JPS5821365A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To obtain the titled IC with a remarkably matched element by adding a completely unrelated non-resistance pattern besides an original resistance pattern so that the conditions of the peripheral pattern distribution of resistors to be mutually matched are euqlized. CONSTITUTION:Floating diffusing regions D1, D2 are formed outside the parallel resistance elements A, B, and both ends of the elements A, B are each connected to wiring 1, 4 and parallel resistance is shaped. The resistance element C which must be matched with the elements A, B is mounted while being separated from the elements A, B while floating diffusing regions D3, D4 are molded at the both sides. A section between the region D1 and the element A, a section between the elements A, B, a section between the element B and the region D2 and sections among the element C and the regions D3, D4 are all made the same size, and the length of each floating region is made the same length as the elements. The conditions of the peripheral pattern distribution of the resistors according to this constitution are equalized, the elements A-C can be formed accurately in the same shape and size, and the IC with the remarkably matched resistance elements is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor integrated circuit device having resistors that require mutual matching, and a device having a plurality of resistors that require the same 4IK peripheral pattern distribution.

Resistors in semiconductor integrated circuit devices are selectively formed by a photosin injection method, a doped oxide method, or the like. In particular, the resistor pattern is created by etching using a mask pattern. A method of forming a resistance region by introducing impurities such as boron, phosphorus, antimony, and arsenic is also used.

On the electronic circuit, the characteristics matched %. In other words, when forming a semiconductor element that requires matching, conventionally, two or more matching elements are used to overcome the effects of variations in layer resistance during impurity diffusion and variations in element dimensions during diffusion mask fabrication. Pattern design has been carried out by arranging the pipes so that the pipes are arranged as close as possible, and the shape and direction of the pattern are 1-.

This is considered to be due to the fact that it is not possible to correct deviations in element dimensions from design values due to interference between patterns during photoetching. In other words, Photo 1: In the true etching technique, patterns drawn on a mask are printed onto a photoresist (photosensitive resin) coated on a silicon substrate by a contact exposure method or a projection exposure method, but at this time the element pattern is When using a negative type photoresist, the areas exposed to light will undergo a photopolymerization reaction and harden, and the areas not exposed to light will be removed by development. matches the element pattern. Therefore, when forming three resistors arranged in parallel, parts other than the resistor pattern are irradiated with light. The exposed areas outside the resistor patterns located at both left and right ends when viewed from the defined plane are more Li than the exposed areas at the t portions (both sides of the central resistor pattern) that are sandwiched between the resistor patterns. As a result, the amount of light irradiated varies depending on the area, and the outer regions receive a lot of light and the degree of polymerization is dense, but the area between the patterns has a small amount of irradiation and the degree of polymerization is coarse. ◎Moreover, as the pattern spacing becomes narrower with miniaturization, the degree of polymerization further decreases. Therefore, in the fixing (rinsing) process during development, the portions that were not sufficiently polymerized (the portions sandwiched between the resistor patterns) are not dissolved. On the other hand, since the outside of the resistance pattern located at both ends of the resistor pattern is sufficiently polymerized, the above-mentioned dissolution is small. Therefore, the width of the resistor pattern at the center inevitably becomes wider than that at both ends, resulting in variations in resistance values.

On the other hand, when using a positive resist, the exposed areas are removed so that the bright areas of the mask match the resistor pattern. Therefore, in this case, the areas of the exposed resist regions are equal. However, the part corresponding to the dark area sandwiched on both sides by the resistor pattern (both II of the center resistor pattern)
), the light goes around from the resistor pattern (bright part) that is in contact with lI, and due to refraction and reflection, the patterns are narrow and mutual interference occurs. exposed to light.

On the other hand, the resistor patterns at both ends of the resistor pattern are unaffected by light from the outside, and the unnecessary exposure is approximately half as high. The result is 9
The width of the resistor pattern at the center becomes wider than the widths of the resistor patterns at both ends, resulting in large variations in resistance values.

Therefore, when using the conventional photolithography method, for example, three slits having the same width are formed parallel to each other at equal intervals.

In the baked resist pattern, the width of the center slit is wider than the width of the slits on both sides. In this way, when forming a semiconductor device that requires conventional alignment, it is difficult to achieve the desired alignment by simply arranging the pattern. I can't get it. Furthermore, during the transfer of the pattern during mask production, the above-mentioned development will cause the mask pattern itself to not have the dimensions as designed, which will increase the deviation of the pattern dimension from the dazzle value. Object of the Invention According to the present invention, the conditions of the peripheral pattern distribution of the resistors to be mutually matched are made the same, so that In addition to the resistance pattern, an unrelated non-resistance pattern from the road side is added.

