Korean J. Crystallography Vol. 19, No. 1, pp.7~13, 2008 Ÿ (ICISS) w š t w (2): t w y w œw Surface Structure Analysis of Solids by Impact Collision Ion Scattering Spectroscopy (2): Atomic Structure of Semiconductor Surface Yeon Hwang Department of Materials Science & Engineering, Seoul National University of Technology, Seoul 139-743, Korea š t w LEED( z )ù RHEED( š z ) t 2 z w w š( œ w ), ISS( Ÿ ), RBS( s z ) t œ w. ƒ y ww z w ww. š Ÿ (ICISS: Impact Collision Ion Scattering Spectroscopy) w, e, d w š w t w w» wš w. t ü» w ƒ ƒ w w w, w z x shadow cone w z (focusing effect) ƒ z (blocking effect) ICISS z š w w w œ w w. š ICISS w t» w, / y w, III-V t w,»q w w w š w. 1. / - vk w w w 3 z SOI w w. ICISS ƒ 180 o ƒà w t d w w. t vk dw. Si(111) t CaF 2 MBE w d k z ICISS wš w. ƒ d w Ca vj F vj Ca F 7 š w,» Ca F 1.0Û0.2. l d CaF 2 CaF. ƒ y j Ca l d w Fig. 1 ƒ. ƒ 1) α =17 o o 171 ƒ w Si t d x F ƒ Ca ƒ». Ca F ƒ Si(111) t l w w ƒ w ƒ o 90 e wù Ca F
8 y w wz Fig. 1. The dependence of the scattered intensity from Ca atoms of CaF/Si(111) surface on the incident angle, α. 1) w ƒ Ca F ƒ» z ƒ ùkù. rl w w w d 0.64Û0.05 Å w. CaF 2 d 0.79 Å 0.15 Å w. w Ca-F w w Si t [ 112 ] w w 17 o, w 2.19 Å. d CaF 2 Ca Fƒ»q Si ww e w ƒ,»q 2-4) Si l d w (Fig. 2). x š, q. Fig. 2(b) T 4 w ƒ x š. Ca Si(111) 2d Si w. ICISS t - d l d w, w, w Fig. 2. The dependence of the scattered intensity from Si atoms of CaF/Si(111) surface on the incident angle, α. 1) (a) T site model, (b) T 4 site model, and (c) H 3 & T 4 mixed site model. The dashed lines mean the simulation. 1) e w w. CaF 2 Ì k z ICISS w ý. Fig. 3 Si(111) t ML(mono-layer) ML CaF 2 k z Ca l He + (He He ) d w o ICISS l. ML w ƒ He α =36 o, 74 o, 106 o, 134 o,
19«1y, 2008 Ÿ (ICISS) w š t w (2): 9 Fig. 3. Scattered intensity from epitaxially grown CaF 2 thin films. (a) Several hundreds layers of CaF 2, and (b) tens of layers of CaF 2. 1) 154 o. y j CaF 2 (111) w d w ew j w. ML w α =60 o, 110 o, 120 o, 140 o vjƒ ùkù j ƒ yw w. ƒ ùkü yw CaSi 2 j CaSi 2 w w ƒ ƒ. ML w CAICISS w w yw d ƒ w. 2. III-V t III-V yw w t ky z t v w. III-V t (NH 4 ) 2 S x w w t S w Fig. 4. The dependence of the scattered intensity from In and As atoms of (NH 4 ) 2 S x treated InAs(001) surface on the azimuth angle, φ. 7) (a) Before heat treatment, (b) heat treated at 380 o C, and (c) heat treated at 430 o C. t ww yw y t. 5,6) Fig. 4 InAs(001) t (NH 4 ) 2 S x w z In As l o d w. d ƒ 7) α = 45 š jš ƒ, φ(azimuth angle) y j. φ ƒ ƒ w. ƒ t (a) w w ƒ z t (b) yw. w (c) S k k z
