Optoelectronic component

Abstract

The invention relates to an optoelectronic component comprising: a substrate; a three-layer arrangement extending in a stacking direction perpendicular to the plane of the substrate, said arrangement comprising: a first semiconductor layer deposited on the substrate; a second semiconductor layer, called the active layer, deposited on the first semiconductor layer; a third N-doped semiconductor layer, called the N-doped layer, deposited on the active layer; the first semiconductor layer being a layer decomposed into at least two zones: an intrinsic zone; a P-doped zone; the N-doped layer and the active layer being arranged so as to at least partially cover the intrinsic zone, at least one electrical contact being arranged on the P-doped zone and at least one electrical contact being arranged on the N-doped layer. Figure: None

Description

Title of the invention: Optoelectronic component TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of optoelectronic components.

[0002] The present invention relates to an optoelectronic component such as a photodetector, an electro-optical modulator, a laser, an amplifier, or an optical switch, adapted for integration into an optoelectronic circuit. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Optoelectronic components, such as laser sources, light amplifiers, photodetectors, or electro-optical modulators, are generally fabricated in bulk III-V semiconductor crystals. Their typical length is on the order of a millimeter, but can extend up to a few hundred microns. The electrical power required to drive these components is on the order of one hundred pW per component. These characteristics limit the integration density of these components in an optoelectronic circuit.

[0004] The design of ultra-compact and high-performance optoelectronic devices is therefore of paramount importance for the development of photonic circuits. To reduce the dimensions of these devices, it is possible to exploit nanophotonic concepts where light is confined to volumes comparable to the order of magnitude of its wavelength in the semiconductor material of the waveguide. Such nanophotonic components rely on a technology based on the realization of a PIN junction. An example of such a device is described, for instance, in the document “Photonic-crystal nano-photodetector with ultrasmall capacitance for on-chip light-to-voltage conversion without an amplifier” (Optica 3, 483 (2016) - K. Nozaki et al) or in patent applications WO202210380 or WO2016207495 describing photonic crystal optoelectronic components.

[0005] The specific design of this type of component makes it possible in particular to carry out ultrafast operations (i.e. greater than 10 GHz) for both OE (Optical to Electrical) type detection and EO (Electrical to Optical) type modulation.

[0006] The response of optoelectronic components, such as photodetectors and electro-optical modulators, depends strongly on their electrical properties arising from the geometric arrangement of the materials that constitute them. In particular, the cutoff frequency of these components is ultimately limited.

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[0011] by the value of the product of the capacitance C and the resistance R of the component. This cutoff frequency can be defined as follows: f = 1 1 cutoff 2nRC To maximize the cutoff frequency, the RC product must be minimized. Known configurations focus on reducing the capacitance of the components, with the series resistance chosen according to the desired application. For electro-optical modulation, minimizing the resistance is also necessary to achieve the highest possible cutoff frequency. Conversely, in the case of photodetection, it is necessary to convert the photocurrent into a voltage. This can be done using a transimpedance amplifier or a series resistor, which can also be used as a load resistor to provide transimpedance gain, in order to convert the photocurrent I into a voltage U using the relationship: U=RI. If the capacitance C can be sufficiently low, a compromise can be made on the resistance R to obtain a sufficiently high cutoff frequency and a voltage U capable of detecting the desired signals.Such a compromise offers numerous advantages, as simple resistors can replace complex, expensive, and energy-intensive transimpedance amplifiers. This compromise is illustrated in [Fig. 1], which shows the evolution of capacitance as a function of resistance for different fixed cutoff frequencies and the optical power required to obtain a voltage of 0.2V (i.e., the typical voltage required to switch a CMOS transistor) as a function of the resistance value, with a photodetector responsiveness of up to 1A / W. For example, to detect a signal with an optical power of -20 dBm (10 pW), the load resistance R must be equal to 20 kΩ. If one wants to be able to operate at a frequency of 10 GHz or higher, the capacitance C must be less than 0.8 fF. The difficulty therefore lies in the possibility of obtaining optoelectronic components with capacitances that must be able to take very low values ​​depending on the application, typically less than or equal to 1 fF. A known solution for reducing the capacitance value is presented in the aforementioned paper “Photonic-crystal nano-photodetector with ultrasmall capacitance for on-chip light-to-voltage conversion without an amplifier” (Optica 3, 483 (2016) - K. Nozaki et al): Figure 2 shows on the left the structure of the optoelectronic component with a PIN junction. The photodetector is fabricated in an airbridged InP-based photonic crystal waveguide, which incorporates a localized InGaAs short absorber. The InP-based structure contains a horizontal PIN junction. According to the paper, this structure presents a very low capacitance, between 0.5 fF and 1 fF, depending on the length of the absorber.

[0012] However, the above solution presents significant technological difficulties for the fabrication of the component, particularly for the fabrication of the N- and P-doped regions. The N-doped region is obtained by ion implantation, and the P-doped region is obtained by zinc diffusion from the same InP layer. The implantation step notably involves a complex substrate transfer for the fabrication of the active InGaAs region. Implantation must be performed at a donor activation temperature too high to be compatible with prior deposition of the InGaAs region. Furthermore, the technology relies on highly advanced growth techniques and on re-epitaxial growth in openings on the order of micrometers in size.

