Paper PS1-ThM6
The Etching Characteristics of Flexible Substrate in Inductively Coupled Plasma System for Flexible Electronics

Thursday, November 1, 2012, 9:40 am, Room 24

Recently, many attention was given to the flexible electronics due to its future applications, such as flexible display and e-paper, etc. In order to fabricate the devices on the flexible substrate, such as PES, PAR, and PI, the etching characteristics of the substrate should be studied respect to other deposited thin film layers because the surface roughness and etch by-products could affect the device performance. Also, the devices can be embedded in the flexible substrate, where the flexible substrate should be etched away.

In this study, polyarylate (PAR) and polyethersulfone (PES) flexible substrates were etched by using inductively coupled plasma (ICP) system at room temperature. BCl₃, CF₄, and Ar mixed chemistry gases were used to achieve a high etch rate and good selectivity respect to the other metal (Al) or oxide (ZnO) layers. The etching charactersits of the flexible susbstrate were studied by varying the process parameters, including process pressure, DC bias voltage, RF power, and gas mixing ratio. In addition to the etch rate and selectivity, the surface chemical bonding structure and roughness were studied because they are the important factors for the device fabrication and performance.

The etch rate and selectivty were measured by using a depth profiler (alpha-step 500, KLA tencor) and the surface roughness was measured by atomic force microscopy (AFM). The chemical states of etched surfaces were investigated with X-ray photoelectron spectroscopy (XPS). The elemental analysis of etched surfaces was investigated with the auger electron spectroscopy (AES) analysis.