Testing for correct undercutting of an electrode during an etching step

• Main Authors: Zingg, Rene P, Gopalan Zingg, Sudha, Doornveld, Herman E, Martens, Theodorus H. G
• Format: Patent
• Language: English
• Published: 22.11.2011

A probe electrode structure on a substrate is described, comprising a first probe electrode and a neighboring second probe electrode on a layer sequence that generally includes, in a direction from the substrate to the probe electrodes, an electrically conductive bottom layer, an electrically insulating center layer and a electrically conductive top layer. The probe-electrode structure of the invention provides a means to detect an undercutting of the first probe electrode in an etching step that aims at removing the top layer from regions outside the first probe electrode. An undercutting that exceeds an admissible distance from the first edge of the first electrode will remove the first top-layer probe section in the first probe opening, which causes a detectable change of the electrical resistance between the first and second probe electrodes.