CN101499470A - Power source layout of integrated circuit and its design method - Google Patents

Abstract

The invention discloses a power layout of an integrated circuit, a method for designing the power layout of the integrated circuit and a method for constructing the power layout of the integrated circuit. The power supply layout mode utilizes a plurality of metal stems with consistent line width to form a power supply network and a power supply ring. In particular, the power supply ring includes a plurality of metal rings formed by a relatively densely packed metal stem in the metal stem, the power supply ring is configured to receive power and distribute the power to electronic components of the integrated circuit.

Description

Integrated circuit power supply layout and its design method

technical field

The present invention relates to the design of the power supply layout of an integrated circuit (Integrated circuit, IC), and in particular, the present invention relates to the layout design of a power supply network (Power mesh) and a power supply ring (Power ring) used in the integrated circuit.

Background technique

Please refer to FIG. 1A , which provides a simplified cross-sectional view of a conventional integrated circuit die (IC die) (or chip) 1 . As shown in FIG. 1A, the crystal circuit bare die 1 includes a semiconductor layer (Semiconductor layer) 10, six consecutive metal layers (Metal layer) (Metal layer) (121-126) from bottom to top, respectively formed in two phases There are several layers of insulating layers (Insulating layer) 14 and a layer of passivation layer (Passivation layer) 16 between adjacent metal layers. The semiconductor layer 10 is used to form electronic devices (not shown) such as transistors, and may also be used for routing electrical connections between these electronic devices. In order to achieve the smallest chip area and the fastest circuit speed, usually only short electrical connections are formed on the semiconductor layer 10 . The metal layers (121-126) are provided for the remaining electrical connections. The number of layers used in the metal layer depends on the complexity of the actual wiring. For example, eight metal layers or even more metal layers are widely used in the design of integrated circuits with high wiring complexity.

Regarding the wiring wiring on the metal layers (121-126), a power distribution network (Powerdistribution network) (not shown) may be formed at the first metal layer 121 and coupled to the electronic components, wherein the power distribution network It can be composed of multiple metal rails (Metal rail) with thinner line width.

Please refer to FIG. 1B . FIG. 1B shows the wires formed on the top metal layer of the integrated circuit die 1 and the metal layer where they are located.

As shown in FIG. 1B , the power supply network 18 is formed at the sixth metal layer 126 and the fifth metal layer 125 . The power supply network 18 consists of a plurality of metal stems (Metal

trunk) (182, 184). In addition, metal stems ( 182 , 184 ) formed at different metal layers ( 126 , 125 ) are interconnected through vias (Via) 142 formed at insulating layer 14 . Also via vias 142, the power supply network 18 is connected to the power distribution network. The metal stems ( 182 , 184 ) are divided into a power metal stem 182 connected to a power supply (Power) and a ground metal stem 184 connected to a ground (Ground). On the same metal layer, the power metal stems 182 and the ground metal stems 184 are alternately arranged. The metal stems ( 182 , 184 ) formed at the sixth metal layer 126 are perpendicular to the metal stems ( 182 , 184 ) formed at the fifth metal layer 125 . The power metal stem 182 formed at the sixth layer 126 is only connected to the power metal stem 182 formed at the fifth layer 125, and the ground metal stem 184 formed at the sixth layer 126 is connected only to the power metal stem 182 formed at the fifth layer 125. The ground metal stem 184 at the place.

Referring to FIG. 1B again, the power supply ring 17 (shown is a small section of the power supply ring 17 ) can be formed at the sixth metal layer 126 . In practice, the power supply ring 17 is composed of two metal rings ( 172 , 174 ) whose wire width is wider than the metal stems ( 182 , 184 ). The two metal rings ( 172 , 174 ) are divided into a power metal ring 172 connected to a power source and a ground metal ring 174 connected to a ground. The metal rings (172, 174) formed at the sixth metal layer 126 will surround the metal stems (182, 184) also formed at the sixth metal layer 126 to form a ring structure (not shown). The power supply ring 17 is used to receive power, and transmit the power to the power distribution network via the power supply network 18, and the power distribution network is used to distribute the power to the electronic components.

When designing an integrated circuit, various specifications need to be collected for the power planning mentioned above to meet the requirements of process, yield and resource occupation, etc. However, due to the many details that need to be coordinated, it must be realized by an experienced layout engineer, which will cause a huge manpower burden.

