Organotin clusters, solutions of organotin clusters, and application to high resolution patterning
Organotin clusters are described with the formula R 3 Sn 3 (O 2 CR′) 5−x (OH) 2+x (μ 3 -O) with 0≤x<2; R=branched or cycloalkyl with 1 to 31 carbon atoms; R′═H or alkyl with 1 to 20 carbon atoms. Three carboxylato ligands are bridging, and two OH ligands are bridging. The remaining two carboxylato ligands are in non-bridging configurations, and the non-bridging carboxylato ligands are exchangeable in solution. Solutions of these clusters are suitable for forming radiation sensitive coatings that can be used to pattern nanometer scale structures. The radiation sensitive coatings are particularly suitable for EUV patterning.
1. A method for synthesizing a tin tri(acetylide) having the formula RSn(C≡CR″) 3 , the method comprising:
in an organic solvent, reacting a compound having the formula HC≡CR″ with a tin tri(diamide) having the formula RSn(NR′″ 2 ) 3 to form a tin tri(acetylide), having the formula RSn(C≡CR″) 3 ,
wherein R is a hydrocarbyl group having from 1 to 31 carbon atoms or a hydrocarbyl group substituted with a heteroatom functional group and/or a halogenated group or substituted with combinations thereof, wherein R″ and R′″ are independently a hydrocarbyl group having from 1 to 31 carbon atoms, wherein R is bound to the tin atom.
2. The method of claim 1 wherein R is a linear alkyl group, a branched alkyl group, an olefinic group, an alkynyl group, a cycloalkyl group, a derivative thereof substituted with a hetero-atom functional group and/or a halogenated group, or combinations thereof and wherein R″ is a linear alkyl group or a branched alkyl group.
3. The method of claim 1 wherein R is a methyl, ethyl, i-propyl, n-butyl, s-butyl, t-butyl, t-amyl, neopentyl group, or combination thereof.
4. The method of claim 2 wherein R is t-butyl and/or wherein R″ is a cyclic alkyl group, an unsaturated alkyl group, or an aromatic alkyl group having no more than 15 carbon atoms.
5. The method of claim 1 wherein the tin tri(diamide) comprises t-butyltin tri(dimethylamide).
6. The method of claim 1 wherein the acetylene comprises phenylacetylene.
7. The method of claim 1 wherein the organic solvent comprises hexane.
8. The method of claim 1 wherein the acetylene comprises phenylacetylene, the tin tri(diamide) comprises t-butyltin tri(dimethylamide), the organic solvent comprises hexane, and the tin tri(acetylide) comprises t-butyltin tri(phenylacetylide).
9. The method of claim 1 wherein the reaction temperature is maintained below 50° C. and a vapor dialkylamine is removed from the reaction.
10. The method of claim 1 wherein a crystalline tin tri(acetylide) having the formula RSn(C≡CR″) 3 is collected.
11. The method of claim 1 wherein R comprises N, S, Si, O, and/or halogen atoms.