282 results about "Epitaxial material" patented technology

The invention discloses a solar cell with alloy as a flexible substrate and a preparation method thereof, a kovar alloy sheet is used as the flexible substrate to be bonded with an epitaxial layer, the coefficient of thermal expansion of the kovar alloy sheet is similar to that of an epitaxial material, and dark cracks of the epitaxial layer caused by cold and hot temperature difference are avoided; moreover, the metal bonding layer adopts a thick-silver thin-gold structure taking silver as a substrate, so that the production cost is greatly reduced, and the weldability of the back electrode is enhanced; and the back electrode also adopts a thick silver and thin gold structure taking silver as a substrate, so that the front warping of the Kovar alloy sheet can be balanced, the weldability of the back electrode is enhanced, the drawing force of the back electrode is improved, the thin gold plated on the thick silver can also prevent silver oxidation and resist the impact of atomic oxygen, and the service life of the solar cell is prolonged.

The invention provides an optimized II-type superlattice infrared detector chip bottom filling method, a preparation method and an infrared detector, and belongs to the field of infrared detectors. The problem that the performance of an infrared detector is affected due to the fact that the filling glue filled in an existing bottom filling process is prone to generating holes and finally causes defects during imaging of an infrared focal plane detector chip is solved. The method comprises the following steps that a dielectric layer is deposited on the surface of an epitaxial material after table top etching is completed, and the height of the dielectric layer is larger than the table top etching depth; after the dielectric layer is deposited, the surface of the dielectric layer is polished to be flat; opening holes in the dielectric layer on the surface of the table board; preparing an indium column in the opening of the dielectric layer, and then performing flip-chip bonding interconnection on the indium column at the epitaxial material end and the indium column on the readout circuit; filling bottom filling glue between the dielectric layer and the reading circuit after the reverse welding interconnection, and then curing the filling glue at high temperature; the invention is applied to the type-II superlattice infrared detector.

The invention discloses a low-divergence-angle narrow-linewidth high-power semiconductor laser. Relates to the technical field of semiconductor lasers, in particular to a low-divergence-angle narrow-linewidth high-power semiconductor laser. According to the invention, the parabolic waveguide structure is etched in the light field expansion area, and the metal reflector is introduced to realize a novel light field expansion and metal reflector integrated structure, and the transverse divergence angle of a laser mode is reduced through the expansion structure at the tail end of the waveguide. The laser comprises a laser gain area, a light field expansion area and a spectrum purification area at the tail of the light field expansion area. The laser gain region, the light field expansion region and the spectrum purification region at the tail part of the light field expansion region are made of the same laser epitaxial material in the longitudinal direction, the laser gain region is adjacent to the light field expansion region along the horizontal light emitting direction, and the light field expansion region is adjacent to the spectrum purification region at the tail part of the light field expansion region along the horizontal light emitting direction; the longitudinal direction is the direction from the substrate to the contact layer.

The present application discloses a structure of a trench-gate power MOSFET and a manufacturing method thereof. The structure includes: a second epitaxial layer; a strip-shaped P pillar, the length direction of the strip-shaped P pillar being parallel to the projection direction of the crystal orientation with the most obvious channel effect on the surface of the epitaxial material; a trench gate, including a trench, the trench being parallel to the length direction of the strip-shaped P pillar or perpendicular to the length direction of the strip-shaped P pillar, and filling a filler into the trench to manufacture the trench gate. When the length direction of the trench is parallel to the length direction of the strip-shaped P pillar, the trench is located directly above the strip-shaped P pillar and has the same width as the strip-shaped P pillar. When the length direction of the trench is perpendicular to the length direction of the strip-shaped P pillar, the width of the trench is not related to the strip-shaped P pillar; a surface source region. The advantage of the present application is that it can reduce the manufacturing steps and simplify the processing technology.

