US20090206946A1 - Apparatus and method for reducing propagation delay in a conductor - Google Patents
Apparatus and method for reducing propagation delay in a conductor Download PDFInfo
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- US20090206946A1 US20090206946A1 US12/378,073 US37807309A US2009206946A1 US 20090206946 A1 US20090206946 A1 US 20090206946A1 US 37807309 A US37807309 A US 37807309A US 2009206946 A1 US2009206946 A1 US 2009206946A1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/52—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames
- H01L23/522—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
- H01L23/5222—Capacitive arrangements or effects of, or between wiring layers
- H01L23/5225—Shielding layers formed together with wiring layers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
Definitions
- the present invention relates to electrical and integrated circuits and, in particular, to an electrical conductor for an electrical and/or integrated circuit.
- the transmission speed of an electrical signal along a conductor medium in an electrical circuit is dependent on several factors.
- the propagation delay of the pulse depends on the length of the medium and the wave velocity.
- the wave velocity, in rum is related to the dielectric constant of the surrounding medium and the speed of light.
- the RC time constant Another factor that delays the signal is caused by the resistance and capacitance of the conductor medium, commonly called the RC time constant.
- the speed of an electrical signal decreases when capacitance increases. Similarly, speed increases when capacitance decreases.
- the capacitance of the conductor medium depends on several factors, mainly the environment surrounding the conductor medium.
- an apparatus for decreasing the propagation delay time of an electrical signal transmitted along a conductor in a circuit includes a first conductor having a length extending from a first area of the circuit to a second area of the circuit and for carrying the electrical signal.
- a second conductor located proximate the first conductor extends substantially parallel and along the first conductor, with the second conductor electrically coupled to the first conductor.
- a conductor for transmitting a clocking signal from a first area to a second area of an integrated circuit.
- the conductor has a first elongated conductive portion extending from the first area to the second area and a second elongated conductive portion located proximate and spaced apart from the first conductive portion and extending substantially parallel with the first conductive portion.
- the conductor also includes a third elongated conductive portion located proximate and spaced apart from the first conductive portion and extending substantially parallel with the first conductive portion.
- the first conductive portion is electrically connected to the second conductive portion and the third conductive portion.
- a method of forming an electrical conductor in a circuit that increases the speed of an electrical signal transmitted along the conductor.
- the method includes the steps of fabricating a first conductor having a length extending from a first area of the circuit to a second area of the circuit, and fabricating a second conductor proximate the first conductor and extending substantially parallel and along the first conductor, the second conductor electrically coupled to the first conductor.
- FIG. 1 is cross-sectional view of a semiconductor (or printed circuit board) substrate illustrating the capacitance between three signal lines (i.e., conductors) in the substrate;
- FIG. 2 is a diagram illustrating a conductor in accordance with the present invention.
- FIG. 3A is a more detailed diagram and top view of the conductor set forth in FIG. 2 ;
- FIG. 3B is a cross-sectional view along line 3 B- 3 B of FIG. 3A ;
- FIGS. 4A-4C illustrate different configurations or embodiments of the conductor in accordance with the present invention
- FIGS. 5A-5C illustrate cross sectional views of different embodiments of the conductor of the present invention.
- FIG. 6A is a graph illustrating the improvement in rise time (i.e. showing propagation delays) of a signal on a conductor in accordance with the present invention.
- FIGS. 6B-6D illustrate each of the configurations for the signal waveforms shown in FIG. 6A .
- FIG. 1 there is shown a cross-sectional view of a medium (semiconductor integrated circuit or printed circuit board, or the like) 8 having a substrate layer 20 , an insulation layer 10 , a first conductor 12 (also referenced as conductor A), a conductor 14 (also referenced as conductor D) and a conductor 16 (also referenced as conductor E) formed in the insulation layer 10 .
- a medium 8 semiconductor integrated circuit or printed circuit board, or the like
- FIG. 1 also shows capacitance paths 18 (illustrated in dotted lines) between the first conductor 12 and the conductors 14 , 16 . Additionally shown in FIG.
- the substrate layer 20 (which may include a conductive layer or other elements) and capacitance paths between the conductor 12 and the substrate layer 20 .
- capacitance paths may exist between the conductor 12 and other elements or materials located proximate (above, beside, below) the conductor 12 , but are not shown for convenience.
- the conductor 12 extends through the medium 8 , many different conductors or elements having different (and dynamic) electrical signals thereon will be positioned proximate the conductor 12 . These couple capacitively to the conductor 12 . It is readily understood that the amount of capacitive coupling depends on several factors, including the distance from the conductor 12 , the length of the coupling region, the rate of change of the potential difference between conductor 12 and each proximate conductor, and the dielectric constant(s) of the material(s) therebetween. The total value of the capacitance is one factor that determines the “speed” and/or propagation delay of an electrical signal transmitted along the conductor 12 . As the capacitance increases, the speed decreases (or propagation delay increases). Therefore, reducing the capacitance that an electrical signal “sees” as it propagates along the conductor 12 will increase its speed (or decrease its propagation delay).
- a signal on one conductor increasing in voltage while a signal on another conductor decreases in voltage generates the maximum capacitive effect, while two signals increasing (or decreasing) together generates the least capacitive effect.
