METHOD FOR PRODUCING ROUGH SURFACE ON SILICON SUBSTRATES FOR THEIR ANODIC ETCHING Russian patent published in 2003 - IPC

FIELD: silicon substrates with surfaces used as ion emitters in analytical devices such as mass-spectrometers. SUBSTANCE: method involves anodic etching in electrolyte incorporating aqueous solution of hydrofluoric acid and alcohol at current density not over 4 mA/sq. cm and also I₂ or iodine- containing compound dissociating in electrolyte to produce iodide-ions, this being followed by subjecting surface obtained to optical radiation in water environment at intensity lower than destruction threshold of mentioned surface. Proposed electrolyte compound for anodic etching of silicon substrates has in its composition aqueous solution of hydrofluoric acid and alcohol and incorporates in addition I₂ or iodine-containing compound dissociating in electrolyte to produce iodide-ions with definite proportion of ingredients. Silicon substrates produced by this method are noted for no or low porosity, high degree of roughness, and high ionizing effectiveness of molecules; they maintain their chemical stability when stored under natural conditions. EFFECT: enhanced sensitivity of analyses using methods of mass-spectrometry and ion mobility spectrometry. 8 cl, 9 dwg