Real-time characterization of film growth on transparent substrates by rotating-compensator multichannel ellipsometry

摘要

A multichannel spectroscopic ellipsometer in the fixed-polarizer-sample-rotating-compensator-fixed-analyzer (PSC↓(R)A) configuration has been developed and applied for real-time characterization of the nucleation and growth of thin films on transparent substrates. This rotating-compensator design over-comes the major disadvantages of the multichannel ellipsometer in the rotating-polarizer-sample-fixed-analyzer (P↓(R)SA) configuration while retaining its high speed and precision for the characterization of thin-film processes in real time. The advantages of the PSC↓(R)A configuration include (i) its high accuracy and precision for the detection of low-ellipticity polarization states that are generated upon reflection of linearly polarized light from transparent film-substrate systems, and (ii) the ability to characterize depolarization of the reflected light, an effect that leads to errors in ellipticity when measured with the P↓(R)SA configuration. A comparison of the index of refraction spectra for a glass substrate obtained in the real-time PSC↓(r)A mode in 2.5 s and in the ex situ fixed-polarizer-fixed-compensator-sample-rotating-analyzer (PCSA↓(R)) mode in ~ 10 rain show excellent agreement, with a standard deviation between the two data sets of 8 x 10-4. computed over the photon energy range from 1.5 to 3.5 eV. First, we describe the PSC↓(R)A ellipsometer calibration procedures developed specifically for transparent substrates. In addition, we describe the application of the multichannel PSC↓(R)A instrument for a study of thin-film diamond nucleation and growth on glass in a low-temperature microwave plasma-enhanced chemical vapor deposition process. # 1998 Optical Society of America OCIS codes: 120.4530,120.2130,310.0310,120.5410,310.1620.