- the capacitive effect is great between non-shielded conductor lines when both signals are active and opposite in direction. This effect remains substantial when one signal is active (increasing or decreasing) and the other signal is static (e.g., one signal is rising to a logic one and the other signal is held at a logic zero).
- FIG. 2 there is illustrated a circuit 100 having a conductor 120 extending from a first circuit 112 located in a first area 114 of an integrated circuit 100 to a second circuit 116 located in a second area 118 of the integrated circuit 100 .
- the conductor 120 has a length L, as shown in FIG. 2 .
- the conductor 120 in accordance with the present invention reduces or decreases the propagation delay time (increases the speed) of an electrical signal transmitted along the conductor 120 .
- the circuit 100 may also be any other electrical circuit, including a printed circuit board. Accordingly, the description of the present invention with respect to integrated circuits is also applicable to printed circuit boards and the like.
- the signal transmitted on the conductor 120 is a clocking signal and the propagation delay of the signal is reduced or decreased, thus increasing the speed of the signal.
- the length L of the conductor 120 should be more than about 250 microns, and preferably about 1000 microns or more. As will be appreciated, when used in an integrated circuit, the length L will most likely be less than 50,000 microns, depending on the size of the integrated circuit substrate.
- the signal(s) transmitted on the conductor 120 are generally about 10 MHz or greater and, preferably, about 200 MHz or greater, to obtain the many advantages of the present invention.
- the conductor 120 includes a first conductor 120 a, a second conductor (or conductive portion) 120 b extending substantially parallel and along the first conductor 120 a, and a third conductor (or conductive portion) 120 c extending substantially parallel and along the first conductor 120 a.
- the conductors 120 a, 120 b, 120 c are shown extending from the first circuit 112 (in the first area 114 ) to the second circuit 116 (in the second area 118 ) (see also FIG. 2 ).
- Each of the conductors 120 a, 120 b, 120 c are made of any conductive metal or material, preferably of low resistance, including copper, tungsten, aluminum, polysilicon or other material, or combination thereof.
- the additional conductor(s) may not run along the conductor 120 a the entire distance L, but instead substantial portions may run along the conductor 120 a.
- FIG. 3B there is shown a cross-sectional view cut along line A-A of FIG. 3A .
- the conductors 120 a, 120 b , 120 c are formed in a insulating layer 200 (of an integrated circuit or printed circuit board, or the like). Additional layers of substrate may be provided, such as a substrate layer 202 .
- the conductors 120 b and 120 c are each spaced apart substantially laterally from the conductor 120 a , with the conductor 120 b positioned along one side of the conductor 120 a and the conductor 120 c positioned along the other side of the conductor 120 a.
- the width of each of the conductors is generally about 0.7 microns and the spacing therebetween is about 0.7 microns.
- the width and spacing dimensions may vary, and elements/dimensions in the figure may vary and may not be drawn to scale. It is expected that next generation processes will generate widths on the order of 0.2 to 0.4 microns, and perhaps even smaller.
- FIGS. 4A-4C there are illustrated different configurations or embodiments for electrically connecting the conductors 120 b, 120 c to the main conductor 120 a .
- the conductors 120 a, 120 b, 120 c are electrically connected at or near the source end, as illustrated, using a conductive material, such as the material used to fabricate the conductors.
- a conductive material such as the material used to fabricate the conductors.
- the designations “source” and “destination” are used for convenience and illustrative purposes only, and that the designations could be switched, such that the source end may refer to the first circuit 112 or first area 114 , or the second circuit 116 or second area 118 .
- the conductor 120 (or 120 a ) may be bi-directional, depending on the desired circuitry and functioning of the integrated circuit (or electrical circuit).
- FIG. 4B there is illustrated another configuration or embodiment of the conductor 120 wherein the conductor 120 a is electrically connected at one end to three separate drivers 210 .
- Each driver 210 drives the respective conductors 120 a, 120 b, 120 c.
- the drivers 210 may include any other type of circuitry, and are not limited to inverters.
- FIG. 4C there is illustrated yet another configuration or embodiment of the conductor 120 wherein a plurality of switches 220 are used to electrically connect the conductor 120 a to the conductor 120 b, and to electrically connect the conductor 120 a to the conductor 120 c.
- the switches could also be tri-state devices. It will be understood to those skilled in the art that other circuits and methods may be used to electrically connect the conductor 120 a to the conductors 120 b, 120 c.
- the conductors 120 b and 120 c could also be utilized by other circuitry (connected as indicated in the figure by the label “TO OTHER CIRCUITRY”) when the conductor 120 a is not active, unused, or when a signal is transmitted whose speed or propagation delay is unimportant. This is accomplished using switches and/or tri-state devices with appropriate control lines, and can be implemented by those skilled in the art.
- the conductor 120 includes a first conductor 120 a, a second conductor (or conductive portion) 120 b extending substantially parallel and along the first conductor 120 a, and a third conductor (or conductive portion) 120 c extending substantially parallel and along the first conductor 120 a.
- the conductors 120 b and 120 c are each spaced apart substantially vertically from the conductor 120 a, with the conductor 120 b positioned along the top side of the conductor 120 a and the conductor 120 c positioned along the bottom side of the conductor 120 a.
- the conductor 120 includes a first conductor 120 a and a plurality of conductors (or conductive portions) 120 b , 120 c, 120 d, 120 e, whereby the conductors 120 b, 120 c, 120 d, 120 e each extend substantially parallel and along the first conductor 120 a.
