JPH09330984A - Layout converting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the number of via holes without greatly changing a layout. SOLUTION: At the time of increasing the number of via hole belonging to a main terminal 50a of a transistor element having one via hole 60 based on the specification for a requested layout, a position where a new via hole communicated with the via hole 60 can be formed without being obstructed by the end of the terminal 50a and already laid wiring 53 in four directions in both the vertical and the horizontal directions is searched. When the position is found as a result of the search, the new via hole is added and, at the same time, the added via hole is connected to the via hole 60 through new wiring. Consequently, the change of the layout can be suppressed, because the position and shape of the terminal 50a are not changed and the position of the wiring 53 is not changed. Therefore, the advantage of the already existing layout can be put in practical use in the new layout.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a layout conversion device for converting an existing layout drawing of a semiconductor device based on required layout specifications, and in particular, it is possible to increase the number of vias by reducing layout changes. For improvement to do.

[0002]

2. Description of the Related Art A layout drawing of a semiconductor device typified by a semiconductor integrated circuit is created manually or by an automatic placement and routing device based on a circuit diagram and layout specifications designed in advance. Here, the layout specification is a design rule (that is, the minimum spacing between wirings such as metal wiring,
Rule regarding minimum distance between via holes for connecting terminals of elements and wiring), wiring width, shape of elements such as transistors, shape of via holes (simply referred to as “via” in this specification) Includes specifications such as.

Further, the layout specification further includes the number of vias per terminal (in this specification, simply "the number of vias").
(Hereinafter referred to as “the upper limit value”), for example, information such as the upper limit value of the number of vias connecting terminals such as the source and drain of the transistor element and the wiring. The automatic placement and routing apparatus inputs the circuit diagram information (information representing the circuit diagram) of the semiconductor device (target device) to be laid out and the layout specification, and based on the automatic placement and routing program, the layout drawing of the target device. Is automatically generated.

Appropriate layout specifications may differ depending on the manufacturing cost and timing of the semiconductor device, the nature of the semiconductor device to be manufactured (eg, power consumption, operating speed, etc.). Therefore, after a layout drawing is created based on a certain circuit diagram and a certain layout specification (hereinafter referred to as "old layout specification"), a layout specification different from the same circuit diagram (hereinafter referred to as "required layout specification") It may be necessary to create a new layout drawing based on the above.

At this time, based on the circuit diagram and the required layout specification, it is shorter and less time to convert an existing layout drawing than to create a new layout drawing manually or by an automatic placement and routing apparatus. New layout drawings can be created at a cost, which may be advantageous in terms of efficiency and cost. At that time, it is possible to perform the conversion manually, but if the scale of the target device is large and there are many portions to be converted, the manual conversion requires a great deal of time and cost. It is customary to perform the conversion using a layout conversion device that automatically executes the conversion based on a program.

There is a case where an appropriate processing process is different depending on the manufacturing cost and manufacturing time of the target device, the nature of the target device to be manufactured, etc., but the resistance value of the wiring, the capacitance value, and the resistance value of the via depending on the processing process. Since the capacitance values and the like are generally different, it is generally necessary to improve the quality of the manufactured target device in terms of reliability, manufacturing cost, power consumption, or operating speed by increasing or decreasing the number of vias.

For example, when the resistance value of the via is excessively large, by increasing the number of vias, the resistance value between the wiring and the terminal of the transistor element can be lowered and the operation speed can be improved. 9 and 10 show examples of layouts having different numbers of vias. In these figures, 8
0a and 80b are a pair of main terminals such as a source terminal and a drain terminal of the transistor element, 81 is a gate terminal of the transistor element, 83 is a wire, 84 is a via, and 85 is an extension part of the wire 83. is there.

In the layout example shown in FIG. 9, the wiring 83 and the main terminal 80a are connected by one via.
On the other hand, in the layout example of FIG. 10, the wiring 83 and the main terminal 8
0a is connected by five vias, and the resistance value between the wiring 83 and the main terminal 80a is about 1/5 in comparison with the layout example of FIG. By using the layout conversion device, for example, the layout drawing shown in FIG. 10 can be automatically obtained based on the layout drawing of FIG. 9 based on the old layout specification and the required layout specification.

[0009]

However, in the conventional layout conversion device, as disclosed in, for example, Japanese Patent Laid-Open No. 6-332982, the rule regarding the number of vias differs between the old layout specification and the required layout specification. If
In particular, when the number of vias is increased in layout conversion, other layout parts (for example, the positions and shapes of elements such as transistor elements, and wiring paths) may be changed significantly. There is a problem in that the features of the layout drawing may not be utilized and may not be practical. Therefore, when it is necessary to increase the number of vias without changing the layout as much as possible, it is necessary to manually convert the vias, which requires a lot of time and labor.

