Method and device for testing stress bias temperature instability of constant electric field

Abstract

The invention relates to a method and a device for testing stress bias temperature instability of a constant electric field. The method comprises the steps of applying a stress voltage to a to-be-tested device according to a preset duration; after the process of applying the stress voltage to the to-be-tested device is finished, applying a scanning voltage to the to-be-tested device, collecting aleakage current and the scanning voltage of the to-be-tested device in real time, and determining a current threshold voltage of the to-be-tested device according to the scanning voltage and the leakage current; according to the current threshold voltage and the initial threshold voltage, determining a current threshold drift amount of the to-be-tested device; judging whether the number of times of applying the stress voltage reaches a preset number of times or not; when it is judged that the number of times of applying the stress voltage is smaller than the preset number of times, adjusting the stress voltage according to the current threshold drift distance; and applying the adjusted stress voltage to the to-be-tested device and maintaining the preset duration, and then returning to thestep of applying the scanning voltage to the to-be-tested device.

Description

technical field [0001] The invention relates to the technical field of characterization and testing of semiconductor device reliability, in particular to a testing method and device for constant electric field stress bias temperature instability. Background technique [0002] Bias Temperature Instability (BTI) is the most common degradation mechanism on Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). BTI refers to the threshold voltage (Threshold Voltage: Vth) drift, saturation current and transconductance reduction, gate leakage current and subthreshold value of the electrical characteristics of the transistor when a bias voltage is applied to the gate of the transistor under certain temperature conditions The effect of degradation such as swing increase, the amount of degradation is often expressed by the threshold voltage drift ΔVth. With the continuous reduction of oxide layer thickness and the introduction of new materials (SiON, high-k dielectric), the imp...

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Problems solved by technology

[0007] The invention provides a test method and device for constant electric field stress bias temperature instability to solve the problem of inaccurate prediction results caused by too large threshold voltage drift

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