[0013] There is therefore a need for an optoelectronic component structure capable of operating at high frequency, simpler to manufacture and allowing capacitances less than or equal to the femtofarad. Summary of the invention

[0014] The invention provides a solution to the problems mentioned above and relates to an optoelectronic component comprising a • A substrate; • An arrangement of three layers extending in a stacking direction perpendicular to the plane of the substrate, said arrangement comprising: • a first semiconductor layer deposited on the substrate; • a second semiconductor layer, called the active layer, deposited on the first semiconductor layer; • a third N-doped semiconductor layer, called the N-doped layer, deposited on the active layer; the first semiconductor layer being a layer decomposed into at least two zones: • an intrinsic zone; • a P-doped zone; the N-doped layer and the active layer being arranged so as to at least partially cover the intrinsic area, at least one electrical contact being arranged on the P-doped area and at least one electrical contact being arranged on the N-doped layer

[0015] Thanks to the invention, the heterogeneous junction formed by the N-layer, the active layer, generally intrinsic, and the P-layer is laterally modified to minimize the capacitance of the structure by locally substituting the P-doped layer under The active layer is replaced by an intrinsic layer to minimize the N and P surfaces facing each other. As we will see later, the intrinsic region can be fabricated, for example, but not limited to, a modified P-doped layer such that the P-doping disappears in the region where the electromagnetic field is confined and is localized solely in the semiconductor region under the P contact. The inventors then observed a very significant reduction in the capacitance of the optoelectronic component according to the invention compared to a prior art vertical PIN structure. The capacitance is reduced by more than an order of magnitude compared to the prior art, making it possible to detect signals well beyond a modulation bandwidth of 1 GHz while using a high load resistance.

[0016] In addition to the characteristics just mentioned, the component according to the invention may have one or more additional characteristics from among the following, considered individually or in all technically possible combinations: • The intrinsic zone and the P-doped zone have different thicknesses. • The thickness of the intrinsic zone is greater than the thickness of the P-doped zone. • The active layer is a layer made of intrinsic semiconductor material. • the first, second and third semiconductor layers are made of a III-V material. • The active layer is a layer made of bulk material or a layer containing quantum wells, quantum rods or quantum dots. • According to a first embodiment, the optoelectronic component according to the invention comprises: • a rib forming a one-dimensional photonic crystal waveguide extending over the substrate in an extension direction parallel to the plane of the substrate, the rib having a plurality of orifices aligned along the extension direction, the rib being formed by the stacking of the intrinsic zone, the active layer, and the N-doped layer, the orifices traversing said stacking; • at least one first P-doped region of the first semiconductor layer forming a lateral extension extending from one side of the rib in a transverse direction, the width of said first P-doped region, measured along the extension direction, being strictly less than the measured length of the rib according to the direction of extent, the intrinsic zone belonging to the rib being in contact with said first P-doped zone, said P-doped lateral extension receiving at least one electrical contact; • the rib being extended at one of its ends, along the direction of extension, by at least one first N-doped extension belonging to the N-doped layer, said N-doped extension receiving at least one electrical contact. According to this first embodiment, the contact between the intrinsic zone and the first P-doped zone is advantageously located at a lateral face of the rib or the contact between the intrinsic zone and the first P-doped zone extends laterally so that a part of the intrinsic zone belongs to the lateral extension or so that a part of the P-doped zone belongs to the rib. Advantageously, the component comprises a second P-doped zone of the first semiconductor layer forming a second lateral extension, said lateral extensions extending on either side of the rib, in a transverse direction, the width of said second P-doped zone, measured along the extension direction, being strictly less than the length of the rib measured along the extension direction, the intrinsic zone belonging to the rib separating the first and second P-doped zones, the second P-doped lateral extension receiving at least one electrical contact. The component comprises a plurality of lateral extensions extending along the rib in the direction of extension. The first semiconductor layer has a second intrinsic zone not covered by the active layer and surrounding the first and second P-doped zones. According to a second embodiment, the optoelectronic component comprises: • A waveguide extending over the substrate in a direction parallel to the plane of the substrate, the waveguide being formed in the stacking of the intrinsic zone, the active layer, and the N-doped layer and comprising: • on one side, along the extension direction, a two-dimensional photonic crystal equipped with a plurality of orifices forming a two-dimensional periodic lattice, the orifices traversing the stacking of the intrinsic zone, the active layer, and the N-doped layer, and • on the other side along the direction of extent, a face with total internal reflection; • the P-doped area of ​​the first semiconductor layer forming a lateral extension extending from the side of the total reflection face of the waveguide, in a transverse direction, the width of the P-doped area, measured along the extension direction, being strictly less than the length of the waveguide measured along the extension direction, the intrinsic area belonging to the waveguide being in contact with the P-doped area, the P-doped lateral extension receiving at least one electrical contact; • the waveguide being extended on the side opposite the total reflection face, in the transverse direction, by an N-doped extension, the N-doped extension receiving at least one electrical contact. According to this second embodiment, the component may include at least one line of orifices located between the plurality of orifices forming a two-dimensional periodic array and the face with total internal reflection. According to this second embodiment, the component may include a plurality of lateral extensions extending along the waveguide in the direction of extension. The component according to this second embodiment may also include at least one pillar formed on the lateral extension of the P-doped area next to the total reflection face of the waveguide, said pillar comprising, in a stacking direction perpendicular to the plane of the substrate, a P-doped area, an area made in the material of the active layer and an N-doped area. According to this second embodiment, the contact between the intrinsic zone and the P-doped zone is located at the total reflection face of the waveguide, or the contact between the intrinsic zone and the P-doped zone extends laterally so that a part of the intrinsic zone belongs to the lateral extension, or the contact between the intrinsic zone and the P-doped zone is located below the stack. The first semiconductor layer has a second intrinsic zone not covered by the active layer and surrounding the P-doped zone. The orifices forming a two-dimensional periodic lattice are arranged to form a triangular lattice. According to a third embodiment, the optoelectronic component is such that: • the P-doped zone is hollow with a cylindrical internal lateral surface; • the intrinsic zone has the shape of a ring or a disc, the external lateral surface of the ring of the intrinsic zone being in contact with the cylindrical internal lateral surface of the P-doped zone; • the electrical contact arranged on the doped P zone is without contact with the intrinsic zone; • the active layer has the shape of a solid disc deposited on and opposite the ring of the intrinsic zone; • the N-doped layer has the shape of a solid disk of the same radius as the solid disk of the active layer and is deposited on and opposite the solid disk of the active layer, the electrical contact being arranged on the N-doped layer. • The radius of the solid disk of the active layer and the radius of the ring of the intrinsic zone are either the same or different. In other words, the radius of the solid disk can be greater than or equal to the radius of the ring of the intrinsic zone, or less than or equal to the radius of the ring of the intrinsic zone. • the intrinsic zone has the shape of a ring, a second P-doped zone in the shape of a disc filling the inside of the ring of the intrinsic zone. • the electrical contact arranged on the doped P zone has the shape of a ring concentric with the ring of the intrinsic zone. • The electrical contact arranged on the P-doped area is formed by several contact areas surrounding the ring of the intrinsic area. • the electrical contact arranged on the N-doped layer has an annular or disc shape.

