Transcript 2015 전략산학_최종 교류회 발표 자료(손병혁 교수님).

Colloidal Silica, Ceria Slurry의
Particle 규명 및 제어 방법 연구
2015년 06월 일
대표 학생
문두식, 정동욱
과제 책임자
손병혁 교수님
(이진규 교수님)
Department of Chemistry,
Seoul National University
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
1/12
2.5년간 전략산학 연구 성과 결산
연구 성과 요약 (’12.07~’14. 12)
1. 참여 기간 : 2012. 07. 01 ~ 현재
2. 전략산학 장학생 현황 :
(총 0 명)
전략산학 연계 취업 현황 : 문두식 (총 1 명)
3. 대표 연구 주제 :
- CMP용 Ceria 나노입자의 합성 연구
- CMP용 Ceria 나노입자의 크기조절 방법 개발 연구
- CMP용 주름진 실리카 (Wrinkled Silica Nanoparticle, WSN) 합성 연구
- WSN의 CMP 특성 분석
2/12
대표 논문 Review
논문 제목 :
- Formation of Wrinkled Silica Mesostructures
Based on the Phase Behavior of Pseudoternary
Systems
논문 내용 :
- 주름진 실리카 나노구조가 형성되는 원인을 의사
삼상계 시스템에 의한 상변화에 따른 결과로 반응
메카니즘을 제안함.
3/12
대표 논문 Review
선정 이유 :
-
본 연구에서 CMP slurry의 주 성분으로 이용되는 주름진 실리카(WSN)
의 형성메카니즘을 밝혀, 양산합성법의 기반을 확보함
저널 정보 :
- 저널명 : Langmuir
- Impact Factor : 4.384
- 저널 랭킹 : 29/247 (상위 12 %)
- 계면화학 분야 최고 저널
4/12
Introduction
 Chemical-Mechanical Polishing/Planarization
: CMP is a process of smoothing surfaces with the
combination of chemical and mechanical force
 Main components
: Polymeric polishing pad, slurry with abrasive particles,
the surface to be polished (wafer)
 CMP Slurries with abrasive particles
: CMP slurries work just like toothpaste
- Particles abrade away unwanted coating from tooth
surface during tooth brushing
- Abrasive : SiC, Al2O3, SiO2, CeO2, TiO2 and so on.
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
5/12
Surface Defects in CMP Process
 CPM slurries consist of abrasive particles 50-500 nm in diameter suspended in DI water
 Scratch formation is attributed to particle-wafer interactions during CMP
 Micro-scratch formation is mostly dependent on the size of the largest abrasive particle
pad
Slurry
← Scratch
substrate
Applied Surface Science, 2012, 258, 8552
Journal of The Electrochemical Society, 2010, 157, H186
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
6/12
Synthesis of CeO2: Low Yield Problem
Method-1
Ce(NO3) 3∙6H2O
H2O
Ethylene glycol
190 ℃, 16 h
900 ℃, 2 h
 Product : 1.4 g

Ce(NO3)3∙6H2O
6.51 g
H2O
30 mL
Ethylene glycol
900 mL
XRD powder patterns of CeO2
(111)
35 ± 3 nm
Standard CeO2
(200)
20
30
40
50
60
70
2 (degree)
20 nm
100 nm
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
7/12
Grain Size
(111) : (200)
22.5 nm
3.3 : 1
80
Synthesis of CeO2: Low Yield Problem
Method-2
Ce(NO3) 3∙6H2O
Polyethylene glycol 600
(PEG 600)
70 ℃, 30 min
Ce(NO3)3∙6H2O - 5 g
PEG 600 – 10 g
110 ℃, 3 h
900 ℃, 2 h
Ce(NO3)3∙6H2O – 7.5 g
PEG 600 – 10 g
50 nm
50 nm
 Product : 110 mg
 Product : 120 mg
- Too small amount to apply them to the CMP process
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
8/12
Wrinkled Silica Nanoparticle (WSN)
Oil layer
Nonpolar solvent
(cyclohexane/toulene etc.)
Cosolvent
(Alkyl alcohols)
Silicate
(TEOS/TPOS/TBOS)
Aqueous layer
Water
Surfactant (CTAB)
Base (urea)
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
9/12
Advantages of the WSN
Tunable synthesis
Mild synthetic condition and high yield
 Over 100 g of WSNs can be produced
via pilot-scale one-pot synthesis
(Yield: over 90%)
 No high temperature and pressure are
needed
Easy surface modification
 Various ligands can be attached to the
surface of WSNs with covalent bonds
 Chemical property and surface charge
can be adjusted
Zeta potentials of surface modified WSNs
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
10/12
CMP test with the WSN
WSN의 경우, 표면 손상률이 다소 높음
WSN
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
11/12
향후 계획
•
WSN의 효과적인 대량 합성법 및 정제법 확립
대량합성 조건 및 정제법 개선
•
WSN을 이용한 CMP 효율 향상
입자의 크기, 표면전하 등을 조절하여 기판 표면의 손상을 줄이는 방법 모색
Materials Chemistry Laboratory
Dept. of Chemistry, Seoul National University
12/12