Dislocation type electric leakage analysis method in grooved MOS device

Abstract

The invention discloses a dislocation type electric leakage analysis method in a grooved MOS device. The method comprises the steps of obtaining defect positions corresponding to light emitting points through an EMMI analysis method, controlling EMMI analysis conditions to enable the diameters of the light emitting points to be smaller than or equal to 1.5 microns, preparing TEM samples at the defect positions through an FIB method, and carrying out TEM analysis on the TEM samples, wherein the centers of the TEM samples and the centers of the defect positions coincide, and the thickness of the TEM samples is larger than or equal to the diameter of the light emitting points at the defect positions. The method can be used for quickly and accurately locating, analyzing and determining electric leakage failure caused by dislocation.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit manufacturing process method, in particular to a dislocation leakage analysis method in a trench MOS device. Background technique [0002] The gate array in a trench MOS device is composed of trenches, which are formed by etching a semiconductor substrate such as a silicon substrate. Dislocation defects are formed in trench MOS devices, and the dislocation defects cause leakage. When the trench MOS device has dislocation leakage, it is necessary to find out the specific position of the dislocation and analyze the dislocation. The current analysis method for dislocation type leakage in trench MOS devices includes steps: [0003] The first step is to perform EMMI (Emission Microscope, light-emitting microscope) positioning at the failure feature point. [0004] EMMI: After a non-equilibrium state is generated in a semiconductor material through a certain form of excitation, there will be a tr...

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Problems solved by technology

[0011] 1. In the first step of EMMI analysis, the leakage point, that is, the luminous point 103 is too large, that is, the diameter of the luminous point 103 is often larger than the actual size of the dislocation defect, and it cannot quickly and completely accurately locate the dislocation defect , which affects the speed and accuracy of the overall analysis

[0012] 2. The thickness of the TEM sample formed in the second step is about 100nm, which often cannot completely cover the entire dislocation defect or even not include the dislocation defect, so that the subsequent TEM observation is very limited, so that it is missed or cannot be comprehensive Understand defect information

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