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A review ofthe applications of Time OfFlight-Secondary Ion Mass Spectroscopy (TOF-SIMS) to control various processes currenfly used in the manufacturing of semiconductor devices with the purpose of their improvement and the consequent enhancement ofthe wafer fab process yield and the IC's performance, is here reported. The fields explored by TOF-SIMS as a surface analysis technique were: diffusion, plasma etch and ash, ion implantation. As concerns diffusion, a work showing the detection of alkaly metals and the consequent, abnormal increase of the silicon oxide growth rate is reported. Another investigation demonstrates the presence of Aluminium contamination and the presence of a uniform, ultra-thin layer of fluorinated polymeric residues left on silicon wafers by a plasma etch process, not detected by the commonly used in-line techniques. In implant, analyses done before and after the ion implantation on the same wafer showed the contamination of Aluminium induced by the implanter itself Another work demonstrates the TOF-SIMS capability to control the implanters performance in separating the different isotopes of the implanted species, in the case ofboron implantation. Finally, in area, the analyses done to control the effectiveness of adhesion promoter for photoresist on Silicon wafer show that poor coverage of the resist adhesion promoter, which can cause the photoresist peeling, can be monitored by characteristic fragments detection by TOF-SIMS. 3
Keywords: TOF-SIMS, diffusion, plasma etch, implant, photo, polymers
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