There is provided a resist underlayer film forming composition for lithography for forming a resist underlayer film capable of being used as a hard mask or a bottom anti-reflective coating, or a resist underlayer film causing no intermixing with a resist and having a dry etching rate higher than that of the resist. A film forming composition comprising a silane compound having an onium group, wherein the silane compound having an onium group is a hydrolyzable organosilane having, in a molecule thereof, an onium group, a hydrolysis product thereof, or a hydrolysis-condensation product thereof. The composition uses as a resist underlayer film forming composition for lithography. A composition comprising a silane compound having an onium group, and a silane compound having no onium group, wherein the silane compound having an onium group exists in the whole silane compound at a ratio of less than 1% by mol, for example 0.01 to 0.95% by mol. The hydrolyzable organosilane may be a compound of Formula: R
1
a
R
2
b
Si(R
3
)
4-(a+b)
. A resist underlayer film obtained by applying the composition as claimed in any one of claims
1
to
14
onto a semiconductor substrate and by baking the composition.
提供了一种用于光刻的抗阻底层膜成分,用于形成可用作硬掩模或底部防反射涂层的抗阻底层膜,或者是不与抗阻混合并具有比抗阻更高的干法蚀刻速率的抗阻底层膜。该膜形成成分包括具有onium基团的
硅烷化合物,其中具有onium基团的
硅烷化合物是具有
水解性的有机
硅烷,其分子中具有onium基团、其
水解产物或其
水解缩合产物。该成分用作光刻的抗阻底层膜形成成分。一种成分包括具有onium基团的
硅烷化合物和不具有onium基团的
硅烷化合物,其中具有onium基团的
硅烷化合物在整个
硅烷化合物中的比例小于1摩尔%,例如为0.01至0.95摩尔%。该
水解性有机
硅烷可以是式:R1aR2bSi(R3)4-(a + b)的化合物。通过将所述任一权利要求1至14中的任一成分应用于半导体基板并烘烤所述成分,可以获得抗阻底层膜。