- the conductors 120 b and 120 c are each spaced apart substantially laterally from the conductor 120 a, with the conductor 120 b positioned along one side of the conductor 120 a and the conductor 120 c positioned along the other side of the conductor 120 a.
- the conductors 120 d and 120 e are each spaced apart substantially vertically from the conductor 120 a, with the conductor 120 d positioned along the top side of the conductor 120 a and the conductor 120 e positioned along the bottom side of the conductor 120 a.
- the conductor 120 in includes the conductors 120 b, 120 c, 120 d, 120 e as set forth in FIG. 5B , and also includes a conductor 120 f, a conductor 120 g, a conductor 120 h , and a conductor 120 i, as shown in FIG. 5C .
- FIGS. 6A-6D there are shown in FIG. 6A signal waveforms in graphical representation illustrating rise times for a prior art conductor shown in FIG. 6B , for one embodiment of the present invention shown in FIG. 6C , and for another embodiment of the present invention shown in FIG. 6D .
- FIG. 6B there is shown the prior art conductor 12 with additional conductors 14 and 16 .
- the width of each conductor 12 , 14 , 16 is about 0.7 microns and the spacing therebetween is about 2.1 microns.
- the conductors 14 and 16 are not electrically connected to the conductors 14 and 16 .
- FIG. 6C there is shown one embodiment of the present invention having the conductor 120 including the conductor 120 a and 120 b.
- the width of each conductor 120 a, 120 b , 14 , 16 is about 0.7 microns and the spacing between the conductors 14 , 120 b and 120 a is about 0.7 microns while the spacing between the conductors 120 a and 16 is about 2.1 microns.
- the conductors 120 a and 120 b are electrically connected while the conductors 14 and 16 are not electrically connected to the conductor 120 .
- FIG. 6D there is shown one embodiment of the present invention having the conductor 120 including the conductor 120 a and 120 b.
- the width of each conductor 120 a, 120 b , 120 c, 14 , 16 is about 0.7 microns and the spacing therebetween is about 0.7 microns.
- the conductors 120 a and 120 b are electrically connected while the conductors 14 and 16 are not electrically connected to the conductor 120 .
- FIG. 6A there is shown a graph of voltage (volts) versus time (nanoseconds) comparing simulation results of the present invention with a prior art conductor.
- An ideal signal waveform for a signal transition from a logic zero (about 0 volts) to a logic one (about 3.3 volts) is identified by reference numeral 600 , and illustrated with an instantaneous rise time.
- the waveform of a signal on the conductor 12 is identified by reference numeral 602 , with the conductors 14 and 16 held at a logic zero.
- the prior art conductor 12 has a rise time (measured at about 90% of the logic one level of about 3.3 volts) of approximately 0.28 nanoseconds due to the capacitive effects of the conductors 14 and 16 on the conductor 12 .
- the conductor 120 a corresponds to the prior art conductor 12 shown in FIG. 6B .
- the waveform of the signal on the conductor 120 a is identified by reference numeral 604 , with the conductors 14 and 16 held at a logic zero.
- the conductor 120 a has a rise time of approximately 0.16 nanoseconds due to the capacitive effects of the conductors 14 and 16 on the conductor 12 .
- the conductor 120 a is “shielded” from some of the capacitive effects of the conductors 14 and 16 on the conductor 120 a.
- the conductor 120 results in an increase in speed and decrease in rise time (with a corresponding decrease in propagation delay) of a signal transmitted on the conductor 120 .
- the waveform of the signal on the conductor 120 a is identified by reference numeral 606 , with the conductors 14 and 16 held at a logic zero.
- the conductor 120 a has a rise time of approximately 0.13 nanoseconds due to the capacitive effects of the conductors 14 and 16 on the conductor 12 .
- the conductor 120 a is “shielded” from some of the capacitive effects of the conductors 14 and 16 on the conductor 120 a.
- the conductor 120 results in an increase in speed and decrease in rise time (with a corresponding decrease in propagation delay) of a signal transmitted on the conductor 120 .
- the decrease/gain in rise time is about 0.15 nanoseconds. As shown, the decrease in rise time (increase in speed) is greater than a factor of two (and the corresponding reduction in propagation delay is greater than 50%).
- the signal on the conductors 120 b and 120 c will have slower rise time in voltage at the end of the conductor line than the conductor 120 a. It will also be understood that the advantages of the present invention are also present for decreases in voltage (fall time) and not limited to increases in voltage (rise time).
- the capacitive effect (which causes delay) becomes-greater as the dimensions of the integrated circuit (including printed circuit boards) decreases, and the next smaller generation of integrated circuits will incur a greater capacitive effect from line to line. Therefore, the present invention will be of increased benefit for future generation devices.
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Abstract
An apparatus and method is provided that reduces the propagation delay in a conductor carrying an electrical signal from a first area of a circuit to a second area of the circuit. The conductor is fabricated to include a first conductor extending from the first area to the second area. The conductor also includes a second conductor extending substantially parallel and along the first conductor and electrically connected to the first conductor. A third and additional conductors may also be used which extend substantially parallel and along the first conductor and are electrically connected to the first conductor. The additional second conductor (and any additional conductors) reduces the capacitance of the conductor thereby reducing the propagation delay in the conductor (increasing the speed of the signal). The additional conductor(s) effectively “shield” the first conductor from some capacitance that the first conductor would normally “see” without the use of such additional conductors.
