Porous silicon oxycarbide integrated circuit insulator

DETAILED DESCRIPTION The present invention provides, among other things, a low dielectric constant IC insulator formed of porous silicon oxycarbide.
In one embodiment, the invention includes an integrated circuit formed on a substrate.
A plurality of transistors is formed on the substrate.
A patterned first conductive layer interconnects ones of the transistors.
A porous silicon oxycarbide layer insulates portions of the first conductive layer from the transistors.
In another embodiment, the invention includes an integrated circuit having a porous silicon oxycarbide layer overlying the circuit elements for protecting the physical integrity of the circuit elements.
Another aspect of the present invention provides a method of fabricating an integrated circuit.
A working surface of a semiconductor substrate is coated with a mixture of oxide and carbon sources.
The mixture of oxide and carbon sources is heated and dried such that the mixture of oxide and carbon sources is transformed into an insulator layer on the integrated circuit.
In one embodiment, the mixture of oxide and carbon sources includes polymeric precursors such as substituted alkoxysilanes.
In another embodiment, the substituted alkoxysilanes are mixed with silicon alkoxides.
In a further embodiment, the mixture of oxide and carbon sources includes methyldimethoxysilane (MDMS) and tetraethoxysilane (TEOS).
In another embodiment, heating and drying the mixture of oxide and carbon sources comprises pyrolyzing the mixture of oxide and carbon sources.
The low dielectric constant porous silicon oxycarbide insulator provides electrical isolation, such as between circuit elements, between interconnection lines, between circuit elements and interconnection lines, or as a passivation layer overlying both circuit elements and interconnection lines.
The low dielectric constant porous silicon oxycarbide insulator of the present invention reduces the parasitic capacitance between circuit nodes.
As a result, the porous silicon oxycarbide insulator advantageously provides reduced noise and signal crosstalk between circuit nodes, reduced power consumption, faster circuit operation, and minimizes the risk of potentially introducing timing faults