US 8,044,442 B2Granted

Metal-insulator-metal (MIM) switching devices

AssigneeThe Regents of the University of California

InventorsHei Kam, Tsu-Jae King

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Abstract

A gated nano-electro-mechanical (NEM) switch employing metal-insulator-metal (MIM) technology and related devices and methods which can facilitate implementation of low-power, radiation-hardened, high-temperature electronic devices and circuits. In one example embodiment a gate electrode is configured as a cantilever beam whose free end is coupled to a MIM stack. The stack moves into bridging contact across a source and drain region when the applied gate voltage generates a sufficient electrostatic force to overcome the mechanical biasing of the cantilever beam. A second set of contacts can be added on the cantilever beam to form a complementary switching structure, or to a separate cantilever beam. The switching can be configured as non-volatile in response to stiction forces. NEM circuits provide a number of advantages within a variety of circuit types, including but not limited to: logic, memory, sleep circuits, pass circuits, and so forth.

Claims19

Dependent claims

An apparatus, comprising:

(a) a cantilever beam configured as a gate electrode;
(b) a gate stack coupled to said cantilever beam having layers comprising:
(i) a first and second channel layer;
and
(ii) a dielectric configured for electrically isolating said first and second channel layers from said cantilever beam;
(c) a first and second pair of output electrodes, each pair of output electrodes comprising a source electrode and drain electrode;
(d) wherein said gate stack is configured for mechanical translation of said first channel layer, under electrostatic force responsive to the application of a first gate voltage, into contact with said first pair of output electrodes, while said second channel layer is held separated from said second pair of output electrodes;
(e) wherein said gate stack is configured for mechanical translation of said second channel layer, under electrostatic force responsive to the application of a second gate voltage, into contact with said second pair of output electrodes, while said first channel is held separated from said first pair of output electrodes;
and
(f) wherein said apparatus is configured for complementary switching in which either said first pair or said second pair of output electrodes is bridged by said first or said second channel layer;
(g) wherein a stiction force arises in response to establishing contacts with said first and second channel layers, said stiction force exceeding the mechanical biasing force supplied by said means for biasing;
and
(h) wherein disconnection of said contact requires application of an opposing electrostatic force which overcomes said stiction force;
(i) a first transistor coupled between a bit-line and said gate electrode in common with said first and second channel layers, with a gate of said first transistor coupled to a write word-line;
and
(j) a second transistor coupled between a bit-line and the interconnection of drain electrodes within said first and second pair of output electrodes, with a gate of said second transistor coupled to a read word-line;
(k) wherein said transistors are configured for storing data from the bit-line in response to activating the write word line, or reading back data onto the bit-line in response to activating the read word line.

14 more elements

An apparatus, comprising:

(a) a gate electrode;
(b) means for mechanical biasing, which is coupled to said gate electrode;
(c) a gate stack coupled to said means for mechanical biasing having layers comprising:
(i) a first and second channel layer;
and
(ii) a dielectric configured for electrically isolating said first and second channel layers from said means for mechanical biasing;
(d) a first and second pair of output electrodes, each pair of output electrodes comprising a source electrode and drain electrode;
(e) wherein said gate stack is configured for mechanical translation of said first channel layer, under electrostatic force responsive to the application of a first gate voltage, into contact with said first pair of output electrodes, while said second channel layer is held separated from said second pair of output electrodes;
(f) wherein said gate stack is configured for mechanical translation of said second channel layer, under electrostatic force responsive to the application of a second gate voltage, into contact with said second pair of output electrodes, while said first channel is held separated from said first pair of output electrodes;
(g) wherein said apparatus is configured for complementary switching in which either said first pair or said second pair of output electrodes is bridged by said first or said second channel layer;
(h) wherein a stiction force arises in response to establishing contacts with said first and second channel layers, said stiction force exceeding the mechanical biasing force supplied by said means for biasing;
(i) wherein disconnection of said contact requires application of an opposing electrostatic force which overcomes said stiction force;
(j) a first transistor coupled between a bit-line and said gate electrode in common with said first and second channel layers, with a gate of said first transistor coupled to a write word-line;
and
(k) a second transistor coupled between a bit-line and the interconnection of drain electrodes within said first and second pair of output electrodes, with a gate of said second transistor coupled to a read word-line;
(l) wherein said transistors are configured for storing data from the bit-line in response to activating the write word line, or reading back data onto the bit-line in response to activating the read word line.

13 more elements

An apparatus for supplying power to a circuit block, comprising:

(a) a first movable gate, comprising:
(i) a first means for mechanical biasing configured as a first gate electrode;
(ii) a first channel layer of P material;
and
(iii) a dielectric configured for electrically isolating said first channel layer from said first means for mechanical biasing;
(b) a second movable gate, comprising:
(i) a second means for mechanical biasing configured as a second gate electrode;
(ii) a second channel layer of N material;
and
(iii) a dielectric configured for electrically isolating said second channel layer from said second means for mechanical biasing;
(c) wherein said first gate electrode is configured to receive a first control signal, and said second gate electrode is configured to receive an inverse of said first control signal;
(d) a first pair of output electrodes comprising a source electrode of P material coupled to a VDD supply voltage, and a drain electrode of P material configured for supplying VDD power to a circuit block;
(e) a second pair of output electrodes comprising a source electrode of N material coupled to a VSS supply voltage, and drain electrode of an N material configured for supplying VSS power to the circuit block;
and
(f) wherein said first and second channel layers are configured for mechanical translation into contact with said first and second pair of output electrodes, respectively, in response to electrostatic forces arising from said first control signal being switched into a first state;
whereby the apparatus is configured to supply power to the circuit block in response to said first state of said control signal, and to electrically isolate the circuit block in response to said second state of said control signal.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/261,865Filed 30 Oct 2008 · continuation
Priority: 1 May 2006
Published: US 2009/0128221 A121 May 2009
Granted: 25 Oct 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G11C 23/00
Digital stores characterised by movement of mechanical parts to effect storage
B82Y 10/00
Nanotechnology for information processing, storage or transmission
H01H 1/0094
Contacts: switches making use of nanoelectromechanical systems [NEMS]
G11C
Static stores