Abstract: Provided is a device for relieving headache and pain caused by temporomandibular joint disorders may include: a body having a neck band surroundingly worn on a user's neck, first connectors extending forwardly from both ends of the neck band by first set lengths, and second connectors extending upwardly from front ends of the first connectors by second set lengths; first low frequency electrostimulators disposed on the second connectors and coming into close contact with the temporalis muscles, when the body is worn on the user's head, to apply low frequencies to the temporalis muscles; and second low frequency electrostimulators disposed on the connected portions between the first connectors and the second connectors and coming into close contact with the masseter muscles, when the body is worn on the user's head, to apply low frequencies to the masseter muscles.

Abstract: A substrate structure include a lower substrate doped with n-type impurities having a first impurity concentration, an epitaxial layer on the lower substrate, and a metallic-contaminant collection area spaced apart from the epitaxial layer in the lower substrate, the metallic-contaminant collection area doped with impurities having a second impurity concentration higher than the first impurity concentration, the metallic-contaminant collection area having lattice defects, and an upper surface of the metallic-contaminant collection area being spaced apart from a top surface of the lower substrate at a distance in a range of about 0.1 ?m to about 3 ?m.

Abstract: A method of fabricating an epi-wafer includes providing a wafer including boron by cutting a single crystal silicon ingot, growing an insulating layer on one surface of the wafer, performing thermal treatment of the wafer, removing the insulating layer formed on one surface of the wafer, mirror-surface-grinding one surface of the wafer, and growing an epitaxial layer on one surface of the wafer and forming a high-density boron layer within the wafer that corresponds to the interface between the wafer and the epitaxial layer.

Abstract: A method of fabricating an epi-wafer includes providing a wafer including boron by cutting a single crystal silicon ingot, growing an insulating layer on one surface of the wafer, performing thermal treatment of the wafer, removing the insulating layer formed on one surface of the wafer, mirror-surface-grinding one surface of the wafer, and growing an epitaxial layer on one surface of the wafer and forming a high-density boron layer within the wafer that corresponds to the interface between the wafer and the epitaxial layer.