摘要:
A novel method suitable for commercially mass production of hollow microneedle with high quality for delivery of drugs across or into biological tissue is provided. It typically includes the following processes: (1) coating an elongated template of a first material with a second material to form a cover; (2) removing tips of the template and cover to form an opening in the cover; and (3) removing the template of the first material to obtain hollow microneedles of the second material. This simple, efficient and cost-effective fabrication method can mass produce hollow microneedle arrays involving no complicated and expensive equipments or techniques, which can be used in commercial fabrication of hollow needles for delivering drugs or genes across or into skin or other tissue barriers with advantages of minimal damage, painless, long-term and continuous usages.
摘要:
Oxygen controlled PVD AlN buffers for GaN-based optoelectronic and electronic devices is described. Methods of forming a PVD AlN buffer for GaN-based optoelectronic and electronic devices in an oxygen controlled manner are also described. In an example, a method of forming an aluminum nitride (AlN) buffer layer for GaN-based optoelectronic or electronic devices involves reactive sputtering an AlN layer above a substrate, the reactive sputtering involving reacting an aluminum-containing target housed in a physical vapor deposition (PVD) chamber with a nitrogen-containing gas or a plasma based on a nitrogen-containing gas. The method further involves incorporating oxygen into the AlN layer.
摘要:
Oxygen controlled PVD AlN buffers for GaN-based optoelectronic and electronic devices is described. Methods of forming a PVD AlN buffer for GaN-based optoelectronic and electronic devices in an oxygen controlled manner are also described. In an example, a method of forming an aluminum nitride (AlN) buffer layer for GaN-based optoelectronic or electronic devices involves reactive sputtering an AlN layer above a substrate, the reactive sputtering involving reacting an aluminum-containing target housed in a physical vapor deposition (PVD) chamber with a nitrogen-containing gas or a plasma based on a nitrogen-containing gas. The method further involves incorporating oxygen into the AlN layer.
摘要:
The current invention introduces a method of crystal film's growth of Gallium Nitride and related alloys over a novel class of the substrates using Vapor Phase Epitaxy technique. This said novel class of the substrates comprises single crystal lattice matched, partially matched or mismatched metallic substrates. The use of such substrates provides exceptional thermal conductivity and application flexibility, since they can be easily removed or patterned by chemical etching for the purposes of additional contact formation, electromagnetic radiation extraction, packaging or other purposes suggested or discovered by the skilled artisan. In particular, if patterned, the remaining portions of the said substrates can be utilized as contacts to the semiconductor layers grown on them. In addition, the said metallic substrates are significantly more cost effective than most of the conventional substrates. The use of Vapor Phase Epitaxy allows growing the epitaxial layers with different and/or variable alloy composition, as well as heterostructures and superlattices.
摘要:
Fabrication of gallium nitride-based light devices with physical vapor deposition (PVD)-formed aluminum nitride buffer layers is described. Process conditions for a PVD AlN buffer layer are also described. Substrate pretreatments for a PVD aluminum nitride buffer layer are also described. In an example, a method of fabricating a buffer layer above a substrate involves pre-treating a surface of a substrate. The method also involves, subsequently, reactive sputtering an aluminum nitride (AlN) layer on the surface of the substrate from an aluminum-containing target housed in a physical vapor deposition (PVD) chamber with a nitrogen-based gas or plasma.
摘要:
The non-polar or semi-polar Nitride film is grown using Metal Organic Vapor Phase Epitaxy over a substrate. The in-situ grown seed layer comprising Magnesium and Nitrogen is deposited prior to the Nitride film growth. The said seed layer enhances the crystal growth of the Nitride material and makes it suitable for electronics and optoelectronics applications. The use of non-polar and/or semi-polar epitaxial films of the Nitride materials allows avoiding the unwanted effects related to polarization fields and associated interface and surface charges, thus significantly improving the semiconductor device performance and efficiency. In addition, the said seed layer is also easily destroyable by physical or chemical stress, including the ability to dissolve in water or acid, which makes the substrate removal process available and easy. The substrate removal provides the possibility to achieve exceptional thermal conductivity and application flexibility, such as additional contact formation, electromagnetic radiation extraction, packaging or other purposes suggested or discovered by the skilled artisan.
摘要:
Fabrication of gallium nitride-based light devices with physical vapor deposition (PVD)-formed aluminum nitride buffer layers is described. Process conditions for a PVD AlN buffer layer are also described. Substrate pretreatments for a PVD aluminum nitride buffer layer are also described. In an example, a method of fabricating a buffer layer above a substrate involves pre-treating a surface of a substrate. The method also involves, subsequently, reactive sputtering an aluminum nitride (AlN) layer on the surface of the substrate from an aluminum-containing target housed in a physical vapor deposition (PVD) chamber with a nitrogen-based gas or plasma.