CN-121997866-A - Method and system for establishing Complementary Metal Oxide Semiconductor (CMOS) model at extremely low temperature

CN121997866ACN 121997866 ACN121997866 ACN 121997866ACN-121997866-A

Abstract

The invention discloses a method and a system for establishing a Complementary Metal Oxide Semiconductor (CMOS) tube model under extremely low temperature, which are characterized in that at least two extremely low temperature points are used for acquiring CMOS tube electrical characteristic curves, or curve fitting is carried out on a CMOS tube with a known model, the CMOS tube electrical characteristic curves under a target temperature T_target are predicted based on the acquired CMOS tube electrical characteristic curves of at least two low temperature points, modeling software is adopted for carrying out curve fitting and parameter lifting on the CMOS tube under the T_target, important parameters are corrected, the CMOS tube electrical characteristic curves under the T_target are reconstructed based on the extracted parameters and corrected parameters, and after the CMOS tube parameter lifting modeling under the T_target is completed through modeling software, the complete modeling of the CMOS tube low temperature electrical behavior is further completed.

Inventors

FAN ZILONG
HU QINGSHENG
ZHU DEJUN
WU XU
LI LIANMING

Assignees

东南大学

Dates

Publication Date: 20260508
Application Date: 20251219

Claims (10)

1. The method for establishing the complementary metal oxide semiconductor die at the extremely low temperature is characterized by comprising the following steps of: at an extremely low temperature point Acquiring an electrical characteristic curve of the CMOS tube or performing curve fitting on the CMOS tube with known model, wherein the extremely low temperature is lower than a temperature threshold value I represents the total number of very low temperature points, ; Based on the acquired CMOS tube electrical characteristic curves of at least two low-temperature points, predicting the CMOS tube electrical characteristic curve under the target low-temperature T_target by adopting a double-temperature-area power law method; Adopting modeling software to carry out parameter extraction on an electrical characteristic curve of the CMOS tube under the T_target, and correcting important parameters, wherein the important parameters comprise parameters which influence the characteristics of the CMOS tube and are related to temperature; Reconstructing an electrical characteristic curve of the CMOS tube under the T_target based on the extracted parameters and the corrected parameters; comparing the reconstructed electrical curve with the predicted electrical characteristic curve, and judging whether the extracted parameters need to be corrected or not; and after the modeling software is used for completing the parameter-raising modeling of the CMOS tube under the T_target, the complete modeling of the low-temperature electrical behavior of the CMOS tube is further completed.
2. The method for establishing the Complementary Metal Oxide Semiconductor (CMOS) tube model under the extremely low temperature according to claim 1, wherein the method for acquiring the electrical characteristic curves of the CMOS tubes at least at two extremely low temperature points comprises the steps of testing the CMOS tubes with different sizes in an extremely low temperature environment, putting a plurality of CMOS tubes with the same size into the CMOS tube in the extremely low temperature environment at one time, controlling the temperature gradient in the test to be less than or equal to 5K/min, and introducing dry nitrogen into a test box.
3. The method for building a complementary metal oxide semiconductor (cmos) model at very low temperature according to claim 1, wherein the target temperature t_target is 77K, and a dual-temperature power law low-temperature prediction method is adopted to obtain an electrical characteristic curve of 77K, which specifically comprises: And taking each acquired electrical characteristic curve as a prediction unit, and predicting the electrical characteristic curve corresponding to the next prediction unit of the target temperature T_target.
4. The method for building a CMOS model at very low temperatures according to claim 3, wherein the obtained actual electrical characteristics of the CMOS at the first temperature and the second temperature are: A first group of curves, namely fixing drain-source voltage Vds1, enabling the CMOS tube to work in a linear region, scanning gate-source voltage Vgs, and synchronously changing bulk source voltage Vbs to obtain a linear region transfer characteristic curve family; the second group of curves is to fix the first body source voltage Vbs1, enable the CMOS tube to have no body effect, scan drain-source voltage Vds and synchronously change gate-source voltage Vgs to obtain an output characteristic curve family; A third group of curves, namely fixing drain-source voltage Vds2, enabling the CMOS tube to be in a deep saturation region, scanning gate-source voltage Vgs, and synchronously changing bulk source voltage Vbs to obtain a threshold voltage characteristic curve family; And a fourth group of curves, namely fixing the second bulk source voltage Vbs2, enabling the CMOS tube to be in a limit bulk effect, scanning the drain-source voltage Vds, and synchronously changing the gate-source voltage Vgs to obtain a mobility characteristic curve family.
