Investigation of the alignment phenomena using a-C:H thin films for liquid crystal alignment materials

Soon Joon Rho, Day Kyu Lee, Hong Koo Baik, Jeoung Yeon Hwang, Yong Min Jo, Dae Shik Seo

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A high pretilt angle is generated by hydrogenated amorphous carbon (a-C:H) thin films treated with an ion beam method. a-C:H thin films are deposited by remote plasma enhanced chemical vapor deposition and are modified by an Ar ion beam at an incidence angle of 45° using an Kaufman ion gun. Ion beam irradiation results in the decrease of the thickness of a-C:H thin films and the increase of the sp2 fraction. The optical transmittance of the ion beam irradiated a-C:H is more affected by thickness than sp2 fraction. An excessive ion beam irradiation, 5 min Ar ion beam, results in the increase of the surface roughness of the a-C:H thin films and the pretilt angle has very low value. The pretilt angle is controlled by the thickness, sp2 fraction and the surface roughness.

Original languageEnglish
Pages (from-to)259-262
Number of pages4
JournalThin Solid Films
Publication statusPublished - 2002 Dec 2


All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

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