Apparatus and method for determination of the lateral undercut of a structured surface layer

The invention relates to a device and a method for determining the extent of an at least partial lateral undercut of a structured surface layer (23) on a sacrificial coating (21). To this end, a part of said structured surface layer (23) comprises at least one passive electronic component (31) with which a measurable physical variable can be determined that is proportional to the extent of the lateral undercut. According to the inventive method for producing said device, at least a part of the surface layer (21) on the structured surface layer (23) is provided in a first etching step with a structure comprising trenches (15'). In a second etching step, a lateral undercut on at least a part of the structured surface layer (23) is carried out starting from said trenches (15'). In the first etching step, at least one passive electronic component (31) is additionally produced by structuring a part of the surface layer (23). During the following undercutting of the surface layer (23) said electronic component is also undercut. The measurable physical variable is determined in a contactless manner, preferably by irradiating the passive component (31) with electromagnetic radiation.