[0017] The optoelectronic component according to the invention may include a passive semiconductor waveguide, said waveguide being integrated into the substrate or fabricated outside the substrate. The passive waveguide may be arranged to be evanescently coupled to the photonic crystal waveguide.

[0018] Advantageously, the intrinsic zone is a zone doped with acceptor atoms passivated by hydrogen atoms.

[0019] The component according to the invention may be one of the following components: • Photodetector; • Electro-optical modulator; • Laser • Amplifier • Switch.

[0020] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0021] The figures are presented for illustrative purposes only and are in no way limiting of the invention. • Fig. 1 shows respectively the evolution of capacitance as a function of resistance for different fixed cutoff frequency values ​​and the optical power required to obtain a voltage of 0.2V for optoelectronic components. • Fig. 2 shows an example of a transverse structure optoelectronic component from the prior art. • Fig. 3 is a schematic top view of an optoelectronic component according to a first embodiment of the invention. • Figures [Fig. 4], [Fig. 5], and [Fig. 6] each illustrate a cross-section of the component of the [Fig.l] along three planes perpendicular to the plane of the substrate of the component of the [Fig.l]. • Fig. 7 is a schematic top view of an optoelectronic component according to a second embodiment of the invention. • Figures 8 and 9 each illustrate a cross-section of the component of [Fig.5] along two planes perpendicular to the plane of the substrate of the component of [Fig.5]. • The [Fig. 10] is a schematic top view of an optoelectronic component according to a third embodiment of the invention. • Fig. 11 illustrates a cross-section of the component of Fig. 8 along a plane perpendicular to the plane of the substrate of the component of Fig. 8. DETAILED DESCRIPTION

[0022] Unless otherwise specified, the same element appearing on different figures has a unique reference.

[0023] In the following description, when reference is made to absolute position qualifiers, such as the terms "top", "bottom", etc., or relative position qualifiers, such as the terms "superior", "inferior", etc., or to orientation qualifiers, such as the term "vertical", reference is made to the orientation of the figures.

[0024] Figure 3 represents an optoelectronic component 1 according to a first embodiment of the invention. The component 1 is, for example, formed on a silicon-on-insulator (SOI) substrate. represented (of course other types of substrates can be used, for example SiN-based).

[0025] An arrangement of three layers extending along a stacking direction perpendicular to the plane of the substrate comprises a first semiconductor layer 2 deposited on the substrate, a second semiconductor layer 3, called the active layer, deposited on the first semiconductor layer 2 and a third N-doped semiconductor layer 4, called the N-doped layer, deposited on the active layer 2.

[0026] The semiconductor materials used for the semiconductor layers are advantageously but not limited to III-V materials, for example GaAs or InP or InGaAsP, the choice of said material depending on the application sought.

