1. A theoretical suggestion to make real clean material surface Sooyeon Yoon and Yup Kim Kyung Hee Univ. Dept. of Phys. 2004 년 한국물리학회 가을 학술 논문 발표회

2. We study a dynamical scaling property of real two dimensional surface eroded from the rough surface by an external particle which does biased random walk. We first prepare the rough surfaces by use of several growth methods, i.e., the random deposition, the restricted solid-on-solid (RSOS) model, and conserved RSOS model. We first show that the roughness of surfaces eroded by unbiased random walking particles in three dimensional space eventually reaches within mono-layer thickness. We also found that the dynamical scaling property of the surface satisfies the scaling ansatz W~f(t/L z ) with the dynamical exponent z=1. When the attractive bias exists, the surface roughness increases logarithmically with size. 2004 년 한국물리학회 가을 학술 논문 발표회 1 AbstractAbstract

3. Surface evolution models with z = 1  Biased-Diffusion-Limited-Erosion (PRE 66, 031105 (2002))  Time-Reversed Dielectric Breakdown Model (PRE 67, 05611(2003))  Surface Growth Model with a Random walk like Nonlocality (PRE 68, 036221 (2003)) Motivation of this study  Theoretical base 2004 년 한국물리학회 가을 학술 논문 발표회 2 Motivation of this study

4.  DLE Model and TDBM (Dynamical Scaling Law : z = 1) white noise  BDLE Model (Dynamical Scaling Law : z = 2) 2004 년 한국물리학회 가을 학술 논문 발표회 3 Motivation of this study

5.  Experimental base  Plasma-surface interaction : A flux of ions emerges from the plasma and a thin film is being etched by accommodation of incident ions on a substrate. (Progress in Surface Science 76, 21 (2004))  Chemical etching : Boiling silicon wafer in an HCL/H 2 O 2 or NH 4 OH/H 2 O 2 solution (RCA review 31, 187 (1970))  Electropolishing : Electrochemical etching of silicon in hydrofluoride containing eletrolytes leads. (PRE 64, 031604 (2001, theoretical base)) 2004 년 한국물리학회 가을 학술 논문 발표회 4 Motivation of this study

6. L Killing plane z max Starting plane zkzk Model 2-dimensional L x L substrate, 1. First make a rough surface(material) with restricted solid-on-solid method, random de- position method. 2. Choose randomly one site (x,y,z) at the starting plane. A particle does the biased random walk with down probability P b in the empty space. 3. If the particle gets to the killing plane, the new one is started from the other randomly selected site among the starting plane. Otherwise, if the particle reaches the nearest neighbor of the rough surface, the incident particle and material particle are removed together. ※ If the sites which the incident particle is located are more two, randomly select one of them. x y z PbPb 2004 년 한국물리학회 가을 학술 논문 발표회 5 Model

7. Results 1-1. Restricted solid-on-solid(RSOS) type growth & Down probability,P b =1/6 2004 년 한국물리학회 가을 학술 논문 발표회 6 Results

8.  Morphology change of RSOS surface t = 0 t =  2004 년 한국물리학회 가을 학술 논문 발표회 7 Results

9. 1-2. Restricted solid-on-solid(RSOS) type growth & Down probability, P b =1 Scaling collapse with z=2 2004 년 한국물리학회 가을 학술 논문 발표회 8 Results

10. ※ Confirm of 2D BDLE ( P b = 1) Erosion is s tarted from the flat surface ( h = 0 ) Dynamic exponent, z = 2 2004 년 한국물리학회 가을 학술 논문 발표회 9 Results

11. 2-1. Random deposition(RD) type growth & Down probability, P b =1/6 2004 년 한국물리학회 가을 학술 논문 발표회 10 Results

12. 2-2. Random deposition(RD) type growth & Down probability, P b =1 2004 년 한국물리학회 가을 학술 논문 발표회 11 Results

13. We study a dynamical scaling property of two dimensional surface eroded from the rough surface by (biased) random walking particles. 1. RSOS type surface eroded by unbiased random walking particles (P b =1/6) 2. RD type surface eroded by unbiased random walking particles (P b =1/6) ?? 3. The attractive bias exists (P b =1), the surface roughness increases logarithmically with size. Conclusions & Discussions 2004 년 한국물리학회 가을 학술 논문 발표회 12 Conclusions & Discussions