Surface treatment of silicon
View Patent ↗A method of forming a resist pattern on a silicon semiconductor substrate having an anti-reflective layer thereon is described. The method includes the steps of a) modifying surface energy of the anti-reflective surface with a chemical treatment composition, b) applying a UV etch resist to the treated anti-reflective surface, and c) exposing the anti-reflective surface to a wet chemical etchant composition to remove exposed areas of the anti-reflective surface. Thereafter, the substrate can be metallized to provide a conductor pattern. The method may be used to produce silicon solar cells.
1. A method of forming an etch resist pattern on a silicon semiconductor substrate having a silicon nitride anti-reflective layer thereon, the method comprising the steps of:
a) modifying surface energy of the anti-reflective layer by contacting the anti-reflective layer with a composition comprising a fluorine-containing surfactant,
wherein the fluorine-containing surfactant is selected from the group consisting of perfluoroalkyl sulfonic acids and salts thereof, perfluoroalkyl phosphates, perfluoroalkyl amines, perfluoroalkyl oxides and perfluoroalkyl sulfonates, and
wherein the composition comprising the fluorine containing surfactant comprises between about 0.01% and about 1.0% by weight of the fluorine containing surfactant;
b) applying an etch resist to the treated anti-reflective layer to create a pattern of etch-resist comprising exposed areas of the anti-reflective layer and etch-resist covered areas of the anti-reflective layer;
c) contacting the exposed areas of the anti-reflective layer with a chemical etchant composition to remove the anti-reflective layer in the exposed areas;
d) stripping away the etch resist; and
e) applying a metal coating on the exposed areas.
2. The method according to claim 1 , wherein the metal coating is applied by plating.
3. The method according to claim 2 , wherein the metal coating is created by electroless or electrolyte plating a metal selected from the group consisting of nickel, copper, silver, and combinations of one or more of the foregoing.
4. The method according to claim 2 , comprising the step of sintering the metal coating to improve adhesion of the metal coating to the silicon substrate.
5. The method according to claim 1 , wherein the etch resist is applied to the substrate by an off contact method.
6. The method according to claim 5 , wherein the etch resist is applied by inkjet printing.
7. The method according to claim 6 , wherein the etch resist is a UV etch resist.