JPS6340347A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To prevent the increase in the coupling capacitance between a polycrystalline Si wiring and a metal wiring by a method wherein another polycrystalline Si film and an interlayer insulating film are formed on both sides of the polycrystalline Si wiring. CONSTITUTION:A polycrystalline Si film 8 is formed on the surface of a field insulating film 2 leaving an interval between them, and interlayer insulating films 9 are formed on the surface of said film 8. A polycrystalline Si wiring 3 is formed on the exposed surface of the insulating film 2 located between said insulating films 9. Then, an interlayer insulating film 40 is formed on the surface of the insulating film 9, the insulating film 2 and the wiring 3, and a wiring 50 is formed on the surface of the insulating film 40 in such a manner that the wiring 50 crosses the wiring 3. As a result, the difference between the upper surface of the wiring 3 and the upper surface of the insulating film 9 can be made small, and the increase in coupling capacitance between the wiring 3 and the wiring 50 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wiring structure of a semiconductor integrated circuit device.

[Prior Art] FIG. 3 is a plan view showing a conventional semiconductor integrated circuit device, and FIG. 4 is a sectional view taken along the line AA in FIG. 3.

In the figure, field insulation l! is provided on the surface of a semiconductor substrate 1!
12 is formed, and this field insulation 1112
A polycrystalline silicon arrangement 3 is formed on the surface. Interlayer insulation 14 is formed on the surface of field insulating film 2 and polycrystalline silicon wiring 3, and aluminum wiring 5 is formed on the surface of interlayer insulation film 4 so as to intersect with polycrystalline silicon arrangement 13. Further, an aluminum interconnect 116 is formed on the surface of the interlayer insulating film 4, and this aluminum interconnect 6 is connected to the polycrystalline silicon interconnect 3 through a contact hole 7 near the intersection of the polycrystalline silicon interconnect 3 and the aluminum interconnect 115. ing.

[Problems to be Solved by the Invention] Since the wiring intersections in the conventional semiconductor integrated circuit device are configured as described above, the polycrystalline silicon wiring 3 and the aluminum wiring 5 intersect with each other. 3, interlayer insulation vA4, and aluminum wiring 5 form a capacitor structure. In this case, since the height difference between the upper surface of the polycrystalline silicon wiring 3 and the surface of the field insulation 1112 is large and a stepped portion is formed, the interlayer insulation 1112
4, the film thickness of the interlayer insulation [14] decreases as shown in the circle A near this stepped portion, and the coupling capacitance between the polycrystalline silicon wiring 3 and the aluminum wiring 5 increases.
There was a problem in that signal crosstalk occurred between the polycrystalline silicon wiring 3 and the aluminum wiring 5.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a semiconductor integrated circuit device in which signal crosstalk between wires is less likely to occur at intersections of wires.

[Means for Solving the Problems 1] A semiconductor integrated circuit device according to the present invention includes forming a field insulating film on the surface of a semiconductor substrate, and forming polycrystalline silicon films at intervals on the surface of the field insulating film. Then, a first interlayer insulating film is formed on the surface of this polycrystalline silicon film, a polycrystalline silicon wiring is formed on the exposed surface of the field insulating film between the first interlayer insulating m, and a first interlayer insulating film is formed. A second interlayer insulating film is formed on the surface of the insulating film, the exposed surface of the remaining field insulating film, and the surface of the polycrystalline silicon wiring, and a metal layer is formed on the surface of the second interlayer insulating film so as to cross the polycrystalline silicon wiring. This is formed by wiring.

[Function] In the present invention, by forming a polycrystalline silicon film and a first interlayer insulating film on both sides of a polycrystalline silicon wiring, the upper surface of the polycrystalline silicon wiring and the upper surface of the first interlayer insulating film are separated. When the second interlayer insulating film is formed, the thickness (m) of the second interlayer insulating film is prevented from decreasing at the intersection between the polycrystalline silicon wiring and the metal wiring. Therefore, an increase in the coupling capacitance between the polycrystalline silicon wiring and the metal wiring is prevented, and signal crosstalk between the wirings is less likely to occur.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

In the description of this embodiment, the description of parts that overlap with the description of the conventional technology will be omitted as appropriate.

FIG. 1 is a plan view showing a semiconductor integrated circuit device according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line A--A in FIG.

