Active solid-state devices (e.g. – transistors – solid-state diode – Field effect device – Having insulated electrode
Reexamination Certificate
2001-11-16
2003-05-13
Nelms, David (Department: 2818)
Active solid-state devices (e.g., transistors, solid-state diode
Field effect device
Having insulated electrode
C257S300000, C257S301000
Reexamination Certificate
active
06563158
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates in general to techniques for regulating or stiffening a voltage and, more particularly, to techniques for regulating or stiffening a voltage within an integrated circuit.
BACKGROUND OF THE INVENTION
When implementing most circuits, it is a relatively standard practice to provide a plurality of capacitors which each have two ends coupled to respective conductive strips. These conductive strips are frequently called “rails”, and carry respective different direct current voltage potentials from a power supply. The capacitors serve to regulate or “stiffen” the supply voltage by eliminating high frequency signal components, including high frequency components induced in the supply voltage by normal operation of the circuitry powered by the supply voltage.
In the context of an integrated circuit, where the voltage stiffening capacitors are parts of the integrated circuit, the capacitors are commonly implemented by providing scattered regions within the integrated circuit which are not used for the operational circuit, and then implementing in each such region a single voltage stiffening capacitor which is as large as possible. Due to process variations or other factors, one or more of the voltage stiffening capacitors in an integrated circuit may have a defect which permits a leakage current of relatively large magnitude to flow therethrough. Such defects typically arise during fabrication of the integrated circuit. However, in some cases such a defect may develop during operational use of the integrated circuit, long after it has been fabricated.
SUMMARY OF THE INVENTION
From the foregoing, it may be appreciated that a need has arisen for a method and apparatus for preventing or limiting leakage current in a voltage stiffening capacitor in an integrated circuit. A first form of the present invention involves an integrated circuit which includes: first and second conductive parts operable to respectively carry first and second supply voltages that are different; and a plurality of voltage stiffening circuit portions which each have first and second nodes respectively coupled to the first and second conductive parts, each of the circuit portions including a capacitance and a current limiting section coupled in series with each other between the first and second nodes thereof, each such current limiting section being selected so that application thereacross of a voltage equal to the difference between the first and second supply voltages would induce through the current limiting section a current flow less than approximately 10 mA.
A second form of the present invention involves an integrated circuit which includes: first and second conductive parts operable to respectively carry first and second voltages which are different; and a plurality of voltage stiffening circuit portions disposed within a contiguous area of the integrated circuit which is free of circuitry other than the circuit portions, the circuit portions each having first and second nodes respectively coupled to the first and second conductive parts, and each including a capacitance and a current limiting section coupled in series with each other between the first and second nodes thereof.
Yet another form of the present invention involves an integrated circuit which includes: first and second conductive parts operable to respectively carry first and second voltages which are different; and a plurality of voltage stiffening circuit portions which each have first and second nodes respectively coupled to the first and second conductive parts, each of the circuit portions including a capacitance and a current limiting section coupled in series with each other between the first and second nodes thereof, wherein the capacitances of the circuit portions each include first and second conductive portions separated by a non-conductive portion, the first conductive portions being electrically separate from each other, and the second conductive portions being respective integral portions of a single conductive member.
Still another form of the present invention involves an integrated circuit which includes: a dynamic random access memory section having a plurality of memory cells which each include a capacitor; first and second conductive parts operable to respectively carry first and second voltages which are different; and a plurality of voltage stiffening circuit portions which each have first and second nodes respectively coupled to the first and second conductive parts, each of the circuit portions including a capacitor and a current limiting section coupled in series with each other between the first and second nodes thereof, the capacitors of the circuit portions each having a structural configuration which is equivalent to a structural configuration of the capacitors in the dynamic random access memory section.
Another form of the present invention involves an integrated circuit which includes: first and second conductive parts operable to respectively carry first and second voltages which are different; a plurality of voltage stiffening circuit portions which each have first and second nodes respectively coupled to the first and second conductive parts, each of the circuit portions including a capacitance and a transistor coupled in series with each other between the first and second nodes thereof, each transistor having a control terminal which is responsive to application thereto of a control signal for controlling a current flow between the first and second nodes through the transistor as a function of the control signal applied thereto; and a circuit portion coupled to the control terminal of each transistor for applying thereto a control signal.
Yet another form of the present invention relates to fabrication of an integrated circuit which includes first and second conductive parts operable to respectively carry first and second supply voltages that are different, and a plurality of voltage stiffening circuit portions that each have first and second nodes respectively coupled to the first and second conductive parts, each of the circuit portions including a capacitance and a resistance coupled in series with each other between the first and second nodes thereof. Fabrication of the integrated circuit involves: providing a substrate; forming in the substrate a portion which extends between spaced first and second locations on the substrate and which implements the resistance; forming an insulating layer over the substrate; forming first and second openings in the insulating layer which respectively extend to the first and second locations; forming conductive first and second contacts in the first and second openings, the first and second contacts being respectively electrically coupled to the substrate at the first and second locations; forming in the insulating layer a recess which is spaced from the substrate, one of the first and second contacts having an upper portion which projects into the recess and the other of the contacts being spaced from the recess; forming on exposed surfaces of the recess and the one of the contacts a first conductive layer; forming a non-conductive layer on the first conductive layer; forming a second conductive layer on the non-conductive layer, the first and second conductive layers and the non-conductive layer collectively forming a capacitor which provides the capacitance of the circuit portion; and forming the first and second conductive parts so that one thereof is electrically coupled to the second conductive layer and the other thereof is electrically coupled to the other of the first and second contacts.
Still another form of the invention relates to fabrication of an integrated circuit which includes first and second conductive parts operable to respectively carry first and second supply voltages that are different, and a plurality of voltage stiffening circuit portions that each have first and second nodes respectively coupled to the first and second conductive parts, each of the circuit portions including a capacitance a
Gallia James D.
Houston Theodore W.
Brady III W. James
Garner Jacqueline J.
Ho Tu-Tu
Nelms David
Telecky , Jr. Frederick J.
LandOfFree
Method and apparatus for voltage stiffening in an integrated... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for voltage stiffening in an integrated..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for voltage stiffening in an integrated... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3026569