Bias voltage temperature instability detection circuit and detection method

Abstract

The invention provides bias voltage temperature instability detection circuit and detection method. The bias voltage temperature instability detection circuit comprises an odd number of fundamental oscillation units. Each fundamental oscillation unit comprises a first transistor, a second transistor, a first control transistor, a second control transistor, an input end and an output end. The detection circuit further comprises third transistors which are located between adjacent fundamental oscillation units. The fundamental oscillation units and the third transistors are connected in series to form an annular oscillator. According to the embodiment of the invention, the bias voltage temperature instability detection circuit can respectively detect the degree of threshold voltage degradation, which is caused by negative bias voltage temperature instability, of a PMOS transistor and the degree of threshold voltage degradation, which is caused by positive bias voltage temperature instability, of an NMOS transistor; by using the third transistors, the degree of threshold voltage degradation, which is caused by bias voltage temperature instability, of an MOS transistor can be amplified; and the final detection result is sensitive and the detection precision is high.

Description

technical field [0001] The invention relates to semiconductor detection technology, in particular to a detection circuit and detection method for bias temperature instability. Background technique [0002] As the integration level of semiconductor integrated circuits becomes higher and higher, the requirements for the performance of transistors are also increased, and therefore, the requirements for the reliability of transistors are also increased. The bias temperature instability of the MOS transistor is an important factor affecting the reliability of the MOS transistor, and the bias temperature instability includes negative bias temperature instability and positive bias temperature instability. In the existing CMOS process, when evaluating the reliability of the PMOS transistor, the stability of negative bias voltage temperature is a main evaluation factor. Negative bias temperature instability means that under the action of negative bias gate voltage and high temperatu...

AI Technical Summary

Problems solved by technology

However, as NMOS transistors with metal gates become more and more common, when the gate structures of the NMOS transistors and PMOS transistors in the inverter are metal gates, a low voltage is applied to the input terminal A1 of the inverter 10 level, the gate of the NMOS transistor of the inverter 11 will be subjected to a high level, and the NMOS transistor of the inverter 11 will also cause threshold voltage degradation due to positive temperature bias instability, both of which will affect the final Oscillation frequency is affected, so that it is impossible to judge the degree of threshold voltage degradation of the PMOS transistors of the inverter 10 and inverter 12 due to negative temperature bias instability based on the final oscillation frequency difference

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