Articles
  • Post-CMP dry etching for the removal of the nanoscale subsurface damage layer from a single crystal La3Ga5SiO14 for a high quality wide band SAW filter device 
  • D.M. Lee, S. Hwanga, B.W. Leeb, K.B. Shimc, S.J. Peartond and H. Cho*
  • Department of Nanosystem and Nanoprocess Engineering, Pusan National University, Kyungnam 627-706, Korea a Department of Nanomedical Engineering, Pusan National University, Kyungnam 627-706, Korea b Department of Materials Engineering, Korea Maritime University, Busan 606-791, Korea c Department of Ceramic Engineering, Hanyang University, Seoul 133-791, Korea d Department of Materials Science and Engineering, University of Florida, Gainesville, FL 32611, USA
Abstract
The nanoscale subsurface damage layer induced on a single crystal La3Ga5SiO14 during the Chemical Mechanical Polishing (CMP) process for surface finishing is removed by a post-CMP dry etching in Cl-2/Ar inductively coupled plasmas. The electrical conductivity is recovered to the initial value (similar to 1x10(-4) Omega(-1)center dot cm(-1)) measured before being CMP-processed with a colloidal silica slurry at etch depths of 43-68 nm, while maintaining a smooth surface morphology. The depth of the subsurface damage layer formed in a langasite single crystal initially increases as a downward force applied to a single crystal La3Ga5SiO14 during the CMP process increases, and then saturates at depths similar to 68 nm, indicating that the subsurface damage layer induced by the mechanical stress does not form to a depth beyond a critical level.

Keywords: subsurface damage layer; single crystal La3Ga5SiO14; chemical mechanical polishing; post-CMP dry etching; Cl-2/Ar inductively coupled

This Article

  • 2007; 8(2): 98-102

    Published on Apr 30, 2007