Depth-profiling analysis of ZnO layers with three morphologies by direct-current glow discharge mass spectrometry

• The capability of direct-current glow discharge mass spectrometry (dc-GD-MS) was demonstrated for depth-profiling analysis of zinc oxide (ZnO) layers on steel substrates. • ZnO-1/steel fabricated by magnetron sputtering presented superior performance with a high depth resolution of 0.22?µm and a clear interface between the ZnO layer and steel substrate. • The effects of layer morphology, thickness and sputtering rate on depth resolutions were investigated and layer morphology had greater impact on depth resolutions.