The invention relates to the technical field of semiconductor equipment, and provides vertical epitaxy equipment and an epitaxy method. The apparatus comprises: a vertical reaction chamber; the wafer boat is used for vertically loading a plurality of wafers at intervals; the driving device is used for driving the boat to enter / exit the vertical reaction cavity; the material supply assembly comprises a process supply pipeline and a switching unit; the process material source comprises a cleaning material source for removing an oxide layer on the surface of the wafer and an epitaxial material source for executing an epitaxial process; the process monitoring device is used for monitoring process end points of the cleaning process and the epitaxial process; and the control device is in communication connection with the switching unit and the process monitoring device, and controls the switching unit to switch the supply of the material source according to the monitoring result of the process monitoring device. According to the vertical epitaxial equipment, the epitaxial process can be continuously executed without transferring the wafers after the oxide removal process of the plurality of wafers is executed in situ in the equipment, so that the output rate and the yield of the equipment are improved, the cost is reduced, and the fragment and pollution risks are reduced.

The invention discloses a preparation method of a semiconductor material and a device, and the method comprises the steps: preparing two substrates, namely a substrate W1 and a substrate W2, stripping a part of the upper part of the substrate W2, bonding the part with a polycrystal Si C surface 110 grown on the substrate W1, forming a polycrystal SiC layer on the W1 and a high-quality single crystal S iC layer on the polycrystal SiC layer, and carrying out the epitaxy of the high-quality S iC layer to form a composite epitaxial material. The chip manufacturing is completed by performing chip process processing on the composite epitaxial material, so that the loss and waste of the SiC material in the preparation process of the SiC material and the device can be effectively reduced, the production efficiency is improved, and the great reduction of the cost of the device is facilitated.

The invention discloses a preparation method and a structure of a photonic integrated device, and the method comprises the steps: sequentially dividing a substrate into a front modulator region, a rear modulator region, a front grating region, a gain region and a rear grating region, and growing a first active layer after manufacturing a selected region epitaxial mask pattern in the gain region, the method comprises the following steps of: growing a first active layer in a front modulator region after mask etching operation, growing a second active layer in a front modulator region after mask etching operation, growing a third active layer in a grating region after mask etching operation, finally performing grating manufacturing, and completing manufacturing of a cladding layer, an electric contact layer, an inverted table shallow ridge waveguide structure, an electric isolation trench and an electrode. According to the method, integration of multiple materials is achieved through one-time selective area epitaxial growth and one-time butt joint growth, the material growth frequency is reduced, and the manufacturing cost is saved; the gain region and the rear modulator region realize forbidden band width offset through selective region epitaxial material growth, and multi-wavelength tuning and efficient modulation are realized through fluorescence wavelength difference design of each region, so that a solution can be provided for integration of a wide-wavelength tunable laser and a double-electro-absorption modulator.

The invention relates to the technical field of semiconductor devices, in particular to a light-emitting diode epitaxial structure and a preparation method thereof. The light-emitting diode epitaxial structure comprises a substrate, an h-BN / O2 layer, a low-temperature GaN buffer layer, an N-type semiconductor layer, a multi-quantum well layer and a P-type semiconductor layer which are arranged in sequence, the h-BN / O2 layer subjected to oxygen plasma treatment is inserted between the heterogeneous substrate and the GaN epitaxial layer, the low-temperature GaN buffer layer is grown on the h-BN / O2 layer by controlling the process conditions, and the h-BN / O2 layer and the low-temperature GaN buffer layer are matched, so that lattice mismatch dislocation, residual stress and thermal mismatch of an epitaxial material grown on the heterogeneous substrate can be effectively modulated, the scattering efficiency under high current is improved, and the light emitting efficiency is improved. The probability of radiation recombination of the heteroepitaxial material is improved, and the requirement for heteroepitaxy is lowered.

The invention relates to a semiconductor device with a temperature sensor and a preparation method thereof, and the key points of the technical scheme are that the method comprises the steps: constructing a super-junction charge balance region on the surface of a substrate, and forming a body region at the top of the super-junction charge balance region; generating a first shallow trench and a second shallow trench on the body region; sequentially depositing an oxidation dielectric layer and first polycrystalline silicon in each of the first shallow trench and the second shallow trench; etching the first polycrystalline silicon in the second shallow trench, and depositing second polycrystalline silicon above the first polycrystalline silicon in the second shallow trench; depositing a dielectric layer on the surface of the body region, and etching in the dielectric layer to form a contact hole; the contact hole is communicated with the first polycrystalline silicon and the second polycrystalline silicon; the temperature detection diode structure is integrated in the epitaxial material of the device, and the problem that the internal thermal characteristics of the device cannot be fed back in time is solved by improving the manufacturing process under the condition that the characteristics of the device are not influenced by utilizing the linear relation between the forward conduction voltage and the temperature of the diode.

