Application of interferometry for 3-dimensional visualization of MgO-layer erosion in a.c.-plasma display panels

We applied the microscopic spectrophotometry for the in situ and real-time investigation of the MgO-layer erosion in an a.c.-plasma display panel cell. In particular, the 3-dimensional visualization of the temporal variation of the MgO-layer thickness was realized from measuring the transmission spectra corresponding to the area of 10×10 μm2 while scanning the sample position using the stepping motor and the micrometer. The main features of the MgO-layer erosion were the formation of two trenches, the bottom of which were near but not coincide with the edges of indium tin oxide (ITO) electrodes, and the re-deposition of the eroded MgO in the region between two ITO electrodes. We discussed the temporal variation of the trench shape and size in detail. Moreover, we presented the correlation between the amount of the eroded and re-deposited MgO.