Paul Scherrer Institut

Eth Zuerich

Ralph Spolenak

Gustav Schiefler

Martin Süss

Jerome Faist

Hans Christian Sigg

A tensile strain state in semiconductor components is adjusted. A pretensioned (tensile strain) layer is applied to a substrate (FIG., (A)). Bridge structures (FIG.(B)) are introduced in the layers by lithography and etching. The bridges are connected to the layer on both sides and are thus continuous. The geometric shape of the bridges, formed with a cross-section modulation, is determined by the windows (FIG.(C)) in the layer. When the substrate is etched selectively, the bridge is undercut through the windows. The geometric structuring of the cross-section (FIG., (D)) causes a redistribution of the originally homogeneous strain when the bridges are detached from the substrate, with the larger cross-sections relaxing at the expense of the smaller cross-sections, where the pretension is increased. Only a multiplication of stresses (or strain) originally present in the sample is possible, with the multiplication factor determined by lengths, widths and depths, and/or the relationships thereof.

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Ralph Spolenak