59 results about "Metal evaporation" patented technology

According to the LED chip assembly and the manufacturing method thereof, a P-type ohmic contact metal layer is embedded into an epitaxial layer in an etching and metal evaporation mode before chip bonding, so that ohmic contact is formed. After transferring, the chip is manufactured by introducing the P-type ohmic contact metal layer into the surface layer of the core particle in an overlay etching manner, so that the light-emitting area of a light-emitting layer is increased, and the brightness of the whole core particle is greatly improved; in addition, due to evaporation of the oxide layer, the epitaxial wafer and the metal can be well wrapped, the difficulty of ultra-planarization is small, fusion of the metal and the epitaxial wafer is indirectly completed through fusion after the substrate is removed, and the operation process is shortened.

This application relates to a layer-by-layer vacuum evaporation device for a crystal tuning fork and its preparation process. The device comprises a frame and a vacuum evaporation chamber mounted on the frame. A evaporation turntable is rotatably mounted in the vacuum evaporation chamber. A plurality of evaporation mounting racks are equidistantly spaced along the circumference of the evaporation turntable. The evaporation mounting racks are rotatably mounted on the evaporation turntable. At least one mask plate is mounted on the evaporation mounting rack, and the mask plate is used to accommodate the tuning fork. The vacuum evaporation chamber has multiple molybdenum evaporation boats located at the center of the evaporation turntable. The molybdenum evaporation boats are used to place and evaporate metal evaporation materials. The vacuum evaporation chamber is provided with a flip assembly. When the evaporation mounting racks pass through the flip assembly, they rotate so that the mask plates pass obliquely over the molybdenum evaporation boats. This application improves production efficiency.

The invention relates to a long-distance span air bridge processing method. The processing method comprises the following steps: depositing a first photoresist layer on a substrate material, performing exposure / development, etching the substrate material by adopting a wet method, forming a first table top on the substrate material, and removing the first photoresist layer; according to the same operation, continuously coating the second photoresist layer to the nth table surface; coating an (n + 1) th photoresist layer on the outer side of the nth table top, performing exposure / development, performing metal evaporation, and removing metal and the (n + 1) th photoresist layer on the outer side of the nth table top to complete air bridge metal deposition; and coating an (n + 2) th photoresist layer, performing exposure / development, completely etching the substrate material in the vertical direction below the air bridge, and then removing the (n + 2) th photoresist layer to complete the air bridge manufacturing process. The problem of light resistance deformation caused by long-distance transconductance can be solved, and a long-span air bridge structure is achieved.

The application discloses a power device packaging method, and provides a packaging frame for packaging a power MOS tube, the packaging frame comprising a metal pad, a first metal layer, a second metal layer, an insulating heat-conducting layer and three metal electrodes arranged at intervals, the insulating heat-conducting layer is annularly arranged at the periphery of the metal pad, the first metal layer and the second metal layer are symmetrically arranged at the two sides of the insulating heat-conducting layer, the first metal layer is connected with the second metal electrode, the second metal layer is connected with the first metal electrode, and the metal pad is connected with the third metal electrode; the drain electrode of the power MOS tube is welded with the metal pad, a metal evaporation process is carried out on the surface of the packaging frame, photolithography is carried out on the surface of the evaporated metal, part of the evaporated metal is removed to form a gate connecting line and a source connecting line on the packaging frame, and the surface of the packaging frame is wrapped with resin and molded to form a straight insertion type package of the power MOS tube, so that the repeated wire bonding process of a single chip is effectively avoided, and the packaging efficiency of the power MOS tube is improved.

