Single capacitor functioning as an rc filter
AssigneeTexas Instruments Incorporated
InventorsLin LI, Xiaoming LI, Xianhui DONG, Weibing JING
Life of this patent
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Abstract
An IC includes an RC filter, a doped layer under a first dielectric layer, a polysilicon layer on the first dielectric layer providing a polysilicon plate for a capacitor of the filter, and gate(s) for MOSFET(s). A second dielectric layer is on the polysilicon plate. An input contact is on one end of the polysilicon plate and an output contact is on the opposite end. A metal layer includes metal providing contact to at least input contact and metal providing contact to the output contact. Analog circuitry includes the MOSFET having an I/O node coupled to the RC filter.
Claims20
A method of forming a resistor capacitor (RC) filter on an integrated circuit (IC), comprising:
- providing a substrate having at least a semiconductor surface with a first dielectric layer on said semiconductor surface;
- forming a doped diffusion layer under said first dielectric layer;
- forming a patterned doped polysilicon layer on said first dielectric layer including forming a polysilicon plate for a capacitor of said RC filter;
- forming a second dielectric layer on said polysilicon plate;
- forming contacts including an input contact of the RC filter contacting one end of said polysilicon plate, an output contact of the RC filter contacting an opposite end of said polysilicon plate, and
- forming a metal layer providing contact to at least said input contact and said output contact.
An integrated circuit (IC) including at least a resistor capacitor (RC) filter, comprising:
- a substrate having a semiconductor surface with a first dielectric layer on said semiconductor surface;
- a doped diffusion layer under said first dielectric layer;
- a patterned doped polysilicon layer on said first dielectric layer including a polysilicon plate for a capacitor of said RC filter and a gate for a metal-oxide-semiconductor field-effect transistor (MOSFET);
- a second dielectric layer on said polysilicon plate;
- contacts including an input contact of the RC filter contacting one end of said polysilicon plate and an output contact of the RC filter contacting an opposite end of said polysilicon plate,
- a metal layer providing contact to at least said input contact and said output contact and
- analog circuitry comprising said MOSFET having an I/O node coupled to said RC filter.
Dependencies are inferred from the claim text.