JPS61168252A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To form a resistor having a small occupying area by superposing the first and second polycrystalline silicon films through an insulating film, and connecting them by a side wall. CONSTITUTION:The first polycrystalline silicon film 12 of high resistivity having a slender pattern is formed on the first insulating film 22 formed on a semiconductor substrate, and the surface is coated with the second insulating film 13. One side wall 14 of the film 12 is exposed, and the second polycrystalline silicon film 15 of high resistivity having a slender pattern connected with the side wall region 15 is formed. The third insulating film 16 is formed on the surface of the film 15, and an electrode 17 is formed on the film 16. Thus, since the second resistor L2 can be superposed on a resistor L1, the occupying area of the resistor can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a semiconductor device and a method for manufacturing the same, and particularly a semiconductor device including a polycrystalline silicon resistor that occupies a small area and has a high resistance value, and a method for manufacturing the same. Regarding.

[Conventional technology]

Conventionally, a polycrystalline silicon resistor with a high resistance value has been formed using only the first polycrystalline silicon rib (1) as shown in FIG. Along with this, it has become necessary to reduce the area occupied by the polycrystalline silicon crotch 1.For this purpose, in order to obtain the same resistance value, the width W of the resistor must be narrowed, and the length L must also be shortened accordingly. was the conventional method.

[Problem that the invention seeks to solve]

However, in order to reduce the occupied area, the width W of the resistor is narrowed to obtain the same resistance value, and the length L is accordingly reduced.
However, considering the current state of lithography technology, it is difficult to accurately form W to 1.0 μm or less, and this has the drawback that the area occupied by the resistor cannot be reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device equipped with a polycrystalline silicon resistor that eliminates the above drawbacks and occupies a small area, and a method for manufacturing the same.

[Failure to solve the problem]

A semiconductor device according to a first aspect of the present invention includes a first insulating film selectively formed on a surface of a semiconductor substrate, and a high resistivity film having an elongated pattern extending and formed on the first insulating film. A first polycrystalline silicon film, a second insulating film surrounding the first polycrystalline silicon film, and a second insulating film connected to at least an exposed sidewall region at one end of the first polycrystalline silicon film. a second polycrystalline silicon film with high resistivity having an elongated pattern formed overlapping the first polycrystalline silicon film through a second insulating film; and a third polycrystalline silicon film covering the second polycrystalline silicon film. and an insulating film.

Further, the method for manufacturing a semiconductor device according to the second invention of the present invention includes:
A step of forming a first polycrystalline silicon film with high resistivity on the surface of the semiconductor substrate on which the first insulating film is selectively formed, a step of selectively removing the polycrystalline silicon film, and a step of selectively removing the polycrystalline silicon film. forming a second insulating film on the surface of the silicon film; selectively removing the second insulating film to expose a part of the surface of the first polycrystalline silicon film; forming a second polycrystalline silicon film with high resistivity in contact with the surface of the insulating film and the exposed surface of the first polycrystalline silicon film, and a third polycrystalline silicon film covering the second polycrystalline silicon film. The method includes a step of forming an insulating film.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an embodiment of the present invention. As shown in FIG. 1, 11 is a silicon oxide film which is a first insulating film formed on a semiconductor substrate. A first polycrystalline silicon film 12 having an elongated pattern and high resistivity is formed on this silicon oxide film 11, and the surface of the first polycrystalline silicon film is covered with a second insulating film 13. I'm sorry,
At least a sidewall region 14 is exposed at one end of the first polycrystalline silicon film, and a high-resistivity second polycrystalline silicon film 15 having an elongated pattern connected to the sidewall region 14 serves as a second insulating film. The first polycrystalline silicon film is formed so as to extend over the first polycrystalline silicon film. The surface of the second polycrystalline silicon film 15 is covered with a third insulating film 16, and the third insulating film 16 has a structure in which an electrode 17 is provided through an opening. As for the resistor in FIG. 1, the resistor of this embodiment is obtained by adding a resistor L2 overlapping the conventional resistor L1.

