Semiconductor integrated circuit

Abstract

To provide a semiconductor integrated circuit capable of achieving high resistance in a small space.SOLUTION: A plurality of polysilicon resistors 402_1 to 402_n extend in a first direction, are formed adjacent in a second direction, and have the same dimensions. A plurality of polysilicon regions 408 for a first contact are formed to come into contact with both one end of a (2j-1)th polysilicon resistor 402 and one end of a (2j)th polysilicon resistor 402, where j is a natural number. A plurality of first contact regions 404 are formed while overlapping with the plurality of polysilicon regions 408 for the first contact, and wires are pulled out from the first contact regions. A plurality of polysilicon regions 410 for a second contact are formed to come into contact with both the other end of the (2j)th polysilicon resistor 402 and the other end of a (2j+1)th polysilicon resistor 402. A plurality of second contact regions 406 are formed while overlapping with the plurality of polysilicon regions for the second contact, and wires are pulled out from the second contact regions.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to semiconductor integrated circuits. [Background technology]

[0002] In response to the increasing demand for energy conservation in recent years, there is a need to reduce the power consumption of semiconductor integrated circuits. To reduce power consumption in semiconductor integrated circuits, it is necessary to increase the impedance of the current path, which in turn requires resistor elements with high resistance values. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2024-13203

[0004] [overview] The present disclosure has been made in light of such a situation, and one of the purposes of an embodiment thereof is to provide a semiconductor integrated circuit that can achieve high resistance in a small space.

[0005] An embodiment of the present disclosure relates to a semiconductor integrated circuit including a resistor string, wherein the resistor string includes a plurality of polysilicon resistors extending in a first direction and adjacently formed in a second direction, the plurality of polysilicon resistors having the same dimensions, a plurality of first polysilicon contact regions each formed to contact one end of the (2j-1)th polysilicon resistor and one end of the (2j)th polysilicon resistor, where j is a natural number, a plurality of first contact regions each formed to overlap the first polysilicon contact regions and to which wiring is drawn, a plurality of second polysilicon contact regions each formed to contact one end of the (2j)th polysilicon resistor and one end of the (2j+1)th polysilicon resistor, and a plurality of second contact regions each formed to overlap the second polysilicon contact regions and to which wiring is drawn.

[0006] Another aspect of the present disclosure relates to a semiconductor integrated circuit including a resistor string, the resistor string including a plurality of polysilicon resistors each having a U-shape, the same dimensions, and arranged in one direction, and a plurality of contact polysilicon regions formed to contact both one end of the jth polysilicon resistor and the other end of the (j+1)th polysilicon resistor, where j is a natural number.

[0007] Any combination of the above components, or mutual substitution of the components or expressions of the present disclosure between methods, devices, systems, etc., are also valid aspects of the present disclosure. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an equivalent circuit diagram of a semiconductor integrated circuit according to an embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of one resistor element in the comparative technique. [Figure 3] FIG. 3 is a layout diagram of a resistor string according to a comparative technique. [Figure 4] FIG. 4 is an enlarged view of a portion of the resistor string of FIG. [Figure 5] FIG. 5 is a layout diagram of a resistor string according to the embodiment. [Figure 6] FIG. 6 is an enlarged view of a portion of the resistor string of FIG. [Figure 7] FIG. 7 is a layout diagram of a resistor string according to the first modification. [Figure 8] FIG. 8 is a layout diagram of a resistor string according to the second modification.

[0009] [Detailed explanation] (Outline of the embodiment) A summary of some exemplary embodiments of the present disclosure is provided. This summary is intended to provide a simplified overview of some concepts of one or more embodiments in order to provide a basic understanding of the embodiments as a prelude to the more detailed description that follows. It is not intended to limit the scope of the invention or disclosure. Furthermore, this summary is not an exhaustive overview of all possible embodiments, nor does it limit essential elements of the embodiments. For convenience, the term "one embodiment" may refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed herein.

[0010] A semiconductor integrated circuit according to one embodiment includes a resistor string, the resistor string including: a plurality of polysilicon resistors extending in a first direction and adjacently formed in a second direction, the resistor string including: a plurality of first polysilicon contact regions each formed in contact with one end of the (2j-1)th polysilicon resistor and one end of the (2j)th polysilicon resistor, where j is a natural number; a plurality of first contact regions each formed overlapping the first polysilicon contact regions and having wiring leading thereto; a plurality of second polysilicon contact regions each formed in contact with the other end of the (2j)th polysilicon resistor and the other end of the (2j+1)th polysilicon resistor; and a plurality of second contact regions each formed overlapping the second polysilicon contact regions and having wiring leading thereto.

