Abstract: The invention relates to an optical, integrated alignment device for accurately aligning and efficiently coupling energy between in-plane optical devices. A semiconductor substrate is etched to include a groove for an optical fiber and a lens for passing an optical signal from a cut fiber to a photodetector. The etched semiconductor substrate may be used to pass an optical signal from a surface light emitting device to a cut fiber. The end of the optical fiber is cut at a slant that redirects an optical signal from the fiber through the lens or vice-versa. The lens focuses the optical signal onto a target.

Abstract: Methods and apparatus for efficiently identifying, selecting and aligning cells within a circuit design are disclosed. Preferably, a net or group-of nets is first identified by the circuit designer. Then, selected cells that are connected to the selected net or group of nets are identified by the placement tool. A qualification or filter may be provided for filtering which cells are selected. For example, the filter may allow only those cells that are source cells, destination cells, placed cells, unplaced cells, etc., or any combination thereof to be selected. The selected cells may be aligned in a direction of an alignment axis, if desired.

Abstract: Methods and apparatus for efficiently identifying, selecting and aligning cells within a circuit design are disclosed. Preferably, a net or group of nets is first identified by the circuit designer. Then, selected cells that are connected to the selected net or group of nets are identified by the placement tool. A qualification or filter may be provided for filtering which cells are selected. For example, the filter may allow only those cells that are source cells, destination cells, placed cells, unplaced cells, etc., or any combination thereof to be selected. The selected cells may be aligned in a direction of an alignment axis, if desired.

Abstract: The invention relates to an optical, integrated alignment device for accurately aligning and efficiently coupling energy between in-plane optical devices. A semiconductor substrate is etched to include a groove for an optical fiber and a lens for passing an optical signal from a cut fiber to a photodetector. The etched semiconductor substrate may be used to pass an optical signal from a surface light emitting device to a cut fiber. The end of the optical fiber is cut at a slant that redirects an optical signal from the fiber through the lens or vice-versa. The lens focuses the optical signal onto a target.

Abstract: A resonant photodetector assembly (10) which uses multiple reflections of light within a photodetector (20) to convert input light into an electrical signal. The photodetector (20) includes a combination of generally planar semiconductor layers including a photodetector active layer (36) where light is converted into an electrical output. The photodetector (20) further includes a first outer electrical contact layer (34) and a second outer electrical contact layer (42). A waveguide (22) is positioned on the photodetector (20) and has a waveguide active layer (26) positioned between a pair of waveguide cladding layers (24, 28), a first end (30) for receiving input light and a second end (50) for reflecting the light. A reflector (32) is positioned on the second end (50) of the waveguide (22) at an angle relative to a line parallel to the substrate (14), where the reflector (32) reflects the light received by the first end (30) of the waveguide active layer (26) towards the photodetector (20).

Abstract: A low dark current photodiode and a method for reducing dark current in a photodiode. A preferred embodiment of the present invention provides a photodiode comprising a barrier layer. The barrier layer comprises a barrier layer material having a wider band-gap than the band-gap of the absorption layer material of the photodiode. The barrier layer comprises sublayers, which are doped to position the high-electric field region at the pn junction of the photodiode in the barrier layer. The method for reducing dark current in a photodiode comprises building a barrier layer into the structure of a photodiode. Building the barrier layer comprises building a layer of semiconductor material with wider band-gap than the i-layer material. Building the barrier layer preferably further comprises doping the barrier layer material to position the high-energy region at the pn junction of the photodiode in the barrier layer, thus reducing dark current.

Abstract: A low dark current photodiode and a method for reducing dark current in a photodiode. A preferred embodiment of the present invention provides a photodiode comprising a barrier layer. The barrier layer comprises a barrier layer material having a wider band-gap than the band-gap of the absorption layer material of the photodiode. The barrier layer comprises sublayers, which are doped to position the high-electric field region at the pn junction of the photodiode in the barrier layer. The method for reducing dark current in a photodiode comprises building a barrier layer into the structure of a photodiode. Building the barrier layer comprises building a layer of semiconductor material with wider band-gap than the i-layer material. Building the barrier layer preferably further comprises doping the barrier layer material to position the high-energy region at the pn junction of the photodiode in the barrier layer, thus reducing dark current.

