Patent classifications
H01L21/7813
Micro-LED display device and a manufacturing method thereof
A micro-LED display device and a manufacturing method thereof are disclosed. The method comprises: forming micro-LEDs (202) on a carrier substrate (201), wherein the carrier substrate (201) is transparent for a laser which is used in laser lifting-off; filling trenches between the micro-LEDs (202) on the carrier substrate (201) with a holding material (209); performing a laser lifting-off on selected ones of the micro-LEDs (202) to lift off them from the carrier substrate (201), wherein the selected micro-LEDs (202) are held on the carrier substrate (201) through the holding material (209); bonding the selected micro-LEDs (202) onto a receiving substrate (207) of the micro-LED display device; separating the selected micro-LEDs (202) from the carrier substrate (201) to transfer them to the receiving substrate (207).
Reusable wide bandgap semiconductor substrate
Multiple wide bandgap semiconductor wafers, each having active circuitry and an epitaxially formed backside drain contact layer, may be constructed from a single bulk semiconductor substrate by: forming foundational layers on the top of the bulk substrate via epitaxy; forming active circuitry atop the foundational layers; laser treating the backside of the bulk substrate to create a cleave line in one of the foundational layers; and exfoliating a semiconductor wafer from the bulk substrate, where the exfoliated semiconductor wafer contains the active circuits and at least a portion of the foundational layers. Wafers containing the foundational layers without complete active devices may be produced in a similar manner. The foundational layers may comprise a drain contact layer and a drift layer, and may additionally include a buffer layer between the drain contact layer and the drift layer.
METHOD OF REMOVING A SUBSTRATE WITH A CLEAVING TECHNIQUE
A method of removing a substrate from III-nitride based semiconductor layers with a cleaving technique. A growth restrict mask is formed on or above a substrate, and one or more III-nitride based semiconductor layers are grown on or above the substrate using the growth restrict mask. The III-nitride based semiconductor layers are bonded to a support substrate or film, and the III-nitride based semiconductor layers are removed from the substrate using a cleaving technique on a surface of the substrate. Stress may be applied to the III-nitride based semiconductor layers, due to differences in thermal expansion between the III-nitride substrate and the support substrate or film bonded to the III-nitride based semiconductor layers, before the III-nitride based semiconductor layers are removed from the substrate. Once removed, the substrate can be recycled, resulting in cost savings for device fabrication.
Silicon carbide components and methods for producing silicon carbide components
A method for producing a silicon carbide component includes forming a silicon carbide layer on an initial wafer, forming a doping region of the silicon carbide component to be produced in the silicon carbide layer, and forming an electrically conductive contact structure of the silicon carbide component to be produced on a surface of the silicon carbide layer. The electrically conductive contact structure electrically contacts the doping region. Furthermore, the method includes splitting the silicon carbide layer or the initial wafer after forming the electrically conductive contact structure, such that a silicon carbide substrate at least of the silicon carbide component to be produced is split off.
SEMICONDUCTOR STRUCTURE AND MANUFACTURING METHOD OF THE SAME
A semiconductor structure is provided. The semiconductor structure includes a lead frame and a sub-substrate disposed on the lead frame, wherein the thickness of the sub-substrate is between 0 and 0.5 μm. The semiconductor structure also includes an epitaxial layer disposed on the sub-substrate. The epitaxial layer includes a buffer layer, a channel layer and a barrier layer. The buffer layer is disposed between the sub-substrate and the channel layer. The channel layer is disposed between the buffer layer and the barrier layer. The semiconductor structure further includes a device layer disposed on the barrier layer and an interconnector structure electrically connected to the epitaxial layer and/or the device layer by a through hole.
TRANSFER OF WIDE AND ULTRAWIDE BANDGAP LAYERS TO ENGINEERED SUBSTRATE
The present disclosure relates to use of 193-nm excimer laser-based lift-off (LLO) of Al.sub.0.26Ga.sub.0.74N/GaN High-electron mobility transistors (HEMTs) with thick (t>10 μm) AlN heat spreading buffer layers grown over sapphire substrates. The use of the thick AlN heat spreading layer resulted in thermal resistance (R.sub.th) of 16 Kmm/W for as-fabricated devices on sapphire, which is lower than the value of ≈25-50 Kmm/W for standard HEMT structures on sapphire without the heat-spreaders. Soldering the LLO devices onto a copper heat sink led to a further reduction of R.sub.th to 8 Kmm/W, a value comparable to published measurements on bulk SiC substrates. The reduction in R.sub.th by LLO and bonding to copper led to significantly reduced self-heating and drain current droop. A drain current density as high as 0.9 A/mm was observed despite a marginal reduction of the carrier mobility (≈1800 to ≈1500 cm.sup.2/Vs). This is the highest drain current density and mobility reported to-date for LLO AlGaN/GaN HEMTs.
Wafer separating method
A wafer separating apparatus is provided which includes a wafer supporting member having an upper surface on which a bonded wafer formed of two wafers bonded with each other is placed; an arm portion arranged outside of the wafer supporting member, the arm portion being movable closer to and away from a bonded portion of the bonded portion of the bonded wafer supported by the supporting portion; and an inflating portion provided in an distal end portion of the arm portion, the inflating portion being inflatable in a direction intersecting the upper surface of the wafer supporting member.
Lift-off method and laser processing apparatus
A lift-off method includes a relocation substrate joining step of joining a relocation substrate to a surface of an optical device layer of an optical device wafer with a joining member interposed therebetween, thereby forming a composite substrate, a buffer layer breaking step of applying a pulsed laser beam having a wavelength transmittable through an epitaxy substrate and absorbable by a buffer layer to the buffer layer from a reverse side of the epitaxy substrate of the optical device wafer of the composite substrate, thereby breaking the buffer layer, and an optical device layer relocating step of peeling off the epitaxy substrate from the optical device layer, thereby relocating the optical device layer to the relocation substrate. In the buffer layer breaking step, irradiating conditions of the pulsed la-ser beam are changed for respective ring-shaped areas of the buffer layer, and the pulsed laser beam is applied to the optical device wafer under the changed irradiating conditions.
SEMICONDUCTOR ELEMENT AND METHOD FOR MANUFACTURING SEMICONDUCTOR ELEMENT
There is provided a semiconductor element containing gallium nitride. The semiconductor element includes a semiconductor layer including a first surface having a first region and a second region that is a projecting portion having a strip shape and projecting relative to the first region or a recessed portion having a strip shape and being recessed relative to the first region. Of the first surface, at least one of surfaces of the first region and the second region includes a crystal plane having a plane orientation different from a (000-1) plane orientation and a (1-100) plane orientation.
Method for producing a detachment area in a solid body
A method for producing a detachment area in a solid body in described. The solid body has a crystal lattice and is at least partially transparent to laser beams emitted by a laser. The method includes: modifying the crystal lattice of the solid by a laser beam, wherein the laser beam penetrates through a main surface of a detachable solid portion of the solid body, wherein a plurality of modifications are produced in the crystal lattice, wherein the modification are formed in a plane parallel to the main surface and at a distance from one another, wherein as a result of the modifications, the crystal lattice cracks the regions surrounding the modifications sub-critically in at least the one portion, and wherein the subcritical cracks are arranged in a plane parallel to the main surface.