4 K (degré Kelvin). [0008] In the jargon of those skilled in the art, the ion implantation which is carried out when the temperature of the substrate is below 200° C., is said to be at room temperature when no heating is intentionally applied to the substrate, or when limited heating is used. Most often, no means of controlling the temperature of the substrate can be used during this so-called implantation at room temperature. But it is also possible to carry out the ion implantation of step 121 while the substrate is cooled using appropriate means. Generally, the temperature of the substrate during step 121 can be higher than 4 K (degree Kelvin).
[0009] De façon préférée, à l’étape 121, les valeurs de dose d’implantation ionique et d’énergie d’implantation ionique peuvent être sélectionnées pour produire une amorphisation du substrat entre sa surface et une valeur de profondeur qui est comprise entre 0,2 pm et 1 pm, mesurée à partir de la surface du substrat. En particulier, ces valeurs de dose et d’énergie d’implantation peuvent être adaptées par rapport à la longueur d’onde du rayonnement qui sera produit dans le substrat pendant l’utilisation du composant et destiné à sortir du substrat. Autrement dit, le volume d’amorphisation, sous la surface du substrat, constitue une couche à effet antireflet dont l’épaisseur peut être optimisée avantageusement par rapport à la longueur d’onde du rayonnement. A titre d’exemple, ce rayonnement qui est produit par le composant peut être de la lumière visible ou du rayonnement infrarouge, par exemple avec une longueur d’onde proche de 1 ,5 pm. [0010] Les ions qui sont implantés à l’étape 121 peuvent être sélectionnés parmi des ions d’aluminium (Al), des ions de bore (B) et des ions d’azote (N). Mais d’autres ions aussi adaptés pour produire des dopages voulus peuvent être utilisés alternativement. [0009] Preferably, in step 121, the ion implantation dose and ion implantation energy values can be selected to produce an amorphization of the substrate between its surface and a depth value which is between 0.2 µm and 1 µm, measured from the surface of the substrate. In particular, these implantation dose and energy values can be adapted with respect to the wavelength of the radiation which will be produced in the substrate during use of the component and intended to exit from the substrate. In other words, the amorphization volume, under the surface of the substrate, constitutes a layer with an antireflection effect, the thickness of which can be advantageously optimized with respect to the wavelength of the radiation. By way of example, this radiation which is produced by the component can be visible light or infrared radiation, for example with a wavelength close to 1.5 μm. [0010] The ions that are implanted in step 121 can be selected from among aluminum ions (Al), boron ions (B) and nitrogen ions (N). But other ions also suitable for producing desired dopings can be used alternatively.
[0011] Préférentiellement, à l’étape 121, la valeur de dose d’implantation ionique peut être comprise entre 1014 et 1016 ions par cm2 (centimètre-carré), et la valeur d’énergie d’implantation ionique peut être comprise entre 20 keV (kiloélectron-volt) et 800 keV. En effet, ces valeurs sont particulièrement appropriées pour produire une réduction d’indice de réfraction qui soit suffisante pour accroître sensiblement l’efficacité de sortie du rayonnement vers l’extérieur du composant. Preferably, in step 121, the ion implantation dose value can be between 10 14 and 10 16 ions per cm 2 (square centimeter), and the ion implantation energy value can be between 20 keV (kiloelectron-volt) and 800 keV. Indeed, these values are particularly suitable for producing a reduction in refractive index which is sufficient to substantially increase the outward radiation output efficiency of the component.
[0012] Avantageusement, et notamment pour réaliser une diode électroluminescente dans le substrat de carbure de silicium, les ions peuvent être implantés dans le substrat à l’étape 121, à travers la portion de sa surface qui est destinée à constituer la fenêtre de sortie du rayonnement, avec un premier couple de valeurs pour la dose d’implantation ionique et l’énergie d’implantation ionique, et avec un second couple de valeurs pour ces paramètres d’implantation ionique, le premier couple de valeurs étant adapté pour doper au moins une partie d’une diode électroluminescente située dans le substrat, à une profondeur mesurée à partir de la surface du substrat qui est supérieure à une épaisseur du volume d’amorphisation, cette épaisseur étant mesurée perpendiculairement à la surface du substrat, et le second couple de valeurs étant adapté pour produire l’amorphisation du substrat dans le volume situé sous sa surface. Une telle combinaison d’implantation ionique est particulièrement avantageuse pour réduire le coût de fabrication de la diode électroluminescente. De préférence, l’implantation avec le premier couple de valeurs et effectuée avant celle avec le second couple de valeurs. [0012] Advantageously, and in particular to produce a light-emitting diode in the silicon carbide substrate, the ions can be implanted in the substrate in step 121, through the portion of its surface which is intended to constitute the exit window. radiation, with a first pair of values for the ion implantation dose and the ion implantation energy, and with a second pair of values for these ion implantation parameters, the first pair of values being adapted to dope at at least a part of a light-emitting diode located in the substrate, at a depth measured from the surface of the substrate which is greater than a thickness of the amorphization volume, this thickness being measured perpendicular to the surface of the substrate, and the second pair of values being adapted to produce the amorphization of the substrate in the volume located under its surface. Such a combination of ion implantation is particularly advantageous for reducing the manufacturing cost of the light-emitting diode. Preferably, the implementation with the first pair of values is carried out before that with the second pair of values.
[0013] De façon générale, le procédé de l’invention peut comprendre en outre l’étape suivante, qui est effectuée le cas échéant après l’étape 121 : [0013] In general, the method of the invention may also comprise the following step, which is carried out if necessary after step 121:
/3/ appliquer un traitement thermique au substrat, ce traitement thermique produisant une activation d’un dopage du substrat par les ions implantés. /3/ apply a heat treatment to the substrate, this heat treatment producing an activation of a doping of the substrate by the implanted ions.