To provide a metal evaporation method in which rare metal can be easily recovered.SOLUTION: A metal evaporation method evaporates at least a part of metal composition by heating, in a non-contact manner in the same container, a metal composition containing rare metal elements and a perovskite-type complex oxide expressed by Formula (1): ABHaO3-b (1) (where A denotes one or more kinds of elements selected from a group consisting of lanthanoid element and elements of group 2 in the periodic table, B denotes one or more kinds of elements selected from a group consisting of elements of group 3 in the periodic table, elements of group 4 in the periodic table and transition metal element of a fourth period of the element periodic table, symbols a and b are amounts of hydrogen and oxygen vacancy, respectively, and represent numerical values in the following range: 0≤a≤1.0, 0≤b≤0.5).SELECTED DRAWING: None

The present application provides a silicon-based resistor and a manufacturing method thereof. The method includes obtaining a resistor substrate and material data of the resistor substrate, calculating the resistance value of the resistor to be manufactured according to the material data, where the material data includes the resistivity, length, and area of the resistor substrate; sequentially performing cleaning and oxidation treatment on the resistor substrate to obtain an oxidized substrate; sequentially performing photolithography, boron implantation, and cleaning treatment on the oxidized substrate to obtain a substrate silicon wafer; sequentially performing metal evaporation, metal photolithography, metal etching, metal degumming, and alloying treatment on the front surface of the substrate silicon wafer to obtain a silicon wafer to be laminated; sequentially performing lamination, etching, and metal evaporation treatment on the silicon wafer to be laminated to obtain a silicon-based resistor with the same resistance value. By manufacturing the silicon-based resistor through this manufacturing method of the silicon-based resistor, the cost is low and the manufactured silicon-based resistor is in chip package, making the occupied area of the silicon-based resistor small, solving the problems of large resistor area, high manufacturing cost, and complex processing technology existing in current resistors.

The invention discloses a gram-scale rare earth metal atomization device, an evaporation module and a using method, and relates to the technical field of metal evaporation and vacuum resistance heating. A cover plate provided with mounting holes in different shapes is used, so that material pipes in different arrangement modes are matched for experiments, and the experiment efficiency is improved. High-temperature, high-speed and long-time stable evaporation of rare earth metal can be realized, a target beam can be obtained under the condition of ensuring the material utilization rate, and the cost is saved.

The disclosure provides a preparation method of a Y-shaped gate and a Y-shaped gate prepared by the method, and can be applied to the field of microelectronics technology. The method comprises the following steps: performing deep ultraviolet light irradiation treatment on a first electron beam photoresist located on the upper surface of a substrate to obtain a first photoresist layer; spin coating a second electron beam photoresist on the surface of the first photoresist layer to obtain a second photoresist layer; performing a first exposure and development operation on the first photoresist layer and the second photoresist layer to obtain a gate cap structure of the Y-shaped gate; performing a second exposure and development operation on the first photoresist layer after the first exposure and development operation to obtain a gate leg structure of the Y-shaped gate; and filling a target metal material into the gate cap structure and the gate leg structure by using a metal evaporation method to obtain the Y-shaped gate.

The invention belongs to the technical field of semiconductor manufacturing processes, and particularly relates to a method for improving metal step coverage of a device. Comprising the following steps: providing a wafer; a wafer is installed, the wafer is installed on a small target of the planetary plate, and the planetary plate is installed in equipment; by rotating the clamping angle of the wafer, the distribution direction of the metal strips in the device is changed, and metal step coverage is improved; the rotating angle of the rotating shaft ranges from 45 degrees to 135 degrees; preparing a metal film, namely preparing the metal film on the surface of the wafer by adopting a metal evaporation process; performing metal photoetching; metal corrosion; and inspection and measurement are carried out, a microscope is adopted for microscopic examination, an electron microscope is adopted for testing, the surface appearance and morphology of the wafer are subjected to microscopic examination, and the width of the metal strip is measured. According to the invention, the mounting angle of the wafer is changed, the direction of the metal step is changed, and the step morphology of the metal strip in the device is improved.

