CN105468821B - Utilize the TSV automatic positioning methods of smallest enclosing circle - Google Patents

Abstract

The TSV automatic positioning method using the smallest enclosing circle belongs to the field of circuit design; the method first establishes a plane Cartesian coordinate system for the layout of a 3D integrated circuit, and projects the coordinates of all standard units in all line networks containing TSVs into the coordinate system. Each net containing TSVs is then processed separately. All standard units in the line network are composed of discrete point sets, and the minimum enclosing circle algorithm of these discrete points is used to solve the minimum enclosing circle of these discrete points. At this time, the coordinates of the center of the circle are the coordinates of all TSVs of the line network. Finally, the above-mentioned processing is performed on all line nets to obtain the coordinates of all TSVs in the 3D integrated circuit. The present invention has the following beneficial effects: the present invention can realize the determination of TSV positions of all wire nets; because the minimum enclosing circle is used to determine the positions of TSVs, it is beneficial to shorten the interconnection length of 3D integrated circuits.

Description

TSV Automatic Positioning Method Using Minimum Enclosing Circle

technical field

The invention relates to an automatic layout technology for a 3D integrated circuit, which belongs to the field of circuit design, and in particular to a TSV automatic positioning method for a 3D integrated circuit.

Background technique

With the development of the integrated circuit industry, the number of transistors in the integrated circuit chip is gradually increasing, and the size of the transistors is also getting smaller and smaller. Due to the increase in the number of transistors in the chip, the length of the interconnection increases, causing the power consumption of the interconnection to gradually exceed the power consumption of the transistors and become the main power consumption of the chip. The increase in interconnect length can also lead to increased routing difficulties, among other problems. As the size of the transistor shrinks, the semiconductor manufacturing process is getting closer and closer to its physical limit, making it difficult to continue shrinking the size of the transistor. All these factors will hinder the development of the integrated circuit industry in accordance with its development plan, that is, Moore's Law. In addition, alternative technologies for traditional semiconductor devices, such as graphene and quantum computers, cannot be applied on a large scale in the short term, so 3D integrated circuits have become a feasible development direction.

Different from the plane layout of traditional integrated circuits, the transistors in 3D integrated circuits are not only distributed on the same plane, but the three-dimensional layout of transistors is realized by stacking multi-layer chips. 3D integrated circuits split the original 2D integrated circuits into multiple chips and stack them up. Afterwards, the vertical interconnection of chips is realized through through-silicon vias (TSVs), and the length of horizontal interconnections is significantly shortened. Therefore, solving the TSV positioning problem has become an important aspect of 3D integrated circuit design.

In order to shorten the interconnection length, the present invention proposes a TSV automatic positioning method using the minimum enclosing circle, which processes each line net containing TSV separately, and uses the coordinates of all standard units in the line net to determine the minimum enclosing of these standard units A circle whose center is the coordinates of the TSV.

Contents of the invention

The invention provides a TSV automatic positioning method for a 3D integrated circuit. The coordinates of the TSV are determined by using the minimum enclosing circle algorithm through the coordinates of the standard unit of the 3D integrated circuit, and the positioning of the TSV is completed to achieve the purpose of shortening the interconnection length; the 3D integrated circuit The TSV automatic positioning system of the circuit includes four parts: input unit, two-boundary point determination circle unit, three-boundary point circumscribed circle unit and enclosing circle verification unit. The function of the input unit is to input the layout of the design, place it in the established coordinate system, and establish a set of boundary points; the function of the second boundary point to determine the circle unit is to use the connection line of the two boundary points as the diameter to determine the circle; the third boundary The point circumscribed circle unit is used to determine the circumcircle of the three boundary points; the enclosing circle verification unit is used to judge whether the circle obtained by the two boundary point determined circle unit and the three boundary point circumscribed circle unit is an enclosing circle, and the unit of the control boundary point set is not more than three.

In order to achieve the above object, the technical method adopted in the present invention is the TSV automatic positioning method utilizing the minimum enclosing circle, which is a TSV automatic positioning method for a 3D integrated circuit. First, a plane rectangular coordinate system of the 3D integrated circuit layout is established, and each Each line network containing TSV is processed separately, and the coordinates of all standard units in the line network are extracted; then, for a line network, the minimum enclosing circle surrounded by all standard units of the line network is calculated, and the center of the circle is set as the coordinate of the TSV; The same processing is carried out for each line net, and finally the coordinates of all TSVs are determined. Specific steps are as follows:

S1. Establish a 3D integrated circuit plane Cartesian coordinate system A. For each line network containing TSV, extract the coordinates of all its standard units, and project these units into the coordinate system A. Perform the following steps for each net with TSVs.