Description
- This application is a continuation application of prior pending U.S. patent application Ser. No. 10/997,089 filed Nov. 23, 2004, which is a divisional of prior pending U.S. patent application Ser. No. 09/757,378 filed on Jan. 9, 2001, which is a continuation of prior U.S. patent application Ser. No. 09/127,050 filed Jul. 31, 1998.
- The present invention relates to electrical and integrated circuits and, in particular, to an electrical conductor for an electrical and/or integrated circuit.
- The transmission speed of an electrical signal along a conductor medium in an electrical circuit (including an integrated circuit and/or semiconductor device) is dependent on several factors. For a pulse transmitted through a conductor medium having a given length and wave velocity, the propagation delay of the pulse depends on the length of the medium and the wave velocity. The wave velocity, in rum, is related to the dielectric constant of the surrounding medium and the speed of light.
- Another factor that delays the signal is caused by the resistance and capacitance of the conductor medium, commonly called the RC time constant. The speed of an electrical signal decreases when capacitance increases. Similarly, speed increases when capacitance decreases. The capacitance of the conductor medium depends on several factors, mainly the environment surrounding the conductor medium.
- Accordingly, there exists a need for an apparatus and method for reducing the effective capacitance in a conductor of an electrical circuit thereby increasing the speed of an electrical signal transmitted along the conductor. Further, there is needed a conductor with relatively low capacitance for increasing the speed of an electrical signal transmitted therealong. Additionally, there is needed a method of constructing a conductor in an electrical circuit that reduces the capacitive effects surrounding the conductor and increases the speed of an electrical signal transmitted on the conductor.
- According to the present invention, there is provided an apparatus for decreasing the propagation delay time of an electrical signal transmitted along a conductor in a circuit. The apparatus includes a first conductor having a length extending from a first area of the circuit to a second area of the circuit and for carrying the electrical signal. A second conductor located proximate the first conductor extends substantially parallel and along the first conductor, with the second conductor electrically coupled to the first conductor.
- In another embodiment of the present invention, there is provided a conductor for transmitting a clocking signal from a first area to a second area of an integrated circuit. The conductor has a first elongated conductive portion extending from the first area to the second area and a second elongated conductive portion located proximate and spaced apart from the first conductive portion and extending substantially parallel with the first conductive portion. The conductor also includes a third elongated conductive portion located proximate and spaced apart from the first conductive portion and extending substantially parallel with the first conductive portion. The first conductive portion is electrically connected to the second conductive portion and the third conductive portion.
- In yet another embodiment of the present invention, there is provided a method of forming an electrical conductor in a circuit that increases the speed of an electrical signal transmitted along the conductor. The method includes the steps of fabricating a first conductor having a length extending from a first area of the circuit to a second area of the circuit, and fabricating a second conductor proximate the first conductor and extending substantially parallel and along the first conductor, the second conductor electrically coupled to the first conductor.
- The foregoing has outlined rather broadly the features and technical advantage of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
- For a more complete understanding of the present invention, and the advantages thereof, reference is made to the following description taken in conjunction with the accompanying drawings, wherein:
-
FIG. 1 is cross-sectional view of a semiconductor (or printed circuit board) substrate illustrating the capacitance between three signal lines (i.e., conductors) in the substrate; -
FIG. 2 is a diagram illustrating a conductor in accordance with the present invention; -
FIG. 3A is a more detailed diagram and top view of the conductor set forth inFIG. 2 ; -
FIG. 3B is a cross-sectional view alongline 3B-3B ofFIG. 3A ; -
FIGS. 4A-4C illustrate different configurations or embodiments of the conductor in accordance with the present invention; -
FIGS. 5A-5C illustrate cross sectional views of different embodiments of the conductor of the present invention; -
FIG. 6A is a graph illustrating the improvement in rise time (i.e. showing propagation delays) of a signal on a conductor in accordance with the present invention; and -
FIGS. 6B-6D illustrate each of the configurations for the signal waveforms shown inFIG. 6A . - With reference to the drawings, like reference characters designate like or similar elements throughout the drawings.
- Now referring to
FIG. 1 , there is shown a cross-sectional view of a medium (semiconductor integrated circuit or printed circuit board, or the like) 8 having asubstrate layer 20, aninsulation layer 10, a first conductor 12 (also referenced as conductor A), a conductor 14 (also referenced as conductor D) and a conductor 16 (also referenced as conductor E) formed in theinsulation layer 10. As will be appreciated, if the medium 8 is printed circuit board, thesubstrate layer 20 may not be present.FIG. 1 also shows capacitance paths 18 (illustrated in dotted lines) between thefirst conductor 12 and theconductors FIG. 1 are the substrate layer 20 (which may include a conductive layer or other elements) and capacitance paths between theconductor 12 and thesubstrate layer 20. In addition, capacitance paths may exist between theconductor 12 and other elements or materials located proximate (above, beside, below) theconductor 12, but are not shown for convenience. - As will be appreciated, as the
conductor 12 extends through the medium 8, many different conductors or elements having different (and dynamic) electrical signals thereon will be positioned proximate theconductor 12. These couple capacitively to theconductor 12. It is readily understood that the amount of capacitive coupling depends on several factors, including the distance from theconductor 12, the length of the coupling region, the rate of change of the potential difference betweenconductor 12 and each proximate conductor, and the dielectric constant(s) of the material(s) therebetween. The total value of the capacitance is one factor that determines the “speed” and/or propagation delay of an electrical signal transmitted along theconductor 12. As the capacitance increases, the speed decreases (or propagation delay increases). Therefore, reducing the capacitance that an electrical signal “sees” as it propagates along theconductor 12 will increase its speed (or decrease its propagation delay). - In general terms, a signal on one conductor increasing in voltage while a signal on another conductor decreases in voltage (resulting in an increase in the voltage difference or “delta” voltage delta over time) generates the maximum capacitive effect, while two signals increasing (or decreasing) together generates the least capacitive effect. In other words, the capacitive effect is great between non-shielded conductor lines when both signals are active and opposite in direction. This effect remains substantial when one signal is active (increasing or decreasing) and the other signal is static (e.g., one signal is rising to a logic one and the other signal is held at a logic zero).
