Method for modeling field effect transistor and circuit simulation method

Abstract

The invention relates to a method for modeling a field effect transistor and a circuit simulation method. The method for modeling the field effect transistor comprises the following steps: calling gate voltage recorded by the selected field effect transistor and the corresponding drain current thereof to obtain relation for change of the drain current of the field effect transistor with the gate voltage; acquiring the relation for the change of first equivalent drain current of the transistor structure with the gate voltage and the relation for change of second equivalent drain current of a shallow trench isolating structure with the gate voltage based on the relation for the change of the drain current of the field effect transistor with the gate voltage; establishing a field effect transistor model according to the relation for the change of the first equivalent drain current of the transistor structure with the gate voltage and the relation for the change of the second equivalent drain current of the shallow trench isolating structure with the gate voltage. The accurate field effect transistor model can be established to improve the precision of circuit simulation.

Description

technical field [0001] The invention relates to the field of integrated circuit design, in particular to a method for modeling a field effect transistor and a circuit simulation method. Background technique [0002] Shallow trench isolation (STI) technology is used to realize isolation between field effect transistors (MOSFETs). The formation principle of the shallow trench isolation structure is to etch a trench on the surface of the silicon substrate corresponding to the shallow trench, and silicon dioxide (SiO 2 ) into the groove. [0003] Shallow trench isolation technology is a substitute for partial isolation silicon oxide isolation technology, and is the mainstream isolation technology for deep submicron processes. The trench of the shallow trench isolation structure has relatively steep side walls, so it has a small area, which can improve the integration degree of the field effect transistor. And because the CMP process is used in its manufacturing process, it ha...

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Problems solved by technology

[0006] However, the field effect transistor model in the prior art simulation system based on BSIM4 etc. ignores the impact of the shallow trench isolation structure on the transistor structure: when the size of the field effect transistor is relatively large, the shallow trench isolation structure has a large impact on the field effect transistor. The impact of parameters and performance can be ignored; but with the continuous development of the integrated circuit industry, the size of the field effect transistor is continuously reduced. The field effect transistor model does not take this result into account and cannot accurately describe the characteristics of real field effect transistors

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