[0027] The active layer 3 is for example formed of a layer of massive intrinsic material; it may further include quantum wells, quantum rods or quantum dots.

[0028] As we will detail later, the first semiconductor layer 2 according to the invention is particular in that it is composed of:

[0029] one or more intrinsic zones 5;

[0030] one or more P 6 doped zones.

[0031] The optoelectronic component comprises a rib 7 formed on the substrate by a multilayer stack and extending along a direction of extent AA' parallel to the plane of the substrate. The rib constitutes a one-dimensional photonic crystal waveguide. The rib comprises a plurality of orifices or holes 8 along its entire height (i.e., along the direction perpendicular to the substrate).

[0032] As shown in [Fig. 4], illustrating a cross-sectional view along a plane PI perpendicular to the plane of the substrate and to the direction of extension, said plane PI cutting the rib at its center, the stacking of the rib 7 comprises at least: • Part of intrinsic zone 5, • Active layer 3 and • the N4 doped layer.

[0033] Thus, unlike the known PIN type stacks of the prior art formed by the particular bottom-to-top arrangement of the three layers respectively doped P, I (intrinsic) and N-doped, the stack here is of type IIN (Intrinsic, Intrinsic, N-doped), the P-type layer being laterally offset as we will see later, so as not to be opposite the N layer.

[0034] The holes are drilled in the ribbed waveguide 7, with the semiconductor partially etched on the sides. The geometric parameters (shape of the holes, size of the holes, lattice constant of the photonic crystal, thickness and width of the waveguide, etc.) are chosen to define a photonic resonator.

[0035] The component 1 further comprises, as illustrated in Figures 3 and 4, two P 6 doped areas belonging to the first semiconductor layer 5, each forming a lateral extension extending respectively on each side of the rib 7, in a transverse direction (i.e. perpendicular to the direction of extension), the width 1 of said P 6 doped areas, measured along the direction of extension, being strictly less than the length L of the rib 7 measured along the direction of extension.

[0036] As illustrated in Figures 3 and 4, the intrinsic zone 5 belonging to the rib 7 is in contact with each of the doped zones P 6 of the lateral extensions. The arrangement according to the invention therefore makes it possible to laterally offset the doped zone P, which is no longer opposite the layer N 4 of the rib 7.

[0037] Each of the P-doped lateral extensions has on its upper face at least one electrical contact 9.

[0038] Fig. 5 illustrates a cross-sectional view along a plane P2 perpendicular to the plane of the substrate and to the direction of extension, said plane P2 cutting the rib at a level where the P-doped lateral extensions are not present.

[0039] According to this embodiment, the contact 10 between the intrinsic zone 5 of the rib 7 and each of the P-doped zones of the lateral extensions is located at a lateral face of the rib 7. This embodiment is not, however, limiting; it is also possible for the contact between the intrinsic zone and the P-doped zone to extend laterally so that a portion of the intrinsic zone belongs to the lateral extension. Conversely, it is also possible, although less desirable, for a portion of the P-doped zone to extend below the active layer of the rib, the latter nevertheless retaining an intrinsic zone.

[0040] According to the embodiment illustrated in Figures 3 and 6, the rib 7 is extended at each of its ends, along the extension direction AA', by a Nil-doped extension belonging to the N-doped layer 4, the N-doped extension receiving at least one electrical contact 12. [Fig. 4] shows a cross-sectional view along a plane P3 of one of the two Nil-doped extensions

[0041] The metallic contacts P and N are made on the side of the waveguide 7, above the P-doped semiconductor and above the N-doped semiconductor at the ends of the structure. This avoids the significant optical losses induced by the metals. The length of the contacts depends on the size of the resonator. The light is confined by total internal reflection in the transverse and longitudinal directions thanks to the structure of the photonic crystal.

[0042] The first semiconductor layer 2 also includes a second intrinsic zone 13 not covered by the active layer 3 and surrounding the P-doped lateral extensions 6.

[0043] The invention is therefore partly based on the fabrication of the first semiconductor layer 2, which is composed of intrinsic regions 5 and 13 and P-doped regions 6. This decomposition can be achieved using various technologies known to those skilled in the art; among them, it is possible to start with a P-doped layer and then mask it over the regions that one wishes to retain as P-doped regions, and to passivate the unmasked regions, for example by implanting hydrogen atoms. The hydrogen will neutralize the acceptors when one seeks to obtain a P-doped semiconductor. This neutralization occurs through the formation of electrically inactive acceptor-hydrogen complexes. It should be noted that other passivation techniques, for example by proton bombardment and by exposure to a hydrogen plasma, can also be implemented within the scope of the invention.The fabrication of intrinsic zones, even if they are obtained from the same layer as the P-doped layer, can lead to a difference in thickness between the P-doped and intrinsic zones due to the etching operations inherent in the masking and implantation technology. This makes it difficult to stop etching precisely at the P-doped zones, so they may have a thickness less than the intrinsic zones. More generally, P-doped and intrinsic zones can have different thicknesses, and it is also possible for P-doped zones to be thicker than intrinsic zones.