The invention discloses a method for judging the source material allowance of an MBE source furnace based on the surface of an epitaxial wafer, and the method comprises the steps: selecting proper points on the surface of the epitaxial wafer, measuring the cycle, the half-peak width and the mismatch value of the surface of the epitaxial wafer through XRD, and respectively calculating the cycle, the half-peak width and the mismatch value of the epitaxial wafer through standard deviation; whether the source materials of the source furnace are insufficient or not is judged by designing a control group, an experience control group and an evidence group and comparing standard deviation ratios of the groups, and the allowance of the source materials of the molecular beam epitaxy source furnace is judged more rigorously. The method allows the sufficiency of the source material of the molecular beam epitaxy source furnace to be monitored in real time, and stable epitaxial wafer growth is ensured through XRD and data analysis. Compared with a traditional statistical method, the method is more accurate and scientific, resource waste is avoided, and the quality of the epitaxial material is improved.

The invention discloses a substrate processing method for improving the imaging quality of an infrared focal plane hybrid chip, and belongs to the technical field of substrate processing. The infrared focal plane hybrid chip is prepared from an array chip and a silicon readout circuit through inverted interconnection of indium columns, an epitaxial layer, a substrate epitaxial interface and a substrate are sequentially arranged above the indium columns in the first direction, and the method comprises the following steps that S1, the substrate is thinned, and degumming and dewaxing treatment is carried out; s2, forming a protective layer on the electrode of the silicon readout circuit; s3, adhering the treated chip and the accompanying chip to a glass substrate, and removing the thinned substrate through chemical mechanical polishing treatment; and S4, removing the epitaxial layer with a set thickness close to the epitaxial interface of the substrate by adopting chemical polishing treatment, and cleaning. The technical scheme has the beneficial effects that the tellurium-zinc-cadmium substrate is removed through chemical mechanical polishing, the loss rate is reduced, the problem of uneven corrosion is solved, the epitaxial material close to the epitaxial interface of the substrate is removed through chemical polishing, and the imaging quality is improved.

The invention relates to the technical field of silicon carbide semiconductor devices, in particular to an integrally-formed equal-depth double-groove SiC MOSFET structure and a preparation method thereof. According to the structure, an N + buffer layer and an N-drift layer are sequentially formed on an N-type SiC substrate, and a main groove and an auxiliary groove which are consistent in depth are formed in the surface of the N-type SiC substrate; a gate oxide layer and a polycrystalline silicon gate are sequentially formed in the main groove, and the auxiliary groove is filled with a SiC epitaxial material which is doped with the drift layer in the same type, so that a charge compensation and electric field regulation and control unit is formed; the P-type body region surrounds the trench structure and forms an N + source region, and the drain electrode is formed through a back metallization process. Through the collaborative design of the equal-depth double grooves, the uniformization of electric field distribution is realized, the on-resistance and the switching loss are effectively reduced, the thermal stability and the reliability of the device are improved, the integrated process is adopted for integration, the process is simplified, the production efficiency and the yield are improved, and the semiconductor device is suitable for high-frequency and high-voltage application scenes and has a wide industrialization prospect.

Some implementations described herein include an optoelectronic device for a low-lighting application and techniques to form the optoelectronic device. The optoelectronic device includes near infrared light vertical-cavity surface emitting laser devices, near infrared light pixel sensors, and visible light pixel sensors. The near infrared light vertical-cavity surface emitting laser devices and the near infrared light pixel sensor include selectively grown epitaxial materials (e.g., silicon germanium, gallium arsenide, or another type III / V material) that improves a performance of the near infrared light vertical-cavity surface emitting laser devices, near infrared light pixel sensors.

