936 results about "Tunnel junction" patented technology

The invention provides a three-junction quantum well solar cell epitaxial structure and a manufacturing method thereof, the three-junction quantum well solar cell epitaxial structure comprises a substrate serving as a first sub-cell, a first tunnel junction, a second sub-cell, a second tunnel junction and a third sub-cell which are sequentially stacked from bottom to top, and the three sub-cells are connected through the tunnel junctions; wherein the first sub-cell is a Ge cell, the second sub-cell is an InGaAs cell, the third sub-cell is a GaInP / AlGaInP quantum well cell, the third sub-cell comprises a (Al < x > 1 < Ga < 1-x > 1 < y > 1 < In < 1-y > 1 < P) back field layer, a quantum well base region, a (Al < x > 4 < Ga < 1-x > 4 < y > 4 < In < 1-y > 4 < P) emitter region and an Al < x > 5 < In < 1-y > 5 window layer which are sequentially stacked from bottom to top, the quantum well base region is composed of a Ga < x > 2 < In < 1-x > 2 layer and a (Al < x > 3 < Ga < 1-x > 3 < y > 3 < In < 1 x is larger than or equal to 0.5 and smaller than or equal to 0.8, y is larger than or equal to 0.5 and smaller than or equal to 0.8, y is equal to 0.5, the GaInP / AlGaInP quantum well structure is used for replacing a traditional AlGaInP material to serve as a top cell material, the open-circuit voltage of the solar cell is increased, and meanwhile the defect that the short-circuit current of the AlGaInP / GaAs / Ge solar cell is insufficient is overcome.

The invention provides a synthetic antiferromagnetic memory cell driven by spin orbit moment without magnetic field assistance, and belongs to the technical field of magnetic memory, the synthetic antiferromagnetic memory cell comprises a magnetic tunnel junction of a multilayer film structure, the magnetic tunnel junction comprises a heavy metal layer and a synthetic antiferromagnetic free layer located on the heavy metal layer; the tunneling insulating layer is located on the synthetic antiferromagnetic free layer, the reference layer is located on the tunneling insulating layer, and the metal electrode layer is located on the reference layer; wherein the synthetic antiferromagnetic free layer comprises an inclined vertical magnetic layer, a non-magnetic metal layer and a coupling magnetic layer which are stacked in sequence, and the inclined vertical magnetic layer and the coupling magnetic layer are subjected to antiferromagnetic coupling through the middle non-magnetic metal layer; the inclined perpendicular magnetic layer has inclined perpendicular anisotropy. According to the invention, deterministic magnetization flipping driven by spin orbit moment and resistance state control of the magnetic tunnel junction memory cell without the assistance of an external magnetic field are realized.

The invention relates to a method for improving epitaxial growth quality of a tunnel junction cascade semiconductor laser. The invention innovatively provides a strain superlattice gradient repair technology. By designing a low-temperature low-speed nucleation-high-temperature high-speed epitaxy composite growth mode, a periodic superlattice buffer layer is introduced to a tunnel junction interface. Wherein lattice strain relaxation is achieved at the rate of 0.5-2 / s in the low-temperature stage, defect coverage is completed at the rate of 4-8 / s in the high-temperature stage, and dislocation line bending is terminated on a superlattice interface through thermodynamic regulation and control. Compared with the traditional process, the scheme can obviously improve the crystal quality, and does not increase the specific contact resistance of the tunnel junction interface.

The invention provides a physical unclonable function magnetic device and an application method thereof, the magnetic device comprises a plurality of magnetic storage units arranged in an array and a control circuit, and each magnetic storage unit comprises a spin orbit moment layer and at least one magnetic tunnel junction arranged on the spin orbit moment layer; and the control circuit is used for applying a composite reconstruction signal with oscillation change to the magnetic memory units, and forming a superposed physical field with oscillation change at the magnetic memory units so as to enable the resistance state of the magnetic tunnel junction to generate oscillation change to realize PUF reconstruction of the plurality of magnetic memory units arranged in an array. In order to solve the problems of limited CRP generated by the PUF circuit and low resource utilization rate, the physical field with oscillation change is formed through the composite reconstruction signal, so that the PUF of the magnetic tunnel junction of the SOT-MRAM generates random oscillation change, the PUF of the magnetic device can be reconstructed, the reconstructed magnetic device can generate new CRP, and the resource utilization rate is improved.