The present invention has been made in order to solve the above-mentioned problems in the conventional device, and an object thereof is to provide a layout conversion device capable of increasing the number of vias while suppressing a layout change. To do.

[0011]

According to a first aspect of the present invention, there is provided a layout conversion device for changing an existing layout drawing on the basis of a required layout specification, in which layout information expressing the layout drawing and the required layout specification are expressed. And a storage unit that stores the required layout specification information to be updated, and the layout information can be updated.
An unprocessed via search unit that sequentially selects an unselected one as an unprocessed via from among the vias on the latest layout drawing expressed by the latest layout information stored in the storage unit; and the unprocessed via search Every time an unprocessed via is selected in the copy section, a via which determines whether or not the number of vias of the terminal to which the unprocessed via belongs on the latest layout drawing is less than the upper limit value specified in the required layout specification. A number determination unit,
It is possible to add a new via on the terminal to which the unprocessed via that has passed the judgment belongs, within the range of the required layout specification, and to connect the unprocessed via with a linear wiring. A via installation position investigation unit that investigates whether or not a position exists based on the latest layout information, and a new via is added to a position that has passed the judgment of the via installation position inspection unit, and the unprocessed A via installation unit that updates the layout information of the storage unit so as to connect to the via with a linear wiring. Then, the via installation position investigation unit proceeds with investigation from the unprocessed via along one or more predetermined directions, and neither the end of the terminal nor the existing wiring becomes a barrier within the range of the required layout specification. Further, it is characterized in that it is determined whether or not there is a position where a new via connected to the unprocessed via by a linear wiring can be added.

The device of the second invention is the layout conversion device of the first invention, wherein the via installation position examining unit determines whether or not the existing wiring becomes a barrier, and determines the existing wiring by the required layout. Within the range of specifications, it is allowed to push back in the direction of advancing the survey, the via installation portion, the position passed for the condition of pushing away the existing wiring in the judgment of the via installation position survey unit, the position concerned A new via is added to connect the unprocessed via with a linear wiring, and at the same time, the layout information of the storage unit is updated so that the existing wiring is pushed away according to the condition. It is characterized by

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> FIG. 1 is a block diagram showing a configuration of a layout conversion apparatus according to a first embodiment. In FIG.
11 is a layout storage unit, 12 is a required layout specification storage unit, 13 is an input processing unit, 14 is a via installation position searching unit,
Reference numeral 15 is a via installation unit, 17 is a layout conversion result storage unit,
Further, 111 to 116 are signal lines. In addition, in FIG. 1, the arrow attached to the signal line represents the direction of movement of the signal.

The layout storage unit 11 is a storage device having, for example, a semiconductor memory or a magnetic memory,
Layout information that represents the layout drawing to be converted (eg, transistor element position, via position,
The route of wiring such as metal wiring) is stored. The required layout specification storage unit 12 is also a storage device having a semiconductor memory, a magnetic memory, etc., and information corresponding to the required layout specifications (for example, the minimum distance between wirings, the minimum distance between vias, the upper limit value of the number of vias, etc.). The required layout specification information is stored.

The input processing unit 13 includes a layout storage unit 11
The layout information stored in the request layout specification information is received via the signal line 111, and the required layout specification information is received from the required layout specification storage unit 12 via the signal line 112.
Further, the via installation position searching unit 14 receives the layout information and the required layout specification information via the signal line 113.
Transfer to.

The via installation position searching section 14 receives the layout information and the required layout specification information, and can additionally install vias on the terminals of the element such as a transistor element within the range satisfying the required layout specification. You can search for a position on the layout drawing. When the position where the via can be installed is found, the coordinates of the position and the layout information are transferred to the via installation unit 15 via the signal line 114.

The via installation part 15 is a via installation position searching part 1.
4, the coordinates of the position where the via can be installed and the layout information are received, and the via is generated at the position on the layout drawing designated by the coordinate. Further, the generated via and the via already installed in common with the via on the common terminal are connected by wiring. That is, the change corresponding to this operation is added to the layout information. And
The changed new layout information is transferred to the via installation position searching unit 14 via the signal line 115.

The via installation position searching unit 14 is used for the via installation unit 1.
The new layout information in which the vias are installed, which is transferred from 5, is received. Then, the via installation position searching unit 14
Further search for locations where vias can be installed within the range that meets the required layout specifications. This search is repeated until there is no position where a via can be installed within the range that satisfies the required layout specification.