Une recristallisation qui pourrait être provoquée par ce traitement thermique est en général partielle, et insuffisante pour modifier significativement la densité du matériau du substrat dans le volume d’amorphisation. Le traitement thermique de cette étape /3/ peut être réalisé à pression atmosphérique, sous argon (Ar), avec une température qui est comprise entre 800°C et 1900°C, de préférence entre 1600°C et 1800°C, pendant une durée qui est inférieure à 1 heure. Au-delà de cette durée, ce traitement thermique pourrait réduire l’effet d’antireflet qui est procuré par l’amorphisation du substrat en dessous de la fenêtre de sortie du rayonnement. Le traitement thermique de l’étape /3/ peut être effectué pendant ou après une implantation d’ions dans le substrat qui est destinée à doper au moins une partie d’une diode électroluminescente qui est située dans ce substrat. Any recrystallization that could be caused by this heat treatment is generally partial, and insufficient to significantly modify the density of the material of the substrate in the amorphization volume. The heat treatment of this step /3/ can be carried out at atmospheric pressure, under argon (Ar), with a temperature which is between 800° C. and 1900° C., preferably between 1600° C. and 1800° C., for a period which is less than 1 hour. Beyond this duration, this heat treatment could reduce the antireflection effect which is provided by the amorphization of the substrate below the radiation exit window. The heat treatment of step /3/ can be performed during or after an implantation of ions in the substrate which is intended to dope at least part of a light-emitting diode which is situated in this substrate.
[0014] Jusqu’avant l’étape 121 qui produit l’amorphisation d’une partie du substrat de carbure de silicium, ce dernier peut être monocristallin, notamment selon le polytype 3C, 6H ou 4H. [0014] Until step 121 which produces the amorphization of part of the silicon carbide substrate, the latter may be monocrystalline, in particular according to the 3C, 6H or 4H polytype.
[0015] Un second aspect de l’invention propose un composant émetteur de rayonnement, qui comprend un substrat de carbure de silicium cristallin, ce substrat ayant une surface et possédant une première valeur de densité de matériau dans un volume situé sous une portion de cette surface qui est destinée à constituer, lors d’une utilisation du composant, une fenêtre de sortie vers l’extérieur du substrat pour du rayonnement en provenance de l’intérieur du substrat, cette première valeur de densité de matériau étant inférieure à une seconde valeur de densité de matériau qui est effective dans le substrat à une profondeur supérieure à une épaisseur du volume correspondant à la première valeur de densité, la profondeur et l’épaisseur étant mesurées perpendiculairement à la surface du substrat, la profondeur étant mesurée à partir de la surface du substrat. A second aspect of the invention proposes a radiation-emitting component, which comprises a substrate of crystalline silicon carbide, this substrate having a surface and possessing a first material density value in a volume located under a portion of this surface which is intended to constitute, during use of the component, an exit window towards the exterior of the substrate for radiation coming from the interior of the substrate, this first material density value being lower than a second value density of material which is effective in the substrate at a depth greater than a thickness of the volume corresponding to the first density value, the depth and the thickness being measured perpendicular to the surface of the substrate, the depth being measured from the substrate surface.
[0016] Pour obtenir une augmentation supérieure de l’efficacité de sortie du rayonnement, un quotient de la première valeur de densité de matériau sur la seconde valeur de densité de matériau peut être inférieur à 0,95, de préférence inférieur à 0,90. [0016] To achieve a greater increase in radiation output efficiency, a quotient of the first material density value to the second material density value may be less than 0.95, preferably less than 0.90 .
[0017] Dans un tel composant, le substrat de carbure de silicium peut être monocristallin, au moins en dehors du volume qui correspond à la première valeur de densité du matériau. [0017] In such a component, the silicon carbide substrate may be monocrystalline, at least outside the volume which corresponds to the first density value of the material.
[0018] Un tel composant peut constituer un émetteur à centre coloré, par exemple pour émettre des photons uniques, ou une diode électroluminescente, situé(e) dans le substrat. Alors, lors de l’utilisation de ce composant, le rayonnement est émis par le centre coloré ou par la diode électroluminescente et traverse la fenêtre de sortie. Le centre coloré ou la diode électroluminescente, selon le cas, est situé(e) sous la surface du substrat à une profondeur qui est supérieure ou égale à l’épaisseur du volume correspondant à la première valeur de densité du matériau. [0018] Such a component can constitute a colored center emitter, for example for emitting single photons, or a light-emitting diode, located in the substrate. Then, during the use of this component, the radiation is emitted by the colored center or by the light-emitting diode and passes through the output window. The colored center or the light-emitting diode, as the case may be, is located below the surface of the substrate at a depth which is greater than or equal to the thickness of the volume corresponding to the first density value of the material.
Brève description des figures Brief description of figures
[0019] Les caractéristiques et avantages de la présente invention apparaîtront plus clairement dans la description détaillée ci-après d’exemples de réalisation non-limitatifs, en référence aux figures annexées parmi lesquelles : The characteristics and advantages of the present invention will appear more clearly in the following detailed description of non-limiting embodiments, with reference to the appended figures, including:
[0020] [Fig. 1a] est une vue en coupe transversale d’un substrat utilisé pour fabriquer un composant photoémetteur, conformément à l’invention ; [0020] [Fig. 1a] is a cross-sectional view of a substrate used to manufacture a light-emitting component, in accordance with the invention;
[0021] [Fig. 1 b] correspond à [Fig. 1a] pour une étape ultérieure du procédé ; [0021] [Fig. 1b] corresponds to [Fig. 1a] for a subsequent step of the method;
[0022] [Fig. 1c] correspond à [Fig. 1a] pour une étape encore ultérieure du procédé ; [0022] [Fig. 1c] corresponds to [Fig. 1a] for an even later stage of the process;
[0023] [Fig. 1d] correspond à [Fig. 1a] pour une étape encore ultérieure du procédé ; [0023] [Fig. 1d] corresponds to [Fig. 1a] for an even later stage of the process;