S2. Put the farthest unit in the line network into the boundary point set, and use the connecting line of these two units as the diameter to obtain a circle. Determine whether the circle is an enclosing circle, and if so, use the center of the circle as the coordinates of all TSVs in the line network. If it is not an enclosing circle, put the unit farthest from the center of the circle into the end of the set. At this point, there are three cells in the collection.

S3. If the three units in the set are on the same straight line or form an obtuse triangle, repeat the process of determining the circle in S2 with the two farthest units among them; if these three units are not on the same straight line and cannot form an obtuse triangle, Then find their circumcircle. Determine whether the circle is an enclosing circle, and if so, use the center of the circle as the coordinates of all TSVs in the line network.

S4. If the circle obtained in S3 is not an enclosing circle, put the unit farthest from the center of the circle into the end of the boundary point set, and delete the first unit in the set, keeping the number of units in the set not exceeding three. Repeat S3 again.

S5. Repeat S3 and S4 until the coordinates of the TSV are determined. Finally repeat S2-S4 for each net until all nets are processed.

In order to realize the above steps, the functions of each unit of the TSV automatic positioning system of the 3D integrated circuit are as follows.

The function of the input unit is as follows: first establish the 3D integrated circuit plane Cartesian coordinate system A, then extract the coordinates of the standard unit of the line network to be processed, and project them into the coordinate system A as discrete points for determining the minimum enclosing circle, and finally determine the discrete points Put the two units with the farthest distance among them into an ordered set, which is the set of boundary points.

The function of the two boundary points to determine the circle unit is as follows: connect the two units with the farthest distance in the boundary point set, and then use the connection line as the diameter to determine a circle.

The function of the circumcircle unit with three boundary points is as follows: use the three units in the boundary point set that are not collinear and cannot form an obtuse triangle to determine the circumcircle of these three units.

The function of the enclosing circle verification unit is as follows: it is used to judge whether the circle obtained by the circle unit determined by the two boundary points and the circumscribed circle unit of the three boundary points is an enclosing circle, if not, the unit farthest from the center of the circle is put into the end of the set of boundary points, And if there are more than three cells in the set, the first cell will be deleted, leaving the set with three points.

The coordinate axis scale of the coordinate system A is consistent with the size of the actual layout, and is accurate to the nanometer level.

The present invention is only suitable for use when the number of TSVs of each net and the layer where the TSVs are located have been determined.

The method of the present invention has the following beneficial effects: the present invention can realize the determination of TSV positions of all wire nets; because the minimum enclosing circle is used to determine the positions of TSVs, it is beneficial to shorten the interconnection length of 3D integrated circuits.

Description of drawings

Fig. 1 is a schematic cross-sectional structure diagram of a certain two layers in a 3D integrated circuit chip;

Fig. 2 is the flowchart of utilizing the minimum enclosing circle to locate TSV;

Fig. 3 is the situation that utilizes at least two boundary points to determine the minimum enclosing circle;

Fig. 4 is the situation that utilizes at least three boundary points to determine the minimum enclosing circle;

Fig. 5 is a schematic flow chart of determining the minimum enclosing circle;

Fig. 6 is a TSV positioning result of a certain wire net in a two-layer 3D integrated circuit;

Fig. 7 is the legend of Fig. 6;

In the figure: 1. TSV, 2. Standard cell, 3. Metal interconnection line, 4. Metal layer, 5. Substrate, 6. Upper layer chip, 7. Lower layer chip, 8. Standard cell of an upper layer chip on a line, 9. The standard unit of a chip in the lower layer of a certain network. 10. The TSV positioned by the smallest enclosing circle in a certain network.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, it is a schematic diagram of the cross-sectional structure of two layers of a 3D integrated circuit chip. The 3D integrated circuit chip includes a TSV1, a standard cell 2, a metal interconnection line 3, a metal layer 4, a substrate 5, an upper chip 6 and a lower chip. 7; The present invention includes four units, which are respectively an input unit, a circle unit determined by two boundary points, a circumscribed circle unit of three boundary points, and an enclosing circle verification unit; the 3D integrated circuit in the present invention is a three-dimensional chip structure, and the 3D integrated circuit Each layer is a two-dimensional chip; the upper chip 6 and the lower chip 7 represent the general structure of the two layers in the 3D integrated circuit; TSV1 is a through-silicon via structure that penetrates the chip substrate 5, realizing the upper chip 6 and the lower chip. Communication between chips 7; the standard unit 2 in the chip is the basic component of the integrated circuit to realize signal processing and storage, and the signal transmission between the standard units 2 is realized through the metal interconnection 3 and TSV1.

