Imaging ellipsometry revisited: Developments for visualization of thin transparent layers on silicon substrates

Review of Scientific Instruments - Tập 67 Số 8 - Trang 2930-2936 - 1996
Gang Jin1, R. Jansson1, Hans Arwin1
1Laboratory of Applied Physics, Department of Physics and Measurement Technology, Linköping University, S-581 83 Linköping, Sweden

Tóm tắt

Imaging ellipsometry is presented as a technique for quantification and visualization of the lateral thickness distribution of thin (0–30 nm) transparent layers on solid substrates. The main advantage of imaging ellipsometry is that every point on a surface is measured at the same time with a high lateral resolution. The method is based on the use of combined null and off-null ellipsometry at an incident angle close to the pseudo-Brewster angle of a high index substrate such as silicon. In the present experimental setup, a xenon lamp, a collimator, and a wavelength-selective filter provide an expanded collimated probe beam with a diameter of 25 mm. Other major components in the system are a polarizer, a compensator, and an analyzer. In this way, a 15×30 mm2 image of a sample surface can be focused onto a charge-coupled-device video camera and transferred to a computer for further evaluation by image processing. Thickness measurements are performed for calibration purposes with ordinary null ellipsometry. The imaging ellipsometer has an accuracy of better than 0.5 nm at a lateral resolution of 5 μm in the present configuration, but improvements of at least a factor of 5 can be foreseen. Several aspects of the ellipsometric imaging system are illustrated in selected applications including continuous protein thickness distributions, stepped silicon dioxide thickness distributions, and visualization of protein patterning of surfaces. The latter can be used in a biosensor system as illustrated here by antigen–antibody binding studies.

Từ khóa


Tài liệu tham khảo

1993, Trends Appl. Spectrosc., 1, 79

1987, Prog. Surf. Sci., 24, 1, 10.1016/0079-6816(87)90065-7

1993, Thin Solid Films, 233–234, 1

1986, J. Appl. Phys., 60, 859, 10.1063/1.337327

1983, J. Phys. (Paris) Colloq., 44, C10

1988, Rev. Sci. Instrum., 59, 2557, 10.1063/1.1139897

1990, J. Non-Cryst. Solids, 121, 294, 10.1016/0022-3093(90)90147-E

1994, J. Phys. II France, 4, 455

1995, Science, 270, 608, 10.1126/science.270.5236.608

1993, J. Colloid Interface Sci., 156, 377, 10.1006/jcis.1993.1125

1986, Appl. Spectrosc., 40, 313, 10.1366/0003702864509204

1995, Anal. Biochem., 232, 69, 10.1006/abio.1995.9959

1987, J. Colloid Interface Sci., 119, 203, 10.1016/0021-9797(87)90260-8

Thông tin
Thông tin xuất bản

Review of Scientific Instruments

Tập 67 Số 8

2930-2936

Thông tin tác giả