Contents of the invention

Therefore, one scope of the present invention is to provide a power supply layout of an integrated circuit die (or chip) and a design method thereof, which integrates a power supply network and a power supply ring, and in particular, the power supply The impedance difference between the network and the power supply ring can be reduced, and the congestion of the wiring between the power supply network and the power supply ring can be effectively alleviated.

According to a preferred embodiment of the present invention, an integrated circuit die comprises a semiconductor layer, a plurality of electronic components formed on the semiconductor layer, N layers of continuous metal layers counted from bottom to top, and a power distribution network , power supply network and power supply ring. The metal layers are insulated from each other and formed on or above the semiconductor layer, and N is a positive integer. The power distribution network includes a plurality of metal rails and is coupled to the electronic component. The power supply network includes a plurality of metal stems, the metal stems are formed at the N-th metal layer to the i-th metal layer, and the metal stems are connected to each other through a plurality of first vias and through a plurality of second vias It is connected with the metal rail, and i is a positive integer smaller than N. The power supply ring includes a plurality of metal rings, the metal rings are formed by some metal stems densely gathered in the metal stems and are connected to the power supply network. The power supply ring is used for receiving power and conducting the power to the power distribution network through the power supply network, and the power distribution network then distributes the power to the electronic components.

In another preferred embodiment of the present invention, the metal ring is also formed at the (N-1)-th metal layer to the i-th metal layer. The metal rings are also connected to each other through a plurality of third vias.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the accompanying drawings.

Description of drawings

FIG. 1A is a simplified cross-sectional view of a conventional integrated circuit die 1 .

FIG. 1B schematically illustrates the wiring lines formed at the metal layers ( 126 , 125 ) of the IC die 1 .

FIG. 2A is a simplified cross-sectional view of an integrated circuit die 2 according to a preferred embodiment of the present invention.

FIG. 2B schematically illustrates the wires formed at the metal layers ( 228 , 227 ) of the IC die 2 .

FIG. 3 is a flowchart of a method for designing an integrated circuit die according to the present invention.

FIG. 4 is an example of an actual design diagram of a corner of a power supply ring generated after adjusting the density of the metal wiring according to the present invention.

Fig. 5 is an example of an actual design diagram of a power supply ring (edge automatic wiring) formed by applying the present invention and using computer automation.

Explanation of reference signs

1, 2: Integrated circuit bare crystal 10, 20: Semiconductor layer

121～126 and 221～228: metal layer

14, 24: insulating layer 142: via window

16, 26: Passivation layer 17, 27: Power supply ring

172, 272: Metal ring for power supply 174, 274: Metal ring for grounding

18, 28: Power supply network 182, 282: Power metal dry

184, 284: Ground metal stem 242: First via

244: Third via window S30～S36: Process steps

Detailed ways

Preferred specific embodiments of the present invention will be described in detail below, so as to fully illustrate the features, spirit, advantages and simplicity of implementation of the present invention.

Please refer to FIG. 2A, which provides a simplified cross-sectional view of an integrated circuit die (or chip) 2 according to a preferred embodiment of the present invention. As shown in FIG. 2A, the crystal circuit die 2 includes a semiconductor layer 20, eight consecutive metal layers (221-228) counted from bottom to top, and several layers respectively formed between two adjacent metal layers. An insulating layer 24 and a passivation layer 26 . The semiconductor layer 20 is used to form electronic components such as transistors (not shown). The number of layers used in the metal layer depends on the complexity of the actual wiring. Therefore, the eight metal layers disclosed in FIG. 2A are only for the convenience of illustration, rather than limiting the present invention.

Regarding the wiring wiring on the metal layers (221-228), a power distribution network (not shown) is formed at the first metal layer 221 and coupled to the electronic components. Likewise, the power distribution network is composed of a plurality of metal tracks with a first line width, and the metal tracks are formed at the first metal layer 221 and coupled to the electronic component.

Please refer to FIG. 2B . FIG. 2B schematically illustrates the wiring lines formed at the top metal layer and the metal layer where they are located.

As shown in FIG. 2B , the power supply network 28 is formed from the Nth metal layer (the eighth metal layer 228 shown in FIG. 2B ) to the i-th metal layer (only the seventh metal layer 227 is shown in FIG. 2B ). ) place. In a specific embodiment, N is an integer greater than or equal to 6, and i is an integer ranging from (N-3) to (N-1).

