Method for removing particles from a semiconductor surface
Method for cleaning a surface is disclosed comprising a cleaning step with an aqueous cleaning medium, which is supplied to said semiconductor surface wherein the cleaning medium comprises cleaning particles suspended in a colloidal form and mechanical agitation is applied to the particles to be removed for at least part of the time during the cleaning step.
1. A method for removing contaminant particles from a semiconductor surface, the method comprising a cleaning step wherein an aqueous cleaning medium is supplied to said semiconductor surface wherein the cleaning medium comprises cleaning particles consisting of colloidal silica and mechanical agitation is applied to the particles to be removed for at least part of the time during the cleaning step, wherein the cleaning medium has a pH-value below 9.
2. The method according to claim 1 , wherein cleaning particles consist of a material being chemically identical to at least one material of the surface to be cleaned.
3. The method according to claim 1 , wherein the average particle size of the cleaning particles is in the range of 1 to 100 nm.
4. The method according to claim 1 , wherein devices on the semiconductor surface have a specific minimum device size and the average particle size of the cleaning particles is smaller than half of the minimum device size.
5. The method according to claim 1 , wherein the concentration of particles in the cleaning medium is in the range of 0.0001 to 1 g/l.
6. The method according to claim 1 , wherein the cleaning particles have a specific particle surface of above 100 m.sup.2/g.
7. The method according to claim 1 , wherein the cleaning medium has an ionic strength of below 2 mol/l.
8. The method according to claim 1 , wherein said cleaning medium comprises an oxidizing agent.
9. The method according to claim 1 , wherein said cleaning medium further comprises a wetting agent.
10. The method according to claim 1 , further comprising a rinsing step after the cleaning step with an aqueous rinsing medium wherein the rinsing medium substantially does not contain particles.
11. The method according to claim 10 , wherein the rinsing step is carried out subsequent to the cleaning step without an intermediate drying of the surface.
12. The method according to claim 10 , wherein the rinsing step is started before the cleaning step is stopped.
13. The method according to claim 1 , wherein the mechanical agitation is applied through ultrasonic energy.