摘要 |
A technique is provided which enables quantitative evaluation of an undercutting of deep trench structures in semiconductor wafers and, in particular, SOI wafers, by means of electrical or optical measuring. A specific control structure (100) having a defined ridge width is used which can be routinely measured in the course of the production process. The control structure comprises two adjacent trenches (5) each which are separated by a ridge having a defined ridge width. By undercutting (U) the adjacent trenches, the regions of undercutting of adjacent trenches may intersect each other starting from a specific minimum ridge width which results in a detachment of the ridge from the bottom making the ridge moveable. Mobility is determined by thermal deflection of the ridge. Arranging a plurality of control structures having various ridge widths enables determination of a quantitative amount of the undercutting.
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