NEW METHOD FOR IN-SITU CONTROL OF BRAGG REFLECTOR FABRICATION

A simple, robust method for real time monitoring of Bragg reflector la yer thickness is described. The method is based on the choice of the a ppropriate ellipsometric measurement wavelength to control the deposit ion of the top layer. This method requires no information on the under lying structure. To evaluate the method, Bragg reflectors were develop ed with SiO2 and SiNx stacks grown by electron cyclotron resonance pla sma chemical vapor deposition. Reflectivity measurements performed on these reflectors confirm the reproducibility and accuracy of the metho d. (C) 1994 American Institute of Physics.