Characterization Technology and Reliability (Local Characterization by Atomic Force Microscopy (AFM)) hjshin@kookmin.ac.kr, 20. 1Tb Gb/s. 10-9 m (Nanotechnology) 21,,,,,.,,,. 1981 Gerd Binnig Heinrich Rohrer tunneling tunneling current scanning tunneling microscopy (STM) 1)... (Scanning Force Microscopy), (Van der Waals Force), (Magnetic Force), (Electrostatic Force), (Friction Force),.,,,,,.,,.,. Fermi level pinning. 93
. SFM Kelvin probe force microscopy 2), piezoelectric force microscopy 3), magnetic force microscopy 4).. 1) FET(Field Effect Transistor) 100 drain source shallow junction channel. p-n channel.. dopant profile. 2). PRAM (phase change random access memory) RRAM (resistive random access memory).... 3) - inversion domains, threading dislocations, pin holes -... 4) ITO (Indium - Tin - Oxide) (Light-emitting Diode), (Liquid crystal display), (Solar cell). ITO (Full color) / (Organic/Polymer LED). ITO (Work Function - 4 5eV; ) hole-injecting. ITO /,. Table 1. 2 doping profiling (shallow pn junction) SKPM 1), SCM 2), SRP 3) gate oxide C-AFM 4) transport behavior SIM 5) failure SKPM, C-AFM (phase change) C-AFM C-AFM TFT (potential conductivity) SKPM, C-AFM ITO SKPM, C-AFM PFM6), SNDM 7) SIM, SKPM C-AFM mapping SNDM Electronic band alignment SKPM band bending Schottky current C-AFM 1) SKPM : Scanning Kelvin Probe Microscopy; 2) SCM : Scanning Capacitance Microscopy; 3) SRP : Spreading Resistance Microscopy; 4) C-AFM : Conducting Atomic Force Microscopy; 5) SIM : Scanning Impedance Microscopy; 6) PFM : Piezo-response Force Microscopy; 7) SNDM : Scanning Non-Dielectric Microscopy 94
ITO. Table.. 2.1,, contact mode, tapping mode, noncontact mode. Contact mode, position sensitive photo diode (PSPD). feedback., N/m., noncontact mode., noncantact mode nm. Van der Waals force 0.1~0.01nN. (amplitude),.. Tapping mode noncontact mode. Noncontact mode,, tapping mode. 2.2 2.2.1 Kelvin probe force microscopy Kelvin Probe Force Microscopy (KPFM) coating Si surface potential. contact potential difference (CPD) Kelvin method capacitance displacement current current. KPFM current electrostatic force, mv sensitivity nm. 95
. Fermi level, voltage CPD. capacitor (U=1/2CV 2 ).. Fig. 1. KPFM system. tip sample dc ac voltage (Vapp = Vdc+ Vac sin wt)..., atom ion, 5), charge trap 6), surface band bending 7). KPFM. Fig. 1 KPFM system. f 0, f 1 surface potential. KPFM electrostatic force feedback CPD voltage CPD, electrostatic force 0 ( force=0, nullifying techniques) voltage CPD. CPD. Fermi level F 1 component surface contact potential lock-in technique F 1 electrostatic force dc voltage feedback loop modulation surface potential. KPFM surface potential electronic state. KPFM, flash memory silicon-oxide-nitrideoxide-silicon (SONOS) system trap charge 8), nanocrystal floating gate memory 9), p-n junction profile 10), open-circuit voltage photo-induced charging rate 11) 96
. tip dc voltage sweep first harmonics term 0 voltage Kelvin probe force spectroscopy (KPFS). KPFS CPD calibration. Highly Oriented Pyrolytic Graphite (HOPG) 5.0eV 12). calibration HOPG. HOPG Pt(111), Au film, ITO Table 2. Pt (111) 5.68 ev Au 5.08 ev, ITO 5.30eV. 13,14) nm. scanning nonlinear dielectric microscopy (SNDM) 16) capacitance, SCM. SCM SNDM MOSFET source drain channel 17), Si carrier 18), SONOS writing erasing trap 19), 20). Table 2. Kelvin Probe Force Spectroscopy HOPG, Pt(111), Au, ITO Sample HOPG Au Pt ITO CPD (Tip-Sample) (V) -0.45-0.37 0.23-0.15 Measurements work function (ev) ref 5.08 5.68 5.3 Literature work function (ev) 5.0 5.1~3 5.6~7 4.0~5.0 2.2.2 Scanning Non-linear Dielectric Microscopy KPFM Scanning capacitance microscopy (SCM). 1984 Matey Blanc SCM 15) metal-oxide-semiconductor (MOS) - (C-V) SPM,. SCM profile Fig. 2. SNDM system. Fig. 2 SNDM system. coating, SiO2 layer, MOS. dc/dv. Fig. 3(a) C-V curve, Fig. 3(b) dc/dv. dc/dv dc/dv. dc/dv. n- type p-type dc/dv p-type, n-type n p. Fig. 3(c) p type n type 97
Fig. 4. PFM system. Fig. 3. (a) C-V curve (b) dc/dv curve (c) p type n type SNDM image. SNDM image. 5 10 19 /cm 3 n+ type Si photolithography boron arsenic. p-type 3 boron 2 10 16 /cm 3, n-type 5 arsenic 13 10 15 /cm 3. doping profile. dynamics 22,23). ( ). Fig. 4 PFM system. contact mode ac dimension, modulated deflection 2.2.3 Piezoelectric force microscopy.,. 21). Fig. 5. (a) 60 nm PZT hysteresis loop, engineering PFM (b) phase (c) amplitude image 98
first harmonic term lock-in-technique., phase. Fig. 5(a) 60 nm PZT hysteresis loop. dc ac. Fig. 5(b) (c) PFM phase amplitude image engineering. 19 nm, PFM. 2.2.4 Magnetic force microscopy MRAM (magnetic random access memory).. 24), magnetic force microscopy (MFM) 4). MFM. Fig. 6 MFM. MFM noncontact mode mode Van der Waals force, long-range force. repulsive attractive...,,,,, probe nanolithography, probe-based data storage system,. / (National Research Lab. R0A-2007-000-20105-0) (ERC, Center for Materials and Processes of Self-Assembly R11-2005-048-00000-0). Fig. 6. MFM. 1. G. Binnig and H. Rohrer, Surface Studies by Scanning Tunneling Microscopy. Phys. Rev. Lett. 49, 57-61 (1982) 2. M. Nonnenmacher, M. P. O Boyle, and H. K. 99
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2005 2006 -. 2005 2006 -. 1991 1994 Case Western Reserve University 1996 Case Western Reserve University 1996.9-97.8 Max-planck Institute fur Metallforschung, Alexander von Humboldt Research Fellow 1997.9-01.8, Samsung Advanced Institute and Technology, Storage Lab., Member of Research Staff 2001.8-02.2, Samsung Advanced Institute and Technology, Storage Lab., Project Manager 2002.3-. 101