- Now referring to
FIG. 2 , there is illustrated acircuit 100 having aconductor 120 extending from afirst circuit 112 located in afirst area 114 of anintegrated circuit 100 to asecond circuit 116 located in asecond area 118 of theintegrated circuit 100. Theconductor 120 has a length L, as shown inFIG. 2 . Theconductor 120 in accordance with the present invention reduces or decreases the propagation delay time (increases the speed) of an electrical signal transmitted along theconductor 120. As will be appreciated, thecircuit 100 may also be any other electrical circuit, including a printed circuit board. Accordingly, the description of the present invention with respect to integrated circuits is also applicable to printed circuit boards and the like. In the preferred embodiment, the signal transmitted on theconductor 120 is a clocking signal and the propagation delay of the signal is reduced or decreased, thus increasing the speed of the signal. To obtain most of the benefits and advantages of the present invention, the length L of theconductor 120 should be more than about 250 microns, and preferably about 1000 microns or more. As will be appreciated, when used in an integrated circuit, the length L will most likely be less than 50,000 microns, depending on the size of the integrated circuit substrate. The signal(s) transmitted on theconductor 120 are generally about 10 MHz or greater and, preferably, about 200 MHz or greater, to obtain the many advantages of the present invention. - Now referring to
FIG. 3A , there is illustrated a more detailed diagram of theconductor 120 of the present invention. Theconductor 120 includes afirst conductor 120 a, a second conductor (or conductive portion) 120 b extending substantially parallel and along thefirst conductor 120 a, and a third conductor (or conductive portion) 120 c extending substantially parallel and along thefirst conductor 120 a. Theconductors FIG. 2 ). Each of theconductors - It will be understood that due to routing and process constraints and requirements, the additional conductor(s) may not run along the
conductor 120 a the entire distance L, but instead substantial portions may run along theconductor 120 a. Now referring toFIG. 3B , there is shown a cross-sectional view cut along line A-A ofFIG. 3A . Theconductors substrate layer 202. Theconductors conductor 120 a, with theconductor 120 b positioned along one side of theconductor 120 a and theconductor 120 c positioned along the other side of theconductor 120 a. As will be appreciated, using present processes and methods, the width of each of the conductors is generally about 0.7 microns and the spacing therebetween is about 0.7 microns. However, the width and spacing dimensions may vary, and elements/dimensions in the figure may vary and may not be drawn to scale. It is expected that next generation processes will generate widths on the order of 0.2 to 0.4 microns, and perhaps even smaller. - Now referring to
FIGS. 4A-4C , there are illustrated different configurations or embodiments for electrically connecting theconductors main conductor 120 a. InFIG. 4A , theconductors first circuit 112 orfirst area 114, or thesecond circuit 116 orsecond area 118. Moreover, the conductor 120 (or 120 a) may be bi-directional, depending on the desired circuitry and functioning of the integrated circuit (or electrical circuit). - Now referring to
FIG. 4B , there is illustrated another configuration or embodiment of theconductor 120 wherein theconductor 120 a is electrically connected at one end to threeseparate drivers 210. Eachdriver 210 drives therespective conductors drivers 210 may include any other type of circuitry, and are not limited to inverters. - Now referring to
FIG. 4C , there is illustrated yet another configuration or embodiment of theconductor 120 wherein a plurality ofswitches 220 are used to electrically connect theconductor 120 a to theconductor 120 b, and to electrically connect theconductor 120 a to theconductor 120 c. The switches could also be tri-state devices. It will be understood to those skilled in the art that other circuits and methods may be used to electrically connect theconductor 120 a to theconductors - As shown in
FIG. 4C , theconductors conductor 120 a is not active, unused, or when a signal is transmitted whose speed or propagation delay is unimportant. This is accomplished using switches and/or tri-state devices with appropriate control lines, and can be implemented by those skilled in the art. - Now referring to
FIGS. 5A-5C , there are shown cross-sectional views of several embodiments of theconductor 120 alternative to the embodiment shown inFIGS. 3A and 3B . InFIG. 5A , theconductor 120 includes afirst conductor 120 a, a second conductor (or conductive portion) 120 b extending substantially parallel and along thefirst conductor 120 a, and a third conductor (or conductive portion) 120 c extending substantially parallel and along thefirst conductor 120 a. Theconductors conductor 120 a, with theconductor 120 b positioned along the top side of theconductor 120 a and theconductor 120 c positioned along the bottom side of theconductor 120 a. - Now referring to
FIG. 5B , there is shown another alternative embodiment of the present invention that includes the features illustrated inFIGS. 3B and 5A . Theconductor 120 includes afirst conductor 120 a and a plurality of conductors (or conductive portions) 120 b, 120 c, 120 d, 120 e, whereby theconductors first conductor 120 a. Theconductors conductor 120 a, with theconductor 120 b positioned along one side of theconductor 120 a and theconductor 120 c positioned along the other side of theconductor 120 a. Theconductors conductor 120 a, with theconductor 120 d positioned along the top side of theconductor 120 a and theconductor 120 e positioned along the bottom side of theconductor 120 a. - Now referring to
