IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Electronics Tuesday Sessions
       Session EL-TuP

Paper EL-TuP24
Dry Etching of Sapphire for the Device Isolation using BCl@sub3@/Cl@sub2@(SiCl@sub4@) Inductively Coupled Plasmas

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Electronic Materials Poster Session
Presenter: C.H. Jeong, Sungkyunkwan University, Korea
Authors: C.H. Jeong, Sungkyunkwan University, Korea
D.W. Kim, Sungkyunkwan University, Korea
J.H. Kim, Sungkyunkwan University, Korea
Y.J. Sung, Samsung Advanced Institute of Technology, Korea
S.H. Chae, Samsung Advanced Institute of Technology, Korea
J.S. Kwak, Samsung Advanced Institute of Technology, Korea
Y.J. Park, Samsung Advanced Institute of Technology, Korea
G.Y. Yeom, Sungkyunkwan University, Korea
Correspondent: Click to Email
Sapphire wafer has been used in the optoelectronics industries as the substrates due to its high chemical and thermal stability. One of the problems in using sapphire wafers to optoelectronic devices such as GaN-based devices is the difficulty in cutting and backside mechanical polishing after completing the device due to the differences in the crystal orientation and the hardness of sapphire itself. Especially, to obtain reliable device isolation, more than 50 wide scribe line width is required for mechanical cutting using a diamond wheel or for scribing using a diamond scriber. However, if the device isolation can be replaced by dry etching followed by the separation of the devices by rolling and stretching, the scribe line width could be reduced to 5 and the yield per wafer could be also increased by 30%. In this study, BCl@sub3@/ SiCl@sub4@ and BCl@sub3@/Cl@sub2@ based inductively coupled plasmas have been used to etch (0001) sapphire wafers to obtain the etch rates over 400nm/min and the influence of the additive gases such as Ar, Kr, HBr, etc. on the sapphire etch characteristics were studied. The etch mechanism of sapphire was also investigated by plasma diagnostics and surface analysis using optical emission spectroscopy during the sapphire etching and X-ray photoelectron spectroscopy after the etching, respectively. For the device isolation, the etch profile containing severe notching is greatly encouraged contrary to the etch profile required for semiconductor devices. The degree of notching on the etch profile was observed as a function of process parameters by scanning electron microscopy and the surface roughness was examined by atomic force microscopy before and after the etching of the samples.