Determination of interface roughness by using a spectroscopic total-integrated-scatter instrument.

Area of Science:

• Materials Science
• Optical Engineering
• Surface Science

Background:

• Accurate characterization of thin films is crucial for semiconductor manufacturing.
• Quantifying surface roughness at interfaces is essential for understanding film properties.

Purpose of the Study:

• To construct and validate a novel spectroscopic total-integrated-scatter instrument.
• To measure diffuse reflectance and transmittance of oxidized silicon wafers.
• To determine root-mean-square (rms) surface roughness of oxide film interfaces.

Main Methods:

• Utilized a Coblentz sphere for scattered light collection.
• Employed a lamp with a monochromator as the light source.
• Measured diffuse reflectance of thermally and chemical-vapor-deposition oxidized silicon wafers.

Main Results:

• The instrument successfully measured diffuse reflectance and transmittance.
• Comparisons with spectrophotometer measurements showed good agreement.
• Parameterized model successfully interpreted scattering data to yield rms surface roughness values.

Conclusions:

• The developed spectroscopic instrument is effective for characterizing thin oxide films.
• The method provides accurate rms surface roughness values for double-layer interfaces.
• This technique offers a valuable tool for quality control in semiconductor fabrication.