Abstract: A stacked semiconductor device includes a first gate structure formed on a substrate, a first insulating interlayer covering the first gate structure on the substrate, a first active pattern formed through and on the first insulating interlayer and contacting the substrate, a second gate structure formed on the first active pattern and the first insulating interlayer, a buffer layer covering the second gate structure on the first active pattern and the first insulating interlayer, a second insulating interlayer formed on the buffer layer, and a contact plug formed through the first and second insulating interlayers, which contacts with the substrate and is insulated from the second gate structure by the buffer layer. Operation failures of a transistor in the stacked semiconductor device can be reduced because the buffer layer prevents a word line from being electrically connected to the contact plug.

Abstract: In a semiconductor device and method of manufacturing the semiconductor device, a punch-through prevention film pattern and a channel film pattern are formed on an insulation layer. The punch-through prevention pattern and the insulation layer may include nitride and oxide, respectively. The punch-through prevention pattern is located under the channel pattern.

Abstract: An isolation structure may include a trench formed on a surface of a substrate. A first isolation pattern may be provided on an inner face of the trench to define an auxiliary trench. A second isolation pattern may be provided on the first isolation pattern to partially fill the auxiliary trench. A third isolation pattern may be provided on the second isolation pattern to fill up the auxiliary trench. The second isolation pattern may have an etching selectivity with respect to the first isolation pattern.

Abstract: An apparatus for compressing fluid comprises a cylinder bore longitudinally penetrating a cylinder block a suction port penetrating to the cylinder bore, and a pair of slot-shaped fluid discharge having one opening at an end portion of the cylinder bore; a piston; a discharge valve assembly movably disposed at the cylinder bore to selectively open and close the fluid discharge ports of the cylinder block, the discharge valve assembly including a valve piston having a flange for limiting movement of the discharge valve assembly; a cylinder head defining a discharge chamber communicating with the fluid discharge ports, the cylinder head having a fluid discharge passage from the discharge chamber. The fluid suction port is selectively opened by the piston reciprocally moving in the cylinder bore to draw in fluid, which is discharged through the fluid discharge ports opened by the movement of the valve piston as the pressure of the fluid in the cylinder bore increases beyond a predetermined threshold.

Abstract: A fluid compressing apparatus including a cylinder block having a cylinder bore with a diameter penetrating through the cylinder block in a lengthwise direction, a discharge chamber having a diameter larger than the diameter of the cylinder bore, and at least one fluid suction port penetrating into the cylinder block including an interconnected space comprising a fluid discharge port. A piston serves to open and close the suction port while linearly reciprocating within the cylinder bore eliminating need for a separate suction valve assembly. A valve plate separates from and opens the discharge port as a result of the high pressure of the fluid in the cylinder bore, thus compressing the fluid until completely discharged; such that the clearance volume in the cylinder bore is minimized improving compression efficiency.

Abstract: An apparatus for compressing fluid comprises: a cylinder block including a cylinder bore with a predetermined diameter penetrating the cylinder block in a lengthwise direction, at least one fluid suction port penetrating in a direction intersecting with the cylinder bore, and at least a pair of fluid discharge ports preferably of a slot shape and having one opening formed at both end portions of the cylinder bore; a piston for reciprocally moving within the cylinder bore; a discharge valve assembly movably disposed at the cylinder bore in order to selectively open and close the fluid discharge ports of the cylinder block, the discharge valve assembly including a valve piston having a flange for limiting movement of the discharge valve assembly; and a cylinder head for forming a discharge chamber communicating with the fluid discharge ports by a connection to the cylinder block, and the cylinder head having a fluid discharge passage of the discharge chamber.

Abstract: A fluid compressing apparatus for drawing, compressing and discharging a fluid including a cylinder block having a cylinder bore of a predetermined diameter penetrating through the cylinder block in a lengthwise direction, a discharge chamber having a diameter larger than the diameter of the cylinder bore, and at least one fluid suction port penetrating into the cylinder block in a substantially perpendicular direction with respect to the lengthwise direction of the cylinder bore, the cylinder block using a certain space thereof that is interconnected with the discharge chamber of the cylinder bore as a fluid discharge port; a piston movably disposed in the cylinder bore of the cylinder block to be linearly reciprocated; a discharge valve assembly having a valve plate disposed to be resiliently biased from the discharge chamber toward the fluid discharge port so as to selectively open or close the fluid discharge port of the cylinder block; and a cylinder head disposed at an end of the discharge chamber of th