1. Highly Ordered Deposition of MgAl-CO3 Layered Double Hydroxides on Si(100) Surface by Solvothermal Treatment
이종현 , 이석우 , 송여진 , 정덕영*
성균관대학교
Skku. Inorganic materials lab.

2. 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.

3. Layered Double Hydroxide (LDH)
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
Skku. Inorganic materials lab.

4. Micropatterning of LDH nanoparticles Microcontact printing (OTS)
CP-TMS
glass
LDH Si OH
Microcontact printing (OTS)
Coating (CP-TMS)
Toluene Reflux(140C , 4hr)
Ultra Sonication(30~60s)
Skku. Inorganic materials lab.

5. Hydrothermal Treatment of LDH particles AES(Auger Electron Spectrum)
Hydrothermal (140C , 5hr)
AES(Auger Electron Spectrum) A B A
OTS region (base resist)
Etching B A B
Si(100)
hydrothermal (180C , 5hr)
Skku. Inorganic materials lab.

6. Experimental section (solvothermal treatment)
1. Wafer cleaning
2. Toluene solvothermal reaction (140C, 4hr)
3. Ultra Sonication 5~10min
4. Dry
Toluene
LDH particles
Substrate
N-type Si(100) :2E14 atoms/cm3 (dopant : phosphorus)
P-type Si(100) :1E15 atoms/cm3 (dopant : boron)
Mg:Al=2:1
Mg:Al=3:1
Mg:Al=4:1
[Mg4Al2(OH)12]CO34H2O
[Mg6Al2(OH)16]CO34H2O
[Mg8Al2(OH)20]CO34H2O
500nm
500nm
500nm
Skku. Inorganic materials lab.

7. Solvothermal Treatment X-RAY diffraction (film)
[Mg4Al2(OH)12]CO34H2O
X-RAY diffraction (film)
SEM image
p-type Si(100)
2m
500nm
n-type Si(100)
2m
500nm
Skku. Inorganic materials lab.

8. X-RAY diffraction (powder & film)
(a) powder
(b) film : substrate :n-type Si(100)
(c) film : substrate :p-type Si(100)
* : (00 l ) diffraction
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
Skku. Inorganic materials lab.

9. Increase of surface coverage (SEM & AFM)
SEM image
Mg:Al=2:1
Mg:Al=3:1
Mg:Al=4:1
2m
2m
1m
Increase of Surface Coverage
AFM image
Skku. Inorganic materials lab.

10. X-RAY diffraction (film)
A trend as temperature
[Mg4Al2(OH)12]CO34H2O
X-RAY diffraction (film)
AFM image
140C
150C
Skku. Inorganic materials lab.

11. Hydrothermal after solvothermal
[Mg4Al2(OH)12]CO34H2O
solvothermal
hydrothermal
2m
500nm 수열
100C 5hr
2m
Increase of Surface Coverage
500nm
Skku. Inorganic materials lab.

12. Conclusion Acknowledgement
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( 140C ) 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.
Acknowledgement
We acknowledge support by the Korean Science and Engineering Foundation through Grant R
Skku. Inorganic materials lab.