FIG. 5C , there is shown yet another alternative embodiment of the present invention. Theconductor 120 in includes theconductors FIG. 5B , and also includes aconductor 120 f, aconductor 120 g, aconductor 120 h, and aconductor 120 i, as shown inFIG. 5C . - Now referring to
FIGS. 6A-6D , there are shown inFIG. 6A signal waveforms in graphical representation illustrating rise times for a prior art conductor shown inFIG. 6B , for one embodiment of the present invention shown inFIG. 6C , and for another embodiment of the present invention shown inFIG. 6D . - In
FIG. 6B , there is shown theprior art conductor 12 withadditional conductors conductor conductors conductors - In
FIG. 6C , there is shown one embodiment of the present invention having theconductor 120 including theconductor conductor conductors conductors conductors conductors conductor 120. - In
FIG. 6D , there is shown one embodiment of the present invention having theconductor 120 including theconductor conductor conductors conductors conductor 120. - Now referring to
FIG. 6A , there is shown a graph of voltage (volts) versus time (nanoseconds) comparing simulation results of the present invention with a prior art conductor. An ideal signal waveform for a signal transition from a logic zero (about 0 volts) to a logic one (about 3.3 volts) is identified byreference numeral 600, and illustrated with an instantaneous rise time. For the prior art conductor illustrated inFIG. 6B , the waveform of a signal on theconductor 12 is identified byreference numeral 602, with theconductors prior art conductor 12 has a rise time (measured at about 90% of the logic one level of about 3.3 volts) of approximately 0.28 nanoseconds due to the capacitive effects of theconductors conductor 12. - Now referring to two of the embodiments of the present invention as illustrated in
FIGS. 6C and 6D , there is a substantial decrease in the rise time and corresponding decrease in the propagation delay (or increase in speed) for theconductor 120 of the present invention. As will be appreciated, theconductor 120 a corresponds to theprior art conductor 12 shown inFIG. 6B . For the conductor 120 (including theconductors FIG. 6C , the waveform of the signal on theconductor 120 a is identified byreference numeral 604, with theconductors conductor 120 a has a rise time of approximately 0.16 nanoseconds due to the capacitive effects of theconductors conductor 12. By adding theadditional conductor 120 b substantially parallel and along theconductor 120 a, theconductor 120 a is “shielded” from some of the capacitive effects of theconductors conductor 120 a. Theconductor 120 results in an increase in speed and decrease in rise time (with a corresponding decrease in propagation delay) of a signal transmitted on theconductor 120. - For the conductor 120 (including the
conductors FIG. 6D , the waveform of the signal on theconductor 120 a is identified byreference numeral 606, with theconductors conductor 120 a has a rise time of approximately 0.13 nanoseconds due to the capacitive effects of theconductors conductor 12. By adding theadditional conductors conductor 120 a, theconductor 120 a is “shielded” from some of the capacitive effects of theconductors conductor 120 a. Theconductor 120 results in an increase in speed and decrease in rise time (with a corresponding decrease in propagation delay) of a signal transmitted on theconductor 120. The decrease/gain in rise time is about 0.15 nanoseconds. As shown, the decrease in rise time (increase in speed) is greater than a factor of two (and the corresponding reduction in propagation delay is greater than 50%). - As will be appreciated, the signal on the
conductors conductor 120 a. It will also be understood that the advantages of the present invention are also present for decreases in voltage (fall time) and not limited to increases in voltage (rise time). - The capacitive effect (which causes delay) becomes-greater as the dimensions of the integrated circuit (including printed circuit boards) decreases, and the next smaller generation of integrated circuits will incur a greater capacitive effect from line to line. Therefore, the present invention will be of increased benefit for future generation devices.
- Although the present invention and its advantages have been described in the foregoing detailed description and illustrated in the accompanying drawings, it will be understood by those skilled in the art that the invention is not limited to the embodiment(s) disclosed but is capable of numerous rearrangements, substitutions and modifications without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (21)
1-20. (canceled)
21. A method of transmitting electrical signals along a first conductor disposed within an integrated circuit and having a length in excess of 10,000 microns, the integrated circuit including a second conductor proximate the first conductor and extending substantially parallel and along the first conductor, the method comprising:
selectively transmitting a single electrical signal at a frequency greater than 200 mega-Hertz (MHz) on both of the first and second conductors; and
selectively transmitting independent electrical signals on the first and second conductors.
