- SEMI MF1389 - Test Method for Photoluminescence Analysis of Single Crystal Silicon for III-V Impurities
This Standard was technically approved by the Silicon Wafer Global Technical Committee. This edition was approved for publication by the global Audits and Reviews Subcommittee on August 31, 2015. Available at www.semiviews.org and www.semi.org in November 2015; originally published by ASTM International as ASTM F1389-92; previously published November 2010.
Electronic-grade polycrystalline silicon producers and users require information regarding impurities for quality assurance as well as for research and development purposes. Polysilicon is float-zoned and a sample from the zoned rod is analyzed following this Test Method to obtain impurity densities that can be related to the impurity content of the starting material (see SEMI MF1723).
Photoluminescence analysis identifies and quantifies the electrically active dopant impurities in monocrystalline silicon. This Test Method addresses boron, phosphorus, arsenic, and aluminum, found as impurities in electronic grade silicon.
This Test Method can be applied to doped and undoped float-zoned or Czochralski material.
This Test Method covers the simultaneous determination of electrically active boron, phosphorus, arsenic, and aluminum content in low-dislocation monocrystalline silicon.
This Test Method can be used for samples that have dopant densities between approximately 1 × 1011 and approximately 5 × 1015 atoms/cm3.
The concentrations obtained using this Test Method is based on an empirically determined relationship of the logarithm of the concentration to the logarithm of specific luminescence line-intensity ratios.
The empirical relationship established assumes a constant sample excitation level for all measurements on a given instrument.
To accommodate differences in instrumentation, two methods are included. Test Method A refers to procedures appropriate for dispersive infrared spectrophotometers operating under the high sample excitation conditions and Test Method B refers to procedures appropriate for Fourier transform instruments operating under low excitation conditions.
Typical calibration curves for each test method are provided. These curves are modified for each instrument using the analysis of standard samples as reference data. Once modified, the curves for a given instrument should produce sample dopant density values that agree with other similarly operated instruments using the same test method. Data obtained using Test Method A may not agree with data obtained using Test Method B, hence values must be reported with reference to the test method used.
Many laboratories use photoluminescence to analyze epitaxial layers. However this application encounters many variables and the underlying physics is not fully understood; hence these test methods do not attempt to outline standard practices regarding such analysis.
Referenced SEMI Standards
SEMI C28 — Specifications for Hydrofluoric Acid
SEMI C30 — Specifications for Hydrogen Peroxide
SEMI C35 — Specifications and Guideline for Nitric Acid
SEMI M59 — Terminology for Silicon Technology
SEMI MF723 — Practice for Conversion Between Resistivity and Dopant or Carrier Density for Boron-Doped, Phosphorus-Doped, and Arsenic-Doped Silicon
SEMI MF1630 — Test Method for Low Temperature FT-IR Analysis of Single Crystal Silicon for III-V Impurities
SEMI MF1723 — Practice for Evaluation of Polycrystalline Silicon Rods by Float-Zone Crystal Growth and Spectroscopy