Gap-fill methods
Provided are gap-fill methods. The methods comprise: (a) providing a semiconductor substrate having a relief image on a surface of the substrate, the relief image comprising a plurality of gaps to be filled, wherein the gaps have a width of 50 nm or less; (b) applying a gap-fill composition over the relief image, wherein the gap-fill composition comprises a first polymer comprising a crosslinkable group, a second polymer comprising a chromophore, wherein the first polymer and the second polymer are different, a crosslinker, an acid catalyst and a solvent, wherein the gap-fill composition is disposed in the gaps; (c) heating the gap-fill composition at a temperature to cause the first polymer to self-crosslink and/or to crosslink with the second polymer to form a crosslinked polymer; (d) forming a photoresist layer over the substrate comprising the crosslinked polymer-filled gaps; (e) patternwise exposing the photoresist layer to activating radiation; and (f) developing the photoresist layer to form a photoresist pattern. The methods find particular applicability in the manufacture of semiconductor devices for the filling of high aspect ratio gaps with an antireflective coating material.
1. A gap-fill method, comprising:
(a) providing a semiconductor substrate having a relief image on a surface of the substrate, the relief image comprising a plurality of gaps to be filled, wherein the gaps have a width of 50 nm or less;
(b) applying a gap-fill composition over the relief image, wherein the gap-fill composition comprises a first polymer comprising a crosslinkable group, a second polymer comprising a chromophore, wherein the first polymer and the second polymer are different, a crosslinker, an acid catalyst, and a solvent, wherein the gap-fill composition is disposed in the gaps;
(c) heating the gap-fill composition at a temperature to cause the first polymer to self-crosslink and/or to crosslink with the second polymer to form a crosslinked polymer;
(d) forming a photoresist layer over the substrate comprising the crosslinked polymer-filled gaps;
(e) patternwise exposing the photoresist layer to activating radiation; and
(f) developing the photoresist layer to form a photoresist pattern.
2. The method of claim 1 , wherein the first polymer and/or the second polymer has a weight average molecular weight Mw of from 3000 to 6000.
3. The method of claim 1 , wherein the gaps have an aspect ratio of 2 or more.
4. The method of claim 1 , wherein the gaps have a width of 15 nm or less.
5. The method of claim 1 , wherein the crosslinkable group comprises a functional group independently chosen from hydroxyl, carboxyl, thiol, amine, epoxy, alkoxy, amide and vinyl.
6. The method of claim 1 , wherein the chromophore is chosen from optionally substituted benzyl, phenyl, naphthyl and anthracenyl.
7. The method of claim 1 , wherein the patternwise exposing is conducted at an exposure wavelength at 193 or 248.
8. The method of claim 1 , wherein the first polymer comprises a unit of the following general formula (I):
wherein: R 1 is chosen from hydrogen, fluorine, C 1 -C 3 alkyl and C 1 -C 3 fluoroalkyl; and R 2 is chosen from: optionally substituted C 1 to C 12 linear, branched or cyclic alkyl; and optionally substituted C 6 to C 15 aryl (e.g. phenyl, napthyl, anthracenyl), optionally containing heteroatoms; wherein at least one hydrogen atom on R 1 and/or on R 2 is substituted with a crosslinkable functional group.
9. The method of claim 1 , wherein the first polymer comprises a unit of the following general formula (I):
wherein R 3 is chosen from hydrogen, fluorine, C 1 -C 3 alkyl and C 1 -C 3 fluoroalkyl; and Ar 1 is an optionally substituted aryl group, wherein at least one hydrogen atom on R 3 and/or on Ar 1 is substituted with a crosslinkable functional group.
10. The method of claim 1 , wherein the weight ratio of the first polymer to the second polymer is from 2:1 to 4:1.