The structure of this embodiment differs from the structure of the semiconductor integrated circuit device shown in FIGS. 3 and 4 in the following points. In other words, field insulation! 12 each other on the surface! ,: Polycrystalline silicon films 8 are formed at intervals, and interlayer insulation 119 is formed on the surface of this polycrystalline silicon 1118. A polycrystalline silicon wiring 3 is formed on the exposed surface of the field insulating film 2 between the interlayer insulation vA9. Interlayer insulation llI is applied to the surface of the interlayer insulation 119, the exposed surface of the remaining field insulation film 2, and the surface of the polycrystalline silicon wiring 3.
40 is formed, and an aluminum wiring 5 is formed on the surface of this interlayer insulating film 40 so as to intersect with the polycrystalline silicon wiring 3.
0 is formed.

In this way, polycrystalline silicon I[I18. By forming the interlayer insulation lll9, the upper surface part of the polycrystalline silicon wiring 3 and the interlayer insulation lll1
Since the difference in height from the top surface of 9 can be reduced,
When the interlayer insulating film 1I40 is formed, the film thickness of the interlayer insulating film 40 is reduced at the intersection of the polycrystalline silicon arrangement 3 and the aluminum arrangement fi50 as shown in the conventional circle A in FIG. It can be prevented. Therefore, in the capacitor structure formed by the polycrystalline silicon arrangement 13, the interlayer insulation m0, and the aluminum wiring 5o, an increase in the coupling capacitance between the polycrystalline silicon wiring 3 and the aluminum wiring 50 is prevented, and the polycrystalline silicon wiring wA3 Signal crosstalk between the aluminum arrangement 950 and the aluminum arrangement 950 can be made less likely to occur.

In the above embodiment, the upper layer wiring is aluminum wiring, but other metal wiring may be used as the upper layer wiring.

[Effects of the Invention] As described above, according to the present invention, a field insulating film is formed on the surface of the semicircular body 1s plate, and polycrystalline silicon films are formed on the surface of the field insulating film at intervals, forming a first interlayer insulating film on the surface of this polycrystalline silicon film;
A polycrystalline silicon wiring is formed on the exposed surface of the field insulation film between the first interlayer insulation films, and the remaining field #! is formed on the surface of the first interlayer insulation film. Exposed front surface rf
A second interlayer insulating film is formed on the surface of the JI3 and polycrystalline silicon wiring, and a metal wiring is formed on the surface of the second interlayer insulating film so as to intersect with the polycrystalline silicon wiring, so that the upper surface of the polycrystalline silicon wiring is The difference in height between the upper surface portion of the first wear barrier RII is reduced, and the film thickness of the second layer barrier RII is prevented from decreasing at the intersection of the polycrystalline silicon interconnect and the metal interconnect. Therefore, an increase in the coupling capacitance between the polycrystalline silicon wiring and the metal wiring is prevented, and it is possible to obtain a semiconductor integrated circuit device in which signal crosstalk between the wirings is less likely to occur at the intersection of the wirings.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a semiconductor integrated circuit device which is a general example of the present invention, and FIG. 2 is a sectional view taken along the line A-A' in FIG. FIG. 3 is a plan view showing a conventional semiconductor integrated circuit device, and FIG. 4 is a cross-sectional view taken along the line AA of the third factor. In the figure, 1 is a semiconductor substrate, 2 is a field 1If
J green film, 3 is a polycrystalline silicon wiring, 4, 9, 40 is an m insulating film, 5, 6, 50 is an aluminum wiring, 7 is a contact hole, and 8 is a polycrystalline silicon film. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A semiconductor substrate, a field insulating film formed on the surface of the semiconductor substrate, a polycrystalline silicon film formed on the surface of the field insulating film at a distance from each other, and a polycrystalline silicon film formed on the surface of the polycrystalline silicon film. a polycrystalline silicon wiring formed on the exposed surface of the field insulating film between the first interlayer insulating films; a second interlayer insulating film formed on the exposed surface of the field insulating film and the surface of the polycrystalline silicon wiring; and a metal formed on the surface of the second interlayer insulating film so as to intersect with the polycrystalline silicon wiring. A semiconductor integrated circuit device equipped with wiring. (2) The semiconductor integrated circuit device according to claim 1, wherein the metal wiring is made of aluminum.