The invention provides a manufacturing method of a type-II superlattice medium-wave infrared focal plane array chip and an infrared detector, and belongs to the field of infrared focal plane array chips. The problem that in the prior art, the surface leakage current of an infrared focal plane array chip is large due to the fact that the mesa etching depth is large is solved. The method comprises the following steps: growing and cleaning an epitaxial material; hard mask deposition, mesa photoetching and etching: obtaining a required mesa pattern on the hard mask through a photoetching technology, then etching an epitaxial material, etching the epitaxial material to form the mesa pattern, the mesa pattern comprising an upper electrode region and a lower electrode region, etching the upper electrode region to the boundary of the barrier layer and the absorption region, and etching the lower electrode region to the boundary of the barrier layer and the absorption region; etching a lower electrode region to the lower ohmic contact layer; manufacturing a metal electrode; a connecting piece is manufactured on the metal electrode to be connected with a reading circuit, and manufacturing of the infrared focal plane array chip is completed; the invention is applied to the II-type superlattice medium-wave infrared detector.

The invention relates to the technical field of semiconductor devices, in particular to a light-emitting diode epitaxial structure which comprises a substrate, and a graphene composite nano layer, an N-type semiconductor layer, a multi-quantum well layer and a P-type semiconductor layer are sequentially stacked on the substrate. The graphene composite nano layer comprises a modified graphene layer and a ZnO sub-layer which are stacked in sequence, the modified graphene layer is arranged on the substrate, and the ZnO sub-layer is arranged on the modified graphene layer; the modified graphene layer is subjected to nitrogen plasma treatment, and the thickness of the modified graphene layer is 10-100 nm; and the thickness of the ZnO sub layer is 20 nm to 200 nm. According to the invention, lattice mismatch dislocation, residual stress and thermal mismatch of the epitaxial material grown on the heterogeneous substrate can be effectively modulated, the scattering efficiency under high current is improved, the probability of radiation recombination of the heterogeneous epitaxial material is improved, and the requirement of heterogeneous epitaxy is relaxed at the same time.

The invention discloses a structure of a trench gate power MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) and a manufacturing method of the trench gate power MOSFET. The structure comprises a second epitaxial layer; the length direction of the strip-shaped P column is parallel to the projection direction of the crystal orientation with the most obvious channel effect on the surface of the epitaxial material; the groove gate comprises a groove, the groove is parallel to the length direction of the strip-shaped P column or perpendicular to the length direction of the strip-shaped P column, the groove is filled with filler, and therefore the groove gate is manufactured, when the length direction of the groove is parallel to the length direction of the strip-shaped P column, the groove is located over the strip-shaped P column, and the width of the groove is consistent with the width of the strip-shaped P column; when the length direction of the groove is perpendicular to the length direction of the strip-shaped P column, the width of the groove is not related to the strip-shaped P column; and a surface source region. The method has the advantages that the manufacturing steps can be reduced, and the machining process is simplified.

The invention discloses an HEMT device capable of regulating and controlling threshold voltage and a preparation method of the HEMT device. The HEMT device comprises a substrate, a nucleating layer, a buffer layer, a channel layer and a barrier layer which are arranged from bottom to top. A source electrode and a drain electrode are arranged at the two ends of the barrier layer respectively, and metal interconnection layers are arranged on the source electrode and the drain electrode; a SiN passivation layer is arranged on the barrier layer; a concave gate structure is arranged in the SiN passivation layer, and gate dielectric layers are arranged on the inner wall of the concave gate structure and the surface of the SiN passivation layer; a gate electrode is arranged on the gate dielectric layer; a SiNx protection layer is arranged above the gate electrode and on the surface of the gate dielectric layer, the gate dielectric layer comprises a dielectric insertion layer and a ferroelectric layer, the dielectric insertion layer is made of an AlN or Al2O3 material, and the ferroelectric layer is made of a material which has a wurtzite structure and contains a third nitride compound of transition metal. According to the invention, the nitride containing the transition metal and having the wurtzite structure as an epitaxial material is introduced as the ferroelectric layer, so that the performance and reliability of the device are improved.