The invention relates to the technical field of laser preparation, and provides a photonic crystal surface emitting laser and a preparation method thereof. The preparation method comprises the following steps: sequentially growing an n-type doped layer, a p-type independent limiting layer and a p + / n + tunnel junction on a GaAs substrate; preparing a patterned mask structure on the p + / n + tunnel junction; the patterned mask structure comprises a plurality of preset patterns; etching the p + / n + tunnel junction according to a preset pattern to obtain a plurality of photonic crystals; sequentially growing an n-type coating layer, an undoped active layer and a p-type coating layer on the photonic crystal; growing a p-type electrode on the p-type coating layer; and growing an n-type electrode on the GaAs substrate. According to the preparation method, the SHB problem can be effectively solved, the multiple photonic crystals can be arranged in different modes to form a pattern capable of achieving the needed light emitting mode, light emitting in all directions can be achieved, the requirements for different light emitting characteristics of the photonic crystal surface emitting laser are met, and the use performance of the laser is guaranteed.

The invention relates to a semiconductor structure, a preparation method thereof and a magnetic tunnel junction sensor. The semiconductor structure comprises a substrate, and a buffer layer, a solid magnetic layer, a tunnel barrier layer, a free layer and a protective layer which are located on the substrate. The solid magnetic layer comprises an antiferromagnetic pinning layer and a reference layer which are stacked, the antiferromagnetic pinning layer is located on the top surface of the buffer layer, and the magnetization direction of the reference layer is pinned by the antiferromagnetic pinning layer; the tunnel barrier layer is located on the top surface of the reference layer; the free layer is located on the top surface of the tunnel barrier layer, the thickness of the free layer in the direction perpendicular to the substrate continuously and smoothly changes in the preset direction, the thickness value distribution of the free layer conforms to a preset gradient function, and a preset included angle is formed between the preset direction and the pinned magnetization direction of the reference layer; the protective layer is on the top surface of the free layer. Multi-range or continuous wide-range detection can be realized in a single-chip semiconductor device, and high sensitivity is realized.

The invention discloses a 23T4M anti-radiation TCAM storage unit circuit which comprises a pre-charging module, an RH reading circuit module, a programmable logic module, a reconfigurable magnetic tunnel junction storage module, a discharging module and an output module. In the RH reading circuit module, the grid electrode of a transistor N7 is connected with the drain electrode of a transistor N8, the grid electrode of the transistor N8 is connected with the drain electrode of the transistor N7, a cross coupling structure is formed, a node S0 and a node S1 are controlled by a node Q and a node QB, meanwhile, the node S0 and the node S1 control the charging and discharging paths of the node Q and the node QB respectively, and after any node is overturned by high-energy particles, the charging and discharging paths of the node Q and the node QB are controlled by the node S0 and the node S1. All the nodes are maintained or charged to recover to the original logic level. According to the method, data upset at a single sensitive node can be completely resisted, and meanwhile, the search error rate of the TCAM is improved.

A magnetic tunnel junction (MTJ) stack, a vertical side surface of the MTJ stack includes a saw tooth edge, the MTJ stack includes vertically aligned layers of a top electrode, a free layer, a tunneling barrier, a reference layer and a bottom electrode, the free layer of the MTJ stack has a tapered edge including a first width at an upper portion of the free layer and a second width at a lower portion of the free layer, the first width is greater than the second width. Forming a first bottom electrode of a first MTJ stack, a second bottom electrode of a second MTJ stack, a first inter-layer dielectric between the first and the second bottom electrode, a first reference layer of the first MTJ stack, a second reference layer of the second MTJ stack, a second inter-layer dielectric between the first reference layer and the second reference layer.

