Correction Of The Multiple Reflection Contribution To The Absorption By Interstitial Oxygen (Oi) In Silicon Wafers By Infrared Spectrometry
Original Publication Date: 1979-Dec-01
Included in the Prior Art Database: 2005-Feb-20
The ASTM (American Society for Testing and Materials) procedure F-120-75 calls for a correction to the absorption coefficient when a specimen with both high refractive index and polished parallel surfaces, such as a polished silicon wafer, is used to make spectrometric measurements. The ASTM F-121 procedure measures interstitial oxygen (Oi) impurity in silicon by measuring the peak height of the 9 mu m peak in the infrared (IR) absorption spectrum. For silicon wafers of thickness in the range of 16 mils, the multiple reflection correction is approximately 15% while the precision of the measurement is around 1%.