The invention discloses a gallium nitride and gallium arsenide lateral monolithic heterogeneous integrated radio frequency chip and a preparation method thereof. Comprising a back metal, a substrate, a gallium nitride device epitaxial layer, a gallium nitride device electrode drain, a gallium nitride device electrode gate, a gallium nitride device electrode source, a back through hole, a gallium arsenide epitaxial transition layer, a gallium arsenide device epitaxial layer, a gallium arsenide device electrode source, a gallium arsenide device electrode gate and a gallium arsenide device electrode drain. Gallium nitride and gallium arsenide epitaxial materials and the radio frequency device share a back metal and a substrate, and the gallium arsenide radio frequency device realizes monolithic heterogeneous integration in the horizontal direction in the mode that a groove is selected on a gallium nitride wafer of a heterogeneous substrate to epitaxially grow a gallium arsenide material and a gallium arsenide device is processed; according to the invention, gallium nitride and gallium arsenide radio frequency devices can have an extremely small space interval, the loss of long-distance transmission signals under high frequency and the influence of parasitic parameters are reduced, the chip area and the chip volume are reduced, and the packaging cost is reduced.

The invention discloses a manufacturing method of a semiconductor device and a semiconductor device structure, and the method comprises the steps: providing a substrate which is provided with a first surface and a second surface which are opposite to each other, and the first surface comprises a first region and a second region; forming a sacrificial layer on the first surface of the substrate; removing the sacrificial layer in the first region; forming a dielectric film or an optical film on the surface of the sacrificial layer of the second region and the first region; removing the dielectric film or the optical film on the upper surface of the sacrificial layer in the second region; removing the sacrificial layer in the second region; a semiconductor epitaxial layer is formed on the second region of the substrate. According to the manufacturing method of the semiconductor device and the semiconductor device structure, epitaxial selected area growth can be achieved, self-passivation is achieved after epitaxial growth is completed, and the phenomenon that the exposed side face of an epitaxial material outside a selected area becomes a non-radiative recombination center or a side face electric leakage channel of a later photoelectric device can be effectively avoided.

The invention provides an evanescent wave coupling structure, a silicon-based semiconductor laser and a laser device.The evanescent wave coupling structure comprises a lower cladding layer, an active layer, a dielectric layer and a ridge waveguide layer, the lower cladding layer is formed below the active layer, so that light in the active layer can be limited by the lower cladding layer and can only be reflected upwards, and the light is coupled and transmitted into the dielectric layer through evanescent waves; and the light is transmitted to the ridge waveguide layer from the dielectric layer through evanescent wave coupling, and the light is output outwards by the ridge waveguide layer. According to the invention, the active layer is arranged to be in a structural form of which the width gradually changes from large to small, so that the light in the active layer is gradually restrained in a smaller area range in a transmission process, thereby improving the coupling efficiency of the light in a coupling process in a vertical direction, and reducing the optical coupling loss. According to the invention, the problems of low coupling efficiency, weak expandability, high process difficulty and the like of the silicon-based waveguide directly coupled with the III-V epitaxial material waveguide are solved.

The invention discloses a packaging structure of a micro-VCSEL chip and a manufacturing method of the packaging structure. The packaging structure of the micro-VCSEL chip comprises a bearing substrate, the micro-VCSEL chip, an isolation insulating layer and a metal interconnection structure, a bearing substrate is selected from a Si composite substrate, an insulating composite substrate, a TGV substrate or an insulating transparent substrate, a micro-VCSEL chip is fixed on substrate bonding metal through mass transfer, and an isolation insulating layer window and a metal interconnection structure are utilized to realize transfer of an electrode from an epitaxial structure to a low-cost substrate; the method comprises the steps of epitaxial wafer preparation, chip miniaturization, mass transfer, insulating layer manufacturing, metal interconnection forming and the like, supports vertical / flip chips and P-side / N-side light emission, and is adaptive to multi-scene requirements. Waste of epitaxial materials is avoided, cost is remarkably reduced, meanwhile, electrical performance, optical performance and reliability of the device are guaranteed, and the application prospect is wide.

