Measurement method of trap energy level distribution in oxide layer of semiconductor device

Abstract

The present invention provides a measurement method of the trap energy level distribution in an oxide layer of a semiconductor device. The basic principle of the measurement method is that firstly thevisible light irradiates a substrate to excite the free carriers, at the same time, by applying a certain voltage, the carriers are injected in a silicon dioxide layer to be captured by the energy level of a trap; then, by a linear warming method, the bound carriers captured by the trap are excited again to change into the free carriers, and a change curve of a current contributed by the part ofcarriers along with the temperature is measured; and finally, according to a thermal simulation current model, the energy level distribution of the trap in the silicon dioxide is obtained. According to the measurement method of the present invention, by the visible light and by applying the voltage, the carriers are injected in the silicon dioxide, and a mode of using the X-rays to irradiate to inject the carriers and the further damage to the silicon dioxide are avoided.

Description

technical field [0001] The invention relates to research on the quality and reliability of semiconductor devices, in particular to a method for measuring trap energy level distribution in oxide layers of semiconductor devices. Background technique [0002] With the rapid development of chip manufacturing technology and the substantial improvement of chip integration, the performance of integrated circuits has become more and more advanced, the device size has become smaller and smaller, and the thickness of the oxide layer has become thinner and thinner. The quality of the oxide layer is directly related to the performance and stability of the device. The trap level of the oxide layer in the device will trap carriers and form semiconductor charges, which will cause the threshold voltage of the device to shift, increase the gate leakage current of the device, and reduce the reliability and long-term stability of the device. Therefore, it is necessary to measure the trap stat...

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Problems solved by technology

[0003] However, since silicon dioxide is an amorphous material with a very wide band gap, low carrier concentration and poor conductivity, it is very difficult to characterize the traps in the silicon dioxide layer.

In addition, X-ray irradiation is often used to inject carriers into the oxide layer, which requires high equipment and cumbersome experimental procedures; and may cause further damage to the oxide layer

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