The invention discloses a preparation method for superfine nano metal powder, which comprises the following steps of: installing a collecting vessel in a closed chamber in advance, placing an adsorbent in the collecting vessel, and then pumping air pressure in the closed chamber to a vacuum state through a vacuum system; closing the vacuum system, and slowly inputting inert gas into the closed cavity; starting a heating device in the closed cavity to evaporate the metal in the closed cavity, and adsorbing and cooling by using a liquid adsorbent to form metal powder; and separating the metal powder deposited in the adsorbent to obtain the superfine nano metal powder. By adopting the preparation method disclosed by the invention, the agglomeration problem and the powder uniformity problem of the superfine nano metal powder are effectively solved, a superfine nano particle product with uniform particles, no agglomeration and good dispersity can be obtained, and large-scale production of the metal powder with high uniformity and high dispersity is facilitated; therefore, the application range of the nano metal powder can be expanded, and the method is suitable for popularization and application.

This application provides a method for fabricating a fast recovery diode, a fast recovery diode, and an electronic device, relating to the field of semiconductor technology. The method for fabricating a fast recovery diode includes: providing a substrate, the substrate including a first surface and a second surface disposed opposite to each other; performing ion doping treatment on the substrate to form ion-doped regions on the first surface and the second surface; etching the first surface based on a predetermined etching region to form a first groove; wherein the depth of the first groove is greater than the thickness of the ion-doped region; the predetermined etching region is located at the center of the first surface; forming a passivation layer in the first groove; and performing metal evaporation on the first surface to form a first metal layer. This method not only reduces the conduction loss of the fast recovery diode, improves energy conversion efficiency, effectively suppresses reverse current, and reduces electromagnetic interference, but also enhances its resistance to avalanche breakdown energy and surge capability.

The invention discloses a particle trapping device suitable for an evaporation overcurrent experiment and a use method of the particle trapping device, and relates to the technical field of metal evaporation experiment research. And meanwhile, the trapping structure space adjusting module can adjust the space position of the distributed trapping sampling module, so that the measurement of the ion proportion and the research on the particle overcurrent distribution characteristics in the metal evaporation experiment process can be realized.

The invention relates to a long-distance air bridge for preventing depression of a bridge floor and a preparation method thereof, and the method comprises the steps: enabling GaAs layers and InGaP layers to be alternately arranged for multiple times to form a first layer to an Nth layer, and enabling an Al < x > Ga < 1-x > As layer to be arranged below the Nth layer; depositing a first photoresist layer on the first layer, performing exposure / development, and etching the first layer to form a first mesa; etching the second layer and then removing the first photoresist layer; coating a second photoresist layer, performing exposure / development, etching the third layer to form a second mesa, and etching the fourth layer to remove the second photoresist layer; sequentially forming a third table-board to an a-th table-board according to the same operation; and coating an (a + 1) th photoresist layer on the outer side of the a-th table top, performing exposure / development, performing metal evaporation, removing metal and the (a + 1) th photoresist layer on the outer side of the a-th table top, and sequentially and completely etching the first layer and the Nth layer below the air bridge to complete the air bridge manufacturing process. According to the invention, a long-span air bridge structure is realized, and a window of an etching process is larger.

The invention provides a manufacturing method of a fast recovery diode, the fast recovery diode and electronic equipment, and relates to the technical field of semiconductor chips. The manufacturing method of the fast recovery diode comprises the steps that a device structure is provided, wherein the device structure comprises a substrate, an oxide layer located on one side of the substrate and a first metal layer located on the side, away from the substrate, of the oxide layer; forming a protection layer on one side, far away from the substrate, of the first metal layer; sequentially carrying out thinning treatment and corrosion treatment on one side, far away from the first metal layer, of the substrate; removing the protective layer; and metal evaporation is performed on the side, away from the first metal layer, of the substrate to form the second metal layer, so that friction between the fast recovery diode and the thinning equipment can be reduced in the thinning process, static electricity is reduced, the sparking phenomenon in the testing process is avoided, and the production efficiency is improved.

