Method for substrate noise analysis

1. A method for substrate noise analysis, the method comprising:

using a first processor based system, creating a circuit schematic comprising a first circuit, an aggressor circuit, and a substrate network coupling the first circuit to the aggressor circuit, wherein the first circuit comprises a transistor, an intra-transistor component being within the transistor, and wherein the substrate network is based on physical features of an expected die size;

using a second processor based system, simulating the circuit schematic thereby resulting in simulation results;

determining when the simulation results are unacceptable;

upon determining when the simulation results are unacceptable, modifying a representation of a physical feature of the intra-transistor component that is present in the circuit schematic during the simulating the circuit schematic, wherein the physical feature comprises at least one of:

a spacing between the intra-transistor component and another intra-transistor component,

a size of the intra-transistor component,

a doping concentration of the intra-transistor component,

a doping type of the intra-transistor component, or

a depth of the intra-transistor component; and

thereafter, creating a layout based on a plurality of properties represented in the circuit schematic.

2. The method of claim 1 , wherein the substrate network comprises a τ-configuration, wherein a first branch comprises a first resistor coupled between a first exterior node of the substrate network and an interior node, a second branch comprises a second resistor coupled between a second exterior node and the interior node, and a third branch comprises a serially connected third resistor and inductor coupled between the interior node and a ground node.

3. The method of claim 1 , wherein the simulation results include a graph of a magnitude of an output signal in a frequency domain.

4. The method of claim 1 , wherein the representation of the physical feature of the intra-transistor component represents a guard-ring structure.

5. The method of claim 1 , wherein the circuit schematic is represented by a circuit netlist, the first circuit is represented by a first subcircuit netlist, the aggressor circuit is represented by a second subcircuit netlist, the substrate network is represented by a third subcircuit netlist, and a multi-terminal model in the first circuit is represented by a fourth subcircuit netlist.

6. The method of claim 1 further comprising:

using a third processor based system, verifying the layout; and

implementing the layout on a semiconductor chip.

7. The method of claim 1 , wherein the first circuit comprises a multi-terminal model of a transistor, wherein the multi-terminal model comprises a source terminal, a gate terminal, a drain terminal, a body terminal, and a guard-ring terminal.

8. A method for substrate noise analysis, the method comprising:

using a first processor based system, creating a circuit schematic comprising a first circuit, an aggressor circuit, and a substrate network coupling the first circuit to the aggressor circuit, wherein the substrate network is based on physical features of an expected die size, wherein the first circuit comprises a multi-terminal model of a transistor, wherein the multi-terminal model comprises a source terminal, a gate terminal, a drain terminal, a body terminal, and a guard-ring terminal;

using a second processor based system, simulating the circuit schematic thereby resulting in simulation results;

determining when the simulation results are unacceptable;

upon determining when the simulation results are unacceptable, modifying a component in the circuit schematic to modify at least one property represented in the circuit schematic; and

thereafter, creating a layout based on a plurality of properties represented in the circuit schematic.

9. The method of claim 8 , wherein the substrate network comprises a τ-configuration, wherein a first branch comprises a first resistor coupled between a first exterior node of the substrate network and an interior node, a second branch comprises a second resistor coupled between a second exterior node and the interior node, and a third branch comprises a serially connected third resistor and inductor coupled between the interior node and a ground node.

10. The method of claim 8 , wherein the simulation results include a graph of a magnitude of an output signal in a frequency domain.

11. The method of claim 8 , wherein the component represents a guard-ring structure, and wherein the component is modified to represent a change in a doping concentration, a width, a depth, a doping type, or a combination thereof.

12. The method of claim 8 , wherein the circuit schematic is represented by a circuit netlist, the first circuit is represented by a first subcircuit netlist, the aggressor circuit is represented by a second subcircuit netlist, the substrate network is represented by a third subcircuit netlist, and the multi-terminal model is represented by a fourth subcircuit netlist.

13. The method of claim 8 further comprising:

using a third processor based system, verifying the layout; and

implementing the layout on a semiconductor chip.

14. A method for substrate noise analysis, the method comprising:

creating a circuit schematic using a first processor based system, wherein the circuit schematic comprises a model representing physical properties of an expected layout, the circuit schematic comprising a transistor device, an intra-transistor component being within the transistor device;

simulating the circuit schematic using a second processor based system;

obtaining data from the simulating of the circuit schematic;

modifying a representation of a physical property of the intra-transistor component based on the data from the simulating, wherein the physical property of the intra-transistor component is at least one of the physical properties of the expected layout that is present during the simulating the circuit schematic, wherein the physical property of the intra-transistor component is at least one of:

a spacing between the intra-transistor component and another intra-transistor component,

a size of the intra-transistor component,

a doping concentration of the intra-transistor component,

a doping type of the intra-transistor component, or

a depth of the intra-transistor component; and

thereafter, creating a post-simulation layout based on the modifying of the intra-transistor component.

15. The method of claim 14 , wherein the circuit schematic comprises a first circuit, an aggressor circuit, and a substrate network coupled between the first circuit and the aggressor circuit, wherein the first circuit comprises a multi-terminal model of a transistor that comprises a drain terminal, a gate terminal, a source terminal, a body terminal, and a guard-ring terminal, wherein each of the multi-terminal model and the substrate network represents at least some of the physical properties of the expected layout.

16. The method of claim 14 , wherein the intra-transistor component is a guard-ring structure.

17. The method of claim 14 , wherein the data includes a graph in a frequency domain of an output signal of the circuit schematic.

18. The method of claim 14 , wherein creating the circuit schematic comprises creating a netlist.

19. The method of claim 14 further comprising:

verifying the post-simulation layout using a third processor based system; and

implementing the post-simulation layout on a semiconductor chip.

20. A method for substrate noise analysis, the method comprising:

using a first processor based system, creating a circuit schematic comprising a first circuit, an aggressor circuit, and a substrate network coupling the first circuit to the aggressor circuit, wherein the substrate network is based on physical features of a substrate, the circuit schematic being created without an initial layout of the substrate comprising the first circuit;

using a second processor based system, simulating the circuit schematic thereby resulting in simulation results;

determining when the simulation results are unacceptable;

upon determining when the simulation results are unacceptable, modifying a representation of a physical feature of a component in the circuit schematic; and

thereafter, creating a post-simulation layout based on a plurality of properties represented in the circuit schematic.