Microwave integrated circuit passive element structure and method for reducing signal propagation losses
First Claim
1. A microwave integrated circuit formed on a silicon substrate and having a passive element for carrying a signal, said passive element comprising:
- an insulating layer overlying said substrate and having a first opening; and
a metal layer overlying said insulating layer, wherein at least a portion of said metal layer contacts a depletion region in said substrate through said first opening.
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0 Petitions
Accused Products
Abstract
A passive element structure and method for a microwave integrated circuit reduces signal propagation losses. In one approach, a passive element (10) has an insulating layer (12) overlying a silicon substrate (14). A metal layer (16) comprising a signal line (18) and a groundplane (20) is disposed overlying the insulating layer (12), and at least a portion of the metal layer (16) contacts the substrate (14) through at least one opening (22, 24) in the insulating layer (12). The silicon substrate (14) has a resistivity greater than 2,000 ohm-cm, and the passive element (10) preferably carries signals having frequencies greater than 500 MHz. Signal losses in the passive element (10) are minimized because the charge density at the surface (15) of the substrate (14) underlying the metal layer (16) is significantly reduced. In one example, the passive element (10) is a coplanar waveguide transmission line.
229 Citations
25 Claims
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1. A microwave integrated circuit formed on a silicon substrate and having a passive element for carrying a signal, said passive element comprising:
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an insulating layer overlying said substrate and having a first opening; and a metal layer overlying said insulating layer, wherein at least a portion of said metal layer contacts a depletion region in said substrate through said first opening. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A microwave integrated circuit formed on a silicon substrate having a resistivity greater than 2,000 ohm-cm and including a passive element for carrying a signal, said signal having a frequency greater than 500 MHz, said passive element comprising:
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an insulating layer overlying said substrate and having an opening; and a metal layer overlying said insulating layer, wherein at least a portion of said metal layer contacts a depletion region in said substrate through said opening. - View Dependent Claims (11)
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12. A microwave integrated circuit formed on a silicon substrate and having a passive element for carrying a signal, said passive element comprising:
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a first metal layer formed on a first depletion region in said substrate; an insulating layer overlying said first metal layer and having an opening; and a second metal layer overlying said first metal layer, wherein at least a portion of said second metal layer contacts a second depletion region in said substrate through said opening. - View Dependent Claims (13)
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14. In a microwave integrated circuit formed on a silicon substrate, a metal-insulator-metal capacitor comprising:
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a first metal layer disposed on a depletion region in said substrate; an insulating layer disposed on said first metal layer; and a second metal layer disposed on said insulating layer. - View Dependent Claims (15, 16)
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17. A method for reducing propagation losses of a signal carried in a microwave integrated circuit formed on a substrate having a surface, wherein said signal has a frequency greater than 500 MHz, comprising the steps of:
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providing a passive element for carrying said signal, said passive element comprising an insulating layer disposed on said surface of said substrate, and a metal layer disposed on said insulating layer; and applying a voltage across said metal layer and said surface of said substrate having a magnitude substantially equal to a flat band voltage corresponding to said substrate, said insulating layer, and said metal layer. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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25. A method for reducing propagation losses of a signal carried in a microwave integrated circuit formed on a silicon substrate having a resistivity of greater than 2,000 ohm-cm and having a surface, wherein said signal has a frequency greater than 500 MHz, comprising the steps of:
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providing a passive element for carrying said signal, said passive element comprising an insulating layer disposed on said surface of said substrate, and a metal layer disposed on said insulating layer; and applying a voltage across said insulating layer and said surface of said substrate having a magnitude substantially equal to a flat band voltage corresponding to said substrate, said insulating layer, and said metal layer.
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Specification