The invention relates to the technical field of LED epitaxial wafers, and discloses a GaN-based LED epitaxial wafer and a preparation method thereof, and the GaN-based LED epitaxial wafer comprises a substrate, a buffer layer, an N-type semiconductor layer, a stress release layer, a multi-quantum well light-emitting layer, an electron blocking layer, and a P-type semiconductor layer. Wherein the N-type semiconductor layer sequentially comprises a first porous low-temperature GaN layer, a second porous AlGaN / GaN superlattice layer, a third high-temperature GaN layer, a fourth porous AlGaN / GaN superlattice layer and a fifth high-temperature GaN layer. By adopting the invention, the generation of defects in the growth process of the epitaxial material can be reduced, the dislocation density of the material is reduced, and the quality of the epitaxial wafer material is remarkably improved, so that the radiation recombination efficiency in the active region of the light-emitting diode is improved, and meanwhile, the proportion of the photon escape body material in the active region can be remarkably improved.

The invention discloses a method for reducing the number of defects of a silicon carbide epitaxial material, which comprises the following steps of: selecting a group of substrates with the same crystal orientation, deflection angle, surface roughness and resistivity as calibration sheets, and etching circles, triangles, quadrangles or polygons on the surfaces of the substrates as triangular defect nucleation points; carrying out epitaxial growth on the calibration sheet by adopting a process that the triangular defect density and the micro-pit defect density are both smaller than half of a product qualified line, and measuring the triangular defect size of a pattern position and the length of a step flowing direction in the vertical direction, and taking the measured values as standard values; when the number of the triangular defects or the micro-pit defects continuously fluctuates in the production process, the process conditions are kept unchanged, a calibration sheet is adopted for epitaxial growth, the sizes of the triangular defects on the surface of the calibration sheet are measured, the difference between the sizes of the triangular defects and a standard value is compared, and the growth temperature is corrected according to the result. And the method is compatible with a mainstream SiC epitaxial process, is suitable for industrial production, and has great popularization value.

The application provides a laser chip with improved reliability and a preparation process thereof, and aims to solve the technical problem that an edge-emitting laser is prone to end face failure.The laser chip comprises a substrate, the back surface of the substrate is provided with an N electrode, the front surface of the substrate is provided with an epitaxial material, the top layer of the epitaxial material is an ohmic contact layer, the epitaxial material is provided with a waveguide, and the vicinity of the waveguide is a waveguide region; an insulating medium layer is arranged on the surface of the epitaxial material, the waveguide region and the insulating medium layer are provided with a P electrode, but the ohmic contact layer in the waveguide region is not provided with the insulating medium layer, and the P electrode is in contact with the ohmic contact layer; the end surface of the laser chip is provided with an electrode-free area, and the electrode-free area is not provided with the insulating medium layer and the P electrode above the electrode-free area.The application further comprises a preparation method of the laser chip.The electrode-free area is arranged on the end surface of the laser, and the electrode-free area can improve the COD threshold level and improve the reliability.

The invention discloses a heat-conducting UV adhesive for a GaN high-electron-mobility transistor and a preparation method of the heat-conducting UV adhesive. The heat-conducting UV adhesive comprises the following components in percentage by weight: polyurethane acrylic resin, an active diluting monomer, a photoinitiator, diamond copper-plated powder and an auxiliary agent. The heat-conducting UV adhesive is used for bonding a diamond substrate and a GaN epitaxial material of a GaN high-electron-mobility transistor device, can overcome the problem that diamond is difficult to bond, effectively bonds the diamond, is firm in bonding, lasting in bonding effect, excellent in heat-conducting property, extremely low in thermal expansion coefficient, excellent in high-temperature resistance and weather resistance, stable in property and high in reliability. And the operation required by curing is simple, convenient and feasible, and the cost is controllable and is far lower than that of a traditional combination method.

