Skku. Inorganic materials lab.Skku. Inorganic materials lab.
Highly Ordered Deposition ofHighly Ordered Deposition of MgAl-CO MgAl-CO33 Layer Layer
ed Double Hydroxides on Si(100) Surface by ed Double Hydroxides on Si(100) Surface by
SolvothermalSolvothermal TreatmentTreatment
이종현 , 이석우 , 송여진 , 정덕영 *
성균관대학교
Abstract
Synthetic MgAl-CO3 layered double hydroxides(LDHs) are inorganic layer-structured materials having homogeneous chemical composition and sub-micron size. They crystallize in a hexagonal systems with structural anisotropy. SEM and AFM images of the film showed that LDHs particles were deposited on Si(100) with high order by solvothermal treatment in toluene.
The surface coverage on Si(100) of LDHs particles increases as the positive charge of layer decreases. The X-ray diffraction spectra of the MgAl-CO3 LDHs deposited on Si(100) showed only the sharp and intense (00l) reflections, suggesting that the LDHs layers are parallel to the plane of Si(100). This work is an important evidence for the direct chemical reaction between Si(100) surface and LDHs particles.
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
OH
OH
OH
OH
CO32-, nH2O
M(II), M(III)
M(II), M(III)
• General formula of synthetic LDH
M(II)1-xM(III)x(OH)2(Am-)x/mnH2O
M(II) = Mg, Ni, Zn
M(III) = Al, Cr, Fe
Am- = exchangeable anion.
0.2 ≤ x ≤ 0.4
1/m ≤ Am-/M(III) ≤ 1
• Schematic structure
Layered Double Hydroxide (LDH)
Micropatterning of LDH nanoparticles
Toluene Reflux(140C , 4hr)
Microcontact printing (OTS)
Coating (CP-TMS)
Ultra Sonication(30~60s)
Cl Cl Cl
o o o
CP-TMSglass
LDH
Si Si Si Si
Si Si Si Si Si Si Si
Si
o o o o o oo o o o
o o o o o o o o oo o o o o o
o o oSi Si
OH OH OH
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
Hydrothermal Treatment of LDH particles
Hydrothermal (140C ,
5hr)
A
B
A
B
AES(Auger Electron Spectrum)
OTS region (base resist) Etching
hydrothermal (180C ,
5hr)
AB Si(100)
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
Experimental section (solvothermal
treatment) 1. Wafer cleaning 2. Toluene solvothermal reaction (140C, 4hr)3. Ultra Sonication 5~10min4. Dry
Substrate N-type Si(100) :2E14 atoms/cm3 (dopant : phosphorus)
P-type Si(100) :1E15 atoms/cm3 (dopant : boron)
Toluene
LDH particles
Mg:Al=2:1
500nm
[Mg4Al2(OH)12]CO34H2O
Mg:Al=3:1
500nm
[Mg6Al2(OH)16]CO34H2
O
Mg:Al=4:1
500nm
[Mg8Al2(OH)20]CO34H
2O
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
10 20 30 40 50 60 70 80
0
5000
10000
15000
20000
(0015)
(0018)
Si(400)
(006)
(009)
(0012)
(003)
I(CPS)
2theta
Solvothermal Treatment
2m
500nm
p-type Si(100)
n-type Si(100)
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
2m
500nm
SEM image
X-RAY diffraction (film) [Mg4Al2(OH)12]CO34H2
O
X-RAY diffraction (powder & film)
(a) powder(b) film : substrate :n-type Si(100) (c) film : substrate :p-type Si(100)* : (00 l ) diffraction
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
Mg:Al
(003) (006) (009)
2:1 7.66Å 3.81Å 2.54Å
3:1 7.82Å 3.91Å 2.61Å
4:1 7.92Å 3.96Å 2.64Å
Increase of surface coverage (SEM & AFM)
2m2m 1m
Mg:Al=2:1 Mg:Al=3:1 Mg:Al=4:1
Increase of Surface Coverage
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
AFM image
SEM image
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
A trend as temperature
AFM image
140C
150C 10 20 30 40 50 60 70 80
1300C
1500C
1400C
Si(400)
Si(200)
(0018)
(0012)(009)
(006)
(003)
intensity
2theta
X-RAY diffraction (film) [Mg4Al2(OH)12]CO34H2
O
Hydrothermal after solvothermal
[Mg4Al2(OH)12]CO34H2
O
수열
100C 5hr
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
2m
500nm
solvothermal
hydrothermal
2m
500nm
Increase of Surface Coverage
Conclusion
Skku. Inorganic materials lab.Skku. Inorganic materials lab.
We have seen that it was possible for MgAl-CO3 LDHs-nano size particles to be deposited on Si(100) without intermediates and to be micro-patterned on the CP-TMS region prepared by cp. LDHs particles were deposited on Si(100) at unique temperature( 140C ) by solvothermal treatment in toluene.
SEM and AFM images of the film showed that LDHs particles were deposited on Si(100) with high order by solvothermal treatment in toluene. The surface coverage on Si(100) of LDHs particles increases as the positive charge of layer decreases. This work is an important evidence for the direct chemical reaction between Si(100) surface and LDHs particles.
AcknowledgementWe acknowledge support by the Korean Science and Engineering Foundation through Grant R02-2000-00065.