[0024] [Fig. 2a] est une vue en coupe transversale d’un composant photoémetteur à centres colorés, tel qu’obtenu par un procédé de fabrication conforme à l’invention ; et[0024] [Fig. 2a] is a cross-sectional view of a light-emitting component with colored centers, as obtained by a manufacturing method according to the invention; And
[0025] [Fig. 2b] correspond à [Fig. 2a] pour une photodiode obtenue par un procédé de fabrication conforme à l’invention. [0025] [Fig. 2b] corresponds to [Fig. 2a] for a photodiode obtained by a manufacturing process according to the invention.
Description détaillée de l’invention Detailed description of the invention
[0026] Pour raison de clarté, les dimensions des éléments qui sont représentés dans ces figures ne correspondent ni à des dimensions réelles, ni à des rapports de dimensions réels. En outre, des références identiques qui sont indiquées dans des figures différentes désignent des éléments identiques ou qui ont des fonctions identiques. [0026] For reasons of clarity, the dimensions of the elements that are shown in these figures correspond neither to actual dimensions nor to actual ratios of dimensions. Furthermore, identical references which are indicated in different figures designate elements which are identical or which have identical functions.
[0027] Conformément à [Fig.1a], un substrat 1 de carbure de silicium (SiC) monocristallin, par exemple de polytype 3C, possède une surface S. Cette surface S peut être recouverte d’un masque 3, appelé masque dur. Le masque dur 3 peut être du type masque métallique, par exemple à base de nickel (Ni), d’aluminium (Al) ou de chrome (Cr). Alternativement, le masque dur 3 peut être en matériau diélectrique, tel que de la silice (SiO2), ou en une résine qui résiste aux procédés d’implantation et qui peut être retirée complètement ensuite. De façon générale, le masque dur 3 peut être en tout matériau adapté pour être gravé localement. In accordance with [Fig.1a], a monocrystalline silicon carbide (SiC) substrate 1, for example of polytype 3C, has a surface S. This surface S can be covered with a mask 3, called a hard mask. The hard mask 3 can be of the metal mask type, for example based on nickel (Ni), aluminum (Al) or chromium (Cr). Alternatively, the hard mask 3 can be made of dielectric material, such as silica (SiO2), or of a resin which is resistant to implantation processes and which can be removed completely afterwards. In general, the hard mask 3 can be made of any material suitable for being etched locally.
[0028] Une couche encapsulante 2, facultative, peut être intermédiaire entre la surface S du substrat 1 et le masque dur 3. Lorsqu’elle est utilisée, la couche encapsulante 2 est destinée à limiter ou supprimer une sublimation d’atomes de silicium qui serait susceptible de se produire à partir de la surface S du substrat 1 lors d’un chauffage, mais d’autres méthodes pour éviter une telle sublimation des atomes de silicium sont connues, et peuvent être utilisées alternativement. Une telle couche encapsulante 2 peut être constituée de carbone graphite (C), par exemple telle qu’obtenue en pyrolysant in-situ une couche de résine photolithographique déposée sur la surface S du substrat 1. Le traitement de pyrolyse de la résine peut être effectué à 750°C pendant 30 minutes sous atmosphère d’azote (N2), par exemple. Une telle couche d’encapsulation 2 est efficace pour protéger le carbure de silicium contre des dégradations activées thermiquement, notamment contre la sublimation d’atomes de silicium (Si) jusqu’à environ 1800°C. An encapsulating layer 2, optional, can be intermediate between the surface S of the substrate 1 and the hard mask 3. When it is used, the encapsulating layer 2 is intended to limit or eliminate a sublimation of silicon atoms which would be liable to occur from the surface S of the substrate 1 during heating, but other methods for avoiding such sublimation of the silicon atoms are known, and can be used alternatively. Such an encapsulating layer 2 can be made of graphite carbon (C), for example as obtained by pyrolyzing in situ a layer of photolithographic resin deposited on the surface S of the substrate 1. The pyrolysis treatment of the resin can be carried out at 750°C for 30 minutes under a nitrogen (N2) atmosphere, for example. Such an encapsulation layer 2 is effective in protecting the silicon carbide against thermally activated degradations, in particular against the sublimation of silicon (Si) atoms up to about 1800°C.
[0029] Le masque dur 3 est alors retiré sélectivement à l’intérieur d’une portion W de la surface S, qui est destinée à constituer une fenêtre de sortie du rayonnement d’un composant photoémetteur réalisé dans le substrat 1. Un tel retrait sélectif du masque dur 3, à l’intérieur de la fenêtre W, peut être réalisé d’une des façons connues de l’Homme du métier, par exemple par lithographie optique ou électronique puis en utilisant un procédé gravure, humide ou à plasma, qui est adapté pour éliminer le masque dur 3 dans chaque zone où ce dernier est exposé, c’est-à dire dans la fenêtre W. Pour créer une telle fenêtre W, un procédé par lift-off peut être utilisé alternativement, pour obtenir le masque dur 3 sélectivement en dehors de la fenêtre W sur le substrat 1 . La configuration qui est montrée par [Fig. 1 b] est alors obtenue. [0029] The hard mask 3 is then selectively removed inside a portion W of the surface S, which is intended to constitute an exit window for the radiation of a light-emitting component produced in the substrate 1. Such removal selection of the hard mask 3, inside the window W, can be made in one of the ways known to those skilled in the art, for example by optical or electronic lithography then using an etching, wet or plasma process, which is adapted to eliminate the hard mask 3 in each zone where the latter is exposed, that is to say in the window W. To create such a window W, a lift-off method can be used alternatively, to obtain the hard mask 3 selectively outside window W on substrate 1 . The configuration which is shown by [Fig. 1 b] is then obtained.