[0044] Component 1 according to the invention may also include a passive waveguide (for example, embedded in the substrate) such that the ribbed waveguide 7 is evanescently coupled to the passive waveguide. The latter ensures the propagation of optical information.

[0045] The use of nanocavity-based components such as rib 7 allows for a significant reduction in their size while maintaining the high optical absorption required for a high-responsive photodetector. The optical bandwidth of these components is also reduced, which can be advantageously used to select signals at specific wavelengths. These detectors combine two functionalities: photodetection and optical filtering. The spectral width of the filter can be controlled by adjusting the evanescent ground coupling strength, the absorption coefficient of the active material, the cavity quality factor, and the number of optical modes in the cavity.

[0046] Light is absorbed in the absorbing active material (bulk or in quantum wells, for example), so that electron-hole pairs (negative and positive charges) are created. By applying a negative voltage to the PIN junction, the photogenerated charges are attracted to the contacts, and a current flows in the circuit. The capacitance of such structures can be calculated using the method finite elements. When made in a classic vertical PIN junction (i.e. with a lower layer disposed under the fully P-doped active layer), their capacitance has values ​​of about a few tens of fF. The capacitor is then equivalent to two parallel plates with surfaces corresponding to P and N doped semiconductors facing each other.

[0047] According to the invention, a reduced-size electronic component is obtained whose capacitance is decreased to detect signals at higher modulation frequencies, by modifying the surface of the plates forming the capacitor.

[0048] To achieve this, the PIN heterojunction according to the invention is modified laterally to minimize the capacitance of the structure by creating intrinsic zones locally where the P-doping was located in the prior art. The P-doped layer is thus modified so that the P-doping disappears in the region where the electromagnetic field is confined and is localized only in the partially etched region of the semiconductor under the P contact and near the edges of the rib (or the cavity more generally).

[0049] As mentioned above, in [Figs. 3] to 6, the P-doping begins directly at the edges of the cavity. By way of illustration, the calculated capacitance of the structure according to the invention is more than 10 times lower than that obtained for P-doping located below the active layer with a component of the same dimensions, thus making it possible to detect signals with a modulation bandwidth well beyond 1 GHz (and even beyond 100 Hz) while using a high load resistance.

[0050] The same type of components can be used for electro-optical modulation. In this case, the chosen active material must, for example, contain quantum wells. When a vertical electric field is created in the structure by applying a reverse voltage to the PIN junction, the absorption and refractive index of the quantum wells are modified by the confined quantum Stark effect.

[0051] It should be noted that the component in [Fig. 3] has been described with two P-type lateral extensions, each having a metallic contact; however, it is possible to have only one lateral extension. This also applies to the N-type extension. Furthermore, it is also conceivable to have several P-type lateral extensions one above the other (i.e., along the extension direction) distributed along the same photonic crystal rib: in this way, several cavities are obtained with a single rib.

[0052] The effect observed previously on the capacity is also found in other types of structures, in particular, in the optoelectronic component of [Fig.7] featuring a two-dimensional photonic crystal waveguide.

[0053] Figure 7 represents an optoelectronic component 21 according to a second embodiment of the invention. The component 21 is, for example, formed on a substrate silicon on insulator SOI (Silicon On Insulator according to English terminology) not shown (of course other types of substrates can be used, for example based on SiN).

[0054] An arrangement of three layers extending along a stacking direction perpendicular to the plane of the substrate comprises a first semiconductor layer 22 deposited on the substrate, a second semiconductor layer 23, called the active layer, deposited on the first semiconductor layer 22 and a third N-doped semiconductor layer 24, called the N-doped layer, deposited on the active layer 22.

[0055] The active layer 23 is for example formed of a layer of massive intrinsic material; it may further include quantum wells, quantum rods or quantum dots.

[0056] As before, the first semiconductor layer 22 according to the invention is particular in that it is composed of:

[0057] one or more intrinsic zones 25;

[0058] one or more P 26 doped zones.

[0059] As illustrated in [Fig. 7] and [Fig. 8], which show a cross-sectional view along a plane PI perpendicular to the plane of the substrate and to the extension direction, said plane PI intersecting the waveguide at its center, the component 21 comprises a waveguide 27 extending over the substrate along an extension direction AA' parallel to the plane of the substrate, the waveguide being formed by the stacking of the intrinsic zone 25, the active layer 23, and the N-doped layer 24. The waveguide 27 comprises - on one side, along the extension direction AA', a two-dimensional photonic crystal equipped with a plurality of orifices 28 forming a two-dimensional periodic lattice (here, non-limitingly, a triangular lattice), the orifices traversing the stacking of the intrinsic zone, the active layer, and the N-doped layer, and - on the other side along the extension direction AA', a face 30 with total internal reflection, the waveguide 27 being formed by the area located between the two-dimensional photonic crystal and the face 30 with total reflection.

[0060] Figure 9 shows a cross-sectional view along a plane P2 not containing the lateral extensions N and P of component 21.

[0061] The P-doped area 26 of the first semiconductor layer 22 forms a lateral extension extending from the side of the total reflection face 30 of the waveguide, in a transverse direction perpendicular to the extension direction. The width 1 of the P-doped area 26, measured along the extension direction, is strictly less than the length L of the waveguide 27 measured along the extension direction.