The utility model discloses an output window for vacuum metal evaporation capable of eliminating backscattered electrons and secondary electrons, metal steam generated by melting of a target material in a crucible rises and is diffused to a coating substrate through a window body of the conveying window to be cooled and deposited to form a film, the conveying window comprises a frame, two opposite sides of the frame are provided with permanent magnet magnetic circuits, and the permanent magnet magnetic circuits are connected with the conveying window. A window for metal steam to rise is arranged between the two permanent magnet magnetic circuits; the permanent magnet magnetic circuit comprises at least two magnet yokes, a permanent magnet arranged between the two magnet yokes and a partition plate, and pole shoes are arranged at the ends, away from the frame and located on the same horizontal plane with the partition plate, of the magnet yokes; the two permanent magnet magnetic circuits are circumferentially and symmetrically distributed according to the center of the output window, and the pole shoes of the magnetic circuits on the two sides are arranged in a staggered manner, so that the bombardment of back scattering electrons and secondary electrons on a coating substrate through the output window is greatly reduced, and the molecular arrangement structure of the substrate is not damaged; therefore, the tensile mechanical strength of the base material is not obviously reduced.

This invention discloses a fast recovery diode with low reverse recovery time and its fabrication method. The fabrication method includes providing a fast recovery diode substrate; sequentially thinning and etching the back side of the fast recovery diode substrate, with a thinning thickness of 40-80 μm and an etching thickness of 1-5 μm; doping the back side of the fast recovery diode substrate with gold; and after gold doping, sequentially thinning and evaporating the metal on the back side of the fast recovery diode substrate to form a back pad metal layer. By doping the substrate with more effective gold, the resulting fast recovery diode exhibits a lower reverse recovery time and superior other performance characteristics.

The invention discloses an evaporation furnace for preparing metal steam, which comprises a furnace body, and the furnace body comprises a gas inlet section for providing protective gas; the metal melting section is used for melting solid metal and forming metal liquid; the metal evaporation section is used for evaporating the metal liquid to form metal steam, the metal melting section is connected with the metal evaporation section, a metal liquid flowing channel allowing the metal liquid to flow into the metal evaporation section from the metal melting section is arranged between the metal melting section and the metal evaporation section, and the output end of the air inlet section is connected with the metal evaporation section; and the furnace inlet section is used for feeding the metal steam into the sintering furnace, and the input end of the furnace inlet section is connected with the metal evaporation section. The invention further discloses a preparation method of the metal vapor and a sintering device. The method has the advantages that the metal vapor can be continuously prepared, the prepared metal vapor is good in uniformity, and the large-scale production requirement of metal coating and sintering of the battery negative electrode material can be met.

The invention discloses a method for preparing a 3 omega electrode of a surface conductive or rough sample, which comprises the following steps of: cleaning a sample to be detected, spin-coating liquid BCB resin and curing, tightly attaching a hollow mask plate to the sample to be detected so as to transfer a pattern on the mask plate to the sample to be detected, fixing the attached hollow mask plate to the sample to be detected, and carrying out surface conductive treatment on the sample to be detected, so as to obtain the 3 omega electrode of the surface conductive or rough sample. And putting the sample into a metal evaporation furnace to evaporate metal, and finally separating the sample to be detected from the hollow mask plate to complete the preparation of the 3 omega electrode. According to the scheme, the characteristic that the liquid BCB resin can be cured after spin coating is utilized, a flat insulating layer can be formed on the surface of a conductive or rough sample, the subsequently prepared 3 omega electrode can be used for testing, meanwhile, the hollow mask and the evaporation clamp system designed in the scheme can avoid using photoresist to photoetch the evaporation electrode, and the test efficiency is improved. The possible electrode falling condition is avoided, and the evaporated metal electrode and the sample can be connected more firmly in the mode that the metal is directly evaporated through the hollowed-out mask.