[0030] Lorsque la couche encapsulante 2 est utilisée, le substrat 1 peut alors être mis en contact avec un plasma d’oxygène (O2) pour retirer la couche encapsulante 2 dans les endroits où elle n’est plus recouverte par le masque dur 3, comme montré par [Fig. 1c]. Alternativement, un procédé de gravure par faisceau d’ions d’oxygène ou un traitement d’oxydation thermique peuvent aussi être utilisés pour retirer les portions découvertes de la couche encapsulante 2. [0031] Des ions, par exemple des ions d’aluminium (Al), de bore (B) ou d’azote (N) selon le type de dopage voulu, sont ensuite implantés dans le substrat 1 , à travers l’ouverture qui a été pratiquée précédemment dans le masque dur 3, et dans la couche encapsulante 2 le cas échéant. Une énergie d’implantation ionique est adoptée, pour que ces ions soient finalement fixés dans une portion V du substrat 1 qui s’étend à partir d’une profondeur P sensiblement égale à 0,25 pm. Alors, le substrat 1 est amorphisé entre sa surface S et cette profondeur P, à cause des collisions contre les atomes de carbone et de silicium du substrat 1 , des ions implantés jusqu’à leurs sites de fixation. Selon l’invention, cette implantation ionique est réalisée à température ambiante, ou à une température de refroidissement, pour favoriser l’amorphisation du substrat 1 à partir de sa surface S jusqu’à la profondeur P, en ligne avec la fenêtre W. Par exemple, les paramètres suivants peuvent être adoptés pour l’implantation ionique : énergie d’implantation sensiblement égale à 200 keV, et dose implantée sensiblement égale à 1 ,75-1015 ions par cm2. Dans ces conditions, la profondeur P est sensiblement égale à 250 nm (nanomètre) si des ions d’aluminium sont utilisés pour l’implantation, et l’amorphisation du substrat 1 sous la fenêtre W produit dans celle-ci un gonflement SW de la surface S, comme montré dans [Fig. 1 d]. Ce gonflement SW, qui est de l’ordre de 50 nm au centre de la fenêtre W, résulte d’une diminution de la densité du matériau du substrat 1 produite par son amorphisation. Il est sensiblement égal à 50 nm pour les conditions d’implantation précitées. Ainsi, la densité du carbure de silicium dans le volume superficiel VS qui est limité par la fenêtre W, la surface S et une profondeur sous cette surface S qui est inférieure ou égale à P, est sensiblement égale à 0,8 fois la densité du carbure de silicium du substrat 1 en dehors de ce volume VS. Cette réduction de densité provoque une diminution de l’indice de réfraction lumineuse du matériau du substrat 1 dans le volume VS. Ce volume à valeur réduite d’indice de réfraction lumineuse produira alors un effet antireflet au moins partiel, pour du rayonnement provenant de la zone de fixation des ions implantés. When the encapsulating layer 2 is used, the substrate 1 can then be brought into contact with an oxygen plasma (O2) to remove the encapsulating layer 2 in the places where it is no longer covered by the hard mask 3 , as shown by [Fig. 1 C]. Alternatively, an oxygen ion beam etching process or a thermal oxidation treatment can also be used to remove the uncovered portions of the encapsulating layer 2. Ions, for example aluminum (Al), boron (B) or nitrogen (N) ions depending on the type of doping desired, are then implanted in the substrate 1, through the opening which was practiced previously in the hard mask 3, and in the encapsulating layer 2 if necessary. An ion implantation energy is adopted, so that these ions are finally fixed in a portion V of the substrate 1 which extends from a depth P substantially equal to 0.25 μm. Then, the substrate 1 is amorphized between its surface S and this depth P, because of the collisions against the carbon and silicon atoms of the substrate 1, of the ions implanted up to their binding sites. According to the invention, this ion implantation is carried out at room temperature, or at a cooling temperature, to promote the amorphization of the substrate 1 from its surface S to the depth P, in line with the window W. For example, the following parameters can be adopted for ion implantation: implantation energy substantially equal to 200 keV, and implanted dose substantially equal to 1.75-10 15 ions per cm 2 . Under these conditions, the depth P is substantially equal to 250 nm (nanometer) if aluminum ions are used for the implantation, and the amorphization of the substrate 1 under the window W produces therein a swelling SW of the surface S, as shown in [Fig. 1d]. This swelling SW, which is of the order of 50 nm at the center of the window W, results from a reduction in the density of the material of the substrate 1 produced by its amorphization. It is substantially equal to 50 nm for the aforementioned implantation conditions. Thus, the density of the silicon carbide in the superficial volume VS which is limited by the window W, the surface S and a depth under this surface S which is less than or equal to P, is substantially equal to 0.8 times the density of the silicon carbide of substrate 1 outside this volume VS. This reduction in density causes a reduction in the luminous refractive index of the material of the substrate 1 in the volume VS. This volume with a reduced luminous refractive index value will then produce an at least partial anti-reflection effect, for radiation coming from the fixing zone of the implanted ions.
[0032] La partie résiduelle du masque dur 3, en dehors de la fenêtre W, est ensuite retirée, de nouveau par gravure humide, puis un traitement thermique est appliqué au substrat pour activer le dopage constitué par les ions implantés. Lors de ce traitement thermique d’activation, le substrat 1 peut être amené à une température sensiblement égale à 1700°C pendant 30 minutes, à pression atmosphérique sous argon (Ar). De tels paramètres de traitement thermique permettent d’activer la fonction de dopage sans réaugmenter significativement la densité du carbure de silicium dans le volume VS. Ainsi, l’efficacité de sortie à travers la fenêtre W, du rayonnement qui provient de l’intérieur du substrat 1 en dessous du volume VS pendant une utilisation du composant fabriqué, est maintenue. The residual part of the hard mask 3, outside the window W, is then removed, again by wet etching, then a heat treatment is applied to the substrate to activate the doping constituted by the implanted ions. During this activation heat treatment, the substrate 1 can be brought to a temperature substantially equal to 1700° C. for 30 minutes, at atmospheric pressure under argon (Ar). Such heat treatment parameters make it possible to activate the doping function without significantly increasing the density of the silicon carbide in the volume VS. Thus, the output efficiency through the window W, of the radiation which comes from the interior of the substrate 1 below the volume VS during use of the manufactured component, is maintained.
