Fabrication of a high-aspect-ratio stainless steel shadow mask and its application to pentacene thin-film transistors

A high-aspect-ratio and high-resolution stainless steel shadow mask for organic thin-film transistors (OTFTs) has been fabricated using a new method which combines micro-electro-discharge machining (micro-EDM) and electrochemical etching (ECE). First, square holes are serially machined using micro-EDM. Then, the ECE process is used to reduce the spacing of holes, which can be reduced down to 3.6 µm. Using this method, a 95 µm thick stainless steel shadow mask can be fabricated with a wall 3.6 µm in width and 150 µm in length. The aspect ratio of the wall is about 26. Source and drain electrodes of OTFTs were successfully patterned on a pentacene active layer through the fabricated shadow mask, and the fabricated pentacene TFTs had good output characteristics.

[1]  M. Datta,et al.  Microfabrication by electrochemical metal removal , 1998, IBM J. Res. Dev..

[2]  T. Jackson,et al.  Solvent-induced phase transition in thermally evaporated pentacene films , 1999 .

[3]  Y. Gianchandani,et al.  Batch mode micro-electro-discharge machining , 2002 .

[4]  Kenichi Takahata,et al.  High-aspect-ratio WC-Co microstructure produced by the combination of LIGA and micro-EDM , 2000 .

[5]  Michael A. Haase,et al.  Pentacene-based radio-frequency identification circuitry , 2003 .

[6]  Takao Someya,et al.  Nanoscale organic transistors that use source/drain electrodes supported by high resolution rubber stamps , 2003 .

[7]  S. Forrest,et al.  Nanolithography based on patterned metal transfer and its application to organic electronic devices , 2002 .

[8]  Sampath Purushothaman,et al.  High-performance bottom electrode organic thin-film transistors , 2001 .

[9]  Mukund R. Patel,et al.  Theoretical models of the electrical discharge machining process. I. A simple cathode erosion model , 1989 .

[10]  Debra J. Mascaro,et al.  Organic thin-film transistors: A review of recent advances , 2001, IBM J. Res. Dev..

[11]  C. Dimitrakopoulos,et al.  Low-voltage organic transistors on plastic comprising high-dielectric constant gate insulators , 1999, Science.

[12]  Jan H. J. Fluitman,et al.  High-resolution shadow-mask patterning in deep holes and its application to an electrical wafer feed-through , 1996 .

[13]  Takahisa Masuzawa,et al.  Wire Electro-Discharge Grinding for Micro-Machining , 1985 .