[20p-C202-1~8] 15.7 Crystal characterization, impurities and crystal defects

[20p-C202-8] Measurement of carbon concentration in silicon crystal
(25) 10¹³/cm³ range by low temperature infrared absorption

〇Naohisa Inoue¹, Shuichi Okuda¹, Shuichi Kawamata¹ (1.Osaka Metropolitan Univ.)

Keywords:silicon crystal, carbon concentration, infrared absorption

We have previously established IR absorption procedure for both single- and poly-Si for both RT and LT down to 1x10¹⁴/cm3. We have recently examined 3x10¹³/cm³ difference at RT. Here LT measurement at LT is examined. Estimated carbon concentration of 5 samples is 1-10x10¹³/cm³. Sample thickness is 4 mm and the frequency resolution is 1 cm-1 at liquid nitrogen temperature. Differential absorption spectra were created for 10 possible pairing. The peak absorbance difference ranges from 5 to 70x10^-5, corresponding to 1- 14x10¹³/cm³. C concentration in samples was estimated to be from 1 to 15x10¹³/cm³ with below +-2x10¹³/cm³ uncertainty.