[0011] With this configuration, the width of the polysilicon resistor is narrower than half the width of the contact region, and two adjacent polysilicon resistors are connected to one contact region, thereby narrowing the spacing between the polysilicon resistors, thereby achieving high resistance while reducing the area.

[0012] In one embodiment, the polysilicon resistors on both sides of the plurality of polysilicon resistors may be dummy resistors that are not used in the actual circuit, thereby improving the relative accuracy of the plurality of polysilicon resistors.

[0013] A semiconductor integrated circuit according to one embodiment includes a resistor string, which includes a plurality of polysilicon resistors each having a U-shape, the same dimensions, and arranged in one direction, and a plurality of contact polysilicon regions formed so as to contact both one end of a j-th polysilicon resistor and the other end of a (j+1)-th polysilicon resistor, where j is a natural number.

[0014] With this configuration, the width of the polysilicon resistor is narrower than half the width of the contact region, and two adjacent polysilicon resistors are connected to one contact region, thereby narrowing the spacing between the polysilicon resistors, thereby achieving high resistance while reducing the area.

[0015] In one embodiment, the polysilicon resistors on both sides of the plurality of polysilicon resistors may be dummy resistors that are not used in the actual circuit, thereby improving the relative accuracy of the plurality of polysilicon resistors.

[0016] (Embodiment) Preferred embodiments will be described below with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing will be designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. Furthermore, the embodiments are merely examples and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0017] In this specification, "a state in which component A is connected to component B" includes not only a case in which component A and component B are directly physically connected to each other, but also a case in which component A and component B are indirectly connected to each other via other components that do not substantially affect the electrical connection between them or that do not impair the function or effect achieved by their connection.

[0018] Similarly, "a state in which component C is provided between component A and component B" includes not only cases in which components A and C, or components B and C, are directly connected, but also cases in which they are indirectly connected via other components that do not substantially affect the electrical connection state between them or impair the functions or effects achieved by their combination.

[0019] 1 is an equivalent circuit diagram of a semiconductor integrated circuit 100 according to an embodiment. The semiconductor integrated circuit 100 includes a resistor string 110. The resistor string 110 includes a plurality of n resistor elements R1 to Rn connected in series between both ends e1 and e2 of the resistor string 110. In this example, n=11. The resistor string 110 is provided with a plurality of taps T. For example, the resistor string 110 is used as a resistive voltage divider circuit that divides the voltage between a first end e1 and a second end e2.

[0020] For example, the resistor string 110 is used in combination with a selector that selects one of multiple voltages generated at multiple taps T1 to T10. Alternatively, in a circuit such as an A / D converter, multiple voltages generated at multiple taps T1 to T10 are used as reference voltages.

[0021] Before describing the resistor string according to the embodiment, a comparison technique will be described.

[0022] (Comparative Technology) 2 is a diagram showing the configuration of one resistor element 200 in the comparative technology. In a typical design, one resistor element 200 is formed as a single structural unit, which includes a polysilicon resistor 202 extending in a first direction (the y direction in the figure) and two contact regions 204, 206 formed on both ends of the polysilicon resistor 202.

[0023] Therefore, the resistor string 110 according to the comparative technique is configured as a combination of the resistor elements 200 in FIG.

[0024] 3 is a layout diagram of a resistor string 300R according to a comparative technique. The resistor string 300 includes n (n=11) resistor elements 200_1 to 200_n. The n resistor elements 200 are arranged adjacent to each other in a second direction (x direction in the drawing).

[0025] Odd-numbered taps T1, T3, ... are formed on one end side of the plurality of resistive elements 200. When j is a natural number, the contact region 204 of each of the 2j-1-th resistive element 200_(2j-1) and the 2j-th resistive element 200_2j is connected to a wiring 302_(2j-1) to form a tap T(2j-1).

[0026] On the other end side of the plurality of resistive elements 200, even-numbered taps T2, T4, ... are formed. When j is a natural number, the contact region 206 of each of the 2j-th resistive element 200_2j and the 2j+1-th resistive element 200_(2j+1) is connected to a wiring 302_2j, forming a tap T(2j).