The invention provides a magnetic random access memory and a preparation method thereof. The magnetic random access memory is applied to a comparison circuit, and comprises a magnetic tunnel junction comprising a free layer, a barrier layer and a reference layer which are stacked in sequence; the spin-orbit torque layer is located on the side, away from the reference layer, of the free layer, the conductive material layer is located on the side, away from the spin-orbit torque layer, of the magnetic tunnel junction, and a conductive material of the conductive material layer has the following characteristics that spontaneous magnetization capacity is achieved, and the resistance temperature coefficient is smaller than 0; the conductive material layer comprises a first part and a second part which are arranged at an interval, the first part is in contact with the reference layer, a first input end of the comparison circuit is electrically connected with the first part, and a second input end of the comparison circuit is electrically connected with the second part. According to the invention, the technical problems that the reading window of the magnetic tunnel junction becomes small and even the reading is wrong and the magnetic random access memory needs to apply an auxiliary magnetic field along the current direction to realize the deterministic overturning of the magnetic moment are at least solved.

The invention provides an ion beam etching system with an etching rate in-situ monitoring function and an etching method, the ion beam etching system is provided with an objective table which can deflect by 90 degrees and an electrical test detection element which can move close to or far away from the objective table, and by the etching method, an ion source is not closed, a sample is not taken out, and the etching rate can be accurately measured. The etching depth can be accurately monitored by measuring the surface resistance of the sample in situ, the etching rate can be reduced in time, and the method is more suitable for the tape-out process. According to the ion beam etching system and the etching method, sputter spectrum monitoring is replaced by sample surface resistance detection, so that the test sensitivity is higher, the system cost is lower, the etching precision in magnetic tunnel junction preparation is greatly improved, the sample is prevented from being excessively etched, the thickness of a sample layer can be kept consistent, the resistance distribution is uniform, and the quality of the magnetic tunnel junction is improved. And the high success rate preparation of the SOT-MRAM memory with large capacity and small size is realized.

The invention provides a surface-emitting gallium nitride VCSEL laser chip and an epitaxial defect suppression preparation method thereof, and relates to the technical field of laser chips, the surface-emitting gallium nitride VCSEL laser chip comprises a substrate, a low-temperature nucleating layer, a high-temperature recovery layer, a stress regulation type nano mask composite defect blocking layer, an n-type nitride DBR reflector, an active region, a polarization enhanced tunnel junction and the like, the defect blocking layer adopts an in-situ silicon nitride nano-porous mask layer to be matched with an aluminum gallium nitride / gallium nitride stress compensation superlattice layer, through pulse type lateral epitaxial overgrowth annihilation penetrating dislocation, and the n-type nitride DBR reflector adopts an AlInN / GaN lattice matching material system to be combined with a hydrogen etching interruption modification technology, so that thick film growth with zero cracks and high reflectivity is realized; a polarization enhanced tunneling junction is used at the top to replace ITO, and the hole tunneling probability is enhanced by piezoelectric polarization in InGaN, so that efficient current injection with low working voltage and no absorption loss is realized, the dislocation density and the device voltage are remarkably reduced, and the yield of an epitaxial wafer and the photoelectric conversion efficiency are improved.

The invention discloses an AlGaInP red light LED chip structure with a polarization-induced tunnel junction and a preparation method thereof. The chip structure sequentially comprises a GaAs substrate, an n-type GaAs buffer layer, an n-type etching barrier layer, an n-type GaAs ohmic contact layer, an n-type limiting layer, a non-doped InGaP / quantum well structure, a p-type spacer layer, a p-type AlGaInP polarization-induced doping layer, an insertion layer and an n-type ohmic contact layer from bottom to top. Wherein the p-type AlGaInP polarization induction doping layer introduces a piezoelectric polarization electric field through an Al component gradual change design, high-density two-dimensional hole gas is formed through induction, and the high-Al component insertion layer and the n-type ohmic contact layer form a tunnel junction; according to the invention, the problems of low p-type doping efficiency and high resistivity of the AlGaInP material with high Al component are fundamentally solved, the epitaxial structure and the chip process are simplified, the series resistance of the chip is reduced, the luminous efficiency is improved, the yield is improved, and the method has remarkable technical and commercial values.