[0033] Selon un perfectionnement de l’invention, l’implantation des ions peut être effectuée en deux étapes distinctes, pour différencier les fonctions d’amorphisation du matériau de carbure de silicium dans le volume VS, et de dopage dans un volume V qui est situé d’un côté opposé à la surface S par rapport au volume VS. Autrement dit, le volume V est situé sous le volume VS dans le substrat 1 , le volume VS étant alors appelé volume superficiel. Dans ces conditions, le volume superficiel VS est essentiellement dédié à produire l’effet antireflet pour favoriser la sortie du rayonnement, et le volume V est dédié à produire le rayonnement. Alors, l’implantation des ions dans le volume V peut être effectuée avec un premier couple de valeurs pour la dose d’implantation ionique et l’énergie d’implantation ionique afin de doper le substrat 1 dans le volume V, puis un second couple de valeurs pour ces paramètres d’implantation afin d’amorphiser le matériau de carbure de silicium dans le volume superficiel VS. La profondeur P correspond alors à une limite supérieure du volume V, en direction de la surface S du substrat 1. Par exemple, les valeurs pour amorphiser le substrat 1 dans le volume superficiel VS peuvent être 1015 ions par cm2 pour la dose d’implantation, et 100 keV pour l’énergie d’implantation, et celles pour créer le dopage dans le volume V peuvent être 1014 ions par cm2 et 200 keV. According to an improvement of the invention, the implantation of the ions can be carried out in two distinct stages, to differentiate the functions of amorphization of the silicon carbide material in the volume VS, and of doping in a volume V which is located on a side opposite the surface S with respect to the volume VS. In other words, the volume V is located under the volume VS in the substrate 1, the volume VS then being called the surface volume. Under these conditions, the superficial volume VS is essentially dedicated to producing the antireflection effect to promote the exit of the radiation, and the volume V is dedicated to producing the radiation. Then, the implantation of the ions in the volume V can be carried out with a first pair of values for the ion implantation dose and the ion implantation energy in order to dope the substrate 1 in the volume V, then a second pair of values for these implantation parameters in order to amorphize the silicon carbide material in the surface volume VS. The depth P then corresponds to an upper limit of the volume V, in the direction of the surface S of the substrate 1. For example, the values for amorphizing the substrate 1 in the surface volume VS can be 10 15 ions per cm 2 for the dose d implantation, and 100 keV for the implantation energy, and those for creating the doping in the volume V can be 10 14 ions per cm 2 and 200 keV.
[0034] [Fig. 2a] est une vue en coupe d’un composant à centres colorés, pour produire des photons uniques. Ces centres colorés, produits par le dopage, sont situés dans le volume V et notés CC, et une partie des photons qu’ils émettent est orientée vers la fenêtre W. Le volume superficiel VS, dans lequel l’indice de réfraction du matériau du substrat 1 est diminué selon l’invention, réduit une réflexion de ces photons sur la surface S, interne au substrat 1 . R désigne le rayonnement qui est constitué par les photons qui sortent par la fenêtre W. A titre d’illustration, [Fig. 2a] montre aussi deux photons R’ qui sont produits par les centres colorés CC en étant dirigés en dehors de la fenêtre W, et qui sont réfléchis vers l’intérieur du substrat 1 par la surface S. [0035] Enfin, [Fig. 2b] est une vue en coupe d’une photodiode fabriquée par le procédé de l’invention. Le substrat monocristallin de carbure de silicium 1 qui est utilisé peut être originellement dopé de type N, et le dopage qui est effectué pour créer le volume superficiel VS peut être de type P, comme le volume V. La limite inférieure du volume V, notée J dans la figure, est la jonction de photodiode. Le composant peut être complété par une électrode arrière 4 et une électrode supérieure 5. L’électrode supérieure 5 peut être formée d’une façon connue de l’Homme du métier, sur le gonflement SW de la surface S. Lorsqu’un courant est injecté entre les deux électrodes 4 et 5, avec une polarisation électrique directe de la photodiode, du rayonnement R est émis par la jonction J, dont une partie sort du substrat 1 par la fenêtre W. De même que précédemment, cette partie du rayonnement qui est produite par la photodiode et qui émerge du substrat 1 est accrue grâce à l’invention. [0034] [Fig. 2a] is a cross-sectional view of a component with color centers, for producing single photons. These colored centers, produced by the doping, are located in the volume V and denoted CC, and part of the photons they emit are oriented towards the window W. The superficial volume VS, in which the refractive index of the material of the substrate 1 is reduced according to the invention, reduces a reflection of these photons on the surface S, internal to the substrate 1. R designates the radiation which is constituted by the photons which leave through the window W. By way of illustration, [Fig. 2a] also shows two photons R' which are produced by the color centers CC while being directed outside the window W, and which are reflected towards the interior of the substrate 1 by the surface S. [0035] Finally, [Fig. 2b] is a cross-sectional view of a photodiode fabricated by the method of the invention. The single-crystal silicon carbide substrate 1 which is used may be originally N-type doped, and the doping which is carried out to create the surface volume VS may be of the P-type, like the volume V. The lower limit of the volume V, denoted J in the figure, is the photodiode junction. The component may be completed by a rear electrode 4 and an upper electrode 5. The upper electrode 5 may be formed in a manner known to those skilled in the art, on the swelling SW of the surface S. When a current is injected between the two electrodes 4 and 5, with a direct electrical bias of the photodiode, radiation R is emitted by the junction J, part of which leaves the substrate 1 through the window W. As before, this part of the radiation which is produced by the photodiode and which emerges from the substrate 1 is increased thanks to the invention.
[0036] Il est entendu que l’invention peut être reproduite en modifiant des aspects secondaires des modes de réalisation qui ont été décrits en détail ci-dessus, tout en conservant certains au moins des avantages cités. Notamment, un composant fabriqué conformément à l’invention peut être d’un autre type qu’un émetteur de photons uniques ou une photodiode. En outre, toutes les valeurs numériques qui ont été citées ne l’ont été qu’à titre d’illustration, et peuvent être changées en fonction de l’application considérée. It is understood that the invention can be reproduced by modifying secondary aspects of the embodiments which have been described in detail above, while retaining at least some of the advantages cited. In particular, a component manufactured in accordance with the invention may be of a type other than a single photon emitter or a photodiode. In addition, any numerical values that have been quoted are for illustrative purposes only, and may be changed depending on the particular application.