Abstract: Method and apparatus for efficiently traversing and placing cells in a circuit design database are disclosed. In one illustrative embodiment, one or more leaf cells are identified as base objects. The base objects are placed and aligned along a selected dominate axis. Once the base objects are identified, an input port is identified by the circuit designer. In many cases, selected base objects will have at least one common input port name, such as “A”. By selecting a common input port name, the corresponding input port for each of the selected base objects is identified. Once identified, the source leaf cells that have an output port that is coupled to the identified input ports can be identified, placed and aligned as desired.

Abstract: A solar cell comprises a superstrate formed from a material that is transparent to light, a first layer formed of delta doped silicon, a plurality of layers formed from semiconductor materials, each characterized by multi-quantum wells and multiple band gaps, a first semiconductor layer having a band gap energy state that is the smallest, the last semiconductor layer having-a band gap that is the largest, and the intermediate semiconductor layers having band gaps transitioning from the smallest to the largest, a second layer overlying the semiconductor layers and formed of delta doped silicon, an n-cap layer formed on the second delta doped layer, and a metal layer formed on the n-cap layer and serving to reflect light into the semiconductor.

Abstract: An angle cavity resonant photodetector assembly (8), which uses multiple reflections of light within a photodetector (14) to convert input light into an electrical signal. The photodetector (14) has a combination of generally planar semiconductor layers including semiconductor active layers (20) where light is converted into an electrical output. The photodetector (14) is positioned relative to a waveguide (10), where the waveguide (10) has a waveguide active layer (22) located between a pair of waveguide cladding layers (24) and (26) and includes a first end (28) for receiving light and a second end (30) for transmitting the light to the photodetector (14). The photodetector (14) has a first reflector (12) and second reflector (16) that provides for multiple reflections across the semiconductor active layers (20).

Abstract: A resonant photodetector assembly (10) which uses multiple reflections of light within a photodetector (20) to convert input light into an electrical signal. The photodetector (20) includes a combination of generally planar semiconductor layers including a photodetector active layer (36) where light is converted into an electrical output. The photodetector (20) further includes a first outer electrical contact layer (34) and a second outer electrical contact layer (42). A waveguide (22) is positioned on the photodetector (20) and has a waveguide active layer (26) positioned between a pair of waveguide cladding layers (24, 28), a first end (30) for receiving input light and a second end (50) for reflecting the light. A reflector (32) is positioned on the second end (50) of the waveguide (22) at an angle relative to a line parallel to the substrate (14), where the reflector (32) reflects the light received by the first end (30) of the waveguide active layer (26) towards the photodetector (20).

Abstract: A resonant photodetector assembly (10) which uses multiple reflections of light within a photodetector (20) to convert input light into an electrical signal. The photodetector (20) includes a combination of generally planar semiconductor layers including a photodetector active layer (36) where light is converted into an electrical output. The photodetector (20) further includes a first outer electrical contact layer (34) and a second outer electrical contact layer (42). A waveguide (22) is positioned on the photodetector (20) and has a waveguide active layer (26) positioned between a pair of waveguide cladding layers (24, 28), a first end (30) for receiving input light and a second end (50) for reflecting the light. A reflector (32) is positioned on the second end (50) of the waveguide (22) at an angle relative to a line parallel to the substrate (14), where the reflector (32) reflects the light received by the first end (30) of the waveguide active layer (26) towards the photodetector (20).

Abstract: A method for fabricating a monolithic micro-optical component. The construction of the micro-optical components is accomplished by using standard semiconductor fabrication techniques. The method comprises the steps of depositing an etch stop layer (44) onto a semiconductor substrate (42); depositing an optical component layer (46) onto the etch stop layer (44); coating the entire surface of the optical component layer with a photoresist material; applying a photoresist mask (50) to the photoresist material on the optical component layer (46); selectively etching away the optical component layer (46) to form at least one optical column (52); forming a pedestal (54) for each of the optical columns (52) by selectively etching away the etch stop layer (44); and finally polishing each of the optical columns (52), thereby forming monolithic optical components (56).

