The current invention provides for encapsulated release structures, intermediates thereof and methods for their fabrication. The multi-layer structure has a capping layer, that preferably comprises silicon oxide and/or silicon nitride, and which is formed over an etch resistant substrate. A patterned device layer, preferably comprising silicon nitride, is embedded in a sacrificial material, preferably comprising polysilicon, and is disposed between the etch resistant substrate and the capping layer. Access trenches or holes are formed in to capping layer and the sacrificial material are selectively etched through the access trenches, such that portions of the device layer are release from sacrificial material. The etchant preferably comprises a noble gas fluoride NGF 2x (wherein Ng=Xe, Kr or Ar: and where x=1, 2 or 3). After etching that sacrificial material, the access trenches are sealed to encapsulate released portions the device layer between the etch resistant substrate and the capping layer. The current invention is particularly useful for fabricating MEMS devices, multiple cavity devices and devices with multiple release features.

Microelectronic mechanical system and methods

A method and apparatus of hermetically passivating a semiconductor device includes sealing a lid directly onto a semiconductor substrate. An active device is formed on the surface of the substrate and is surrounded by a substantially planar lid sealing region, which in turn is surrounded by bonding pads. A first layer of solderable material is formed on the lid sealing region. A lid is provided which has a second layer of solderable material in a configuration corresponding to the first layer. A solder is provided between the first layer and second layer of solderable materials. In the preferred embodiment, the solder is formed over the second layer. Heat is provided to hermetically join the lid to the semiconductor device without requiring a conventional package. Preferably the first and second layers are sandwiches of conventionally known solderable materials which can be processed using conventional semiconductor techniques. An angle between the lid and the semiconductor device can be controlled by adjusting relative widths of one or both the layers of solderable materials.

Method of and apparatus for sealing an hermetic lid to a semiconductor die

An adjustable diffractive light modulator is used to equalize the power level of wavelength multiplexed signals in wavelength division multiplexing applications. An optical channel transmits a multi-wavelength input signal through a wavelength demultiplexer. The input signal comprises a plurality of component signals defined according to a plurality of wavelengths. The de-multiplexer spatially separates the multi-wavelength input signal into its respective plurality of component signals, which are transmitted through a plurality of optical channels onto a plurality of controllable diffractive light modulators. The diffractive light modulators are advantageously comprised of grating light valves. Component signals are reflected off their respective diffractive light modulators and collected in a plurality of optical channels for re-transmission into a wavelength multiplexer. The reflected signals are combined through a multiplexing process and transmitted as an output beam. Control of the diffractive light modulator is achieved by sensors measuring the power level of signals passing through the plurality of optical channels. The measured power levels of light are converted to digital values which are input into an electronic controller for processing. Control output signals from the controller are used to independently control individual pixels within the diffractive light modulator to equalize the reflected light signals.

Method and apparatus for dynamic equalization in wavelength division multiplexing

A method and apparatus for reducing speckle uses polarization averaging. A polarizing beam splitter divides a first polarized laser output into a second polarized laser output and a third polarized laser output. A plurality of mirrors creates an optical path difference between the second and third polarized laser outputs. The optical path difference is at least about a coherence length for the first polarized laser output. The second and third polarized laser outputs are combined into a fourth laser output, which illuminates an depolarizing screen. If a human eye or an optical system having a intensity detector views the depolarizing screen, the eye or the intensity detector will detect reduced speckle, which results from uncorrelated speckle patterns created by the second polarized laser output and the third polarized laser output.

Method and apparatus for reducing laser speckle using polarization averaging

A device comprising movable micro-structures configured to contact a substrate is disclosed. The substrate has a metal-insulator-metal construction with an upper metal layer and an insulator being patterned to provide substrate contact regions to a lower metal layer. The micro-structures have metal under layers for providing ribbon contact regions and non-contact regions. In use, a bias voltage is applied across the micro-structures and the top metal layer of the substrate causing the micro-structures and the substrate to contact through the contact regions. During contact, the contact regions are maintained at a potential that is substantially less than the applied bias voltage, thereby reducing the formation of asperities and/or sticking between contacting parts. The micro-structures are preferably ribbon structures in an optical MEM device configured to modulate light.

Reduced formation of asperities in contact micro-structures

A retroreflecting modulator including a lens, a light guide, a light modulator, and a reflective surface. Incident light falls on the lens, where it is focused as a spot on a focal surface. The light guide transmits the focused light to the light modulator, where it is modulated and reflected back, via the reflective surface and light guide, to the lens. The lens emits the modulated light in the opposite direction as the incident light. The preferred light-receiving and focusing device is a specialty sphere lens, the preferred light guide is a fiber optic plate, and the preferred light modulator is a liquid crystal modulator. The retroreflecting modulator may be spatially-unresolvable, where a single signal modulates the light, or spatially-resolvable, where the modulation signal depends upon the direction of the incident light.

Yong-Sheng Chao

Papers

Integrated optical retroreflecting modulator