The invention discloses a method for composite etching of an electroplating gold plating layer, which comprises the following steps of: manufacturing a photoetching pattern on the front surface of gallium arsenide epitaxy, then evaporating a metal contact layer, depositing a SiNx protective mask layer, performing Mesa mesa etching on the gallium arsenide epitaxy, exposing a high-aluminum layer on the side surface of an epitaxial material, and forming an aluminum oxide limiting layer by adopting a wet oxidation process; a second SiNx protective mask layer continues to be deposited, and the metal contact layer is exposed through dry etching; forming a seed gold layer by adopting magnetron sputtering TiW / Au metal, and forming a photoresist mask with a target electrode pattern on the seed gold layer; electroplating thick gold on the photoresist mask pattern; the photoresist mask layer is removed after completion; the method of combining dry etching and wet etching is adopted to remove the gold plating layer in the non-electroplating area, so that the lateral corrosion of the metal layer is obviously reduced, the high-precision and high-fidelity electrode pattern transfer is realized, the lateral corrosion of the metal layer is reduced, and the passivation protection effect of the device is improved.

The invention discloses a high-linearity AlGaN / GaN device based on a ferroelectric medium, a conductor layer and an AlGaN layer are arranged on a GaN layer, a barrier layer is formed, a ferroelectric film is arranged between a grid electrode and the barrier layer, and the high-linearity AlGaN / GaN device based on the ferroelectric medium is obtained. In the prior art, the linearity of a device is improved to a certain extent, but the complexity of the device is increased due to higher design requirements on a process and an epitaxial material. According to the invention, a layer of ferroelectric medium is introduced under the gate, and polarization regulation and control of the AlGaN / GaN HEMT are realized by utilizing the characteristic that the polarization intensity of the ferroelectric medium can be modulated by an external electric field and an extremely high dielectric constant, so that relatively flat transconductance is obtained. According to the high-linearity AlGaN / GaN HEMT device, the ferroelectric material is introduced and the parameters of the ferroelectric material are optimized, so that the electrical characteristics of the AlGaN / GaN HEMT device are successfully regulated and controlled, the peak transconductance is broadened, and the high-linearity AlGaN / GaN HEMT device based on the ferroelectric gate medium is realized. Therefore, an important theoretical and experimental basis is provided for further improving the performance of the device and expanding the application field.

The invention discloses a vacuum packaging method of an MEMS device and the MEMS device, relates to the field of semiconductor packaging, and aims to solve the problem that the vacuum degree is low when the device is packaged in a wafer cap through a bonding material. The packaging method comprises the following steps: providing a substrate, an MEMS structure and a silicon cap, wherein the silicon cap is provided with a first surface and a second surface which are opposite to each other; a groove is machined in the second face, close to the substrate, of the silicon cap, a plurality of through holes penetrating through the first face and the second face are formed in the silicon cap, and the through holes are communicated with the groove; connecting the MEMS structure to the substrate through the first bonding layer; connecting the second surface of the silicon cap to the substrate through a second bonding layer, so that an accommodating cavity for accommodating the MEMS structure is defined between the groove and the substrate; placing the substrate, the MEMS structure and the silicon cap in a vacuum environment suitable for a molecular beam epitaxy process; and carrying out a molecular beam epitaxy process in the through hole of the silicon cap, so that the epitaxial material epitaxially extends in the through hole along the direction from the first surface to the second surface and is continuously filled to block the through hole, thereby realizing high-vacuum packaging of the device.

This invention discloses a method and structure for fabricating a photonic integrated device. The method includes: dividing a substrate sequentially into a pre-modulator region, a post-modulator region, a pre-grating region, a gain region, and a post-grating region; growing a first active layer after fabricating a selected-area epitaxial mask pattern in the gain region; growing a second active layer in the pre-modulator region after mask etching; growing a third active layer in the grating region after mask etching; finally, fabricating the grating; and completing the fabrication of the cladding, electrical contact layer, inverted shallow ridge waveguide structure, electrical isolation trench, and electrodes. This method achieves the integration of multiple materials through a single selected-area epitaxial growth and a single docking growth, saving material growth steps and reducing manufacturing costs. The gain region and post-modulator region achieve bandgap shift through selected-area epitaxial material growth, and the design of photofluorescence wavelength differences in each region enables multi-wavelength tuning and efficient modulation, providing a solution for the integration of wide-wavelength tunable lasers and dual-electric absorption modulators.