FIGS. 2(a) to 2(C) are cross-sectional views showing an embodiment of the present invention in the order of steps to explain it. This example can be implemented through the following steps.

First, as shown in FIG. 2(a), a semiconductor substrate 21,
An oxide film 22 as a first insulating film selectively provided on one surface of this substrate, a source/drain region 23, and a polycrystalline silicon film 24 as a gate electrode are formed by a known method. An opening is formed in the oxide film 25 previously provided on the source/drain region 23. Then, as shown in FIG. Subsequently, a first polycrystalline silicon film 26 with high resistivity is deposited so that it contacts the source/drain region 23 at the opening and forms the oxide film 22.
extend to the surface of

Next, as shown in FIG. 2(b), a second insulating film 27 is formed on the surface of the first polycrystalline silicon film 26. As the second insulating film 27, a silicon oxide film or a silicon nitride film is suitable. Next, the second insulating film 27 is selectively removed so that at least the sidewall region 28 of the first polycrystalline silicon film 26 is exposed. Subsequently, a second polycrystalline silicon film Iji 29 with high resistivity is deposited on top of the second insulating film 27 and brought into contact with the first polycrystalline silicon film 26 in the sidewall region 28 .

Finally, as shown in FIG. 2C, a third insulating film 30 is formed on the surface of the second polycrystalline silicon film 29, and a fluid phosphosilicate glass film 31 is further formed on the upper surface of the third insulating film 30. By forming the metal electrode 32 in contact with at least the second polycrystalline silicon film 30 after reducing the level difference, a semiconductor device including a polycrystalline silicon resistor that occupies a small area according to this embodiment is formed. can.

〔Effect of the invention〕

As explained above, according to the present invention, the first polycrystalline silicon layer and the second polycrystalline silicon film are formed in an overlapping manner with an insulating film interposed therebetween, and are connected at the side wall region, so that only the overlapping portion has resistance. Since the length can be increased, the area occupied by the resistor can be reduced without reducing the element size, which is effective for increasing the density of semiconductor devices. Moreover, this structure can be easily manufactured by the method of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a simplified diagram of an embodiment of the present invention, and FIGS. 2(a) to (
C) is a cross-sectional view shown in order of steps for explaining the method of one embodiment of the present invention, and FIG. 3 is a cross-sectional view of a resistor portion of a conventional semiconductor device. 1... First polycrystalline silicon side, 11...
...First insulating film, 12... First polycrystalline silicon film, 13... Second insulating film, 14...
...Side wall region, 15...Second polycrystalline silicon film, 16...Third insulating film, 17...
Electrode, 21... Semiconductor substrate, 22...
1st &tllP%, 23...source/drain, 24...gate electrode, 25...
Silicon oxide wire, 26...First polycrystalline silicon material, 27...Second insulating film, 28...
- Side wall region, 29... second polycrystalline silicon crotch, 30... third edge 1tiigllL31...
...Phosphorsilicate glass It cost, 32... Electrode. Figure 2

Claims (1)

[Claims] (1) a first insulating film selectively formed on the surface of a semiconductor substrate; a first polycrystalline silicon film with high resistivity having an elongated pattern extending over the first insulating film; a second insulating film covering the first polycrystalline silicon film;
A second polycrystalline silicon film having a high resistivity and having an elongated pattern connected to at least the exposed sidewall region at one end of the polycrystalline silicon film and overlapping the first polycrystalline silicon film via a second insulating film. A semiconductor device comprising: a polycrystalline silicon film; and a third insulating film covering the second polycrystalline silicon film. (2) forming a first polycrystalline silicon film with high resistivity on the surface of the semiconductor substrate on which the first insulating film is selectively formed; and selectively removing the polycrystalline silicon film; forming a second insulating film on the surface of the polycrystalline silicon film; selectively removing the second insulating film to expose a part of the surface of the first polycrystalline silicon film; forming a second polycrystalline silicon film with high resistivity in contact with the surface of the second insulating film and the exposed surface of the first polycrystalline silicon film; and covering the second polycrystalline silicon film. A method for manufacturing a semiconductor device, comprising the step of forming a third insulating film.