Resist Adsorption On The Wafer Cobalt Deposition Pretreatment

At the current width of all the different processes of the formation of cobalt will be to do at pre-deposition of cobalt oxide in order to ensure the removal of cobalt deposition in the follow-up will be completed successfully in order to create a good CoSi2.However,removal of oxide layer with hydrofluoric acid at the same time always be subject to external defects(Photo resist re-deposition) impact.External defects(Photo resist re-deposition) are a direct consequence of the pollution caused by deposition of cobalt did not follow up,but not cobalt deposition on cobalt salicide caused yield losses caused are the main reason for yield loss of 5%-10%.The study address the removal of oxide layer problem arising from defects,improve wafer yield for the high value of the theory and application.This paper is based on the experiment,through a combination of practice and theory of defects in the structure of photo-resists Absorption characteristics of the formation mechanism of the removal method of depth and research.First of all,the introduction of this thesis research the meaning,status and job content and work required from the introduction of the starting wet cleaning,etching of cobalt salicide process with the principle.And for the semiconductor manufacturing process Absorption of photo-resists(Photo resist re-deposition) defect(Defect) online detection problem under the optical microscope to determine the PR re-dep defect of the method,introduce the PR re-dep defect in the electron microscope under the structure and composition characteristics.Designed replication PR re-dep defect of the experiment and the experimental results in the semiconductor manufacturing process PR re-dep defect the formation of the three necessary elements:a.photo-resist residues;b High-dose and high-energy ion implantation;c Running cargo quantity.Of PR re-dep defect the formation mechanism of inference,the principle of photo-resists Absorption:many photo-resist residues after HF etching products into the wet bed,HF filter tank filter can not be too many photo-resists,after high-energy,high-dose ion implantation at the wafer into the slot for HF before the deposition of cobalt oxide are absorbed to remove photo-resist residues,which formed a PR re-dep defect.And,from the practice,the proposed products to enter the tank to do HF oxide removal prior to wet cleaning with a rotating part to remove defects in the oxide layer and then removed after the SCl wet cleaning to ensure clean wafer surface.And by scanning electron microscopy to confirm the number of wafer surface defects,as well as wafer testing,and yield an acceptable test to confirm the validity of this method and security. Through the work of this paper,a fundamental solution to pre-deposition of cobalt PR re-dep defect detection of defects in this process to remove the problem and avoid the resulting yield loss(each about 5%-10%the rate of yield loss),save production cost.