The power supply network 28 is composed of a plurality of metal stems (282, 284) having a second line width, and formed on different metal layers (such as the eighth metal layer 228 and the seventh metal layer 227 shown in FIG. 2B ). The metal stems ( 282 , 284 ) at are connected to each other through the first via 242 formed at the insulating layer 24 . Also via a second via (not shown) formed at the insulating layer 24, the power supply network 28 is connected to the power distribution network (not shown). In practice, if eight metal layers are used, the wiring of the metal trunk will be applied to the eighth and seventh metal layers. For complex wiring and wiring, it will even be applied to the sixth and fifth metal layers. Six metal layers are used, and the wiring of the metal stem is generally applied to the sixth and fifth metal layers.

In a specific embodiment, the second line width is wider than the first line width. That is to say, in this embodiment, the line width of the metal stem ( 282 , 284 ) can be wider than the line width of the metal track.

Also shown in FIG. 2B , the metal stems ( 282 , 284 ) are divided into a power metal stem 282 for connecting to a power source and a grounding metal stem 284 for connecting to a ground. On the same metal layer, the power metal stems 182 and the ground metal stems 184 are alternately arranged. The metal stems ( 282 , 284 ) formed at adjacent metal layers (eg, the eighth metal layer 228 and the seventh metal layer 227 ) are perpendicular to each other. The power supply metal stems 282 formed on adjacent metal layers (for example, the eighth metal layer 228 and the seventh metal layer 227) are connected to each other, and formed on the adjacent metal layers (for example, the eighth metal layer 228 It is connected with the ground metal stem 282 at the seventh metal layer 227).

Referring to FIG. 2B again, the power supply ring 27 (shown as a small section of the power supply ring 27 ) can be formed at the topmost metal layer 228 . The power supply ring 27 may be composed of a plurality of metal rings ( 272 , 274 ) having the second line width. That is to say, in an embodiment of the present invention, the line width of the metal rings (272, 274) can be the same as the line width of the metal stems (282, 284). The present invention uses adjusting the density between the metal stems (282, 284) to form the required structure of the metal rings (272, 274). A power supply ring 27 formed by defining metal stems (282, 284) receives power and conducts it via the power supply network 28 to the power distribution network. The power distribution network is used to distribute the power to the electronic components.

According to the wiring and wiring technology of the present invention, the impedance difference between the power supply network 28 and the power supply ring 27 will be reduced, thereby avoiding the burning of the metal wiring. In addition, in order to alleviate the congestion (Congestion) of the wiring of the power supply network 28 and the power supply ring 27, in another preferred embodiment of the present invention, also shown in FIG. 2B, the metal ring (272, 274) It can also be formed on the (N-1)th metal layer to the i-th metal layer.

Also following the features, spirit and advantages of the present invention, the present invention also discloses a method 3 for designing an integrated circuit die (or chip). Basically, the integrated circuit die includes a semiconductor layer and N layers of continuous metal layers counted from bottom to top, wherein N can be a positive integer greater than or equal to 6. The metal layers are insulated from each other and formed on or over the semiconductor layer. The process steps of the integrated circuit die design method 3 according to the present invention will be described in detail below.

Please refer to FIG. 3 , first, the design method 3 executes step S30 , disposing a plurality of electronic components on the semiconductor layer.

Next, the design method 3 executes step S32, configuring a power distribution network at the first metal layer. The power distribution network is composed of a plurality of metal tracks with a first line width, and is coupled to the electronic component.

Next, the design method 3 executes step S34, configuring the power supply network at the N-th metal layer to the i-th metal layer, wherein it is assumed that i is an integer ranging from (N-3) to (N-1) . The power supply network can be composed of a plurality of metal stems with a second line width, and the second line width can be set wider than the first line width. The metal stems are connected to each other through a plurality of first vias, and connected to the metal rails through a plurality of second vias.

Finally, the design method 3 executes step S36 , at the Nth metal layer, the density between the metal stems is adjusted to form the required structure of the power supply ring.

In order to alleviate the congestion of the power supply network and the wiring of the power supply ring, the design method 3 further configures the metal ring at the (N-1)th metal layer to the i-th metal layer.

In a specific embodiment of the present invention, since the metal wiring with the same line width can be used to generate the required power supply ring, the density of the metal wiring can be automatically adjusted by the computer to form the required power supply ring. required power supply ring. In this way, it is no longer necessary to spend extra manpower to make additional wiring for the power supply ring for different circuit layouts.