The via installation position searching unit 14 transfers the coordinates of the position and the layout information at that time to the via installation unit 15 via the signal line 114 each time a position is newly found, and the via installation position is searched. After the via is installed in the unit 15, new layout information in which the via is installed is received from the via installing unit 15. If the position no longer exists, the layout information after conversion held by the via installation position searching unit 14 at that time is transferred to the layout conversion result storage unit 17 via the signal line 116.

The layout conversion result storage unit 17 is a storage device having a semiconductor memory, a magnetic memory, etc., and stores the converted layout information transferred from the via installation position searching unit 14.

FIG. 2 is a block diagram showing the internal structure of the via installation position searching unit 14. As shown in FIG. 2, the via installation position searching unit 14 includes a storage unit 21 and an unprocessed via searching unit 2.
2, a via number determination unit 23, a via installation position investigation unit 24, and a via installation position transfer unit 25. Storage unit 21
Stores the layout information and the required layout specification information transferred from the layout storage unit 11 and the required layout specification storage unit 12. Further, the stored layout information is constantly updated with new layout information transferred from the via installation unit 15. That is, the storage unit 21 always stores new layout information.

FIG. 3 is a flow chart showing the procedure of processing executed by the via installation position searching unit 14 and the via installation unit 15. In FIG. 3, X is the upper limit value of the number of vias, which is included in the required layout specifications. Further, steps S1 to S5 are executed by the via installation position searching unit 14, and step S6 is executed by the via installation unit 15. The via installation position searching unit 14 will be described below with reference to FIGS. 2 and 3.
The operation of the via installation portion 15 will be described in detail.

As shown in FIG. 3, when the process is started,
In step S1, it is determined whether or not the processing has been completed for all vias on the layout drawing represented by the layout information. If step S1 is not the first time but after step S6 described later, all the vias including the vias installed in step S6, that is, the vias newly installed by the via installing part 15 are determined. Be the target.

That is, it is always determined whether or not the processing has been completed for all vias on the layout drawing corresponding to the new layout information at that time. If all vias have been processed, the process ends. If there is an unprocessed via, the process proceeds to step S2, and one via is selected from the unprocessed vias. Then, the identification name for identifying the selected via is set in the variable v. The variable v is a variable that stores the identification name of the via. The processing of steps S1 and S2 is executed by the unprocessed via search unit 22.

Next, in step S3, the via number determination unit 23 determines that the number of vias on the terminal where the via v (the via whose identification name is set in the variable v) is set to the upper limit value X. It is determined whether or not it is smaller. If the number of vias is not less than the upper limit value X, the process returns to step S1. On the contrary, if the number of vias is less than the upper limit value X, the process proceeds to step S4.

In step S4, the via installation position investigation unit 2
By 4, it is investigated whether or not a new via can be installed on the vertical straight line and the horizontal straight line passing through the center of the via v. From the center of the via v, other wiring can be found in the directions of up, down, left, and right, reach the end of the terminal where the via v is installed, or satisfy the required layout specifications and then add a new wiring. Investigations will continue until a point where vias can be installed is reached. Here, "set a via"
Here, not only simply providing a via, but also connecting a newly provided point and a point at which the via v is already provided with a wire are connected in a straight line.

Next, the processing shifts to step S5,
In step S4, it is determined whether a position where a via can be installed has been found. This processing is also executed by the via installation position investigation unit 24. If no position is found,
The process returns to step S1. Conversely, when the position is found, the coordinates of the position are transferred to the via installation unit 15 by the via installation position transfer unit 25. Further, at this time, the layout information is stored in the storage unit 21 as the via installation unit 1
5 is transferred. Then, the process proceeds to step S6.

In step S6, the via installation portion 15 installs a new via at the position found in step S4. That is, a via is newly generated on the same terminal as the via v, and is connected to the via v by a linear wiring. Then, the changed layout information corresponding to this processing is returned to the storage unit 21, and the layout information stored in the storage unit 21 is updated by the new layout information returned from the via installation unit 15. And
The process returns to step S1. Hereinafter, the same processing is repeated.

The above processing will be further described by taking the layout drawing of FIG. 4 as an example. In FIG. 4, 50a, 50
b is a pair of main terminals such as a source terminal and a drain terminal of the transistor element, 51 is a gate terminal of the transistor element,
52, 53, 54 are wirings such as metal wirings, 55, 6
0 is a via for connecting the wirings 52 and 54 and the terminals 50b and 50a, respectively, and x and y are the horizontal direction and the vertical direction on the layout drawing, respectively.