Claims

Revendications Claims
[Revendication 1] Procédé de fabrication d’un composant émetteur de rayonnement à partir d’un substrat (1) de carbure de silicium cristallin, le procédé comprenant : [Claim 1] A method of manufacturing a radiation emitting component from a substrate (1) of crystalline silicon carbide, the method comprising:
/1/ dans une surface (S) du substrat (1 ), déterminer au moins une portion de ladite surface qui est destinée à constituer, lors d’une utilisation du composant, une fenêtre (W) de sortie vers l’extérieur du substrat du rayonnement (R) en provenance de l’intérieur dudit substrat ; et /1/ in a surface (S) of the substrate (1), determining at least a portion of said surface which is intended to constitute, during use of the component, an exit window (W) towards the outside of the substrate radiation (R) from within said substrate; And
121 pendant que le substrat (1) possède une température inférieure à 200°C, implanter des ions dans le substrat, à travers la portion de la surface (S) dudit substrat qui est destinée à constituer la fenêtre (W) de sortie du rayonnement (R), avec des valeurs de dose d’implantation ionique et d’énergie d’implantation ionique qui sont adaptées pour produire une amorphisation du substrat dans un volume (VS) situé sous ladite surface du substrat. 121 while the substrate (1) has a temperature below 200°C, implanting ions into the substrate, through the portion of the surface (S) of said substrate which is intended to constitute the radiation exit window (W) (R), with ion implantation dose and ion implantation energy values which are adapted to produce amorphization of the substrate in a volume (VS) located under said surface of the substrate.
[Revendication 2] Procédé selon la revendication 1 , suivant lequel, à l’étape 121, les valeurs de dose d’implantation ionique et d’énergie d’implantation ionique sont sélectionnées pour produire une amorphisation du substrat (1) entre la surface (S) dudit substrat et une valeur de profondeur (P) comprise entre 0,2 pm et 1 pm, mesurée à partir de ladite surface du substrat. [Claim 2] Method according to claim 1, according to which, in step 121, the values of ion implantation dose and ion implantation energy are selected to produce an amorphization of the substrate (1) between the surface ( S) of said substrate and a depth value (P) comprised between 0.2 μm and 1 μm, measured from said surface of the substrate.
[Revendication 3] Procédé selon la revendication 1 ou 2 suivant lequel, à l’étape 121, la valeur de dose d’implantation ionique est comprise entre 1014 et 1016 ions par cm2, et la valeur d’énergie d’implantation ionique est comprise entre 20 keV et 800 keV. [Claim 3] Method according to claim 1 or 2 according to which, in step 121, the ion implantation dose value is between 10 14 and 10 16 ions per cm 2 , and the implantation energy value ion is between 20 keV and 800 keV.
[Revendication 4] Procédé selon l’une quelconque des revendications précédentes suivant lequel, à l’étape 121, les ions sont implantés dans le substrat (1 ), à travers la portion de la surface (S) dudit substrat qui est destinée à constituer la fenêtre (W) de sortie du rayonnement, avec un premier couple de valeurs pour la dose d’implantation ionique et l’énergie d’implantation ionique, et avec un second couple de valeurs pour ladite dose d’implantation ionique et ladite énergie d’implantation ionique, le premier couple de valeurs étant adapté pour doper au moins une partie d’une diode électroluminescente située dans le substrat, à une profondeur (P) mesurée à partir de la surface du substrat qui est supérieure à une épaisseur du volume (VS) d’amorphisation, ladite épaisseur étant mesurée perpendiculairement à la surface du substrat, et le second couple de valeurs étant adapté pour produire l’amorphisation du substrat dans le volume (VS) situé sous la surface dudit substrat. [Claim 4] Method according to any one of the preceding claims, according to which, in step 121, the ions are implanted in the substrate (1), through the portion of the surface (S) of the said substrate which is intended to constitute the radiation exit window (W), with a first pair of values for the ion implantation dose and the ion implantation energy, and with a second pair of values for the said ion implantation dose and the said energy of ion implantation, the first pair of values being adapted to dope at least part of a light-emitting diode located in the substrate, at a depth (P) measured from the surface of the substrate which is greater than a thickness of the volume (VS) of amorphization, said thickness being measured perpendicular to the surface of the substrate, and the second pair of values being adapted to produce the amorphization of the substrate in the volume (VS) located under the surface of said substrate.
[Revendication 5] Procédé selon l’une quelconque des revendications précédentes, comprenant en outre l’étape suivante, effectuée après l’étape 121 : [Claim 5] A method according to any preceding claim, further comprising the following step, performed after step 121:
