Test structure for electrical assessment of UV laser direct fine patterned material

Abstract

We propose a test structure to electrically assess direct laser fine patterning, which is entering a microelectronic era (below 10μm). Indium-Tin-Oxide (ITO) was used as a material example. High speed ITO patterning with laser ablation can contribute short turn-around-time development of opto-electrical devices, such as organic light emitting diode. However, not only machine-induced line-edge fluctuation but also the process (e.g. heat) induced material degradation may affect electrical linewidth. The aim of our test structure is to assess such critical dimension change through measurement of electrical property (i.e. conductivity). It consists of Kelvin-connection straight lines and Greek crosses with various widths. Ultraviolet (UV) laser process as well as lithography and plasma etching were applied with the same test structure. The measurement revealed that the applied direct patterning condition induced small damage, showing applicability of direct patterning in microelectronics R&D.