The utility model discloses a precious metal evaporation material pelletizing device which comprises an evaporation material and a frame body, the lower end of the frame body is connected with a bottom plate, the evaporation material is arranged on the bottom plate, and the frame body is connected with a plurality of cutter bodies. The upper ends of the plurality of cutter bodies are connected with a connecting frame; the frame body is connected with an air cylinder I; the upper end of the connecting frame is fixedly connected with the output end of the first air cylinder. The multiple cutter bodies are driven by a first air cylinder to move up and down at the same time. The upper end of each cutter body is connected with a cutter rest; an adjusting mechanism is connected among the plurality of knife rests; the multiple tool rests move on the connecting frame at equal intervals through the adjusting mechanism. According to the evaporation material cutting device, the multiple cutter bodies are movably connected to the connecting frame, the distance between the multiple cutter bodies is adjusted at equal intervals through the adjusting mechanism, the distance between every two adjacent cutter bodies is kept consistent, and it is guaranteed that the lengths of cut evaporation materials are consistent.

The utility model discloses perovskite laminated solar cell coating equipment, which comprises a coating bin, a vacuum chamber, a metal evaporator and a double-layer barrier plate, a feeding component is mounted on the surface of the metal evaporator, an auxiliary roller is mounted in the vacuum chamber above an oil immersion sealing box, and the auxiliary roller is mounted in the vacuum chamber above the oil immersion sealing box. A main transmission roller is mounted in the vacuum chamber above the auxiliary roller, an unfolding roller is mounted in the vacuum chamber on one side of the main transmission roller, a clamping cavity is formed in the vacuum chamber on one side of the unfolding roller, a rack is mounted at the bottom of the coating bin, and the vacuum chamber is arranged in the coating bin; a double-layer barrier plate is mounted in the vacuum chamber, a clamping piece is mounted in the vacuum chamber on one side of the double-layer barrier plate, and a metal evaporator is mounted in the vacuum chamber on one side of the clamping piece. The clamping cavity disclosed by the utility model is used for fixing a coating material, preventing the coating material from displacing in a coating process, and ensuring the coating accuracy and repeatability.

The application provides a manufacturing method of a Y-shaped metal structure in a Y-gate transistor, which comprises the following steps: (1) applying a first layer of photoresist on a substrate and performing first-time opening mapping; (2) performing second-time opening mapping on both sides of the upper end of the first-time opening mapping line groove; (3) performing reflow on the upper edges of the first-time opening mapping line groove and the second-time opening mapping line groove by using temperature rising; (4) applying a second layer of photoresist and performing third-time opening mapping by using I-line or an electron beam; (5) performing acid etching on the substrate; and (6) performing metal evaporation deposition to form a Y-gate transistor metal structure. The opening mapping line groove has a large width, the bottom of the formed Y-gate transistor metal structure is not prone to cracks, and the yield is high; by controlling the shape and size of the second-time opening mapping line groove, the lower bottom morphology of the Y-shaped metal structure can be better adjusted; the target temperature of the temperature rising is less than Tg, so that photoresist passivation deformation only occurs in the electron beam opening mapping area, and the overall Gate uniformity is improved.

The invention provides a preparation method of a photocathode. The preparation method comprises the following steps: providing a substrate, an alkali metal evaporation source and a non-metal evaporation source; and realizing non-metal intermittent deposition and alkali metal continuous deposition on the surface of the substrate by adopting an alkali metal evaporation source and a non-metal evaporation source in a high-vacuum environment so as to prepare the corresponding photocathode. According to the method, non-metal intermittent deposition and alkali metal continuous deposition are adopted, it is ensured that in the photocathode preparation process of different devices, different batches of photocathodes prepared by different persons keep almost consistent high quantum efficiency, and the quantum efficiency of 100% of the photocathodes is maximized; the non-substrate surface can be inhibited from generating a photocathode with high quantum efficiency by non-metal intermittent and alkali metal continuous deposition, and the interference of dark current in the preparation process is remarkably reduced; and compared with sequential deposition and co-evaporation, the preparation difficulty is greatly reduced, the consumption of an evaporation source is greatly reduced, the preparation time is shortened, the service life of the photocathode is prolonged, and a foundation is laid for realizing industrial full-automatic production of the photocathode.

