Monoalkyl Tin Nano-Cluster Films Reveal a Low Environmental Impact under Simulated Natural Conditions

Environ Toxicol Chem. 2019 Dec;38(12):2651-2658. doi: 10.1002/etc.4580. Epub 2019 Nov 9.


Recently, monoalkyl oxo-hydroxo tin clusters have emerged as a new class of metal-oxide resist to support the semiconductor industry's transition to extreme ultraviolet (EUV) lithography. Under EUV exposure, these tin-based clusters exhibit higher performance and wider process windows than conventional polymer materials. A promising new monoalkyl precursor, [(BuSn)12 O14 (OH)6 ][OH]2 (BuSn), is still in its infancy in terms of film formation. However, understanding potential environmental effects could significantly affect future development as a commercial product. We synthesized and explored the toxicity of nano-BuSn in the alga Chlamydomonas reinhardtii and the crustacean Daphnia magna at exposure concentrations ranging from 0 to 250 mg/L. Nano-BuSn had no effect on C. reinhardtii growth rate irrespective of concentration, whereas high nanoparticle concentrations (≥100 mg/L) increased D. magna immobilization and mortality significantly. To simulate an end-of-life disposal and leachate contamination, BuSn-coated film wafers were incubated in water at various pH values and temperatures for 14 and 90 d to investigate leaching rates and subsequent toxicity of the leachates. Although small quantities of tin (1.1-3.4% of deposited mass) leached from the wafers, it was insufficient to elicit a toxic response regardless of pH, incubation time, or temperature. The low toxicity of the tin-based thin films suggests that they can be an environmentally friendly addition to the material sets useful for semiconductor manufacturing. Environ Toxicol Chem 2019;38:2651-2658. © 2019 SETAC.

Keywords: Atomic force microscopy; Ecotoxicity; Organotin thin film; Semiconductor; Time-of-flight secondary ion mass spectrometry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chlamydomonas / drug effects*
  • Chlamydomonas / growth & development
  • Daphnia / drug effects*
  • Daphnia / growth & development
  • Oxides / analysis
  • Oxides / toxicity
  • Tin / analysis
  • Tin / toxicity*
  • Water Pollutants, Chemical / analysis
  • Water Pollutants, Chemical / toxicity*


  • Oxides
  • Water Pollutants, Chemical
  • Tin