A magnetic memory device includes a magnetic tunnel junction (MTJ) stack, a spin-orbit torque (SOT) induction wiring disposed over the MTJ stack, a first terminal coupled to a first end of the SOT induction wiring, a second terminal coupled to a second end of the SOT induction wiring, and a shared selector layer coupled to the first terminal.

A magnetoresistive memory cell includes a magnetic polarizer layer having a hard magnetization along a hard magnetization direction, a first magnetic tunnel junction located on a first side of the magnetic polarizer layer and including a first reference layer having a first side facing the magnetic polarizer layer, a first free layer facing a second side of the first reference layer, and a first tunnel barrier layer located between the first free layer and the first reference layer. The memory cell also includes a second magnetic tunnel junction located on a second side of the magnetic polarizer layer and including a second reference layer having a second side facing the magnetic polarizer layer, a second free layer facing a first side of the second reference layer, and a second tunnel barrier layer located between the second free layer and the second reference layer.

The invention is suitable for the technical field of semiconductors, and provides a blue-green double-peak LED epitaxial growth method, which comprises the following steps: processing a substrate, growing a low-temperature GaN buffer layer, growing a non-doped GaN layer, growing a Si-doped N-type GaN layer, growing a multi-quantum well layer, growing an AlGaN electron barrier layer, growing a Mg-doped P-type GaN layer, and cooling. Wherein the growth of the multi-quantum well layer sequentially comprises the steps of growing a first MQWs, growing a tunnel junction layer, growing a second MQWs and growing an AlGaN / GaN superlattice layer, the tunnel junction layer is introduced into the multi-quantum well layer to enhance tunneling of holes, meanwhile, the AlGaN / GaN superlattice layer is introduced, gradual change of an Al component in AlGaN is controlled by controlling the introduction time of TMAl, the problem of light emitting peak broadening is solved, and the light emitting efficiency is improved. The quantum well is ensured to emit blue light and green light at the same time, the color saturation of the light is improved, and the color temperature is reduced.

A magnetic tunneling junction (MTJ) device structure and the method of constructing such device are disclosed. Also disclosed are methods of using the device for spin-dependent transport characterization through biomolecules for structure and dynamic function analysis in physiological environments.

The invention relates to an anti-radiation five-junction solar cell and a preparation method thereof, and belongs to the technical field of semiconductor devices. The radiation-proof five-junction solar cell comprises a substrate, and a first buffer layer, a first component order change buffer layer, a fourth sub-cell, a second component order change buffer layer, a fourth tunnel junction, a fifth sub-cell and an electrode contact layer which are sequentially stacked on a first surface of the substrate, a second buffer layer, a third tunnel junction, a third sub-cell, a second tunnel junction, a second sub-cell, a first tunnel junction, a first sub-cell and a cap layer are sequentially stacked on the second surface of the substrate; and the base region thicknesses of the second sub-cell, the third sub-cell and the fourth sub-cell are smaller than the respective emitter region thicknesses. The anti-radiation five-junction solar cell comprises a plurality of sub-cells with quantum well structures, so that the anti-radiation performance of the solar cell can be effectively improved, and the last-stage use efficiency of the solar cell is further remarkably improved.

A light emitting element includes, successively from a lower side to an upper side, a first light emitting part having a first active layer, a tunnel junction part, and a second light emitting part having a second active layer. The first active layer includes a plurality of first well layers, and a first barrier layer positioned between two adjacent first well layers among the first well layers. The second active layer includes a plurality of second well layers, and a second barrier layer positioned between two adjacent second well layers among the second well layers. The second barrier layer is a nitride semiconductor layer containing an n-type impurity and gallium, and has an n-type impurity concentration higher than that of the first barrier layer. An n-type impurity concentration peak in the second barrier layer is located on a first light emitting part side.