The invention is suitable for the technical field of display panel evaporation alignment devices, and provides a display panel evaporation alignment device and evaporation device.The display panel evaporation alignment device comprises a substrate bearing mechanism, a mask bearing mechanism and a temperature control magnetic attraction platform, and the substrate bearing mechanism is arranged in a metal evaporation cavity; the mask bearing mechanism is movably arranged in the metal evaporation cavity; the temperature control magnetic attraction platform is movably arranged in the metal evaporation cavity, the temperature control magnetic attraction platform comprises a temperature control magnetic attraction assembly, a plurality of carrying table positioning pin assemblies and at least one anti-warping supporting pin assembly, the carrying table positioning pin assemblies are used for applying first pressing force to the substrate so as to press the aligned substrate and the mask plate, and the anti-warping supporting pin assemblies are used for supporting the substrate and the mask plate; the anti-warping supporting pin assembly is used for applying second pressing force to the edge area of the substrate. According to the display panel evaporation alignment device provided by the invention, substrate warping caused by pressing of the carrier positioning pin assembly can be counteracted, so that the evaporation shadow effect is remarkably improved, and the uniformity of an evaporation film layer is improved.

The invention provides an indium column preparation method, an indium column and an infrared detector, and belongs to the technical field of infrared detectors. The method solves the problems that in an existing infrared detector electrode climbing growth process, a side wall electrode is too thin in thickness, large in impedance and the like, and comprises the following steps that a table top of each contact layer is formed through a conventional table top manufacturing process, and then photoetching trepanning, passivating trepanning and cleaning are conducted; growing ubm metal in the open pores by adopting a metal evaporation process to form a ubm electrode, and then stripping and cleaning the ubm electrode; indium column photoetching holes are formed in the ubm electrodes through the photoetching technology, indium layers grow in the indium column photoetching holes, and then stripping and cleaning are carried out; the cleaned chip is subjected to a backflow process, and uniform indium column welding spots with the same horizontal height on the upper surface are obtained through melting of indium columns and the surface tension effect after the backflow process; the method is applied to preparation of the indium column of the infrared detector.

This invention relates to the field of gallium arsenide-based high-frequency device manufacturing technology, specifically a method and structure for fabricating a Y-shaped gate to reduce gate resistance. The method involves forming a first layer of negative photoresist with an inverted trapezoidal cross-section on a GaAs wafer, depositing a 30nm~80nm sacrificial passivation layer, coating a second layer of negative photoresist, and photolithographically etching out a window. A suspended region is formed through dry etching and O2 plasma etching, followed by metal evaporation and non-destructive lift-off to obtain the Y-shaped gate. This invention fundamentally eliminates the lift-off failure problem caused by the "top-heavy" effect, overcomes the process bottleneck of gate metal thickness, and achieves a significant increase in gold layer thickness, effectively reducing gate resistance. Furthermore, this invention provides a Y-shaped gate structure fabricated by this method, which has high bottom support strength and exhibits no process stress damage in its Schottky contact with the GaAs substrate, significantly improving the high-frequency performance and reliability of the device.

The utility model provides a wafer cover plate compression ring, a metal evaporation slide tray and a metal evaporation machine table. The wafer cover plate compression ring structure comprises a frame; the slide way is located in the frame, and a limiting piece is arranged on the inner wall of the slide way; the pressing ring can move along the slide way, the first end of the pressing ring is arranged in the slide way, and the second end of the pressing ring can extend out of the frame along the slide way; the self-locking device is located in the sliding way and connected with the first end of the pressing ring, the self-locking device can slide along the sliding way so as to drive the pressing ring to move along the sliding way, and the self-locking device can be matched with the limiting piece so as to fix the extending position of the pressing ring. According to the technical scheme, the original screw fixing mode of the compression ring is canceled, the movement mode of the compression ring is changed into the telescopic mode, and the fixing mode is changed into the self-locking mode, so that the hidden crack of the wafer caused by vibration of the wafer due to screw loosening and incapability of fixing the wafer cover plate caused by rotation of the compression ring is avoided.

