Abstract: An optical switch device includes a rolling shutter or membrane attached at one of its edges to a substrate near an optical port in the substrate. The rolling shutter can assume one of two states. In a first closed state, the membrane is uncoiled onto the substrate over the port such that light directed at the port impinges on the shutter. In a second open state, the membrane is rolled up away from the port such that light directed at the port impinges on the port. In one embodiment, a mirror is formed on the membrane such that when the membrane is in the closed state over the substrate, light directed at the port is reflected by the mirror. In one configuration, the optical port includes a hole or aperture such light passed through the port without interference. The device can include a latch electrode the far end of the membrane such that when it is rolled out, it can be held in position by a latching voltage applied across the latch electrode and the substrate.

Abstract: A microelectro-mechanical device which includes a fixed electrode formed on a substrate, the fixed electrode including a transparent, high resistance layer, and a moveable electrode formed with an anisotropic stress in a predetermined direction and disposed adjacent the fixed electrode. The device includes first and second electrically conductive regions which are isolated from one another by the fixed electrode. The moveable electrode moves to cover the fixed electrode and to electrically couple to the second conductive region, thus electrically coupling the first and second conductive regions, in response to a potential being applied across the fixed and moveable electrodes. The fixed electrode is transparent to electromagnetic signals or waves and the moveable electrode impedes or allows transmission of electromagnetic signals or waves.

Abstract: A microelectro-mechanical device which includes a fixed electrode formed on a substrate, the fixed electrode including a transparent, high resistance layer, and a moveable electrode formed with an anisotropic stress in a predetermined direction and disposed adjacent the fixed electrode. The device includes first and second electrically conductive regions which are isolated from one another by the fixed electrode. The moveable electrode moves to cover the fixed electrode and to electrically couple to the second conductive region, thus electrically coupling the first and second conductive regions, in response to a potential being applied across the fixed and moveable electrodes. The fixed electrode is transparent to electromagnetic signals or waves and the moveable electrode impedes or allows transmission of electromagnetic signals or waves.

Abstract: An optical switch device includes a rolling shutter or membrane attached at one of its edges to a substrate near an optical port in the substrate. The rolling shutter can assume one of two states. In a first closed state, the membrane is uncoiled onto the substrate over the port such that light directed at the port impinges on the shutter. In a second open state, the membrane is rolled up away from the port such that light directed at the port impinges on the port. In one embodiment, a mirror is formed on the membrane such that when the membrane is in the closed state over the substrate, light directed at the port is reflected by the mirror. In one configuration, the optical port includes a hole or aperture such light passed through the port without interference. The device can include a latch electrode the far end of the membrane such that when it is rolled out, it can be held in position by a latching voltage applied across the latch electrode and the substrate.

Abstract: An optical switch device includes a rolling shutter or membrane attached at one of its edges to a substrate near an optical port in the substrate. The rolling shutter can assume one of two states. In a first closed state, the membrane is uncoiled onto the substrate over the port such that light directed at the port impinges on the shutter. In a second open state, the membrane is rolled up away from the port such that light directed at the port impinges on the port. In one embodiment, a mirror is formed on the membrane such that when the membrane is in the closed state over the substrate, light directed at the port is reflected by the mirror. In one configuration, the optical port includes a hole or aperture such light passed through the port without interference. The device can include a latch electrode the far end of the membrane such that when it is rolled out, it can be held in position by a latching voltage applied across the latch electrode and the substrate.

Abstract: A microelectro-mechanical device which includes a fixed electrode formed on a substrate, the fixed electrode including a transparent, high resistance layer, and a moveable electrode formed with an anisotropic stress in a predetermined direction and disposed adjacent the fixed electrode. The device includes first and second electrically conductive regions which are isolated from one another by the fixed electrode. The moveable electrode moves to cover the fixed electrode and to electrically couple to the second conductive region, thus electrically coupling the first and second conductive regions, in response to a potential being applied across the fixed and moveable electrodes. The fixed electrode is transparent to electromagnetic signals or waves and the moveable electrode impedes or allows transmission of electromagnetic signals or waves.

Abstract: A spatial light modulator formed of a moveable electrode which is disposed opposite a fixed electrode and is biased to roll in a preferred direction upon application of an electric field across the electrodes to produce a light valve or light shutter. In one embodiment, the moveable electrode is restrained at one end and coils about the fixed end in a preferential roll direction. The bias is achieved by inducing anisotropic stress or anisotropic stiffness.

Abstract: A spatial light modulator formed of a moveable electrode which is disposed opposite a fixed electrode and is biased to roll in a preferred direction upon application of an electric field across the electrodes to produce a light valve or light shutter. In one embodiment, the moveable electrode is restrained at one end and coils about the fixed end in a preferential roll direction. The bias is achieved by inducing anisotropic stress or anisotropic stiffness.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A permeable base transistor (30) including a metal base layer (34) embedded in a semiconductor crystal (32) to separate collector (38) and emitter (40) regions and form a Schottky barrier with each is diclosed. The metal base layer has at least one opening (37) through which the crystal semiconductor (32) joins the collector (38) and emitter (40) regions. Ohmic contacts (42,44) are made to the emitter (38) and collector (40) regions. The width of all openings (37) in the base layer (34) is of the order of the zero bias depletion width corresponding to the carrier concentration in the opening. The thickness of the metal layer (34) is in the order of 10% of this zero bias depletion width. As a result, a potential barrier in each opening limits current flow over the lower portion of the bias range.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is optionally separated so that the substrate can be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: A bistable electrostatic light valve display in which a movable electrode is disposed opposite a fixed electrode and is biased to move in a preferred direction upon application of an electric field across the electrodes to produce a light valve or light shutter. In one embodiment, the movable electrode is restrained at one end and coils about the fixed end in a preferential roll direction. The bias is achieved by inducing anisotropic stress or anisotropic stiffness. In another embodiment, the moveable electrode is restrained at both ends and is biased upwardly by anisotropic stress or stiffening.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline mateGOVERNMENT SUPPORTWork described herein was supported by the U.S. Air Force.

Abstract: The base layer of a power permeable base transistor is formed as comb structures with grating teeth of the combs extending into active regions of semiconductor material. Extended active regions are separated by inactive regions over which collector contacts extend. Large devices have digitated base layers. The comb structures are fabricated by sputtering a uniform layer of tungsten and forming a nickel mask over the tungsten by both X-ray and photolithography techniques. The tungsten exposed by the nickel mask is then etched to leave the comb structures.

Abstract: A vertical transistor device is characterized by active regions vertically separated by a narrower control region. The control region is defined by conducting layer extensions which extend into a groove within which semiconductor material is regrown during device fabrication. The device is further characterized by regions of isolating material, located horizontally adjacent to the active regions, said isolating material serving to reduce parasitic capacitance and improve thermal distribution within the device, thereby improving frequency and power performance.

Abstract: A permeable base transistor (30) including a metal base layer (34) embedded in a semiconductor crystal (32) to separate collector (38) and emitter (40) regions and form a Schottky barrier with each is disclosed. The metal base layer has at least one opening (37) through which the crystal semiconductor (32) joins the collector (38) and emitter (40) regions. Ohmic contacts (42,44) are made to the emitter (38) and collector (40) regions. The width of all openings (37) in the base layer (34) is of the order of the zero bias depletion width corresponding to the carrier concentration in the opening. The thickness of the metal layer (34) is in the order of 10% of this zero bias depletion width. As a result, a potential barrier in each opening limits current flow over the lower portion of the bias range.