[0027] 4 is an enlarged view of a portion of the resistor string 300R of FIG. 3. The minimum size of the contact region 206 in the x direction is assumed to be d. The minimum distance between adjacent contact regions 206 is assumed to be g. In this case, the minimum value W of the length (width) of the resistor string 300R in the x direction is assumed to be MIN teeth, W MIN =n×d+(n-1)×g In other words, the size of the resistor string 300R is limited by the size of the contact region 206 and the spacing between them, making it difficult to reduce the area of ​​the resistor string 300R.

[0028] Next, the resistor string 400 according to the embodiment will be described.

[0029] 5 is a layout diagram of a resistor string 400 according to the embodiment. The resistor string 400 includes a plurality of polysilicon resistors 402, a plurality of first contact regions 404, a plurality of second contact regions 406, a plurality of first contact polysilicon regions 408, and a plurality of second contact polysilicon regions 410.

[0030] Figure 6 is an enlarged view of a portion of the resistor string 400 of Figure 5. Multiple polysilicon resistors 402 extend in a first direction (y-direction) and are formed adjacent to each other in a second direction (x-direction). The multiple polysilicon resistors 402 have the same dimensions.

[0031] Where j is a natural number, the odd-numbered (2j-1)th first contact polysilicon region 408_(2j-1) is formed so as to contact both one end of the (2j-1)th polysilicon resistor 402_(2j-1) and one end of the (2j)th polysilicon resistor 402_(2j).

[0032] The odd-numbered (2j-1)-th first contact regions 404_(2j-1) are formed to overlap with the corresponding first contact polysilicon regions 408_(2j-1). In this example, the first contact regions 404 are formed to be inset with respect to the first contact polysilicon regions 408. Wiring that becomes a tap T(2j-1) is drawn out from each first contact region 404_(2j-1).

[0033] Furthermore, where j is a natural number, the even-numbered (2j)-th second contact polysilicon region 410_(2j) is formed so as to contact both the other end of the even-numbered (2j)-th polysilicon resistor 402_(2j) and the other end of the (2j+1)-th polysilicon resistor 402_(2j+1).

[0034] The even-numbered (2j) second contact regions 406_(2j) are formed to overlap with the corresponding second contact polysilicon regions 410_(2j). In this example, the second contact regions 406 are formed to be inset with respect to the second contact polysilicon regions 410. Wiring that becomes a tap T(2j) is drawn out from each second contact region 406_(2j).

[0035] The above is the configuration of the resistor string 400. Next, its advantages will be explained.

[0036] The minimum size in the x direction of the contact polysilicon regions 408 and 410 is assumed to be d', and the minimum distance between adjacent contact polysilicon regions 408 and 410 is assumed to be g'.

[0037] When k is an integer that satisfies n=2k−1, the minimum value W′ of the length (width) in the x direction of the resistor string 400 in FIG. 5 is MIN is roughly, W' MIN ≒k×d'+k×g' This becomes:

[0038] The comparative technique (FIGS. 3 and 4) and the embodiment (FIGS. 5 and 6) are compared. Assuming that d'≒d and g'≒g, k≒n / 2, so W' MIN ≒W MIN That is, according to the embodiment, the area of ​​the resistor string 400 can be reduced to about half that of the comparative technique.

[0039] Next, a modification of the resistor string 400 will be described.

[0040] (Variation 1) 7 is a layout diagram of a resistor string 400A according to Modification 1. The resistor string 400A has polysilicon resistors 402_0 and 402_(n+1) at both ends thereof as dummy resistors. One end of each of these dummy resistors is open, and they do not contribute to the resistance value of the resistor string 400.

[0041] By providing dummy resistors on both sides, the width of resistor string 400A is slightly wider than resistor string 400 of FIG. 5, but the trade-off is improved relative precision of the multiple polysilicon resistors.

[0042] (Variation 2) 8 is a layout diagram of a resistor string 400B according to Modification 2. In this modification, the polysilicon resistors 402_1 to 402_n have a U-shape (a U-shape with a 90-degree angle) and have the same dimensions.

[0043] When j is a natural number, the jth contact polysilicon region 414_j is formed so as to contact both one end of the jth polysilicon resistor 402_j and the other end of the (j+1)th polysilicon resistor 402_(j+1).

[0044] The j-th contact region 412_j is formed to overlap with the corresponding contact polysilicon region 414_j. A wiring that serves as a tap Tj is drawn out from the j-th contact region 412_j.

[0045] According to the second modification, the width in the x direction is approximately doubled compared to the resistor string 400 in Fig. 3, but the length in the y direction is approximately half that of the resistor string 400 in Fig. 3, so the area remains almost the same. In the second modification, the taps can be formed aligned on the same side.