The present invention discloses a method for preparing a rare-earth-doped GaN nanofilm, comprising the following steps: Step 1: A gallium metal evaporation pool and a rare-earth europium metal evaporation pool are respectively provided in the first and third air inlet channels of a reactor, and the substrate is provided at the bottom of the reactor; Step 2: A mixture of nitrogen and hydrogen as a carrier gas mixed with ammonia is introduced into the reactor through the second air inlet channel, and hydrogen chloride is flowed as a reaction gas through the first and third air inlet channels respectively provided with the gallium metal evaporation pools and the rare-earth europium metal evaporation pools, thereby forming a europium-doped GaN single crystal film on the substrate; Step 3: The europium-doped GaN single crystal film obtained in Step 2 is placed in a furnace for annealing under the following annealing conditions: nitrogen or ammonia, an annealing temperature of 1000-1200°C, and an annealing time of 0.5-4 hours. The GaN nanofilm obtained by the preparation method of the present invention is uniformly doped with rare earth ions and can be integrated into the GaN crystal lattice.

The invention discloses a preparation device and a preparation method of a ternary alloy. The preparation device comprises a central furnace body, a metal A evaporation chamber, a metal B evaporation chamber, a metal C evaporation chamber and a condensation chamber, the condensation chamber is located at the axial top of the central furnace body and communicated with the interior of the central furnace body, the metal evaporation chambers are communicated with the interior of the central furnace body through the corresponding overflow ports, and temperature gradient distribution in the central furnace body is achieved by controlling the evaporation temperature of metal in the process so that target ternary metal can be synthesized from the metal in the steam state. Finished products are collected in the condensation chamber. According to the method, the ternary alloy is synthesized in an evaporation and condensation mode, temperature gradient distribution is utilized, the temperature is gradually reduced from bottom to top, and energy can be fully utilized.

This invention relates to the field of vacuum coating technology and discloses a linear metal evaporation source for vacuum coating. The linear metal evaporation source of this invention includes a container, a nozzle, and a crucible. The container includes a metal outer cover and an inner liner, with heat-insulating material filling the space between the outer cover and the inner liner. The inner liner is a heater, and its cavity includes a primary evaporation zone, a pressurization zone, a secondary evaporation zone, and a heating zone. The nozzle has a slit-shaped nozzle orifice and is located at the top of the inner liner. The crucible is located within the primary evaporation zone. The linear metal evaporation source of this invention is placed within the vacuum chamber of a vacuum coating apparatus. The inner liner heats the metal to be coated in the primary evaporation zone, causing the metal to vaporize and reach saturated vapor pressure. The metal vapor is transported to the nozzle at saturated vapor pressure, and the nozzle ejects the metal vapor in a linear jet manner, depositing it on the workpiece to form a uniform and dense metal coating layer. This results in high coating efficiency and good film quality.

The invention relates to the technical field of semiconductor devices, in particular to a preparation method of a GaN HEMT (High Electron Mobility Transistor) with a grid air bridge structure, which comprises the following steps of: 1, cleaning an epitaxial wafer, and defining ohmic contact areas of a source electrode and a drain electrode; carrying out metal evaporation, metal lift-off and annealing treatment on the epitaxial wafer to prepare a source electrode and a drain electrode; 2, depositing a first passivation layer on the epitaxial wafer on which the source electrode and the drain electrode are prepared, and performing isolation; step 3, etching a contact window on the isolated first passivation layer; 4, preparing a columnar light resistor on the first passivation layer to define an air bridge region; step 5, depositing a second passivation layer on the first passivation layer on which the columnar photoresist is prepared; step 6, etching the second passivation layer to expose the columnar photoresist and the contact window; 7, after etching is completed, grid metal is deposited; and step 8, removing metal except the gate metal and all light resistors. The parasitic capacitance of the device can be effectively reduced.