Integrated driver electronics for MEMS device using high voltage thin film transistors
First Claim
1. An apparatus comprising:
- a substrate;
a driver circuit including a plurality of high-voltage thin-film transistors (HVTFTs) formed on the substrate, each HVTFT including a controlling gate electrode, a source electrode, and a drain electrodearranged such that the source electrode is separated from the controlling gate electrode by a first distance, and the drain electrode is spaced from the controlling gate electrode such that a shortest distance between any part of the drain electrode and the controlling gate electrode is significantly larger than the first distance, and such that a first break down voltage between the drain electrode and the source electrode is larger than a second break down voltage between the controlling gate electrode and the source electrode; and
a plurality of actuated MEMS devices formed on the substrate, wherein each of the actuated MEMS device is connected to the drain electrode of an associated HVTFT of the plurality of HVTFTs.
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Accused Products
Abstract
An apparatus integrating electrostatically actuated MEMS devices and high voltage driver (actuator) electronics on a single substrate, where the driver electronics utilize offset-gate high voltage thin-film transistors (HVTFTs) that facilitate the transmission of high actuating voltages using relatively low control voltages, thereby facilitating the formation of large arrays of electrostatically-actuated MEMS devices. The driver circuit is arranged such that the high actuating voltage is applied to an actuating electrode of the actuated MEMS device and drain electrode of the HVTFT when the HVTFT is turned off, thereby minimizing dielectric breakdown. When the HVTFT is turned on in response to the relatively low control voltage, the high actuating voltage is discharged to ground from the drain (offset) electrode to the source (not offset) electrode.
66 Citations
20 Claims
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1. An apparatus comprising:
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a substrate;
a driver circuit including a plurality of high-voltage thin-film transistors (HVTFTs) formed on the substrate, each HVTFT including a controlling gate electrode, a source electrode, and a drain electrodearranged such that the source electrode is separated from the controlling gate electrode by a first distance, and the drain electrode is spaced from the controlling gate electrode such that a shortest distance between any part of the drain electrode and the controlling gate electrode is significantly larger than the first distance, and such that a first break down voltage between the drain electrode and the source electrode is larger than a second break down voltage between the controlling gate electrode and the source electrode; and
a plurality of actuated MEMS devices formed on the substrate, wherein each of the actuated MEMS device is connected to the drain electrode of an associated HVTFT of the plurality of HVTFTs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus comprising:
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a substrate;
an actuated MEMS device including;
an actuating electrode formed over the substrate; and
a MEMS structure including a movable portion located adjacent to the actuating electrode, wherein the MEMS structure is formed such that the movable portion is actuated into a first position relative to the substrate when the electrode generates a first electrostatic field, and the movable portion is actuated into a second position relative to the substrate when the electrode generates a second electrostatic field; and
an actuating circuit mounted on the substrate for selectively applying one of a first actuating voltage to the actuated MEMS device, whereby the actuating electrode generates the first electrostatic field, and a second actuating voltage to the actuating electrode, whereby the actuating electrode generates the second electrostatic field, wherein the actuating circuit includes a high-voltage thin-film transistor (HVTFT) formed on the substrate, the HVTFT including a controlling gate electrode, a source electrode, and a drain electrode arranged such that a portion of the source electrode is separated from the controlling gate electrode by a first distance, and the drain electrode is arranged in an offset position such that the drain electrode is laterally offset from the controlling gate electrode by an offset distance that is substantially greater than the first distance. - View Dependent Claims (11, 12, 13, 14)
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15. An apparatus comprising:
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a control logic circuit for generating control signals having a maximum logic voltage;
a low voltage source;
a high voltage source for providing an actuating voltage that is substantially higher than the maximum logic voltage;
a first high voltage thin-film transistor (HVTFT) including a controlling gate electrode coupled to the control circuit, a source electrode positioned relatively close to the controlling gate electrode and coupled to the low voltage source, and a drain electrode positioned relatively far from the controlling gate electrode and coupled to the high voltage source; and
an actuated MEMS device connected to the drain electrode of the first HVTFT. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification