A method for fabricating a self-aligned via structure includes forming a tri-layer mask on an ILD layer over a lower metal wiring layer, the tri-layer mask includes first and second insulating layers and a metal layer in between the insulating layers; defining a trench pattern through the first insulating layer and metal layer, the trench pattern having a first width; defining a first via pattern in a lithographic mask over the trench pattern, the first via pattern having a second width that is larger than the first width; growing a metal capping layer on an exposed sidewall of the trench pattern to decrease the first width to a third width that defines a second via pattern; transferring the trench pattern into the ILD layer to form a trench; and transferring the second via pattern through the ILD layer and into the metal wiring layer to form a via.

The invention provides an unpowered anti-frost anti-heave heat gathering device and subgrade thereof, comprising a solar heat absorber, a circulating tube, a transducer, and a heat gathering tube, wherein the solar heat absorber and the transducer are connected by the circulating tube to form a circulation loop, through which a liquid state circulating working medium flows, the solar heat absorber is configured to absorb solar energy and transfer heat to the transducer through the liquid state circulating working medium, the heat gathering tube comprises a heat absorption section and a heat release section in communication, the heat absorption section is inserted into the transducer for absorbing heat from the transducer and transferring heat to the heat release section, and the heat release section is inserted into a subgrade for heating the subgrade.

The invention provides an unpowered anti-frost anti-heave heat gathering device and subgrade thereof, comprising a solar heat absorber, a circulating tube, a transducer, and a heat gathering tube, wherein the solar heat absorber and the transducer are connected by the circulating tube to form a circulation loop, through which a liquid state circulating working medium flows, the solar heat absorber is configured to absorb solar energy and transfer heat to the transducer through the liquid state circulating working medium, the heat gathering tube comprises a heat absorption section and a heat release section in communication, the heat absorption section is inserted into the transducer for absorbing heat from the transducer and transferring heat to the heat release section, and the heat release section is inserted into a subgrade for heating the subgrade.

The present disclosure discloses a heating system coupling a passive phase change energy storage sunlight room with an air source heat pump. The heating system includes a passive phase change energy storage sunlight room (7), phase change heat storage units, a to-be-heated room (8), and an air source heat pump air heater arranged between the passive phase change energy storage sunlight room (7) and the to-be-heated room (8), wherein each phase change heat storage unit (11) consists of a plurality of phase change heat storage modules (1). An opening in the front part of each phase change heat storage module faces an interior of the passive phase change energy storage sunlight room, and the phase change heat storage modules located on the top are spliced transversely, and the vent in the top of each phase change heat storage module is connected with the ventilation port of the room.

The present disclosure discloses a heating system coupling a passive phase change energy storage sunlight room with an air source heat pump. The heating system includes a passive phase change energy storage sunlight room (7), phase change heat storage units, a to-be-heated room (8), and an air source heat pump air heater arranged between the passive phase change energy storage sunlight room (7) and the to-be-heated room (8), wherein each phase change heat storage unit (11) consists of a plurality of phase change heat storage modules (1). An opening in the front part of each phase change heat storage module faces an interior of the passive phase change energy storage sunlight room, and the phase change heat storage modules located on the top are spliced transversely, and the vent in the top of each phase change heat storage module is connected with the ventilation port of the room.

A heating and cooling system for a building having a passive source of heat energy, a heat sink reservoir to store heat energy in, and a first heat exchange system operating a temperature of 15 degrees Celsius or less and being operatively connected to said reservoir. There is a second heat exchange system operating at a temperature of above 15 degrees Celsius which is also operatively connected to the heat sink reservoir and a thermal mass wall which is connected to the heat exchanger systems. In one aspect, the invention provides a dynamic wall having a first insulating layer on an interior surface of the wall, a thermal mass adjacent to the first insulating layer, a second insulating layer on an outside surface of the thermal mass and a heat exchanger operatively connected to said thermal mass to add or subtract heat from said thermal mass wall.

The Fresnel Snow Melter is an industrial snow removal device which uses concentrated solar energy to heat snow or ice such that it melts into water. This is achieved by focusing sunlight through a Fresnel lens onto snow using a frame and lattice structure, on a day with adequate sunlight. Depending on the sunlight, the resulting water can then be evaporated by continued use of the device.

The present invention provides a self-supporting chimney apparatus. The chimney apparatus having at least one inflatable compartment. In some embodiments, the chimney apparatus may have a plurality of toroidal compartments, with the dimensions of the toroidal compartments calculated to maximize the structural integrity of the chimney apparatus, and with the pressure in the compartments dynamically adjusted to minimize deflection under wind loading. The self-supporting chimney apparatus may be used to construct an improved solar updraft tower, with the shape of the tower, the greenhouse surrounding its base, and the ground under the greenhouse optimized together to minimize energy losses. The efficiency of the power plant based on the design is further enhanced by combining solar thermal energy generation with photovoltaic energy generation and utilizing the waste heat of the latter.

A parabolic trough reflector assembly consists of (1) a free-hanging, flexible rectangular sheet that is highly reflective of solar radiation and (2) support hardware which critically supports the reflecting sheet at two opposing edges. Methods are disclosed for providing linear dimensions and edge slopes for the reflecting sheet that are consistent with a parabolic trough having specific predetermined dimensions and a predetermined focal length. Methods are disclosed for providing uniform loading for a reflecting sheet when it is critically supported as a free-hanging element. The methods involve tapering the thickness of a sheet, applying variable-thickness coatings to a sheet of uniform thickness, or fabricating discreet thickness variations into a sheet of otherwise uniform thickness.

A method for fabricating a self-aligned via structure includes forming a tri-layer mask on an ILD layer over a lower metal wiring layer, the tri-layer mask includes first and second insulating layers and a metal layer in between the insulating layers; defining a trench pattern through the first insulating layer and metal layer, the trench pattern having a first width; defining a first via pattern in a lithographic mask over the trench pattern, the first via pattern having a second width that is larger than the first width; growing a metal capping layer on an exposed sidewall of the trench pattern to decrease the first width to a third width that defines a second via pattern; transferring the trench pattern into the ILD layer to form a trench; and transferring the second via pattern through the ILD layer and into the metal wiring layer to form a via.