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Issm 2010-po-o-102 ppt-for_cdrom_final_revised
- 1. ISSM 2010 NiPt SALICIDE Process Optimization for 28nm CMOS Manufacturing James M.M. Chu (Speaker) Application Dept. Manager SE Asia/Greater China Region FSI International James.chu@fsi-intl.com ISSM 2010 1 G-Number
- 2. NiPt Silicide forCMOS Source Gate Drain Scaling NiSi Contact electrode Contact electrode NiSi 65nm NiSi 45nm Gate Stack NiSi 28nm NiSi NiSi STI STI Si ISSM 2010 2 G-Number
- 3. NiSi Encroachment Defects Spiking Piping 65nm node and beyond : Ni(Pt 5-10%) replace Ni for defect control. But … residual surface Pt removal become a challenge !!! ISSM 2010 3 G-Number
- 4. Motivations Tostay withcurrent material (NiPt) and chemistry (SPM) for SALICIDE formation To scale NiSi into 28nm CMOS device To optimize wet selective etch process – Support the residual NiPt removal on the film thickness and Pt% proposed – Reduce the process cycle time ISSM 2010 4 G-Number
- 5. NiPt Salicide Process Process Flow (Fig.1) Surface preparation: wet + dry in-situ Metal Dep.: Ni(Pt) + TiN cap→ main focus of this presentation 1st Anneal (RTP-1): 200-300°C range Selective wet etching→ main focus of this presentation 2nd Anneal (RTP-2): > 500°C Defect inspection: SEM e-beam BVC inspection WAT Measurement: Sheet Resistance / Uniformity ISSM 2010 5 G-Number
- 6. Pt Reaction Model Common Pt reaction model - Aqua regia base : Pt + 4NO3- + 8H + Pt(4+) + NO2 + 4H2O Silicide Pt(4+) + 6Cl - + 2H + H2PtCl6 Attacked ! - Hydrochloric acid base : Pt + 2H2O2 + 4H + Pt(4+) + 4H2O Pt(4+) + 6Cl - + 2H + H2PtCl6 Sulfuric Acid Peroxide Pt reaction model - Sulfuric acid base (main focus of this presentation) Take place Pt + H2SO4 + H2O2 Pt(OH)2++ + PtO++ + H2SO3 On high temperature ISSM 2010 6 G-Number
- 7. Batch/SW Processor Comparison HT SPM HT SPM wafers wafers wafer Closed chamber Closed chamber Fig.2(a) Batch wafer type Fig.2(b) Single wafer type ISSM 2010 7 G-Number
- 8. Pt% / NiPtFilm Optimization on Rs/BVC increasing film thickness BVC Count (a.u.) BVC Count (a.u.) x15 Low Pt % 5% Pt NiPt Film High Pt % 10% Pt A B C Same NiPt film thickness NiPt Thickness NiPt film thickness (same Pt%) Fig.3(a) Pt additive on BVC performance Fig. 3(b) NiPt thickness vs. BVC ISSM 2010 8 G-Number
- 9. Pt% / NiPtFilm Optimization on Rs/BVC Sheet Resistance (a.u.) BVC Count (a.u.) BVC - - - Rs - - - Ο A B C NiPt film thickness (same Pt%) Linear ProgramNiPt Thickness thickness / Pt% for NiPt film Fig.3(c) Ni thickness vs. Rs Fig.3(d) Linear program for Pt Additive to NiPt film thickness for BVC and Rs ISSM 2010 9 G-Number
- 10. Process Window -Cycle Time NiPt Thickness B Low Pt% High Pt% Batch type HT SPM Baseline Pt-free Batch type HT SPM Baseline Dual Cycles Pt-free Single wafer ). u a e m ssec o P type r HT SPM Pt-free Pt-free Fig. 4 (a) Process time comparison Fig.4 (b) Process cycle time of batch type to single wafer type improvement it wet chemical etch processor . ( ISSM 2010 10 G-Number
- 11. Process Window –SW Time SPM Process 90 120 150 180 210 time (s) A Pt-free Pt-free Pt-free - - High Pt% NiPt Thickness B - Pt-free Pt-free Pt-free - (Å) C - - Pt-free Pt-free Pt-free Table 1 Process window of single wafer wet etch processor over various Pt additive and NiPt film thickness ISSM 2010 11 G-Number
- 12. Process Selectivity Rs UniformityVariation Range a N_Diff b P_Diff NU variation range 0.45% NU variation range 0.35% Process Time Process Time c N_Poly d P_Poly NU variation range 0.49% NU variation range 0.35% Process Time Process Time Fig. 5 Rs Uniformity variation range by different wet etch process times ISSM 2010 12 G-Number
- 13. Summary 28nm NiPt Salicideprocess with co-optimization of NiPt film thickness, Pt additive and the complementary wet selective etch processor Results • Satisfactory Rs/ Rs uniformity performance • 15x Improvement on NiSi encroachment through BVC count • 15x Improvement in cycle time with single wafer system ISSM 2010 13 G-Number
Editor's Notes
- #2 Title Slide If your Presentation Title is very long you may need to use plain text instead of bold or modify the font size to fit.
- #7 From the known chemistry to react with Platinum, mainly the chlorine play the key role as major reactant. It is known that two major approaches to generate chlorine in acidic environment, One approach is to use Aqua Regia, the relevant reaction model is in formula (1) The other approach is to use Hydrocloric Acid Peroxide Mixture (or so called HPM), the relevant reaction model is in formula (2) Through the survey from original material corrosion research, it was reported that Sulfuric acid Peroxide Mixture (SPM) will react with Platinum when temperature is high. This newly discovered application has the hypothesis reaction model as formula (3), Basically, it utilize the OH- radical which exist in high temperature SPM to react with Platinum.
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