Fixed point analysis method for bottom of super junction groove

Abstract

The invention discloses a fixed point analysis method for the bottom of a super junction groove, comprising the following steps: manufacturing a fixed point mark in the position where a sample needs to be analyzed; grinding the side face of the sample until the distance between the residual sample at the side face grinding part and the fixed point mark reaches a first preset distance; obliquely grinding the front face of the sample in a first preset angle until the width of the residual sample at the grinding part reaches a first preset grinding width; and carrying out surface fixed point analysis on the mark position where the distance between the surface of the sample and the bottom of the groove is less than a second preset distance by using focused ion beams. The method disclosed by the invention can realize accurate positioning of a failure point of the bottom of the super junction groove.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a fixed-point analysis method for the bottom of a super junction trench. Background technique [0002] When performing failure analysis and analysis of the current consumption or BV (breakdown voltage) failure of the super junction gate at zero voltage, after the failure point is located, there are certain technical difficulties in the next step of analysis. The prior art faces the following technical problems when implementing fixed-point analysis: [0003] 1. Since the channel depth of the super junction reaches tens of microns, and the focused ion beam analysis exceeds the depth of 20 microns, the analysis is difficult, and it is impossible to directly analyze the bottom of the channel through the focused ion beam. [0004] 2. The failure point is generally small, and the grinding accuracy cannot meet the failure point location analysis. [0005] 3. It is difficult to determine...

AI Technical Summary

Problems solved by technology

[0003] 1. Since the channel depth of the super junction reaches tens of microns, and the focused ion beam analysis exceeds the depth of 20 microns, the analysis is difficult, and it is impossible to directly analyze the bottom of the channel through the focused ion beam

[0004] 2. The failure point is generally small, and the grinding accuracy cannot meet the failure point location analysis

[0005] 3. After thinning directly on the surface of the device, the method of focusing ion beam analysis is difficult because it is impossible to judge the specific thinning depth

[0006] To sum up, for the current consumption or breakdown voltage of the super junction gate at zero voltage, if the failure point is at a deep position in the channel (deeper refers to more than 20 microns), it is currently impossible to accurately determine the morphology of the fixed point analysis. Whitespace

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