Silsesquioxane compound mixture, method of making, resist composition, and patterning process

A method for preparing a mixture of silsesquioxane compounds having a high proportion of silsesquioxane compounds bearing bulky substituent groups on side chain and having a degree of condensation of substantially 100%, said method comprising:

• a first stage wherein a silane feed is hydrolyzed in the presence of an acid or base catalyst, said silane feed comprising a trifunctional silane bearing a bulky substituent group on side chain represented by the general formula (1):
• wherein Y is an organic group of 3 to 20 carbon atoms, optionally having a functional group, containing an aliphatic branched, cyclic or polycyclic structure in which the atom at the silicon-bonding site is a carbon having at least two bonds with atoms other than hydrogen and halogen atoms in addition to said silicon, or an organic group of 6 to 18 carbon atoms, optionally having a functional group, containing an aromatic structure having a substituent group other than hydrogen and halogen atoms at a site neighboring the silicon-bonding site;
• X1, X2 and X3 are each independently a hydrogen atom, halogen atom, straight, branched or cyclic alkoxy group of 1 to 6 carbon atoms, or aryloxy group of 6 to 10 carbon atoms, and
• a second stage wherein dehydrating condensation reaction is carried out in the presence of at least 0.5 mol % based on the silane feed of a strong base catalyst using an organic solvent in an amount of at least two times the weight of hydrolyzates resulting from hydrolysis while allowing the water resulting from condensation to transfer to the organic solvent.

A silsesquioxane compound mixture comprising silsesquioxane compounds having a degree of condensation of substantially 100%, said mixture being prepared by performing:

• a first stage wherein a silane feed is hydrolyzed in the presence of an acid or base catalyst, said silane feed comprising a trifunctional silane represented by the general formula (1):
• wherein Y is an organic group of 3 to 20 carbon atoms, optionally having a functional group, containing an aliphatic branched, cyclic or polycyclic structure in which the atom at the silicon-bonding site is a carbon having at least two bonds with atoms other than hydrogen and halogen atoms in addition to said silicon, or an organic group of 6 to 18 carbon atoms, optionally having a functional group, containing an aromatic structure having a substituent group other than hydrogen and halogen atoms at a site neighboring the silicon-bonding site;
• X1, X2 and X3 are each independently a hydrogen atom, halogen atom, straight, branched or cyclic alkoxy group of 1 to 6 carbon atoms, or aryloxy group of 6 to 10 carbon atoms, and
• a second stage wherein dehydrating condensation reaction is carried out in the presence of at least 0.5 mol % based on the silane feed of a strong base catalyst while removing water out of the reaction system.

A silsesquioxane compound mixture comprising silsesquioxane compounds having a degree of condensation of substantially 100%, said mixture being prepared by performing:

• a first stage wherein a silane feed is hydrolyzed in the presence of an acid or base catalyst, said silane feed comprising a trifunctional silane represented by the general formula (1):
• wherein Y is an organic group of 3 to 20 carbon atoms, optionally having a functional group, containing an aliphatic branched, cyclic or polycyclic structure in which the atom at the silicon-bonding site is a carbon having at least two bonds with atoms other than hydrogen and halogen atoms in addition to said silicon, or an organic group of 6 to 18 carbon atoms, optionally having a functional group, containing an aromatic structure having a substituent group other than hydrogen and halogen atoms at a site neighboring the silicon-bonding site;
• X1, X2 and X3 are each independently a hydrogen atom, halogen atom, straight, branched or cyclic alkoxy group of 1 to 6 carbon atoms, or aryloxy group of 6 to 10 carbon atoms, and
• a second stage wherein dehydrating condensation reaction is carried out in the presence of at least 0.5 mol % based on the silane feed of a strong base catalyst using an organic solvent in an amount of at least two times the weight of hydrolyzates resulting from hydrolysis while allowing the water resulting from condensation to transfer to the organic solvent.

A silsesquioxane compound mixture comprising at least 40 mol % based on silicon of silsesquioxane octet having a degree of condensation of substantially 100%, in which side chains comprise at least 75 mol % of side chains selected from:

• organic groups containing an aliphatic branched, cyclic or polycyclic structure of 3 to 20 carbon atoms, optionally containing a halogen (inclusive of fluorine), oxygen or sulfur atom, in which the atom at the silicon-bonding site is a carbon having at least two bonds with atoms other than hydrogen and halogen atoms in addition to said silicon, or an aromatic structure of 6 to 18 carbon atoms, optionally having a functional group, having a substituent group other than hydrogen and halogen atoms at a site neighboring the silicon-bonding site, said organic groups being capable of imparting adhesive nature to the molecule, and
• organic groups containing an aliphatic branched, cyclic or polycyclic structure of 3 to 20 carbon atoms, optionally containing a halogen (inclusive of fluorine), oxygen or sulfur atom, in which the atom at the silicon-bonding site is a carbon having at least two bonds with atoms other than hydrogen and halogen atoms in addition to said silicon, or an aromatic structure of 6 to 18 carbon atoms, optionally having a functional group, having a substituent group other than hydrogen and halogen atoms at a site neighboring the silicon-bonding site, said organic groups having as a functional group a group which when deblocked, can impart alkali solubility to a molecule protected with an acid labile protective group.