[0062] As in the first embodiment, the intrinsic zone 25 belonging to the waveguide is in contact with the doped zone P 26 forming the lateral extension.

[0063] The arrangement according to the invention therefore makes it possible to laterally move the doped P zone which is no longer opposite the N 24 layer of the waveguide 27.

[0064] The doped lateral extension P 26 has on its upper face at least one electrical contact 29.

[0065] The contact 31 between the intrinsic zone 25 of the waveguide 27 and the P-doped zone 26 of the lateral extension is located at the level of the internal total reflection face 30. This embodiment is not, however, limiting; it is also possible for the contact between the intrinsic zone and the P-doped zone to extend laterally so that a portion of the intrinsic zone belongs to the lateral extension. Conversely, it is also possible, although less desirable, for a portion of the P-doped zone to extend below the active layer of the waveguide, the latter nevertheless retaining an intrinsic zone.

[0066] The waveguide 27 is extended on the side opposite the total reflection face 30, in the transverse direction, by an N-doped extension 32, the N-doped extension receiving an electrical contact 33.

[0067] In the two-dimensional photonic crystal waveguide of [Fig. 5], holes or orifices are drilled into the semiconductor and arranged in a 2D lattice (typically, but not limited to, a triangular lattice). A waveguide is formed between the hole lattice and the semiconductor, which is partially etched on one side of the structure. The geometric parameters (hole shape, hole size, lattice constant of the photonic crystal, waveguide thickness and width, etc.) are chosen to form either a resonator or a waveguide. The contact lengths of the P and N extensions depend on the length of the resonator or waveguide. Light is confined in the transverse direction by reflection on the internal total reflection face and by the photonic crystal lattice, and optionally in the longitudinal direction (in the case of the resonator) by the photonic crystal.

[0068] The first semiconductor layer 22 also includes a second intrinsic zone 34 not covered by the active layer 23 and surrounding the P-doped lateral extension 26.

[0069] The invention is based, as with the first embodiment, on the fabrication of the first semiconductor layer 22, which is composed of intrinsic zones 25 and 34 and the P-doped zone 26. The technologies described above for the fabrication of this layer also apply in the case of this second embodiment.

[0070] The component 21 according to the second embodiment of the invention may also include a passive waveguide (for example embedded in the substrate) so that the waveguide 27 is evanescently coupled to the passive waveguide.

[0071] It should be noted that the optoelectronic component according to the second embodiment may also include one or more lines of orifices located between the waveguide 27 and the internal total reflection face 30.

[0072] Alternatively, the optoelectronic component according to the second embodiment of the invention may comprise one or more pillars formed on the lateral extension 26 of the P-doped area next to the total reflection face 30, each of said pillars comprising, in a stacking direction perpendicular to the plane of the substrate, a P-doped area, an area made in the material of the active layer and an N-doped area.

[0073] The effect observed previously on the capacitance is also found in the optoelectronic component of [Fig. 10] based on a microdisk resonator.

[0074] Figure 10 thus represents an optoelectronic component 41 according to a third embodiment of the invention. The component 41 is, for example, formed on a silicon-on-insulator (SOI) substrate, not shown (of course, other types of substrates can be used, for example, SiN-based).

[0075] An arrangement of three layers extending along a stacking direction perpendicular to the plane of the substrate comprises a first semiconductor layer 42 deposited on the substrate, a second semiconductor layer 43, called the active layer, deposited on the first semiconductor layer 42 and a third N-doped semiconductor layer 44, called the N-doped layer, deposited on the active layer 43.

[0076] The active layer 43 is for example formed of a layer of intrinsic material.

[0077] As before, the first semiconductor layer 42 according to the invention is particular in that it is composed of:

[0078] one or more intrinsic zones 45;

[0079] one or more P 46 doped zones.

[0080] Component 41 comprises - a hollow P 46 doped zone with an internal cylindrical lateral surface 50 formed in the first semiconducting layer 42; - an intrinsic zone 45 having the shape of a ring (or a solid disk according to a variant not shown) formed in the semiconductor layer 42, the external lateral surface of the ring of the intrinsic zone 45 being in contact with the cylindrical internal lateral surface 50 of the doped zone P; - the active layer 43 having the shape of a solid disk deposited on and opposite the ring 45 of the intrinsic zone; - the N 44 doped layer having the shape of a solid disk of the same radius as the solid disk of the active layer 43 and deposited on and opposite the solid disk of the active layer.

[0081] An electrical contact 47 is arranged on the P-doped area so as not to contact the ring 45 of the intrinsic area. By way of illustration and without limitation, the electrical contact 47 here has the shape of a ring concentric with the ring 45 of the intrinsic area. It should be noted that the shape of the contact 47 could be different, for example, square. Furthermore, the electrical contact arranged on the P-doped area could also be formed by several contact areas surrounding the ring of the intrinsic area, for example, a discontinuous ring with P-doped, or even intrinsic, areas between the contact areas forming the discontinuous ring.

