JPS58140151A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To realize high speed action of a semiconductor integrated circuit device by a method wherein aluminum wiring layers are used both for bit lines and word lines, and transfer transistors and cell plates are formed of polycrystalline silicon films. CONSTITUTION:Active regions 101 and polycrystalline silicon films 102 form transfer gates and cell plates at every other piece. Bit lines 104 are formed of the first aluminum layers, and are connected to the cells through contacts 103. Polycrystalline silicon word lines are connected to the first aluminum layers 105 through the contacts 103, and moreover connected to the word lines 107 formed of the second aluminum wiring layers through through-holes 106.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor integrated circuit device, and particularly to a memory device.

As methods for realizing large-capacity storage devices, dynamic,
Mesori cells, especially l-transistor/cell systems, are common, and a higher degree of integration is achieved by employing a two-layer polycrystalline silicon film structure.

However, in order to realize the 256-bit storage device, there is a problem that a high yield cannot be obtained unless the process steps are simplified. A circuit format shown in FIG. 1 was proposed to realize integration. Note that Figure tJJ1 is a plan view, and Figure 1 (B) is a circuit diagram. In this method, adjacent word lines form transfer gates and capacitance plates of cells in contact with the iII. If a polycrystalline silicon film is used for the word line, the wiring resistance of the word line is large, so writing A large amount of noise is generated on the word line during reading.

The drawback was that cell information was lost. As a method to solve this drawback, a method has been proposed in which a high melting point metal film is used as a substitute for the polycrystalline silicon film in the gate electrode.
There is a problem in that the reliability of changes over time in the characteristics of transistors and memory devices is significantly inferior to that of polycrystalline silicon gate systems.

An object of the present invention is to propose a highly reliable semiconductor memory device with simple manufacturing process steps.

The memory device according to the invention is a one transistor/cell dynamic in which adjacent polysilicon word lines form transfer gates and capacitance plates of adjacent cells.

In the memory device, the IFj feature includes an aluminum wiring connected to the polycrystalline silicon word line through a plurality of contacts and serving as a low-resistance backing wiring for the word line.

According to this invention, aluminum wiring can be formed in both the X and Y directions, and the storage device can operate at high speed, has a simple process, and can lower the word line resistance to a required value, resulting in a highly reliable memory device. Next, an embodiment of the present invention will be described with reference to the drawings.The first section is a plan view of one embodiment.In the figure, 101 defines an active region, 102 is a polycrystalline silicon film and forms a transfer gate and a cell plate for every other cell.A bit line 104 is made of first aluminum and is connected to the cell through a contact 103. The polycrystalline silicon word line 102 is connected to the first aluminum film 1 through 103.
A word line 107 is connected to 05 and further formed by a second aluminum wiring through a through hole 106.
is connected to.

FIG. 2 is a sectional view taken along the line AA' in FIG. 1 (5). 201 is a p-type silicon substrate, and 202 is a field oxide film. 203 is a capacitor gate oxide film, 204
is the transfer gate oxide film, 9,205,206
are a cell plate and a transistor gate ttrjX formed of a polycrystalline silicon film. Bit #209
is made of first aluminum and is connected to the cell portion through a diffusion Nk207. The second aluminum wiring 211 passes through the upper part of the cell, and the interlayer insulating films 208 and 210 separate the polycrystalline silicon and the first aluminum arrangement, and the first aluminum wiring and the second aluminum wiring, respectively.

In the dormitory example, aluminum wiring is used for both the bit line and the word line, making it possible to achieve high-speed operation. Also, the transfer transistor and cell plate are
Since it is formed from a polycrystalline silicon film, a highly reliable device can be realized. Since the resistance value of the word line can be lowered to a desired value, word line noise can be minimized and stable operation can be achieved.

[Brief explanation of drawings]

Fig. 1 (b) is a plan view and a sectional view of an embodiment of the invention in the first section and Fig. 2 is a diagram of a part of the first section. In the figure, 101... active region, 102...
・Polycrystalline silicon fist word line, 103...Contact, 104...First aluminum wiring *<bit &), 105...Second aluminum wiring (
(for word line lining), 106...Through hole, 107...Second aluminum word line, 2
01...p-type silicon:", t[%202...
...Field oxide film, 203...Capacitance gate oxide film, 204...Transfer φ gate oxide film, 205...Capacity plate polycrystalline silicon J
IL2os...Transfer K) Polycrystalline silicon film, 207...N diffusion layer for bit line, 2
08...First interlayer insulating film, 209...
・First aluminum wiring (biy)*), 210...
. . . second interlayer insulating film, 211 . . . second aluminum dispersion (word l/iA).

Claims (2)

[Claims] (1) A semiconductor integrated circuit device using an insulated gate field effect transistor using a polycrystalline silicon film as a gate electrode, in which a polycrystalline silicon word line is used as a transfer line.
In a one-transistor/cell memory device forming the gate and capacitive plate of another cell, the word line is connected through a plurality of contacts to the polycrystalline word line, and the word line has a low resistance. A semiconductor memory device characterized by having an aluminum layer serving as a chemical backing layer. (2) The material of the word string low-resistance backing wiring is aluminum, and the wiring piece material of the bit line is also made of aluminum, resulting in an aluminum two-layer wiring structure. The semiconductor integrated circuit device according to item (1).