Reduced surface charging in silicon-based devices
First Claim
1. A method of treating silicon-based surfaces of a micro-device structure comprising a plurality of movable surfaces, the method comprising:
- a. heating the micro-device structure in a vacuum environment by maintaining a temperature sufficient to remove residual water or moisture from the surfaces; and
b. exposing the micro-device structure to a pacifying gas environment after maintaining the temperature.
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Accused Products
Abstract
A grating light valve with reduced surface charging is disclosed. Surface charging is measured by the propensity an insulating surface to accept and transport a charge. The grating light valve of the instant invention has a plurality of spaced and movable ribbons formed from Si3N4 coupled to a substrate structure formed of SiO2. A portion of the ribbons are moved to alternate between conditions for constructive and destructive interference with an incident light source having a wavelength λ by applying the appropriate switching voltages across the portion of ribbons and the substrate structure. When charging occurs on surfaces of the grating light valve, the switching voltages required to operate the grating light valve are shifted and diminishing the performance of the grating light valve. By drying silicon-based surfaces of the grating light valve and exposing the silicon-based surfaces of the grating light valve to a Nitrogen-rich pacify gas environment, the surfaces of the grating light valve exhibit reduced charging and consistent response to applied bias voltages. In the drying step, residual water or moisture is removed from the surfaces by elevating the temperature of the grating light valve structure in a vacuum environment. Preferably, the drying is carried at temperatures of 250 degrees Celsius or greater and at vacuum pressures of 10−6 Torr or less. After the surface of the grating light valve are dried, the surfaces are exposed to the Nitrogen-rich pacifying gas environment at ambient temperature. Presumably, the Nitrogen-rich pacify gas environment blankets the silicon-based surfaces of the grating light valve with adsorbed, physisorbed, or chemi-adsorbed Nitrogen and thus reduces the propensity of those surfaces to accept water or moisture, which is believed to facilitate the charging. After the surfaces of the grating light valve are treated according to the current invention, charging of the surface remains low and stable even for several days in open air conditions.
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Citations
34 Claims
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1. A method of treating silicon-based surfaces of a micro-device structure comprising a plurality of movable surfaces, the method comprising:
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a. heating the micro-device structure in a vacuum environment by maintaining a temperature sufficient to remove residual water or moisture from the surfaces; and
b. exposing the micro-device structure to a pacifying gas environment after maintaining the temperature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 34)
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11. A method of making a MEM device comprising the steps of:
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a. removing moisture from one or more surfaces of a MEM structure by heating the one or more surfaces under a vacuum at a temperature sufficient to remove water or moisture from the one or more surfaces, wherein the heating comprises maintaining the temperature for a period of time; and
b. exposing the one or more surfaces to a pacifying gas after maintaining the temperature for the period of time. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method of making a micro-device comprising:
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a. removing moisture from surfaces of a MEM structure and a die structure by heating at a temperature of 250 Celsius or higher in a vacuum, wherein the heating comprises maintaining the temperature for a period of time;
b. exposing the MEM structure and the die structure to a pacifying gas environment after the heating; and
c. sealing the die such that the MEM structure is positioned within the die structure. - View Dependent Claims (29, 30, 31, 32, 33)
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Specification