At step S2, it is assumed that the via 60 of FIG. 4 is selected as the unprocessed via v. Then
If the upper limit X is, for example, 3, the number of vias of the terminal 50a to which the via v belongs (= 1) in step S3.
Is determined to be less than the upper limit value X, and then the process of step S4 is executed.

In step S4, as shown in FIG. 5, on the layout drawing, along the four directions of the horizontal direction x and the vertical direction y around the via 60 (the direction of the arrow in FIG. 5),
A survey will be conducted on possible locations for vias. The required layout specification defines the distance between the via to be newly installed and the existing via 60.

In the four directions, the end of the terminal 50a is reached by the distance between the vias in the leftward direction, the rightward direction is similarly blocked by the other end of the terminal 50a, and the existing wiring is present in the downward direction. It is blocked by (existing wiring) 54. That is, there is no position where new vias can be installed in these three directions. On the other hand, in the upward direction, there is a position where a new via can be installed without being blocked by the end of the terminal 50a or the existing wiring. In step S4, this position is found.

The via installation section 15 for executing the processing of step S6 provides a new via 61 at the position found in step S4 as shown in FIG. A straight line 71 connects between (6). That is, the via 61 is installed.
Then, the layout information stored in the storage unit 21 of the via installation position searching unit 14 is updated with the layout information corresponding to the layout drawing of FIG. In step S1 executed next, unprocessed vias including the via 61 are searched, and in step S2, for example, the via 61 is the via v.
Is selected as.

When the via 61 is selected as the via v in step S2, as shown in FIG. 6, there is no longer a position where a new via can be installed including the upward direction. At this time, even if the number of vias of the terminal 50a is less than the upper limit value X,
No new via is installed in the terminal 50a, and the process returns to step S1 to search for a new unprocessed via. When there are no more unprocessed vias on the newest layout drawing, all processing is complete.

As described above, by using the layout conversion apparatus of this embodiment, the layout drawing illustrated in FIG.
It is possible to obtain a new layout drawing illustrated in FIG.
That is, the layout of existing wiring is not changed except for the addition of a new wiring portion that connects a newly installed via and an existing via, and the position and shape of elements such as transistor elements are not changed. Based on the required layout specifications without changing other layouts such as
The number of vias on the device terminals can be increased.

As described above, in the device of this embodiment,
When the number of vias is increased, the layout change can be suppressed less than that of the conventional layout conversion device, so that there is an advantage that the characteristics (advantages) of the layout before the change can be maintained.

<Second Embodiment> Next, a layout conversion device according to a second embodiment will be described. In step S4, the via installation position investigation unit 24 of the device of the first embodiment determines whether a new via can be installed without changing the already drawn wiring (existing wiring). Was there. On the other hand, processing may be performed such that it is possible to push away the wiring that has already been drawn and determine whether a new via can be installed. The via installation position investigation unit 24 of the device according to the second embodiment performs the process of step S4 in this manner.

Taking as an example the case where the via 61 of FIG. 6 is selected as the via v in step S2, in step S3, the number of vias of the terminal 50a to which the via v belongs (=
2) is determined to be less than the upper limit value X (for example, = 3). Then, in the subsequent step S4, as shown in FIG. 7, a new via is formed in each of the upward, downward, left, and right directions (arrow directions in FIG. 7) centered on the via 61 on the layout drawing. The possible installation positions of are investigated.

At this time, the investigation is continued in each direction until the end of the terminal 50a is reached or a point where the via can be installed after satisfying the required layout specifications. Then, when the existing wiring is reached in the process of investigating in a certain direction, it is determined whether or not the existing wiring can be pushed away in the investigating direction within a range satisfying the required layout specification (for example, the interval between wirings). If it can be pushed away, the existing wiring is pushed away and it is determined whether a new via can be installed. Needless to say, also at this time, "to install a via" means not only to simply provide a new via, but also to connect a position where a new via is provided and a position of the via v in a straight line with a wiring. It also includes.

As shown in FIG. 8, the wiring 53 already drawn exists in the upper direction of the via 61, and it is impossible to install a new via as it is. However, a part 56 of the wiring 53 can be pushed upward as shown in FIG. 8 while keeping the distance between the wiring 53 and another wiring such as the wiring 52 to be equal to or more than the minimum distance defined in the required layout specifications. If it is, after pushing it away,
It is determined whether a new via can be installed.

Then, when the via can be installed, as shown in FIG. 8, a new via 62 is provided and the via 61 which is the via v is provided in step S6.
A linear wiring 72 is drawn between the and. That is, a new via 62 is installed.