/3/ appliquer un traitement thermique au substrat (1 ), ledit traitement thermique produisant une activation d’un dopage du substrat par les ions implantés. /3/ applying a heat treatment to the substrate (1), said heat treatment producing an activation of a doping of the substrate by the implanted ions.
[Revendication 6] Procédé selon la revendication 5, suivant lequel le traitement thermique de l’étape 73/ est réalisé à pression atmosphérique, sous argon, avec une température comprise entre 800°C et 1900°C, de préférence entre 1600°C et 1800°C, pendant une durée inférieure à 1 heure. [Claim 6] Process according to claim 5, according to which the heat treatment of step 73/ is carried out at atmospheric pressure, under argon, with a temperature of between 800°C and 1900°C, preferably between 1600°C and 1800°C, for a period of less than 1 hour.
[Revendication 7] Procédé selon l’une quelconque des revendications précédentes, suivant lequel le substrat (1) de carbure de silicium est monocristallin avant l’étape 121. [Claim 7] A method according to any preceding claim, wherein the silicon carbide substrate (1) is single crystal prior to step 121.
[Revendication 8] Composant émetteur de rayonnement, comprenant un substrat (1) de carbure de silicium cristallin, ledit substrat ayant une surface (S) et possédant une première valeur de densité de matériau dans un volume (VS) situé sous une portion de ladite surface qui est destinée à constituer, lors d’une utilisation du composant, une fenêtre (W) de sortie vers l’extérieur du substrat pour du rayonnement (R) en provenance de l’intérieur dudit substrat, ladite première valeur de densité de matériau étant inférieure à une seconde valeur de densité de matériau qui est effective dans le substrat à une profondeur supérieure à une épaisseur du volume correspondant à la première valeur du matériau, la profondeur et l’épaisseur étant mesurées perpendiculairement à la surface du substrat, la profondeur étant mesurée à partir de ladite surface du substrat. [Claim 8] Radiation-emitting component, comprising a substrate (1) of crystalline silicon carbide, said substrate having a surface (S) and having a first material density value in a volume (VS) located under a portion of said surface which is intended to constitute, during use of the component, an exit window (W) towards the exterior of the substrate for radiation (R) coming from the interior of said substrate, said first material density value being less than a second material density value which is effective in the substrate at a depth greater than a thickness of the volume corresponding to the first material value, the depth and the thickness being measured perpendicular to the surface of the substrate, the depth being measured from said surface of the substrate.
[Revendication 9] Composant selon la revendication 8, dans lequel un quotient de la première valeur de densité de matériau sur la seconde valeur de densité de matériau est inférieur à 0,95, de préférence inférieur à 0,90. [Claim 9] A component according to claim 8, wherein a quotient of the first material density value to the second material density value is less than 0.95, preferably less than 0.90.
[Revendication 10] Composant selon la revendication 8 ou 9, dans lequel le substrat (1) de carbure de silicium est monocristallin, au moins en dehors du volume (VS) correspondant à la première valeur de densité de matériau. [Claim 10] Component according to Claim 8 or 9, in which the silicon carbide substrate (1) is monocrystalline, at least outside the volume (VS) corresponding to the first material density value.
[Revendication 11] Composant selon l’une quelconque des revendications 8 à 10, formant un émetteur à centre coloré ou une diode électroluminescente, situé(e) dans le substrat (1 ), et tel que lors de l’utilisation dudit composant, le rayonnement (R) soit émis par le centre coloré ou par la diode électroluminescente et traverse la fenêtre (W) de sortie, ledit centre coloré ou ladite diode électroluminescente étant située sous la surface (S) du substrat à une profondeur (P) qui est supérieure ou égale à l’épaisseur du volume (VS) correspondant à la première valeur de densité de matériau. [Claim 11] Component according to any one of Claims 8 to 10, forming a colored center emitter or a light-emitting diode, located in the substrate (1), and such that when using the said component, the radiation (R) is emitted by the colored center or by the light-emitting diode and passes through the exit window (W), said colored center or said light-emitting diode being located under the surface (S) of the substrate at a depth (P) which is greater than or equal to the volume thickness (VS) corresponding to the first material density value.
PCT/FR2023/050089 2022-02-08 2023-01-23 Production of a radiation-emitting component from a silicon carbide substrate WO2023152432A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FRFR2201064 2022-02-08
FR2201064A FR3132592A1 (en) 2022-02-08 2022-02-08 FABRICATION OF A RADIATION EMITTING COMPONENT FROM A SILICON CARBIDE SUBSTRATE

