REAL-TIME SPECTROSCOPIC ELLIPSOMETRY FOR CHARACTERIZATION OF NUCLEATION, GROWTH, AND OPTICAL FUNCTIONS OF THIN-FILMS

We have exploited the unique capabilities of a rotating-polarizer mult ichannel spectroscopic ellipsometer in real time studies of the evolut ion of microstructure and optical functions for various thin film mate rials. With a 16 ms acquisition time for approximately 50 point spectr a from 1. 3 to 4.3 eV, the precision of the ellipsometer is (0.04-degr ees, 0.12-degrees) in (PSI, DELTA) for a Si surface at 2.5 eV. Real ti me investigations of aluminum prepared by physical vapor deposition an d hydrogenated amorphous semiconductors prepared by plasma-enhanced ch emical vapor deposition are highlighted here. We focus on capabilities that elude a real time discrete-wavelength approach. For aluminum, th is includes determining (i) the optical functions of small Al particle s ( < 50 angstrom diameter) in the nucleation regime for comparison wi th those of bulk Al, and (ii) an electron mean free path that characte rizes the effect of defects on the optical functions of the particles. For the amorphous semiconductors, this includes determining (i) the o ptical gap from real time measurements, and (ii) the monolayer-scale c oalescence behavior that correlates well with the device suitability o f the material.