Claims
- 1. A low voltage coefficient capacitor, in an integrated circuit, comprising:on an area of field oxide, first and second bottom electrodes of a first layer of polysilicon, said polysilicon having metallic conduction; a layer of a dielectric covering both the first and second bottom electrodes; contact holes in the dielectric layer; first and second top electrodes of a second layer of polysilicon, said polysilicon having semiconductive conduction, each top electrode overlying a bottom electrode while leaving said contact holes clear; thin film wiring extending from the first bottom electrode, through the contact holes, to the second top electrode; thin film wiring extending from the second bottom electrode, through the contact holes, to the first top electrode; no insulation between the thin film wiring and the bottom electrodes, other than said dielectric layer.
- 2. The capacitor of claim 1 wherein the first layer of polysilicon has a resistivity between about 0.6 and 1 mohm-cm.
- 3. The capacitor of claim 1 further comprising a layer of a silicide, selected from the group consisting of tungsten silicide, titanium silicide, and cobalt silicide, between the first layer of polysilicon and the dielectric.
- 4. The capacitor of claim 1 wherein each bottom electrode has an area between about 400 and 250,000 sq. microns.
- 5. The capacitor of claim 4 wherein the bottom electrodes are adjacent to one another and separated by between about 0.6 and 20 microns.
- 6. The capacitor of claim 1 wherein said dielectric is selected from the group consisting of high temperature oxide, thermal oxide, oxide-nitride-oxide, silicon nitride, tetraethoxyortho-silicate, or tantalum oxide.
- 7. Claim 1 wherein the capacitor has a capacitance of about 283 pF for a 300×500 micron pair of plates.
- 8. Claim 1 wherein the capacitor has a voltage coefficient of capacitance that is less than about 2 ppm/V.
Parent Case Info
This is a division of patent application Ser. No. 08/953,530, filing date Oct. 20, 1997, Cross-Coupled Capacitors For Improved Voltage Coefficient, assigned to the same assignee as the present invention.
US Referenced Citations (8)