The invention discloses an SOT-MRAM differential storage unit and a working method thereof, and belongs to the field of nonvolatile memories. The SOT-MTJ unit comprises an SOT-MTJ unit, a bidirectional selector, a transistor, a diode, a source line, a word line and two complementary bit lines, each SOT-MTJ unit is provided with a magnetic tunnel junction (MTJ) structure and a spin-orbit torque (SOT) layer; the two spin-orbit torque SOT layers are connected through the bidirectional selector, the other end of one spin-orbit torque SOT layer is connected with a first port of the transistor, a second port of the transistor is connected with one bit line, a third port of the transistor is connected with the word line, and the other end of the other spin-orbit torque SOT layer is connected with the other bit line; the tops of the two MTJ structures are connected and then connected with the anode of the diode, and the cathode of the diode is connected with the source line. The present invention is applicable to high-reliability storage and cache applications.

The invention provides an epitaxial structure of a GaAs solar cell and a growth method thereof, the epitaxial structure comprises a substrate, a first tunnel junction, a DBR layer, a middle cell, a second tunnel junction and a top cell which are sequentially stacked from bottom to top, and the substrate is used as a bottom cell; the DBR layer is formed by alternately growing an Al < x > Ga < 1-x > As layer and an In < y > Ga < 1-y > As layer, the Al < x > Ga < 1-x > As layer is doped with a C element, the In < y > Ga < 1-y > As layer is doped with a Zn element, and the C element has very high doping efficiency and solubility in the Al < x > Ga < 1-x > As layer with a high Al component, so that the bottleneck of low doping efficiency of Zn is overcome, two materials in the DBR layer can both realize high-concentration and uniform P-type doping, and the doping efficiency is improved. The barrier at the Al < x > Ga < 1-x > As / In < y > Ga < 1-y > As heterogeneous interface is greatly reduced, and the series resistance caused by the DBR layer is remarkably reduced.

The embodiment of the invention provides a physical unclonable function generator and a true random number generator. The physical unclonable function generator comprises a storage array and a control unit, a storage unit in the storage array comprises a magnetic storage device, and the magnetic storage device comprises a magnetic tunnel junction; the control unit is used for controlling the application of a magnetic field along a target direction to the storage array, and reading the resistance state of the storage unit to generate a physical unclonable function after the application of the magnetic field is stopped; wherein the target direction is perpendicular to or approximately perpendicular to the magnetic moment direction of the free layer in the magnetic tunnel junction in the in-plane direction, and the randomness and uniformity of the physical unclonable function are improved.

The invention provides a vertical cavity surface emitting laser and an epitaxial growth method thereof, and belongs to the technical field of semiconductors. The vertical cavity surface emitting laser comprises a substrate, an N-DBR, an active region growth layer, an oxidation limiting layer, a tunnel junction, a P-DBR and a surface ohmic contact layer which are stacked in sequence. The tunnel junction comprises a p + + layer, a first diffusion barrier layer, an n + + layer and a second diffusion barrier layer which are stacked in sequence. The p + + layer and the n + + layer are obtained through pulse doping growth, and P-DBR growth is carried out after stepped heating is carried out on the tunnel junction. The invention provides a comprehensive process based on pulse doping, an in-situ protection layer and stepped heating control, pulse doping is adopted when the n + + / p + + layer of the tunnel junction grows, the first diffusion barrier layer, the second diffusion barrier layer and the stepped heating process in subsequent growth are combined, and doping diffusion is remarkably inhibited while high conductivity of the tunnel junction is maintained.

The invention relates to the technical field of scanning tunneling microscopes, and discloses a scanning probe measuring device and a control method for pinpoint-to-pinpoint imaging, two pinpoints are oppositely arranged, and the pinpoints are accurately controlled and movably positioned based on a basic working mode of a scanning probe microscope. A needle tip-tunnel junction-needle tip working structure is established, after bias voltage is applied externally, electron tunneling between needle tips only relates to a small number of atoms or single atoms at the tail ends of the needle tips, the tunneling effect that the small number of atoms contribute to electrons is achieved, and therefore small number or single atom imaging is achieved. The device can be rapidly transplanted to application scenes of low temperature, strong magnetic field, optical measurement and the like, the double-needle-point structure is regulated and controlled through piezoelectric displacement or an electric field, tunnel junction width and barrier height can be optimized in real time, and research on dynamic construction and dynamic electrical characteristics of nanoscale tunnel junctions is greatly facilitated.