Please refer to Figure 4 and Figure 5. FIG. 4 is an actual design diagram of a corner of the power supply ring produced by adjusting the density of the metal wiring according to the present invention. FIG. 5 is an actual design diagram of a power supply ring (edge automatic wiring) formed by computer automation in response to different circuit layouts.

Through the detailed description of the preferred specific embodiments above, it is hoped that the features and spirit of the present invention can be described more clearly, rather than limiting the scope of the present invention by the preferred specific embodiments disclosed above. On the contrary, the intention is to cover various changes and equivalent arrangements within the scope of the claimed patent scope of the present invention. Therefore, the scope of the claimed scope of the present invention should be interpreted in the broadest way based on the above description, so as to cover all possible changes and equivalent arrangements.

Claims (15)

1. A power supply layout of an integrated circuit, comprising: semiconductor layer; a plurality of electronic components formed on the semiconductor layer; N layers are continuous metal layers counted from bottom to top, the metal layers are insulated from each other and formed on or over the semiconductor layer, N is a positive integer; a power distribution network comprising a plurality of metal rails and coupled to the electronic component; A power supply network, the power supply network includes a plurality of metal stems, the metal stems are formed at the Nth metal layer to the i-th metal layer, the metal stems are connected to each other through a plurality of first vias and are connected to each other through a plurality of first vias The second via is connected to the metal track, i is a positive integer less than N; and The power supply ring, the power supply ring includes a plurality of metal rings, the metal rings are formed by the densely gathered metal stems in the metal stem, and the power supply ring is used to receive power and conduct the power through the power supply network to The power distribution network distributes the power to the electronic components. 2. The power supply layout of an integrated circuit as claimed in claim 1, wherein the metal track has a first line width and the metal stem has a second line width, and the second line width is larger than the first line width. 3. The power supply layout of an integrated circuit as claimed in claim 1, wherein the metal track is formed at the first metal layer. 4. The power supply layout of an integrated circuit as claimed in claim 1, wherein the power supply ring surrounds the power supply network. 5. A method for designing a power supply layout of an integrated circuit, the integrated circuit die comprising a semiconductor layer and N layers of continuous metal layers from bottom to top, the metal layers are insulated from each other and formed on the semiconductor layer or Above, N is a positive integer, and the method includes the following steps: disposing a plurality of electronic components on the semiconductor layer; At the first metal layer, a power distribution network is configured, the power distribution network includes a plurality of metal rails, and the metal rails are coupled to the electronic component; A power supply network is configured at the N-th metal layer to the i-th metal layer, and the power supply network includes a plurality of first metal stems, and the first metal stems are connected to each other through a plurality of first vias and through a plurality of The second via is connected to the metal track, i is a positive integer less than N; and Adjusting the density of the metal stem around the power supply network to form a power supply ring, the power supply ring includes a plurality of metal rings, the power supply ring is used to receive power and conduct the power through the power supply network to the power distribution network, and the power distribution network then distributes the power to the electronic components. 6. The method of claim 5, wherein N is greater than or equal to six. 7. The method of claim 5, wherein the metal track has a first line width and the metal stem has a second line width, and the second line width is greater than the first line width. 8. The method of claim 5, wherein i ranges from (N-3) to (N-1). 9. The method as claimed in claim 8, wherein the metal ring is formed at the N-th metal layer to the i-th metal layer. 10. The method according to claim 5, wherein the metal stem at the jth metal layer is perpendicular to the metal stem at the (j-1)th metal layer, and j is greater than or equal to (i+1) less than A positive integer equal to N. 11. The method of claim 8, wherein the wiring density of the metal stems forming the power supply ring is greater than the wiring density of the metal stems of the power supply network. 12. A method for constructing a power supply layout of an integrated circuit, the method comprising the following steps: configuring a power supply network comprising a plurality of metal traces; and adjusting the density of the metal wiring around the power supply network to form a power supply ring for receiving power; Wherein, the degree of density between the metal wirings is defined by the user and then executed in a computer-automatic manner. 13. The method of claim 12, wherein the power supply network and the power supply ring are formed on metal layers of the integrated circuit. 14. The method of claim 12, wherein the metal wiring forming the power supply ring is denser than the metal wiring of the power supply network. 15. The method as claimed in claim 12, wherein the computer-automated means is automatic wiring for the edge of the power supply network to form the power supply ring.

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