In FIG. 7, when the distance between the via 61 and the wiring 53 is, for example, the minimum distance between the via and the wiring defined by the required layout specification, the layout conversion apparatus of the first embodiment On the terminal 50a, the number of vias can no longer be increased, whereas by using the layout conversion device of this embodiment, the number of vias can be further increased.

As described above, the layout conversion apparatus of this embodiment has an advantage that the range of the number of vias that can be increased within the range of the required layout specifications is further expanded. That is, a more preferable layout drawing can be obtained. In addition, when increasing the number of vias, other than adding a new wiring part that connects a newly installed via and an existing via, and pushing out existing wiring within the range that satisfies the required layout specifications. To
The existing wiring is not changed, and other layout portions such as the position and shape of elements such as transistor elements are not changed. Therefore, compared to the conventional layout conversion device, there are advantages that the layout is less changed and the characteristics of the layout before the change can be maintained.

[0044]

According to the device of the first invention, the number of vias of terminals on an existing layout drawing can be increased within the range of required layout specifications. Moreover, since new vias are installed within the range where the terminal ends and the existing wiring do not hinder, for example, the layout of the position, shape, etc. of the element having the terminals is not changed, and the layout can be improved compared to the conventional device. Minimal changes. That is, the number of vias can be changed while maintaining the advantages of the existing layout before the change.

In the device of the second invention, a new via is installed while allowing existing wiring to be pushed away within the range of the required layout specification, so that the range of the number of vias that can be increased within the range of the required layout specification is set. Expand further. That is, a more preferable layout drawing can be obtained.

In addition, adding a new wiring portion connecting a newly installed via and an existing via,
Since existing wiring is not changed except pushing away existing wiring within the range satisfying the required layout specifications, the change in layout can be suppressed as compared with the conventional device. That is, the number of vias can be changed while maintaining the advantages of the existing layout before the change.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to a first embodiment.

FIG. 2 is a block diagram of a via installation position searching unit according to the first embodiment.

FIG. 3 is a flowchart showing a processing procedure of the device according to the first embodiment.

FIG. 4 is a layout diagram illustrating the operation of the device according to the first embodiment.

FIG. 5 is a layout diagram illustrating the operation of the device according to the first embodiment.

FIG. 6 is a layout diagram illustrating the operation of the device according to the first embodiment.

FIG. 7 is a layout diagram illustrating the operation of the device according to the second embodiment.

FIG. 8 is a layout diagram illustrating the operation of the apparatus according to the second embodiment.

FIG. 9 is a layout diagram for explaining the operation of the conventional device.

FIG. 10 is a layout diagram for explaining the operation of the conventional device.

[Explanation of symbols]

15 via installation section, 21 storage section, 22 unprocessed via search section, 23 via number determination section, 24 via installation position investigation section.

Claims (2)

[Claims] 1. A layout conversion device for changing an existing layout drawing based on required layout specifications, storing layout information expressing the layout drawings and required layout specification information expressing the required layout specifications, and From the storage unit whose layout information is updatable and the vias on the latest layout drawing represented by the latest layout information stored in the storage unit, one unselected one is sequentially selected as an unprocessed via. Every time an unprocessed via is selected by the processed via search unit and the unprocessed via search unit, the number of vias of the terminal to which the unprocessed via belongs is specified in the required layout specification on the latest layout drawing. On the terminal to which the unprocessed via that has passed the determination and the via number determination unit that determines whether it is less than the upper limit Based on the latest layout information, it is possible to add a new via within the range of the required layout specification and whether or not there is a position where it can be connected to the unprocessed via with a linear wiring. The via installation position investigation unit to be investigated by adding a new via at a position that has passed the judgment of the via installation position investigation unit, and further, connecting the unprocessed via with a linear wiring, the memory A via installation section for updating the layout information of a part, the via installation position investigation section proceeds with investigation from the unprocessed via along one or more predetermined directions, and within the range of the required layout specification, To determine whether or not there is a position where a new via connected to the unprocessed via with a linear wiring can be added without the terminal end or the existing wiring becoming a barrier. Layout conversion device characterized. 2. The layout conversion device according to claim 1, wherein the via installation position examining unit determines whether or not the existing wiring is a barrier, and determines the existing wiring within the range of the required layout specification. Allowing to push away in the direction of advancing the investigation, the via installation portion, a position that has passed the condition to push away the existing wiring in the determination of the via installation position investigation unit, a new via at the position At the same time as connecting to the unprocessed via with a linear wiring, so as to dispose the existing wiring by pushing away according to the above conditions,
A layout conversion device, characterized in that the layout information in the storage unit is updated.