10 y w wz Fig. 5. CAICISS spectra along (a) [ 111 ] and (b) [ 111 ] azimuth angle. 7)»q InAs(001) w.»q S φ»q w S InAs(001) t ww e, In e As e wù ewš w. Fig. 5 380 C w t o [ 111 ] [ 111 ] w l d w. 7) [ 111 ] w t 1d As e š 3d As. w [ 111 ] w l 3d As. Fig. 5(b) Svj (a). t 1d As 3d As S ey ùk ü. 1d As S ƒ 2 d In w ü w ƒ» z w In w vjƒ wù (b) In w vjƒ x w. s 1d As S ƒ [ 111 ] w l w x wš ùkü. 3. / w š t w ƒ ww x w w w w w t w ù MBE w w. Si(111) t Ag Stranski- Krastanov. 8)» ICISS w Ag w ý. Fig. 6 Si(111)-7X7 t Ag w w CAICISS w w l. 9) 1/3 ML(1 ML = 7.83Ü10 14 atoms/cm ) 2.»q ƒ š (300~600 o C), Ag 2 ( 3Ü 3 -Ag) x w z 3 w. (300 o C w) j l Ag l w d x w As w. rp 2 vj ƒƒ Ag Si l He, Fig. 6. CAICISS spectra of the Ag grown Si(111) surface. 8)
19«1y, 2008 Ÿ (ICISS) w š t w (2): 11 Ag l w vj w w vj (L) û ùkù w (C) ù. L 2 ù d t Ag l 1z š, C 3 Ag ü. j 1z ƒ z ƒ 2z ƒ ƒw, w š w. xk ƒ ù ¾, d TPƒ ¾ j k. w ¾ d TP Ag v w. l SEM w 2 Ag, Ag v, s³, Ag w. 4. / Agƒ Si(111) t 3Ü 3 R30 o -Ag t w t w š 10) z w û. X- z ù STM w w ƒ. 11-13) Fig. 7 ICISS w ƒ 0 o ~45 o [ 112 ] [ ] w d w ICISS. 14) 110 Ag vj α w d, Ag ƒ 2 w w. Si(111) t Ag HCT(honeycomb triplet). Ag-Ag 5.1Û0.2 Å. 5. t w Fig. 8 GaAs(001) t»q 550 C o AlAs MBE j ICISS rp (α =45 o ). 15) MBE As source 235 C š jš o, Al source 817~956 C y g o. Al ƒ 868 o C ¾ rp j yƒ AlAs ƒ û. Al source Fig. 7. Scattered intensity of He atoms from XR30 o -Ag surface. 14) simulation. (a) Experimental results, and (b)~(e)
12 y w wz Fig. 8. Time-of-flight ICISS spectra of MBE AlAs growth on the GaAs(111) surface. 15) The temperature of Al source is (a) 817 o C, (b) 868 o C, (c) 902 o C, and (d) 956 o C. Fig. 9. Schematic diagram of the GaAs(001) surface at the incident angle of 45 o. 956 C Ga As w vj o ƒ wš Al v jƒ AlAs ƒ x w. Fig. 8 rp Fig. 9 [011], t 1, 2d» w. d AlAs w v Ga ƒ Al w ƒ Ga rp» w w Ga As w vj ƒ 1/2 û. Fig. 8(d) vj ƒ w 4 AlAs 0.25 ML/min. 6. ICISS š t w t ù y w w r. ICISS. (1) t w. (2) t - d ¾ w. (3) t ù y w w w ƒ w. (4) y w. ICISS š t» ƒ, š z (RHEED) z ww w w. š ƒ œ». š x 1) Katayama, M., King, B. V., Nomura, E. and Aono, M., Vacuum, 42, 321 (1991). 2) Himpsel, F. J., Hillebrecht, F. U., Hughes, G., Joordan, J. L., Karlsson, U. O., McFeely, F. R., Morar, J. F. and Rieger, D., Appl. Phys. Lett., 48, 596 (1986) 3) Batstone, J. L., Phillips, J. M. and Hunke, E. C., Phys. Rev. Lett., 60, 1394 (1988). 4) Tromp, R. M. and Reuter, M. C., Phys. Rev. Lett., 61, 1756 (1988). 5) Nannichi, Y., Fan, J., Oigawa, H. and Koma, A., Jpn. J. Appl. Phys., 27, L2367 (1988).
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