The invention provides a multi-junction cascade photonic crystal surface emitting laser and a preparation method thereof. The multi-junction cascade photonic crystal surface emitting laser comprises a substrate; the three-dimensional photonic crystal structure is arranged on the substrate, the three-dimensional photonic crystal structure comprises a longitudinal periodic structure formed by a plurality of laminated structures which are sequentially stacked in the vertical direction of the substrate, each laminated structure comprises an active layer and a photonic crystal layer, and the photonic crystal layer provides optical feedback for the active layer to form optical resonance; a transverse periodic structure is formed in each photonic crystal layer; and the plurality of tunnel junctions are arranged between the two adjacent laminated structures and are used for electrically connecting the two adjacent laminated structures.

Embodiments of present invention provide a magnetoresistive random-access-memory (MRAM) device. The MRAM device includes a reference layer; a tunnel barrier layer next to the reference layer; and a free layer next to the tunnel barrier layer, where the free layer includes a crystalline AIMnGe layer in a C38 structure formed on a magnetic seed layer, and the magnetic seed layer is a crystallized MnCo2Si layer or a crystallized MnCo2Ge layer having a cubic Heusler structure with a (001) texture. A method of forming the MRAM device is also provided.

A magnetoresistive memory cell includes a magnetic polarizer layer having a hard magnetization along a hard magnetization direction, a first magnetic tunnel junction located on a first side of the magnetic polarizer layer and including a first reference layer having a first side facing the magnetic polarizer layer, a first free layer facing a second side of the first reference layer, and a first tunnel barrier layer located between the first free layer and the first reference layer. The memory cell also includes a second magnetic tunnel junction located on a second side of the magnetic polarizer layer and including a second reference layer having a second side facing the magnetic polarizer layer, a second free layer facing a first side of the second reference layer, and a second tunnel barrier layer located between the second free layer and the second reference layer.

A magnetoresistive memory cell includes a first electrode; a second electrode; and a layer stack located between the first electrode and the second electrode and comprising, from one end to another, a first reference layer, a first tunnel barrier layer, a free layer, a second tunnel barrier layer, and a second reference layer. A first one of the first reference layer and the second reference layer comprises a positive spin polarization material. A second one of the first reference layer and the second reference layer comprises a negative spin polarization material. A magnetization direction of the second reference layer is parallel to a magnetization direction of the first reference layer.

Techniques are provided for tuning junction resistances of superconducting tunnel junction devices (e.g., Josephson junctions). For example, a method comprises measuring a resistance of a superconducting tunnel junction device, determining a difference between the measured resistance of the superconducting tunnel junction device and a target resistance for the superconducting tunnel junction device, and performing a hybrid tuning process to shift a resistance of the superconducting tunnel junction device from the measured resistance to the target resistance, the hybrid tuning process comprising a laser tuning process and a controlled-current tuning process.

To provide a new multilayer thin film exhibiting a tunnel magnetoresistance effect.SOLUTION: The present invention is a multilayer thin film having an insulating layer and a magnetic layer sandwiching the insulating layer. At least one of the magnetic layers is made of a Co-based alloy containing Al and / or Ga. For example, Co is contained in an amount of 58.5 to 63 at% with respect to the entire Co-based alloy. The Co-based alloy constituting a magnetic layer may be a β phase. The insulating layer is, for example, MgO or MgAl2O4. The magnetic layer on the other side of the insulating layer may be CoFeB (alloy) in addition to CoAl. Each layer is formed by sputtering, and planarization, crystallization, and the like are performed by heat treatment. A magnetic tunnel junction (MTJ) having the multilayer thin film of the present invention exhibits a high magnetoresistance change ratio (MR ratio), and can be applied to a next-generation magnetoresistance memory (MRAM) or the like.SELECTED DRAWING: Figure 3

A method for fabricating semiconductor device includes the steps of first forming a magnetic tunneling junction (MTJ) on a substrate, forming a first spin orbit torque (SOT) layer on the MTJ, forming an inter-metal dielectric (IMD) layer around the first SOT layer, forming a second SOT layer on the IMD layer, forming a first hard mask on the second SOT layer, patterning the first hard mask along a first direction, and then patterning the first hard mask along a second direction.