There are two cases for determining the minimum enclosing circle of discrete points. As shown in Figure 3: the minimum enclosing circle determined by at least two boundary points, at this time the minimum enclosing circle is the circle formed by the line connecting these two points; as shown in Figure 4: the minimum enclosing circle determined by at least three boundary points enclosing circle, the minimum enclosing circle at this time is the circumcircle of the triangle formed by these three points.

The following are the specific implementation steps of the present invention, which are illustrated by taking Fig. 5 and Fig. 6 as examples.

The input unit includes the coordinates of the standard cell 2 in each line network containing TSV1 and the planar rectangular coordinate system of the layout; for example, the coordinate system in Figure 6, and the standard cell 8 of the upper chip and the standard cell 9 of the lower chip of the line network ; Its function is used to establish the planar Cartesian coordinate system of the layout, extract the coordinates of all standard cells of a certain line network, and project them into the coordinate system.

S1. Use the input unit to establish a 3D integrated circuit Cartesian coordinate system A (as shown in FIG. 6 ), extract the coordinates of the standard unit from all line networks containing TSVs, and project them into the coordinate system A. Perform the following processing for each net containing TSVs separately.

The circle unit determined by two boundary points includes a plane Cartesian coordinate system, a set of boundary points, and standard unit 2 in the set. This cell uses the line connecting the two furthest cells in the set to determine the circle. The enclosing circle verification unit includes a Cartesian coordinate system, a set of boundary points and the standard unit 2 in the set, and a circle defined by a circle unit defined by two boundary points or a circumscribed circle unit of three boundary points. Its function is used to judge whether a circle is an enclosing circle, if not, put the unit farthest from the center of the circle into the end of the set, and keep the number of units in the set not to exceed three.

S2. Take the line network ① in Figure 5 as an example, which contains four standard units a, b, c and d that are not completely on the same layer. As shown in ② of Figure 5, first put the two farthest units a and d into the boundary point set P, and use the connection line of these two units as the diameter to determine a circle with the center t. Because the TSV of the line network cannot be determined by only two boundary points as in Figure 3, the circle is not the enclosing circle of all the units of the line network. Then put the farthest unit b from the center t into the end of the set P.

The circumscribed circle unit with three boundary points includes a plane Cartesian coordinate system, a set of boundary points, and standard unit 2 in the set. This element uses the triangle formed by the three elements in the set to determine the circumcircle.

S3. As shown in ③ of Figure 5, the units in the set P are a, d and b at this time. Because the triangle adb is not an obtuse triangle, the circumcircle of the triangle adb is determined by the three-boundary circumcircle unit, and the center of the circle is t. However, the circle is not the enclosing circle of all units of the line network, so the unit c that is farthest from the center t is put into the last set P, and the first unit in P, namely unit a, is deleted.

S4. As shown in ④ of Figure 5, the units in the set at this time are d, b and c. Because the triangle dbc is an obtuse triangle, two boundary points are used to determine the circle unit, and a circle is determined with the connection line of the farthest unit b and c as the diameter, and the center of the circle is t. Because the circle is not the enclosing circle of all units of the line net, put the unit a farthest from t into the end of the set P, and delete the first unit in P, that is, unit d. As shown in ⑤ of Figure 5, the units in the set P are b, c and a at this time. Because the triangle bca is not an obtuse triangle, the circumcircle of the triangle bca is determined by the three-boundary circumcircle unit, and the center of the circle is t. Because the circle is the enclosing circle of all the units of the line network, and the enclosing circle is the circumscribed circle determined by the three boundary points, and the possibility of the enclosing circle determined by the two boundary points is excluded, so the circle is the smallest of all the units of the line network Surrounding circle. At this time, the coordinates of all TSVs of the line network are assigned as the coordinates of the center t. FIG. 6 shows the result of determining TSV10 by using the minimum enclosing circle for a certain line network in a two-layer 3D integrated circuit.

S5. Perform the processing as in S2-S4 for all nets containing TSVs, until the TSV positions of all nets are determined.

