Method for measuring accumulated thickness of MOS (metal oxide semiconductor) tube gate oxide layer

Abstract

The invention discloses a method for measuring the accumulated thickness of an MOS (metal oxide semiconductor) tube gate oxide layer, comprising the following steps: S1, regulating a test voltage to be close to a breakdown voltage between a grid and a substrate; S2, measuring the capacitance of a gate oxide layer in accordance with the test voltage in the S1; and S3, calculating the accumulated thickness of the gate oxide layer in accordance with the capacitance in the S2. The calculation formula of the accumulated thickness of the gate oxide layer is as follows: Tox=epsilon*epsilon0*A / Cox, wherein Tox represents the accumulated thickness of the gate oxide layer, Cox represents the capacitance of the gate oxide layer, epsilon represents a vacuum permittivity, epsilon0 represents a dielectric constant and A represents a capacitance area. The method provided by the invention is applied to measuring the thinner MOS tube gate oxide layers.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for measuring the cumulative thickness of a gate oxide layer of a MOS transistor. Background technique [0002] In the field of semiconductor manufacturing technology, finished semiconductor devices include many basic devices such as MOS transistors. In order to grasp the process parameters of MOS, it is necessary to measure the accumulated thickness of the gate oxide layer of MOS transistors. In the prior art, the method for measuring the thickness of the MOS tube gate oxide layer accumulation is: (1), according to the power supply voltage is ±Vdd, measure the capacitance value Cox of the MOS tube gate oxide layer; (2), calculate the capacitance value Cox of the MOS tube according to the capacitance value Cox The cumulative thickness of the gate oxide layer. Among them, the NMOS tube is +Vdd, and the PMOS tube is -Vdd. The formula for calculating t...

AI Technical Summary

Problems solved by technology

[0004] To sum up, the method for measuring the thickness of the gate oxide layer of MOS transistors in the prior art has the disadvantage that it is not suitable for the measurement of the gate oxide layer of MOS transistors with a thinner thickness.