Publications (1)

Publication Number Publication Date
WO2023152432A1 true WO2023152432A1 (en) 2023-08-17

Family

ID=81648856

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FR2023/050089 WO2023152432A1 (en) 2022-02-08 2023-01-23 Production of a radiation-emitting component from a silicon carbide substrate

Country Status (2)

Country Link
FR (1) FR3132592A1 (en)
WO (1) WO2023152432A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1263058A2 (en) * 2001-05-29 2002-12-04 Toyoda Gosei Co., Ltd. Light-emitting element
US20100001312A1 (en) * 2008-07-01 2010-01-07 Epistar Corporation Light-emitting device and method for manufacturing the same
US20210091270A1 (en) * 2017-07-14 2021-03-25 Agc Glass Europe Light-emitting devices having an anti reflective silicon carbide or sapphire substrate and methods of forming the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1263058A2 (en) * 2001-05-29 2002-12-04 Toyoda Gosei Co., Ltd. Light-emitting element
US20100001312A1 (en) * 2008-07-01 2010-01-07 Epistar Corporation Light-emitting device and method for manufacturing the same
US20210091270A1 (en) * 2017-07-14 2021-03-25 Agc Glass Europe Light-emitting devices having an anti reflective silicon carbide or sapphire substrate and methods of forming the same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
VLASKINA S. I.: "Silicon carbide LED", SEMICONDUCTOR PHYSICS, QUANTUM ELECTRONICS & OPTOELECTRONICS, 2002, VOL. 5, NO 1, 1 January 2002 (2002-01-01), pages 71 - 75, XP055965268, Retrieved from the Internet <URL:http://journal-spqeo.org.ua/users/pdf/n1_2002/5_1_071.pdf> [retrieved on 20220927] *

Also Published As

Publication number Publication date
FR3132592A1 (en) 2023-08-11

Similar Documents

Publication Publication Date Title
EP0201127A1 (en) P-i-n photodiode with low leakage current
EP0760162B1 (en) Method for production of a structure with a low level of dislocations and having an oxide layer buried in a semiconductor substrate
FR2734401A1 (en) Field emission cold cathode with improved insulation
FR2967813A1 (en) METHOD FOR PRODUCING A BENTALLIC METAL LAYER STRUCTURE
EP1178522A1 (en) Formation of Quantum Dots
EP0262030B1 (en) Method of producing an electrical contact on a phgcdte substrate, and its use in producing an n/p diode
FR3008227A1 (en) PROCESS FOR THE ELECTRIC ACTIVATION OF DOPING SPECIES IN A GAN FILM
EP2504895B1 (en) Laser emission system, heterostructure and active zone comprising coupled sub-quantumwells, use for a laser emiission at 1.55 micrometers
EP0092266A1 (en) Process for manufacturing GaAs field effect transistors by ion implantation, and transistor made by this process
EP3590129B1 (en) Method for manufacturing a donor substrate for making optoelectronic devices
WO2023152432A1 (en) Production of a radiation-emitting component from a silicon carbide substrate
EP2979306A1 (en) Process for manufacturing a multi-junction structure for a photovoltaic cell
FR2905799A1 (en) IMPLEMENTING A GAN SUBSTRATE
WO2013102664A1 (en) Structured substrate for leds with high light extraction
EP0245169A1 (en) HgCdTe avalanche photodiode
WO2023152433A1 (en) Creation of a radiation output window for a light-emitting component
WO2017042486A1 (en) Method for manufacturing an electronic junction device and associated device
FR2724068A1 (en) SEMICONDUCTOR LASER DEVICE AND METHOD FOR MANUFACTURING THE SEMI-CONDUCTIVE LASER DEVICE
EP0142891B1 (en) Infrared-sensitive charge-coupled device and method of manufacturing the same
EP4187622B1 (en) Optoelectronic device comprising a semiconductor layer based on gesn and having a monocrystalline portion with a direct strip structure and an underlying barrier zone
FR2649537A1 (en) Integrated optoelectronic device including a light-emitting diode
EP0689088B1 (en) Method of manufacturing an array of all-optical vertical cavity quantum well components
EP4022688A1 (en) Method for manufacturing a photovoltaic cell
FR2801726A1 (en) Method for manufacturing photovoltaic element and corresponding cell, in particular for solar cells
WO2023275320A1 (en) Optoelectronic component that is insensitive to dislocations

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23706660

Country of ref document: EP

Kind code of ref document: A1