MEMS RF switch integrated process
First Claim
1. The partially fabricated low temperature organic photoresist materials-achieved MEMS switch comprising:
- a plurality of metallic switch elements held captive in melded multiple thin reflow rounding shaped sacrificial layers of said organic photoresist coating materials on an insulting substrate member;
a dielectric shell enclosure surrounding said metallic switch elements and said melded multiple thin reflow rounding shaped-sacrificial layers on said insulating substrate member;
a radio frequency transmission line having lengthwise portions extending outside of and inside of said dielectric shell enclosure and including electrical connection with selected of said metallic switch elements inside of said dielectric shell enclosure;
a plurality of dielectric shell enclosure-traversing aperture paths communicating from outside to inside of said dielectric shell enclosure; and
a wet photoresist consuming reactant material received within said dielectric shell enclosure through said plurality of dielectric shell enclosure-traversing aperture paths communicating from outside to inside thereof to release said metallic switch elements from said captivity.
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Accused Products
Abstract
A capacitance coupled, transmission line-fed, radio frequency MEMS switch and its fabrication process using photoresist and other low temperature processing steps are described. The achieved switch is disposed in a low cost dielectric housing free of undesired electrical effects on the switch and on the transmission line(s) coupling the switch to an electrical circuit. The dielectric housing is provided with an array of sealable apertures useful for wet, but hydrofluoric acid-free, removal of switch fabrication employed materials and also useful during processing for controlling the operating atmosphere surrounding the switch—e.g. at a pressure above the high vacuum level for enhanced switch damping during operation. Alternative arrangements for sealing an array of dielectric housing apertures are included. Processing details including plan and profile drawing views, specific equipment and materials identifications, temperatures and times are also disclosed.
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Citations
19 Claims
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1. The partially fabricated low temperature organic photoresist materials-achieved MEMS switch comprising:
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a plurality of metallic switch elements held captive in melded multiple thin reflow rounding shaped sacrificial layers of said organic photoresist coating materials on an insulting substrate member; a dielectric shell enclosure surrounding said metallic switch elements and said melded multiple thin reflow rounding shaped-sacrificial layers on said insulating substrate member; a radio frequency transmission line having lengthwise portions extending outside of and inside of said dielectric shell enclosure and including electrical connection with selected of said metallic switch elements inside of said dielectric shell enclosure; a plurality of dielectric shell enclosure-traversing aperture paths communicating from outside to inside of said dielectric shell enclosure; and a wet photoresist consuming reactant material received within said dielectric shell enclosure through said plurality of dielectric shell enclosure-traversing aperture paths communicating from outside to inside thereof to release said metallic switch elements from said captivity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 11)
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8. A wafer of oxide and nitride materials inclusive, low temperature photoresist processing based, hermetically sealable, transmission line fed, capacitance coupled, radio frequeny MEMS switch die comprising the combination of:
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a plurality of static metallic elements of said transmission line and switch received in each die of in insulating substrate wafer member; an electrical insulating switch-closed capacitance determining coating over selected of said operationally static metallic elements of said transmission line and switch in each said die; said switch-closed capacitance determining coating consisting of one of aluminum oxide, silicon nitride and silicon oxide materials; a first fused multiple layers sacrificial photoresist coating covering selected portions of said insulating substrate member and electrical insulating coated operationally static metallic elements in each said die; a shaped thin metal film movable switch element received on a top surface of said first sacrificial photoresist layer coating in each said die; an adhesion promoting thin layer of different metal covering an external surface portion of said thin metal film movable switch element; a second sacrificial photoresist layer coating covering selected portions of said shaped thin metal film movable switch element, said first sacrificial photoresist layer coating and said insulating substrate member and electrical insulation coated operationally static metallic elements in each said die; a silicon nitride shell member laterally surrounding and covering said second sacrificial photoresist layer coating on said insulating substrate member in each said die; a plurality of apertures received in said silicon nitride shell member and communicating from within to external of said dielectric shell member in each said die; an adhesion promoting thin layer of alumina covering an external surface portion of said silicon nitride shell member in each said die; an aperture closing film of silicon dioxide covering said shell member adhesion promoting alumina layer in each said die; and a sacrificial photoresist layer-consuming liquid reagent communicating via said silicon nitride shell member plurality of apertures from outside to inside of said shell member in each said die. - View Dependent Claims (9, 10)
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12. A metallic movable member MEMS switch comprising.
a fixed position first metallic switch element received on an insulating switch substrate member; -
a movement configured second metallic switch element connected with said insulating switch substrate member and covering said fixed position first metallic switch element; a first dielectric material shell enclosure surrounding said metallic switch elements and attached to said insulating switch substrate member; said dielectric material shell enclosure including a plurality of dispersed shell traversing apertures communicating between interior and exterior regions thereof; an aperture-sealing second dielectric material coating, differing from said first dielectric material, and covering said dielectric shell and said plurality of dispersed shell traversing apertures; and a thin layer of adhesion promoting material lying intermediate an exterior surface of said first dielectric material shell enclosure and an interior surface of said aperture-sealing second dielectric material coating. - View Dependent Claims (13, 14)
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15. The partially fabricated sacrificial organic photoresist material-achieved metallic movable member MEMS switch comprising:
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a fixed position first metallic switch element held captive on an insulating switch substrate member; a reflow tapered multiple layered first coating of sacrificial organic photoresist material overlying said first metallic switch element; a second metallic switch element connected with said insulating switch substrate member and received on said reflow tapered multiple layered first coating of sacrificial organic photoresist material; said reflow tapered multiple layered first coating of sacrificial organic photoresist material lying intermediate said fixed position first metallic switch element and said second metallic switch element ad holding said switch elements in fixed relative position captivity; a reflow tapered multiple layered second coating of sacrificial organic photoresist material overlying said second metallic switch element and said multiple layered first coating of sacrificial organic photoresist material; a dielectric shell enclosure surrounding said metallic switch elements and said first and second multiple layered coatings of sacrificial organic photoresist material and also connecting with said insulating switch substrate member; a thin layer of adhesion promoting material lying intermediate connecting portions of said dielectric shell enclosure and said insulating switch substrate member. - View Dependent Claims (16)
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17. The partially fabricated low temperature sacrificial organic photoresist materials-achieved metallic movable member MEMS switch comprising:
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a radio frequency transmission line connected fixed position metallic switch element received on a switch insulating substrate member; a movement configured metallic switch element overlying said fixe position metallic switch element on said insulating substrate member; a melded sub layers first coating of said sacrificial photoresist material lying intermediate said fixed position metallic switch element and said movable metallic switch element; a melded sub layers second coating of said sacrificial photoresist material overlying said movement cold metallic switch element; a dielectric shell enclosure surrounding said metallic switch elements on said insulating substrate member, a radio frequency transmission line having lengthwise portions extending outside of and inside of said dielectric shell enclosure and including electrical connection with selected of said metallic switch elements inside of said dielectric shell enclosure; a plurality of dielectric shell enclosure-traversing aperture paths communicating from outside to inside of said dielectric shell enclosure; and a wet photoresist consuming reactant material received within said dielectric shell enclosure through said plurality of dielectric shell enclosure-traversing aperture paths communicating from outside to inside thereof to release said metallic switch elements from said melded multiple sub layers photoresist coatings. - View Dependent Claims (18, 19)
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Specification