JPH06244190A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To cancel a parasitic quantity between signal wiring and a substrate and improve the quantity of the output waveform by extending conductor along the wiring and separately applying a signal, which is almost the same as a signal applied to the wiring, to the conductor. CONSTITUTION:An oxide film 3 is formed on a substrate 2, signal wiring 1 is buried in the oxide film 3 and conductor 4 is buried in the oxide film 3 so as to surround the signal wiring 1. An amplifier 5a for applying an input signal to the signal wiring 1, an amplifier 5b for separately applying the same signal as the signal applied to the signal wiring 1 to the conductor 4 and an amplifier 5c for distributing the signal to the amplifier 5a and 5b are connected to the semiconductor integrated circuit. When a square wave signal is applied to the amplifier 5c, a signal which passes through the conductor is influenced by the parasitic quantity generated between the substrate and the wiring, however, a signal which passes through the wiring gets almost no influence from the parasitic quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit,
In particular, the present invention relates to a circuit in which the waveform of a transmitted signal is prevented from changing due to an external factor such as a parasitic capacitance as the circuit speed increases.

[0002]

2. Description of the Related Art With the increase in density and speed of circuit operation in semiconductor integrated circuits, the output waveform is apt to be blunted by the parasitic capacitance generated between the signal wiring and the adjacent conductor.

FIG. 3 is a cross-sectional view of wiring in a conventional type semiconductor integrated circuit, in which an oxide film 3 as an insulating layer is formed on a conductive substrate 2 and signal wiring is formed thereon. 1 is provided. An input signal is supplied to the signal wiring 1 from an amplifier 6 as shown in FIG.

A capacitance component is parasitic between the wiring 1 and the substrate 2, and the magnitude of this capacitance is proportional to the area of the signal wiring 1. Therefore, as the integrated circuit becomes larger, the wiring 1
As the length becomes longer, the parasitic capacitance becomes larger, so that the waveform of the output signal is blunted, causing a problem such as a signal transmission delay.

[0005]

SUMMARY OF THE INVENTION In view of the problems of the prior art as described above, the main object of the present invention is to cancel the parasitic capacitance between the signal wiring and the substrate and improve the quality of the output waveform. It is to provide an integrated circuit.

[0006]

According to the present invention, in the semiconductor integrated circuit having a signal wiring, a conductor extending along the wiring and a signal applied to the wiring are provided. And a means for separately applying substantially the same signals to the conductors. This is achieved by providing a semiconductor integrated circuit.

[0007]

With this configuration, the conductor extending along the wiring is always kept at the same potential as the wiring, so that no electric charge is accumulated, and therefore the signal wiring has a parasitic capacitance from the conductor. The signal transmitted through the wiring is not dulled without being affected by.

Further, since the wiring and the conductor are supplied with signals separately from each other, the stray capacitance is parasitic only between the substrate and the conductor, and the waveform of the signal transmitted through the conductor is rounded. The signal that transmits the wiring itself does not dull.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing an embodiment of a semiconductor integrated circuit according to the present invention. A substrate 2, an oxide film 3 formed on the substrate, and a signal wiring 1 embedded in the oxide film 3 are shown.
And a conductor 4 embedded in the oxide film 3 so as to surround the signal wiring 1. This semiconductor integrated circuit is shown in FIG.
As shown in FIG. 5, an amplifier 5a for applying an input signal to the signal wire 1, an amplifier 5b for independently applying the same signal as the signal applied to the signal wire 1 to the conductor 4, and an amplifier 5a, 5b. An amplifier 5c for distributing a signal is connected to.

If, for example, a square wave signal as shown in FIG. 5A is applied to the amplifier 5c, the amplifiers 5a, 5
By b, the same signal is independently input to the wiring 1 and the conductor 4. The signal transmitted through the conductor 4 is affected by the parasitic capacitance generated between the conductor 4 and the output signal thereof has a waveform as shown in part (b) of FIG. However, the signal transmitted through the wiring 1 is hardly affected by the parasitic capacitance, and the output signal thereof has a waveform as shown in the part (c), and is hardly rounded.

This is because the same signal is applied to the signal wiring and the conductor, so that the potential difference V is always maintained at 0 between them in the relational expression of Q = CV. From
This is because the charge Q is not accumulated, the effective value of the parasitic capacitance C becomes 0, and the signal wiring is not affected by the parasitic capacitance, so that the load of the amplifier output is reduced.

[0013]

As described above, the simple structure reduces the rounding of the signal waveform transmitted through the wiring, which enables high-speed operation and high-quality waveform transmission.

[Brief description of drawings]

FIG. 1 is a cross-sectional perspective view of a wiring of a semiconductor integrated circuit according to the present invention.

FIG. 2 is a circuit diagram according to the present invention.

FIG. 3 is a cross-sectional perspective view of wiring of a conventional semiconductor integrated circuit.

FIG. 4 is a conventional circuit diagram.

FIG. 5 is a diagram showing a waveform transmission train.

[Explanation of symbols]

 1 signal wiring 2 substrate 3 oxide film 4 conductors 5a, 5b, 5c amplifier 6 amplifier

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H01L 27/04 D 8427-4M 9355-4M H01L 23/12 Q 9355-4M 23/14 X

Claims (1)

[Claims] 1. In a semiconductor integrated circuit having signal wiring, a conductor extending along the wiring and a signal substantially the same as a signal applied to the wiring are separately applied to the conductor. And a semiconductor integrated circuit.