5. The method for building a complementary metal oxide semiconductor (cmos) model at very low temperatures according to claim 3, wherein the power law method is used to predict the electrical characteristics corresponding to a prediction unit of t_target, specifically: Setting a power law scaling relationship between current and temperature: ; Wherein I (-) represents the current at the corresponding temperature, To solve for the parameter C, D, let t= Will all Substituting data of the electrical characteristic curve under the corresponding prediction unit into a power law scaling relation of current and temperature to obtain values of C and D simultaneously, and substituting T=T_target into a relational expression to obtain the electrical characteristic curve under the temperature of T_target corresponding to the prediction unit.
6. The method of claim 1, wherein the important parameters include carrier mobility μ, saturation velocity vsat, and threshold voltage V th .
7. The method for building a Complementary Metal Oxide Semiconductor (CMOS) model at very low temperature as claimed in claim 1, wherein after the modeling software curve fitting and parameter extraction, the important parameters are corrected by adopting correction terms based on a physical scattering mechanism, specifically: Calculating a base temperature index: ; Wherein X represents any important parameter, X # ) Indicating a temperature of The value of the time-critical parameter X # -, X ) At a temperature of The value of the parameter of interest in time, , For all of A set of formations; Adjusting a base temperature index: ; Wherein k_process is a process-related correction factor; Calculating the basic value of important parameters without considering the special effect of very low temperature under the T_target: ; Calculating a correction value of an important parameter under T_target: ; Wherein, the For the coulomb scattering coefficient, Is the surface roughness scattering coefficient.
8. The method for building a cmos model at very low temperatures according to claim 1, wherein determining whether the extracted parameters need to be corrected is performed by quantifying a deviation between the reconstructed electrical curve and the predicted electrical characteristic using a maximum error and an average error, and if the quantified result is greater than a predetermined deviation threshold, selecting parameters other than the important parameters from the extracted parameters to adjust such that the quantified result is less than or equal to the predetermined deviation threshold.
9. The method for building a complementary metal oxide semiconductor (cmos) model at very low temperatures according to claim 1, wherein the very low temperature rule is set when curve fitting is performed by modeling software: μ(77K)>μ(218K)、V th (77K)>V th (218K); Where μ represents carrier mobility, and V th represents threshold voltage.
10. A system for establishing a Complementary Metal Oxide Semiconductor (CMOS) model at extremely low temperature is characterized by comprising The data acquisition module is used for acquiring an actual electrical characteristic curve of the CMOS tube in an extremely low temperature environment; the curve prediction module is used for predicting the CMOS tube electrical characteristic curve at the target temperature T_target by adopting a power law method based on the acquired CMOS tube characteristic curve; The parameter correction module is used for extracting parameters of the electrical characteristic curve of the CMOS tube at the temperature of T_target by adopting parameter extraction software and correcting important parameters in the extracted parameters; the curve reconstruction module is used for reconstructing the electrical characteristic curve of the CMOS tube under the T_target by adopting parameter extraction software based on the extracted parameters and the corrected parameters; the comparison module is used for comparing the reconstructed electrical characteristic curve with the electrical characteristic curve predicted by the power law method and judging whether the extracted parameters need to be corrected or not; And the modeling module is used for completing parameter extraction modeling at the temperature of T_target through parameter extraction software and further completing complete modeling of the low-temperature electrical behavior of the MOS tube.