Next, referring to FIG. ifi, the semiconductor integrated circuit I according to the present invention! Let's clarify a direct example. ◎ Figure 1g1 shows a case where a resistance element is formed whose resistance value is required to have a ratio of 1:2, and three diffused resistance elements A, B, and e having the same shape and dimensions are formed. Semiconductor groups [K] are formed by parallel etching at equal intervals. One end of each of the resistive elements A and B is connected through the aluminum contact parts 2 and 3t.

The other end is connected to EII4 through contact portions 5.6t, respectively. Both ends of resistive element C are connected to traces 8 and 9 through contacts (6.7), respectively. Resistance elements A, B, and e have the same shape and size, and have the same impurity content, so if their respective resistance values are taken into account, the arrangement is 1!1.
The resistance value between BI2. The resistance value between the wires 8°9 is 几. However, in the past, it has not been possible to make the resistive elements A, B, and Ct exactly the same shape and size.

In this invention, in order to make the peripheral pattern distribution of the resistive elements A, B, and C the same, these resistive elements A, B, and C are connected to each other in a circuit (unrelated floating diffusion region DI).

D2 is provided. Diffusion region D1 is element B of resistance element A.
On the opposite side, the elements A and B are arranged parallel to each other with an interval dl equal to the interval d1 between them, and their length Jl is the same as that of elements i, B, and e. Similarly, floating diffusion regions having a length of 11 are provided on the opposite side of the resistive element C from the element B, parallel to each other with an interval ALT. The widths of the regions Dt and Di do not need to be the same as the widths of the resistive elements A, B, and C.

According to the above configuration, the peripheral pattern distribution conditions of each pattern of resistive elements A, B, and C are exactly the same9. Floating regions Dt, D! at the same time as the friend resist patterns forming resistive elements M, B, CI! A resist pattern for each element is also formed at the same time.
The effects on B and CK are exactly the same9. A thousand resistors with the same dimensions.

B and C are obtained, and the width of element B is never larger than the six widths of elements A and C.

In Fig. 182, resistor elements arranged in parallel to each other, B
Floating diffusion regions Dt, Dzt- are formed outside of.

Both ends of the resistance elements M and B are connected to the arrangement @1 and 4, respectively, to form a parallel resistance. These are resistive elements.

A resistive resistive element C is formed apart from and matched with B, with floating diffusion regions DB, D4 on both sides of the resistive element C.
are formed simultaneously. Area DI element network.

The distances between elements A and B, between element B region D8, and between element C and regions Dz and D4 are all the same. In this case as well, the dimensions of resistance elements A, B, and C must be strictly 1! ! can be matched. FIG. 3 shows a case where another element E-IIX is formed in place of the floating region D2 in FIG. 111. The spacing between elements E and 0 is dl.

-For example, the resistance pattern width is 10s and the pattern interval is 1
In the case of 0μ, Tokyo Ohka Kogyo negative resist (L) MR
-83), the thickness of the silicon oxide film is 0.7μ,
Hydrofluoric acid and ammonium fluoride were used as the etching solution.
In the conventional resistor formed with the buffer art i (F) of 6, the matching part between both ends and the center was 2 to 5X, which was within IX in this example. For example, in FIG. 1, after pattern formation, after exposure and development, there is no resist in the areas of patterns A, B, C, DI, and D2, and the other areas are exposed. The polymerized resist remains, but pattern A is the opposite.

The present invention is also applicable to the case of using a positive type photoresist in which the B, e, Dt, and Di portions are irradiated with light and those portions are removed.

[Brief explanation of drawings]

The s1 diagram is an example of the invention i & 2 which requires alignment.
FIG. 2 is a plan view showing a case in which two resistance elements are arranged side by side, FIG. Melt. A, 13. G: Resistance element as a semicircular element. L)l, L)2. D3. D4: Engraving of floating diffusion region drawing (no change in content) 1. 2. Procedural amendment (1 set) / 1. Indication of incident 1988 Patent Application No. 504
No. 08 No. 2, Title of the invention: Semiconductor integrated circuit device 3,
Relationship with the case of the person making the amendment Applicant: 5-33-1-6, Shiba 5-chome, Minato-ku, Tokyo Description and drawings to be amended 7 Contents of the amendment

Claims (1)

[Claims] Each resistor has a strip-shaped resistor of Ila having substantially the same resistance, and for a resistor that does not have a resistor adjacent to either the left or right side of the plurality of resistors, the resistor is identical to the resistor. A semiconductor integrated circuit device characterized by having a non-resistive element made of a material arranged therein.