Abstract: An angle cavity resonant photodetector assembly (8), which uses multiple reflections of light within a photodetector (14) to convert input light into an electrical signal. The photodetector (14) has a combination of generally planar semiconductor layers including semiconductor active layers (20) where light is converted into an electrical output. The photodetector (14) is positioned relative to a waveguide (10), where the waveguide (10) has a waveguide active layer (22) located between a pair of waveguide cladding layers (24) and (26) and includes a first end (28) for receiving light and a second end (30) for transmitting the light to the photodetector (14). The photodetector (14) has a first reflector (12) and second reflector (16) that provides for multiple reflections across the semiconductor active layers (20).

Abstract: The invention relates to an optical integrated circuit microbench system for accurately aligning optical fiber and waveguides to efficiently couple energy between optical devices. This is accomplished by using the anisotropic etch characteristics of III-V semiconductor materials in two orthogonal directions. One etch direction serves to provide a channel for precise fiber-positioning; the other direction, which is orthogonal provides a reflecting surface for directing the optical energy onto optical devices.

Abstract: A micromirror device (10) is provided with a rotatable optical component (22) for use in a digital image processing application. The micromirror device (10) includes a semiconductor wafer (12), having a recess (14) formed therein, and a platform (20) with the optical component (22) deposited thereon that is movably coupled to the side surface of the recess (14). A first magnetic field source (24) is disposed around the periphery of the optical component (22) on the platform (20) and a second magnetic field source (26) is disposed proximate to this first magnetic field source (24), such that these magnetic field sources are selectively activatable to generate an electromagnetic field for rotating the platform (20). More specifically, the second magnetic field source (26) is disposed on the angular side surfaces of the recess (14) or adjacent to the recess (14) on a top surface of the wafer (12).

Abstract: An interconnected apparatus for producing a low loss, reproducible electrical interconnection between a semiconductor device and a substrate includes a rod and rod receptor. The rod, generally cylindrically shaped, is attached to the semiconductor device and includes an outer circumferential wall which comes into contact with the rod receptor during a bonding process. A lip portion is formed on one end of the rod receptor for interlocking engagement with the rod. The rod receptor is plated on the substrate and includes a generally circularly shaped body which forms a centrally disposed well for receiving the rod. A lip portion is formed on one end or mouth of the rod receptor for interlocking engagement with the rod. When the rod and corresponding receptor are aligned and brought together, the rod deforms and interlocks with its corresponding rod receptor. A thermo-compression bonding process is utilized to bond the rod to the rod receptor, thereby producing a strong interlocking bond.

Abstract: An interconnected apparatus for producing a low loss, reproducible electrical interconnection between a semiconductor device and a substrate includes a rod and rod receptor. The rod, generally cylindrically shaped, is attached to the semiconductor device and includes an outer circumferential wall which comes into contact with the rod receptor during a bonding process. A lip portion is formed on one end of the rod receptor for interlocking engagement with the rod. The rod receptor is plated on the substrate and includes a generally circularly shaped body which forms a centrally disposed well for receiving the rod. A lip portion is formed on one end or mouth of the rod receptor for interlocking engagement with the rod. When the rod and corresponding receptor are aligned and brought together, the rod deforms and interlocks with its corresponding rod receptor. A thermo-compression bonding process is utilized to bond the rod to the rod receptor, thereby producing a strong interlocking bond.

Abstract: The invention relates to an optical integrated alignment device for accurately aligning optical fiber and waveguides to efficiently couple energy between optical devices. This is accomplished by using the anisotropic etch characteristics of III-V semiconductor materials. One orthogonal etch direction serves to provide a channel for precise fiber-positioning; the other direction, which is also orthogonal provides a reflecting surface for directing the optical energy between optical devices; and finally, a non-selective etch to form a micro-optical lens to focus optical energy to an optical device.

Abstract: A method for fabricating a monolithic micro-optical component. The construction of the micro-optical components is accomplished by using standard semiconductor fabrication techniques. The method comprises the steps of depositing an etch stop layer (44) onto a semiconductor substrate (42); depositing an optical component layer (46) onto the etch stop layer (44); coating the entire surface of the optical component layer with a photoresist material; applying a photoresist mask (50) to the photoresist material on the optical component layer (46); selectively etching away the optical component layer (46) to form at least one optical column (52); forming a pedestal (54) for each of the optical columns (52) by selectively etching away the etch stop layer (44); and finally polishing each of the optical columns (52), thereby forming monolithic optical components (56).