Test structure and test method for gate oxide integrity

Abstract

The invention relates to a test structure and a test method for gate oxide integrity. The test structure comprises the components of a semiconductor substrate on which an N well and a P well are separately formed; a gate electrode structure which comprises a gate oxide and a gate electrode, wherein the gate structure is partially arranged above the N well and is partially arranged above the P well; and a source region and a drain region which are respectively arranged in the N well and the P well at two sides of the gate electrode structure, wherein a gradually increased stress voltage is applied on the gate electrode structure. The test structure can effectively evaluate device damage of the gate electrode in a patterning process. Not only is detecting efficiency improved, but also the area of the test structure can be further reduced.

Description

technical field [0001] The invention relates to a semiconductor manufacturing process, and in particular, the invention relates to a test structure and a test method for the integrity of a gate oxide layer. Background technique [0002] With the continuous development of technology, the thickness of the gate oxide layer of integrated circuits is also reduced from 20-30nm to less than 1nm. The gate oxide layer continues to develop towards the film direction, but the power supply voltage should not be lowered. At higher electric field strengths, the performance of the gate oxide is bound to become a prominent issue. [0003] Poor electrical resistance of gate oxide will cause unstable electrical parameters of MOS devices, such as: threshold voltage drift, transconductance drop, leakage current increase, etc., which will further cause gate oxide breakdown, resulting in device failure and causing the entire integrated circuit to fall into paralyzed state. Therefore, the break...

AI Technical Summary

Problems solved by technology

Although the test structure can accurately test the integrity of the gate oxide layer 103, the test structure and the test method need to consume a large amount of test cycle time. With the development of technology, the test capability of the test structure is limited. , but if the test cycle time is reduced, the test results cannot be guaranteed, so there is currently no way to reduce the test cycle time while ensuring that the test results are still acceptable

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