The attachment of acetyl-protected alkynethiol groups onto silicon(100) surfaces was achieved using a hydrosilylation methodology. Subsequent deprotection of the thiols using either hydrochloric acid or ammonia solution was investigated using X-ray photoelectron spectroscopy (XPS), and compared with similar reaction in solution. It was found that ammonia solution was more efficient than hydrochloric acid for the deprotection step. However, the deprotection was much less efficient on the surface than in solution. 2010 IEEE.