The present invention firstly establishes a plane Cartesian coordinate system for the layout of the 3D integrated circuit, and projects the coordinates of all standard units in all the wire nets containing TSVs into the coordinate system. Each net containing TSVs is then processed separately. All standard units in the line network are composed of discrete point sets, and the minimum enclosing circle algorithm of these discrete points is used to solve the minimum enclosing circle of these discrete points. At this time, the coordinates of the center of the circle are the coordinates of all TSVs of the line network. Finally, the above processing is performed on all wire nets to obtain the coordinates of all TSVs in the 3D integrated circuit.

Claims (9)

1. using the TSV automatic positioning methods of smallest enclosing circle, this method is a kind of automatic positioning sides TSV of 3D integrated circuits Method, it is characterised in that：The plane right-angle coordinate for initially setting up 3D integrated circuit diagrams distinguishes each gauze containing TSV It is handled, extracts the coordinate of all standard blocks in gauze；Then it for each gauze, is calculated and owns the gauze The center of circle, is set to the coordinate of TSV by the smallest enclosing circle that standard block surrounds；Identical processing is carried out to each gauze, finally Determine the coordinate of all TSV；It is as follows：

S1. 3D integrated circuit planar rectangular coordinate systems A is established；The gauze for containing TSV for each extracts its all standard list The coordinate of member, will be in these cell projections to coordinate system A；Following steps are executed to each gauze for having TSV respectively；

S2. the farthest unit of distance in the gauze is put into the point set of boundary, it is that diameter obtains that the line of the two units, which is used in combination, To a circle；Judge whether this circle is to surround circle, if so, just using the center of circle of this circle as all TSV's of this gauze Coordinate；Justify if not surrounding, the unit farthest apart from the center of circle is put into the last of set；At this point, there are three units in set；

S3. if three units in set are in same straight line or constitute obtuse triangle, with wherein apart from farthest two A unit repeats to determine the process of circle in S2；If these three units are not at same straight line and cannot constitute obtuse triangle, Then find out their circumscribed circle；Judge whether this circle is to surround circle, if so, just using the center of circle of this circle as this gauze The coordinate of all TSV；

S4. if the circle that S3 is obtained is not to surround circle, the unit farthest apart from the center of circle is put into the last of boundary point set, and delete Except first unit in set, the element number in set is kept to be no more than three；Repeat S3；

S5. S3, S4 are executed repeatedly, until the coordinate of TSV determines；S2-S4 finally is repeated to each gauze, until institute is wired Until net has all been handled；

Each step is implemented as follows：

S1. 3D integrated circuit rectangular coordinate system A, the extraction standard list from all gauzes containing TSV are established using input unit The coordinate of member, and project in coordinate system A；Following processing is carried out to each gauze containing TSV respectively；

Two boundary points determine that circle unit includes the standard block (2) in plane right-angle coordinate, boundary point set, and set； Two boundary points determine that circle unit determines circle using the line of two farthest units of distance in set；Surrounding circle authentication unit includes Standard block (2) in rectangular coordinate system, the conjunction of boundary point set sum aggregate, and determine circle unit or three boundary points by two boundary points Circle determined by circumscribed circle unit；Its function is for judging whether one circle is that encirclement is justified, if it is not, will will be apart from the center of circle Farthest unit is put into set finally, and the element number in set is kept not exceed three；

S2. gauze is containing there are four standard block a, b, c and the d for being not entirely in same layer；First by two farthest lists of distance First a and d is put into the point set P of boundary, and is that diameter determines a circle, center of circle t, by distance using the line of the two units Center of circle t farthest cells b is put into the last of set P；

Three boundary point circumscribed circle units include the standard block (2) in plane right-angle coordinate, boundary point set, and set； Three boundary point circumscribed circle units determine circumscribed circle using the triangle that three units in set are constituted；

S3. the unit in set P is a, d and b；Because triangle adb is not obtuse triangle, three boundary circumscribed circles are utilized Unit determines the circumscribed circle of triangle adb, center of circle t；However the circle nor all units of the gauze encirclement circle, then will It is last that the unit c farthest apart from center of circle t is put into set P, and deletes first unit in P, i.e. unit a；

S4. the unit in gathering is d, b and c；Because triangle dbc is obtuse triangle, is determined and justified using two boundary points Unit determines a circle, center of circle t using the line apart from farthest unit b and c as diameter；Because the circle is not the gauze institute There is the encirclement of unit to justify, so the farthest unit a of distance t are put into the last of set P, and deletes first unit in P, i.e., singly First d；The unit in set P is b, c and a at this time；It is external using three boundaries because triangle bca is not obtuse triangle Circle unit determines the circumscribed circle of triangle bca, center of circle t；Because the circle is the encirclement circle of all units of the gauze, and the encirclement Circle is the circumscribed circle that three boundary points determine, and eliminates two boundary points and determine the possibility for surrounding circle, so the circle is the gauze The smallest enclosing circle of all units；The coordinate of all TSV of the gauze is assigned a value of to the coordinate of center of circle t at this time；