Description

Method and system for establishing Complementary Metal Oxide Semiconductor (CMOS) model at extremely low temperature Technical Field The invention belongs to the technical field of semiconductors, and particularly relates to a method and a system for establishing a Complementary Metal Oxide Semiconductor (CMOS) model at extremely low temperature. Background Since the open research of various radioactive phenomena by scientists such as ethics, beckle and curies at the end of the 19 th century, people have continuously explored and expanded the application fields of radioactive phenomena in production and life. How to realize the accurate detection of radioactive rays and high-energy particles is always a hot spot research topic in the fields of nuclear physics and nuclear electronics. In recent years, new semiconductor radiation detectors, typified by tellurium-zinc-cadmium detectors and high-purity germanium detectors, have received attention because of their high radiation absorptivity and energy conversion rate. The method can rapidly detect ultra-trace X/gamma rays, and has wide application prospects in the radiation detection and imaging fields such as environmental radioactivity monitoring, radiation source identification, metal component analysis, geological mapping and research, mineral and raw material investigation, safety inspection, emergency monitoring, biomedical imaging, space detection, celestial body physics, high-energy physics research and the like. In order to fully exploit the excellent performance of such radiation detectors at low temperatures, front-end readout circuits are typically operated in a low temperature environment, typically in a liquid nitrogen tank (77K). However, existing integrated circuit fabrication processes have significant drawbacks with respect to CMOS tube simulation models for this temperature. The conventional method predicts 77K electrical data by adopting a 4K+218K linear interpolation method, ignores key physical effects such as extremely low-temperature carrier freezing, impurity ionization rate dip, mobility temperature dependence and the like, causes prediction errors to reach 15% -20%, and cannot meet circuit design requirements, and the linear interpolation method only depends on a single temperature parameter, does not consider CMOS tube structure and technological parameters, and is limited to devices with specific sizes in applicability. The technical blank severely restricts the prediction and optimization of scientific researchers on the performance of the CMOS tube in the low-temperature environment, and a designer cannot utilize an effective and accurate model to improve the circuit performance through simulation and only depends on a large number of experimental tests, so that the method is time-consuming and labor-consuming, and has higher cost and risk. Disclosure of Invention The invention aims to: in order to solve the problems in the prior art, the invention provides a method and a system for establishing a Complementary Metal Oxide Semiconductor (CMOS) tube model at extremely low temperature, wherein the CMOS tube electrical characteristic curves at target low temperature are predicted by a method combining theory and modeling software curve fitting through a plurality of CMOS tube electrical characteristic curves at low temperature points of a known model, so that a reliable CMOS tube model at target low temperature is established. The invention provides a method for establishing a Complementary Metal Oxide Semiconductor (CMOS) model at extremely low temperature, which comprises the following steps: at an extremely low temperature point Acquiring an electrical characteristic curve of the CMOS tube or performing curve fitting on the CMOS tube with known model, wherein the extremely low temperature is lower than a temperature threshold valueI represents the total number of very low temperature points,; Based on the acquired CMOS tube electrical characteristic curves of at least two low-temperature points, predicting the CMOS tube electrical characteristic curve under the target low-temperature T_target by adopting a double-temperature-area power law method; Adopting modeling software to carry out parameter extraction on an electrical characteristic curve of the CMOS tube under the T_target, and correcting important parameters, wherein the important parameters comprise parameters which influence the characteristics of the CMOS tube and are related to temperature; Reconstructing an electrical characteristic curve of the CMOS tube under the T_target based on the extracted parameters and the corrected parameters; comparing the reconstructed electrical curve with the predicted electrical characteristic curve, and judging whether the extracted parameters need to be corrected or not; and after the modeling software is used for completing the parameter-raising modeling of the CMOS tube under the T_target, the complete modeling of the low-temperatur