非侵蚀性阴离子对薄膜铝孔蚀电位的影响

<正> 一、引言 孔蚀与许多因素有关。侵蚀离子的种类、浓度、溶液pH值及温度对点蚀都有影响。溶液中非侵蚀性阴离子(本文用Mp表示)的存在通常能减轻或抑制孔蚀。18-8不锈钢浸在室温3％NaNO_3+3％NaCl溶液里可25年不出现孔蚀。向含Cl~-的溶液中加入适量的NO_3~-或CrO_4~(2-)

EFFECTS OF NON-AGGRESSIVE ANIONS ON CRITICAL PITTING POTENTIAL OF THIN-FILM ALUMINUM

The effects of non-aggressive anions Mp (NO_3~(2-), CrO_4~(2-), SO_4~(2-))in sodium chloride solution on the critical pitting potential E_c of a thin aluminum film in integrated circuit were studied. It was found that these ions shifted E_c to more noble values and, up to a given concentration of chloride, E_C and Mp], followed the relation: E_c=a+blogMp]. From the preceding relations for several concentration of chlorides, an equation logCl~-]=Alog Mp] +B was obtained. The efficiency of inhibition decreased in the order: NO_3~->CrO_4~(2-)》SO_4~(2-). It was supposed that the cause of inhibition was the reversible competitive adsorption of non-aggressive anions with chloride ion, and the difference of inhibition efficiency depended mostly on the oxidation ability of these anions.