S5. to all, the gauze containing TSV carries out the processing such as S2-S4, until the positions TSV of institute's wired network all determine；

Plane right-angle coordinate is established to the domain of 3D integrated circuits first, by all standard lists in all gauzes containing TSV In the coordinate projection to coordinate system of member；Then each gauze for containing TSV is handled respectively；By all marks in the gauze Quasi- unit forms discrete point set, the smallest enclosing circle of these discrete points is solved using smallest enclosing circle algorithm, at this time the seat in the center of circle Mark is just the coordinate of all TSV of the gauze；Above-mentioned processing finally is done to institute's wired network, obtains all TSV in 3D integrated circuits Coordinate.

2. the TSV automatic positioning methods according to claim 1 using smallest enclosing circle, it is characterised in that：Realize the 3D The function of system each unit of the TSV automatic positioning methods of integrated circuit is as follows；

The function of input unit is as follows：3D integrated circuit planar rectangular coordinate system A are initially set up, then to by the mark of processing gauze Quasi- unit coordinate extracts, and projects in coordinate system A, as the discrete point for determining smallest enclosing circle, finally determines discrete point The two units are put into an ordered set by middle two units apart from lie farthest away, which is boundary point set.

3. the TSV automatic positioning methods according to claim 1 using smallest enclosing circle, it is characterised in that：Two boundary points Determine that the function of circle unit is as follows：By two farthest unit lines of distance in the point set of boundary, then using line as diameter Determine a circle.

4. the TSV automatic positioning methods according to claim 1 using smallest enclosing circle, it is characterised in that：Three boundary points The function of circumscribed circle unit is as follows：The unit not conllinear and that obtuse triangle cannot be constituted using three in the point set of boundary, Determine the circumscribed circle of these three units.

5. the TSV automatic positioning methods according to claim 1 using smallest enclosing circle, it is characterised in that：Circle is surrounded to test The function of demonstrate,proving unit is as follows：For judge two boundary points determine circle unit and the obtained circle of three boundary point circumscribed circle units whether be Circle is surrounded, if it is not, the unit farthest apart from the center of circle is put into the last of boundary point set, and if unit in set More than three, first unit will be deleted, the point in set is made to remain three.

6. the TSV automatic positioning methods according to claim 1 using smallest enclosing circle, it is characterised in that：Coordinate system A's Reference axis scale is consistent with the size of practical domain, and is accurate to nanoscale.

7. the TSV automatic positioning methods according to claim 1 using smallest enclosing circle, it is characterised in that：Realize the TSV The 3D IC chips of automatic positioning method include TSV (1), standard block (2), metal interconnecting wires (3), metal layer (4), lining Bottom (5), upper layer chip (6) and lower layer chip (7)；3D IC chips include four units, respectively input unit, two sides Boundary's point determines circle unit, three boundary point circumscribed circle units and surrounds circle authentication unit；3D integrated circuits are a kind of three-dimensional chip knots Each layer of structure, 3D integrated circuits is all two-dimentional chip；Upper layer chip (6) and lower layer chip (7) represent in 3D integrated circuits Two layers of general structure；TSV (1) is the through-silicon via structure for penetrating chip substrate (5), realizes upper layer chip (6) and lower layer chip (7) communication between；Standard block (2) in chip is basic composition portion of the integrated circuit realization to signal processing and storage Point, and pass through the signal transmission between metal interconnecting wires (3) and TSV (1) realization standard blocks (2).

8. the TSV automatic positioning methods according to claim 1 using smallest enclosing circle, it is characterised in that：It determines discrete There are two kinds of situations for the smallest enclosing circle of point；The smallest enclosing circle at least determined by two boundary points, smallest enclosing circle is just at this time It is the circle that this 2 lines are diameter composition；The smallest enclosing circle at least determined by three boundary points, smallest enclosing circle is just at this time It is the circumscribed circle for the triangle that these three points are constituted.

9. the TSV automatic positioning methods according to claim 1 using smallest enclosing circle, it is characterised in that：Input unit The plane right-angle coordinate of coordinate and domain including each gauze Plays unit (2) containing TSV；Its function is for establishing The plane right-angle coordinate of domain, extracts the coordinate of all standard blocks of some gauze, and projects in coordinate system.