[0082] An electrical contact 48 is arranged on the N-doped layer 44. The electrical contact 48 here has the shape of a solid disk but could have another shape, for example annular.

[0083] As before, component 41 may also include a passive semiconductor waveguide, said waveguide being integrated into the substrate or made outside the substrate and evanescently coupled to the stack of the N, active and intrinsic layers 44, 43 and 45.

[0084] If the intrinsic area has the shape of a solid disk according to an unrepresented variant formed in the semiconductor layer 42, it is understood that the P-doped area 46 in the center of the component is no longer present.

[0085] According to the embodiment shown in Figures 10 and 11, the radius of the solid disk of the active layer 43 is equal to the radius of the ring of the intrinsic zone 45. According to another embodiment, the radius of the solid disk of the active layer may be greater or less than the radius of the ring of the intrinsic zone.

[0086] In component 41, light is confined by total internal reflection at the edges of the structure formed by the stacking of the active and intrinsic N layers 44, 43, and 45. Gallery modes appear, their frequencies being directly related to the geometric parameters of the structure (size, exact shape, thickness). The size of the N contact must be small enough to avoid optical losses, but large enough to ensure low contact resistance and eliminate higher-order modes.

[0087] The components according to the invention can be integrated into a dielectric material (for example SiO2) and / or integrated on a photonic circuit.

[0088] The optoelectronic component according to the invention can function as a light emitter or receiver; it thus finds applications in particular for obtaining a photodetector, electro-optical modulator, laser, amplifier or optical switch.

Claims

Demands

1. Optoelectronic component (1, 21, 41) comprising: - A substrate; - An arrangement of three layers extending in a stacking direction perpendicular to the plane of the substrate, said arrangement comprising: • a first semiconductor layer (2, 22, 42) deposited on the substrate; • a second semiconductor layer (3, 23, 43), referred to as the active layer, deposited on the first semiconductor layer (2, 22, 42); • a third N-doped semiconductor layer (4, 24, 44), referred to as the N-doped layer, deposited on the active layer (3, 23, 43); the first semiconductor layer (2, 22, 42) being a layer decomposed into at least two regions: - an intrinsic region (5, 25, 45); - a P-doped region (6, 26, 46);the N-doped layer (4, 24, 44) and the active layer (3, 23, 43) being arranged so as to at least partially cover the intrinsic area (5, 25, 45), at least one electrical contact (9, 29, 47) being arranged on the P-doped area (6, 26, 46) and at least one electrical contact (12, 33, 48) being arranged on the N-doped layer (4, 24, 44).;

2. Optoelectronic component (1) according to claim 1 characterized in that the intrinsic zone (5) and the P-doped zone (6) have different thicknesses.

3. Optoelectronic component (1) according to claim 1 or 2 characterized in that the thickness of the intrinsic zone (5) is greater than the thickness of the P-doped zone (6).

4. Optoelectronic component (1) according to any one of the preceding claims characterized in that the active layer (3) is a layer of intrinsic semiconductor material.

5. Optoelectronic component according to any one of the preceding claims characterized in that the first, second and third semiconductor layers are made of a III-V material.

6. Optoelectronic component according to any one of the preceding claims characterized in that the active layer is a bulk material layer or a layer comprising quantum wells, quantum rods or quantum dots.

7. Optoelectronic component (1) according to any one of the preceding claims characterized in that it comprises: - a rib (7) forming a one-dimensional photonic crystal waveguide extending over the substrate in an extension direction parallel to the plane of the substrate, the rib having a plurality of orifices (8) aligned along the extension direction, the rib (7) being formed by the stacking of the intrinsic zone (5), the active layer (3), and the N-doped layer (4), the orifices (8) traversing said stacking;- at least one first P-doped zone (6) of the first semiconductor layer (2) forming a lateral extension extending from one side of the rib (7), in a transverse direction, the width (1) of said first P-doped zone (6), measured along the extension direction, being strictly less than the length (L) of the rib (7) measured along the extension direction, the intrinsic zone (5) belonging to the rib (7) being in contact with said first P-doped zone (6), said P-doped lateral extension (6) receiving at least one electrical contact (9); - the rib (7) being extended at one of its ends, along the extension direction, by at least one first N-doped extension (11) belonging to the N-doped layer (4), said N-doped extension (11) receiving at least one electrical contact (12).

8. Optoelectronic component according to the preceding claim characterized in that the contact between the intrinsic zone and the first P-doped zone is located at a lateral face of the rib or the contact between the intrinsic zone and the first P-doped zone extends laterally so that a part of the intrinsic zone belongs to the lateral extension or so that a part of the P-doped zone belongs to the rib.

9. An optoelectronic component according to any one of claims 7 or 8 characterized in that it comprises a second P-doped zone of the first semiconductor layer forming a second lateral extension, said lateral extensions extending on either side of the rib, in a transverse direction, the width of said second P-doped zone, measured along the extension direction, being strictly less than the length of the rib measured along the extension direction, the intrinsic zone belonging to the rib separating the first and second P-doped zones, the second P-doped lateral extension receiving at least one electrical contact.

