JPS6318656A - Resistor for semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To implement high density in layout, by providing two opening parts in a silicon film so that a specified distance is provided from the periphery of the silicon film in an insulating film, which covers the silicon film, and connecting the silicon film and an electrode on an insulating film. CONSTITUTION:An insulating film 3 is attached so as to cover a silicon film 2, which is selectively formed on an insulating film 1. The entire silicon film 2 other than contact windows is covered with the insulating film 3. The silicon film 2 and electrodes 4 on the insulating film 3 are connected. Thus, the overlapped part is made to correspond to the positioning margin of the insulating film and the electrodes in only one process. High density can be implemented in this layout, and high density interconnection can be also implemented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit device, and particularly to a highly accurate silicon film resistor formed on an insulating film.

[Conventional technology]

Conventionally, a silicon film resistor formed on an insulating film has a structure shown in FIGS. 3 and 4.

FIG. 3 is a plan view thereof, and FIG. 4 is a sectional view thereof. In the figure, 1 is an insulating film, 2 is a silicon film of one conductivity type, such as polyrecon, 3 is an insulating film grown on the surface of the silicon film, 4 is an electrode, and the insulating film 3 is buttered to expose both ends of the silicon film. It is connected to the silicon film through the contact portion.

[Problem that the invention seeks to solve]

In the conventional resistor described above, the electrode 4 is formed so as to cover both ends of the silicon film 2, so that the electrode width needs to include the overlap between the silicon film 2 and the electrode 4 in addition to the resistance width. This overlap is usually about 2μ due to the precision of patterning and the margin of positioning of the electrode process with respect to the silicon film, so for example, if the resistance width is 6μ, the electrode width will be 6+2X2=10μ. For this reason,
The resistance spacing is determined by the electrode spacing, not the silicon coating spacing. For example, if the resistor spacing and electrode spacing are 2μ, the resistor part has a pitch of 8μ, but the electrode part has a pitch of 12μ, which means that the resistor spacing must be made wider than necessary.
The drawback is that a high-density layout cannot be achieved. Furthermore, the width of the wiring is usually about 4 to 6 μm, but in the conventional example described above, the width of the resistive electrode portion is 10 μm, so there is also a problem in increasing the density of the wiring.

[Means for Solving the Problems] The present invention aims to increase the density of the layout by reducing the electrode width of the resistor. That is,
The gist of the present invention is to cover a silicon film with an insulating film, and to form at least two openings on the silicon film in the insulating film at a predetermined distance from the periphery of the silicon film,
This is a resistor for a semiconductor integrated circuit characterized by connecting a silicon film and an electrode on an insulating film.

[Embodiment 1] Next, the present invention will be explained with reference to the drawings. Fig. 1 is a plan view of an embodiment of the present invention, and Fig. 2 is a plan view of a pattern constituting the same.

In the figure, 1 is an insulating film, 2 is a silicon coating, 3 is an insulating film, and 4 is an electrode. The difference from the conventional method is that the silicon coating 2 is entirely covered with an insulating film 3 except for the contact window.

〔Effect of the invention〕

By covering the periphery of the silicon film 2 with the insulating film 1 in this manner, the electrode width is reduced to only the width of the contact window and the overlap between the contact window and the electrode 4. The overlap between the conventional silicon film and the electrode required a margin for positioning in two steps: the silicon film and the insulating film, and the insulating film and the electrode. Since it only requires a margin for positioning, 1μ, which is half of the conventional one, is enough. Therefore, if the contact window is 4μ, the electrode width will be 6μ.

For this reason, for example, if the resistor spacing and electrode spacing are 2μ, the resistors can be designed with an 8μ pitch instead of the conventional 12μ pitch.
It is possible to increase the density of the layout. In addition, with regard to wiring, the width of the electrode part is now 6μ instead of the conventional 10μ due to the present invention.
This made it possible to increase the density of wiring.

Although the area of the contact portion of the resistor according to the present invention is smaller than that of the conventional example, since the contact resistance is about 20Ω with a contact window of 4 μm, it is sufficient to take this into consideration when designing the resistor in advance, and this is not a drawback.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a silicon film resistor according to the present invention, and FIG.
The figures are a sectional view of FIG. 1, FIG. 3 is a plan view of a conventional film resistor, and FIG. 4 is a sectional view of FIG. 3. 1... Insulating film, 2... Silicon coating. 3... Insulating film, 4... Electrode.

Claims (1)

[Claims] A second insulating film is attached to completely cover a silicon film selectively formed on the first insulating film, and at least two insulating films are disposed on the silicon film at a predetermined distance from a periphery of the silicon film. A resistor for a semiconductor integrated circuit, which has two openings and connects the silicon film and an electrode on the second insulating film.