[0046] In the second modification, dummy resistors may be added to both ends, as in the first modification, thereby further improving the relative accuracy of the polysilicon resistor 402.

[0047] The embodiments described using specific terms merely illustrate the principles and applications of the present invention, and many modifications and changes in arrangement are permitted to the embodiments as long as they do not deviate from the spirit of the present invention as defined in the claims.

[0048] (Addendum) One aspect of the technology disclosed in this specification can be understood as follows.

[0049] (Item 1) A semiconductor integrated circuit including a resistor string, The resistor string comprises: a plurality of polysilicon resistors extending in a first direction and adjacently formed in a second direction, the polysilicon resistors having the same dimensions; a plurality of first contact polysilicon regions formed so as to contact both one end of the (2j-1)th polysilicon resistor and one end of the (2j)th polysilicon resistor, where j is a natural number; a plurality of first contact regions formed to overlap the plurality of first contact polysilicon regions and having wirings drawn out therefrom; a plurality of second contact polysilicon regions formed to contact both the other end of the (2j)th polysilicon resistor and the other end of the (2j+1)th polysilicon resistor; a plurality of second contact regions formed to overlap the plurality of second contact polysilicon regions and having wirings drawn out therefrom; A semiconductor integrated circuit comprising:

[0050] (Item 2) 2. The semiconductor integrated circuit according to item 1, wherein the polysilicon resistors provided on both sides of the plurality of polysilicon resistors are dummy resistors.

[0051] (Item 3) A semiconductor integrated circuit including a resistor string, The resistor string comprises: a plurality of polysilicon resistors each having a U-shape, the polysilicon resistors having the same dimensions, and arranged side by side in one direction; a plurality of contact polysilicon regions formed so as to contact both one end of the j-th polysilicon resistor and the other end of the (j+1)-th polysilicon resistor, where j is a natural number; a plurality of contact regions formed to overlap the plurality of contact polysilicon regions and having wirings drawn out therefrom; A semiconductor integrated circuit comprising:

[0052] (Item 4) 4. The semiconductor integrated circuit according to item 3, wherein the polysilicon resistors provided on both sides of the plurality of polysilicon resistors are dummy resistors. [Explanation of symbols]

[0053] 100 Semiconductor Integrated Circuit 110 Resistor String T1, T2... Tap e1 1st end e2 2nd end 200 Resistor element 202 Polysilicon Resistor 204,206 Contact Area 300 resistor string 302 Wiring 400, 400A, 400B resistor string 402 Polysilicon Resistor 404 First Contact Area 406 Second Contact Area 408 Polysilicon region for first contact 410 Polysilicon region for second contact 412 Contact Area 414 Polysilicon area for contact R1, R2... Resistive elements

Claims

1. A semiconductor integrated circuit including a resistor string, The resistor string comprises: a plurality of polysilicon resistors extending in a first direction and adjacently formed in a second direction, the polysilicon resistors having the same dimensions; a plurality of first contact polysilicon regions formed so as to contact both one end of the (2j-1)th polysilicon resistor and one end of the (2j)th polysilicon resistor, where j is a natural number; a plurality of first contact regions formed to overlap the plurality of first contact polysilicon regions and having wirings drawn out therefrom; a plurality of second contact polysilicon regions formed so as to contact both the other end of the (2j)th polysilicon resistor and the other end of the (2j+1)th polysilicon resistor; a plurality of second contact regions formed to overlap the plurality of second contact polysilicon regions and having wirings drawn out therefrom; A semiconductor integrated circuit comprising:

2. 2. The semiconductor integrated circuit according to claim 1, wherein the polysilicon resistors provided on both sides of said plurality of polysilicon resistors are dummy resistors.

3. A semiconductor integrated circuit including a resistor string, The resistor string comprises: a plurality of polysilicon resistors each having a U-shape, the polysilicon resistors having the same dimensions, and arranged side by side in one direction; a plurality of contact polysilicon regions formed so as to contact both one end of the j-th polysilicon resistor and the other end of the (j+1)-th polysilicon resistor, where j is a natural number; a plurality of contact regions formed to overlap the plurality of contact polysilicon regions and having wirings drawn out therefrom; A semiconductor integrated circuit comprising:

4. 4. The semiconductor integrated circuit according to claim 3, wherein the polysilicon resistors provided on both sides of said plurality of polysilicon resistors are dummy resistors.

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