10. Optoelectronic component according to any one of claims 7 9 8 characterized in that it comprises a plurality of lateral extensions extending along the rib in the direction of extension.

11. Optoelectronic component according to claim 7 and claim 9 characterized in that the first semiconductor layer comprises a second intrinsic zone not covered by the active layer and surrounding the first and second P-doped zones.

12. Optoelectronic component (21) according to any one of claims 1 to 5 characterized in that it comprises: - A waveguide (27) extending over the substrate along an extent direction parallel to the plane of the substrate, the waveguide (27) being formed in the stacking of the intrinsic zone (25), the active layer (23), and the N-doped layer (24) and comprising: • on one side, along the extent direction, a two-dimensional photonic crystal provided with a plurality of orifices (28) forming a two-dimensional periodic lattice, the orifices (28) traversing the stacking of the intrinsic zone (25), the active layer (23), and the N-doped layer (24), and • on the other side along the extent direction, a face (30) with total internal reflection;- the P-doped area (26) of the first semiconductor layer (22) forming a lateral extension extending from the side of the total reflection face (30) of the waveguide (27), in a transverse direction, the width (1) of the P-doped area (26), measured along the extension direction, being strictly less than the length (L) of the waveguide measured along the extension direction, the intrinsic area (25) belonging to the waveguide (27) being in contact with the P-doped area (26), the P-doped lateral extension receiving at least one electrical contact (29); - the waveguide (27) being extended on the side opposite the total reflection face, in the transverse direction, by an N-doped extension, the N-doped extension receiving at least one electrical contact (33).

13. Optoelectronic component according to the preceding claim characterized in that it comprises at least one line of orifices located between the plurality of orifices forming a two-dimensional periodic array and the face with total internal reflection.

14. Optoelectronic component according to any one of claims 12 or 13 characterized in that it comprises a plurality of lateral extensions extending along the waveguide in the direction of extension.

15. Optoelectronic component according to any one of claims 12 to 14 characterized in that it comprises at least one pillar formed on the lateral extension of the P-doped area next to the total reflection face of the waveguide, said pillar comprising, in a stacking direction perpendicular to the plane of the substrate, a P-doped area, an area made in the material of the active layer and an N-doped area.

16. Optoelectronic component according to any one of claims 12 to 15 characterized in that the contact between the intrinsic zone and the P-doped zone is located at the total reflection face of the waveguide or the contact between the intrinsic zone and the P-doped zone extends laterally so that a part of the intrinsic zone belongs to the lateral extension or the contact between the intrinsic zone and the P-doped zone is located below the stack.

17. Optoelectronic component according to any one of claims 12 to 16 characterized in that the first semiconductor layer comprises a second intrinsic zone not covered by the active layer and surrounding the P-doped zone.

18. Optoelectronic component according to any one of claims 12 to 17 characterized in that the orifices forming a two-dimensional periodic array are arranged to form a triangular array.

19. Optoelectronic component (41) according to any one of claims 1 to 5 characterized in that: - the P-doped zone (46) is hollow with a cylindrical internal lateral surface; - the intrinsic zone (45) has the shape of a ring or a disk, the external lateral surface of the ring of the intrinsic zone being in contact with the cylindrical internal lateral surface of the P-doped zone (46); - the electrical contact (47) arranged on the P-doped zone is without contact with the intrinsic zone (45); - the active layer (43) has the shape of a solid disk deposited on and opposite the ring of the intrinsic zone (45); - the N-doped layer (44) has the shape of a solid disk of the same radius as the solid disk of the active layer (43) and deposited on and opposite the solid disk of the active layer, the electrical contact (48) being arranged on the N-doped layer.

20. Optoelectronic component according to the preceding claim characterized in that the radius of the solid disk of the active layer is different from the radius of the ring of the intrinsic zone.

21. Optoelectronic component according to claim 19 or 20 characterized in that the intrinsic zone has the shape of a ring, a second P-doped disk-shaped zone filling the interior of the ring of the intrinsic zone.

22. Optoelectronic component according to any one of claims 19 to 21 characterized in that the electrical contact arranged on the doped area P has the shape of a ring concentric with the ring of the intrinsic area.

23. Optoelectronic component according to any one of claims 19 to 21 characterized in that the electrical contact arranged on the doped P area is formed by several contact areas surrounding the ring of the intrinsic area.

24. Optoelectronic component according to any one of claims 19 to 23 characterized in that the electrical contact arranged on the N-doped layer has an annular or disc shape.

25. Optoelectronic component according to any one of the preceding claims characterized in that it comprises a passive semiconductor waveguide, said waveguide being able to be integrated into the substrate or made outside the substrate.

26. An optoelectronic component according to the preceding claim and according to any one of claims 12 to 18, characterized in that the passive waveguide is arranged to be evanescently coupled to the photonic crystal waveguide

27. ​​Optoelectronic component according to any one of the preceding claims characterized in that the intrinsic zone is a zone doped with acceptor atoms passivated by hydrogen atoms.

28. Optoelectronic component according to any one of the preceding claims characterized in that said component is one of the following components: - Photodetector; - Electro-optical modulator; - Laser - Amplifier - Switch.

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