22. The method of claim 21 , further comprising:
closing a first switch selectively connecting a first end of the first conductor to a first end of the second conductor when selectively transmitting the single electrical signal on both of the first and second conductors; and
opening the first switch when selectively transmitting independent electrical signals on the first and second conductors.
23. The method of claim 22 , further comprising:
closing a second switch selectively connecting a second end of the first conductor to a second end of the second conductor when selectively transmitting the single electrical signal on both of the first and second conductors; and
opening the second switch when selectively transmitting independent electrical signals on the first and second conductors.
24. The method of claim 21 , further comprising:
selectively transmitting the single electrical signal concurrently on a third conductor as well as on both of the first and second conductors, the third conductor proximate to the first and second conductors and extending substantially parallel and along the first and second conductors.
25. The method of claim 24 , further comprising:
selectively transmitting the single electrical signal concurrently on a fourth conductor as well as on all of the first, second and third conductors, the fourth conductor proximate to the first, second and third conductors and extending substantially parallel and along the first, second and third conductors.
26. The method of claim 24 , wherein the first, second and third conductors are arranged vertically with respect to each other.
27. The method of claim 24 , wherein the first, second and third conductors are arranged horizontally with respect to each other.
28. The method of claim 24 , wherein the first, second and third conductors are arranged diagonally with respect to each other.
29. A method of switching electrical signals within an integrated circuit, the method comprising:
selectively switching a single electrical signal having a frequency greater than 200 mega-Hertz (MHz) onto both of first and second conductors each having a length greater than 10,000 microns and disposed proximate to and extending substantially parallel and along each other; and
selectively switching independent electrical signals onto the first and second conductors.
30. The method of claim 29 , further comprising:
closing both of a first switch selectively connecting a first end of the first conductor to a first end of the second conductor and a second switch selectively connecting a second end of the first conductor to a second end of the second conductor when selectively transmitting the single electrical signal on both of the first and second conductors.
31. The method of claim 29 , further comprising:
disconnecting at least one of the first end of the first conductor from the first end of the second conductor and the second end of the first conductor from the second end of the second conductor when transmitting the independent electrical signals on the first and second conductors.
32. The method of claim 29 , further comprising:
disconnecting both the first end of the first conductor from the first end of the second conductor and the second end of the first conductor from the second end of the second conductor when transmitting the independent electrical signals on the first and second conductors.
33. An integrated circuit, comprising:
a first conductor having a length in excess of 10,000 microns; and
a second conductor proximate the first conductor and extending substantially parallel and along the first conductor,
wherein a single electrical signal having a frequency greater than 200 mega-Hertz (MHz) is selectively transmitted on both of the first and second conductors and independent electrical signals are selectively transmitted on the first and second conductors.
34. The integrated circuit of claim 33 , further comprising:
a first switch selectively connecting a first end of the first conductor to a first end of the second conductor when selectively transmitting the single electrical signal on both of the first and second conductors.
35. The integrated circuit of claim 34 , further comprising:
a second switch selectively connecting a second end of the first conductor to a second end of the second conductor when selectively transmitting the single electrical signal on both of the first and second conductors.
36. The integrated circuit of claim 33 , further comprising:
a third conductor selectively carrying the single electrical signal concurrently with both of the first and second conductors, the third conductor proximate to the first and second conductors and extending substantially parallel and along the first and second conductors.
37. The integrated circuit of claim 36 , further comprising:
a fourth conductor selectively carrying the single electrical signal concurrently with the first, second and third conductors, the fourth conductor proximate to the first, second and third conductors and extending substantially parallel and along the first, second and third conductors.
38. The integrated circuit of claim 36 , wherein the first, second and third conductors are arranged vertically with respect to each other.
39. The integrated circuit of claim 36 , wherein the first, second and third conductors are arranged horizontally with respect to each other.
40. The integrated circuit of claim 36 , wherein the first, second and third conductors are arranged diagonally with respect to each other.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/378,073 US20090206946A1 (en) | 1998-07-31 | 2009-02-11 | Apparatus and method for reducing propagation delay in a conductor |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12705098A | 1998-07-31 | 1998-07-31 | |
US09/757,378 US6842092B2 (en) | 1998-07-31 | 2001-01-09 | Apparatus and method for reducing propagation delay in a conductor |
