Nitrile/fluoroalcohol-containing photoresists and associated processes for microlithography
AssigneeE. I. Du Pont de Nemours and Company
InventorsMichael Fryd, Frank L Schadt, III, Mookkan Periyasamy
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Abstract
Nitrile/fluoroalcohol-containing photoresists and associated processes for microlithography are described. These photoresists are comprised of a fluoroalcohol functional group and a nitrile-containing compound which together simultaneously impart high ultraviolet (UV) transparency and developability in basic media to these materials. The materials of this invention have high UV transparency, particularly at short wavelengths, e.g., 157 nm, which makes them highly useful for lithography at these short wavelengths.
Claims49
A photoresist comprising:
- (a) a polymer having:
- (i) a repeat unit derived from at least one ethylenically unsaturated compound containing a fluoroalcohol functional group having the structure:
- —C(Rf)(Rf′)OH
- wherein Rf and Rf′ are the same or different fluoroalkyl groups of from 1 to about 10 carbon atoms or taken together are (CF2)n wherein n is an integer ranging from 2 to about 10;
- and
- (ii) a repeat unit derived from at least one ethylenically unsaturated compound having the structure:
- (H)(R1)C═C(R2)(CN)
- wherein R1 is a hydrogen atom or CN group, R2 is an alkyl group of 1 to about 8 carbon atoms, hydrogen atom, or CO2R3 group wherein
- R3 is an alkyl group of 1 to about 8 carbon atoms or hydrogen atom;
- and
- (b) at least one photoactive component.
A process for preparing a photoresist image on a substrate comprising, in order:
- (A) applying a photoresist composition on a substrate to form a photoresist layer, wherein the photoresist composition comprises:
- (i) a polymer having:
- (a) a repeat unit derived from at least one ethylenically unsaturated compound containing a fluoroalcohol functional group having the structure:
- —C(Rf)(Rf′)OH
- wherein Rf and Rf′ are the same or different fluoroalkyl groups of from 1 to about 10 carbon atoms or taken together are (CF2)n wherein n is an integer ranging from 2 to about 10;
- and
- (b) a repeat unit derived from at least one ethylenically unsaturated compound having the structure:
- (H)(R1)C═C(R2)(CN)
- wherein R1 is a hydrogen atom or CN group, R2 is an alkyl group of 1 to about 8 carbon atoms, hydrogen atom, or CO2R3 group wherein
- R3 is an alkyl group of 1 to about 8 carbon atoms or hydrogen atom;
- and;
- (ii) at least one photoactive component;
- (B) imagewise exposing the photoresist layer to form imaged and non-imaged areas;
- and
- (C) developing the exposed photoresist layer having imaged and non-imaged areas to form the photoresist image on the substrate.
A coated substrate for photoimaging to form a semiconductor device comprising a substrate having a coating of a photoresist composition applied to a surface thereof comprising
- (a) a polymer having:
- (i) a repeat unit derived from at least one ethylenically unsaturated compound containing a fluoroalcohol functional group having the structure:
- —C(Rf)(Rf′)OH
- wherein Rf and Rf′ are the same or different fluoroalkyl groups of from 1 to about 10 carbon atoms or taken together are (CF2)n wherein n is an integer ranging from 2 to about 10;
- and
- (ii) a repeat unit derived from at least one ethylenically unsaturated compound having the structure:
- (H)(R1)C═C(R2)(CN)
- wherein R1 is a hydrogen atom or CN group, R2 is an alkyl group of 1 to about 8 carbon atoms, hydrogen atom, or CO2R3 group wherein R3 is an alkyl group of 1 to about 8 carbon atoms or hydrogen atom;
- and
- (b) at least one photoactive component.
Dependencies are inferred from the claim text.