US10/997,089 US7495526B2 (en) | 1998-07-31 | 2004-11-23 | Apparatus and method for reducing propagation delay in a conductor system selectable to carry a single signal or independent signals |
US12/378,073 US20090206946A1 (en) | 1998-07-31 | 2009-02-11 | Apparatus and method for reducing propagation delay in a conductor |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/997,089 Continuation US7495526B2 (en) | 1998-07-31 | 2004-11-23 | Apparatus and method for reducing propagation delay in a conductor system selectable to carry a single signal or independent signals |
Publications (1)
Publication Number | Publication Date |
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US20090206946A1 true US20090206946A1 (en) | 2009-08-20 |
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ID=22428070
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/757,378 Expired - Lifetime US6842092B2 (en) | 1998-07-31 | 2001-01-09 | Apparatus and method for reducing propagation delay in a conductor |
US10/997,089 Expired - Fee Related US7495526B2 (en) | 1998-07-31 | 2004-11-23 | Apparatus and method for reducing propagation delay in a conductor system selectable to carry a single signal or independent signals |
US12/378,073 Abandoned US20090206946A1 (en) | 1998-07-31 | 2009-02-11 | Apparatus and method for reducing propagation delay in a conductor |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/757,378 Expired - Lifetime US6842092B2 (en) | 1998-07-31 | 2001-01-09 | Apparatus and method for reducing propagation delay in a conductor |
US10/997,089 Expired - Fee Related US7495526B2 (en) | 1998-07-31 | 2004-11-23 | Apparatus and method for reducing propagation delay in a conductor system selectable to carry a single signal or independent signals |
Country Status (3)
Country | Link |
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US (3) | US6842092B2 (en) |
EP (1) | EP0977263A3 (en) |
JP (1) | JP2000174017A (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0977263A3 (en) * | 1998-07-31 | 2002-07-10 | STMicroelectronics, Inc. | Apparatus and method for reducing propagation delay in a conductor |
KR20030028563A (en) * | 2001-06-07 | 2003-04-08 | 코닌클리즈케 필립스 일렉트로닉스 엔.브이. | Controllable delay circuit for delaying an electric signal |
US8212634B2 (en) * | 2009-06-04 | 2012-07-03 | International Business Machines Corporation | Vertical coplanar waveguide with tunable characteristic impedance design structure and method of fabricating the same |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3659227A (en) * | 1970-09-08 | 1972-04-25 | Gen Electric | Switch-controlled directional coupler |
US3678415A (en) * | 1969-06-30 | 1972-07-18 | Nippon Electric Co | Multiple port hybrid circuit |
US5027088A (en) * | 1989-03-14 | 1991-06-25 | Kabushiki Kaisha Toshiba | Signal wiring board |
US5043792A (en) * | 1989-04-17 | 1991-08-27 | Nec Corporation | Integrated circuit having wiring strips for propagating in-phase signals |
US5689217A (en) * | 1996-03-14 | 1997-11-18 | Motorola, Inc. | Directional coupler and method of forming same |
US5742210A (en) * | 1997-02-12 | 1998-04-21 | Motorola Inc. | Narrow-band overcoupled directional coupler in multilayer package |
US5815031A (en) * | 1993-10-21 | 1998-09-29 | Advanced Micro Devices, Inc. | High density dynamic bus routing scheme |
US7495526B2 (en) * | 1998-07-31 | 2009-02-24 | Stmicroelectronics, Inc. | Apparatus and method for reducing propagation delay in a conductor system selectable to carry a single signal or independent signals |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61119060A (en) * | 1984-11-14 | 1986-06-06 | Toshiba Corp | Signal propagation path for semiconductor integrated circuit |
JPH0237763A (en) * | 1988-07-27 | 1990-02-07 | Nec Corp | Semiconductor integrated circuit |
JPH0473951A (en) * | 1990-07-16 | 1992-03-09 | Nec Ic Microcomput Syst Ltd | Semiconductor device |
JPH04142074A (en) * | 1990-10-02 | 1992-05-15 | Seiko Epson Corp | Semiconductor device |
JPH05136125A (en) * | 1991-11-14 | 1993-06-01 | Hitachi Ltd | Clock wiring and semiconductor integrated circuit device having clock wiring |
JPH09237870A (en) * | 1996-03-01 | 1997-09-09 | Hitachi Ltd | Signal-line driving device |
-
1999
- 1999-07-27 EP EP99305955A patent/EP0977263A3/en not_active Withdrawn
- 1999-07-30 JP JP11216821A patent/JP2000174017A/en active Pending
-
2001
- 2001-01-09 US US09/757,378 patent/US6842092B2/en not_active Expired - Lifetime
-
2004
- 2004-11-23 US US10/997,089 patent/US7495526B2/en not_active Expired - Fee Related
-
2009
- 2009-02-11 US US12/378,073 patent/US20090206946A1/en not_active Abandoned
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3678415A (en) * | 1969-06-30 | 1972-07-18 | Nippon Electric Co | Multiple port hybrid circuit |
US3659227A (en) * | 1970-09-08 | 1972-04-25 | Gen Electric | Switch-controlled directional coupler |
US5027088A (en) * | 1989-03-14 | 1991-06-25 | Kabushiki Kaisha Toshiba | Signal wiring board |
US5043792A (en) * | 1989-04-17 | 1991-08-27 | Nec Corporation | Integrated circuit having wiring strips for propagating in-phase signals |
US5815031A (en) * | 1993-10-21 | 1998-09-29 | Advanced Micro Devices, Inc. | High density dynamic bus routing scheme |
US5689217A (en) * | 1996-03-14 | 1997-11-18 | Motorola, Inc. | Directional coupler and method of forming same |
US5742210A (en) * | 1997-02-12 | 1998-04-21 | Motorola Inc. | Narrow-band overcoupled directional coupler in multilayer package |
US7495526B2 (en) * | 1998-07-31 | 2009-02-24 | Stmicroelectronics, Inc. | Apparatus and method for reducing propagation delay in a conductor system selectable to carry a single signal or independent signals |
Also Published As
Publication number | Publication date |
---|---|
JP2000174017A (en) | 2000-06-23 |
US7495526B2 (en) | 2009-02-24 |
US20050093640A1 (en) | 2005-05-05 |
US6842092B2 (en) | 2005-01-11 |
EP0977263A3 (en) | 2002-07-10 |
US20010018988A1 (en) | 2001-09-06 |
EP0977263A2 (en) | 2000-02-02 |
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