Microsoft Word The full thesis [v20] Cover & Abstract

Al 
4.28 
Ni 
5.15 
Pt 
5.65 
 
 
Figure 3.2: The band diagram of sets of Al-AlO
x
-Al, Ni-NiO
x
-Ni, Al-AlO
x
-Pt 
 
Table 3.1 shows work functions of each material, aluminum, nickel, and platinum. 
The combination of Al-AlO
x
-Pt has asymmetrical structure. The work function differences 
are 0 eV and 1.3 eV for symmetrical structure and asymmetric structure, respectively, 
subtracting work function of aluminum from platinum. Figure 3.2 illustrates the band 
diagram of sets of Al-AlO
x
-Al, Ni-NiO
x
-Ni, Al-AlO
x
-Pt. The band diagram also presents 

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30 
work function difference of each material using the distance from the top of oxide to the 
material block.
Figure 3.3 shows the TEM image of cross-section view of Al-AlO
x
-Al MIM structure. 
The thickness of native oxide layer is about 5.6 nm. The aluminum and nickel is easy to 
obtain thin native oxide layer so that these materials were used to form bottom electrode.
Figure 3.3: The TEM image of cross-section view of Al-AlO
x
-Al MIM structure 

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31 
-0.10
-0.05
0.00
0.05
0.10
-6.0x10
-5
-3.0x10
-5
0.0
3.0x10
-5
6.0x10
-5
Current density (A/um
2
)
Volatage (V)
Al-AlOx-Al
Ni-NiOx-Ni
Al-AlOx-Pt
(a)
-1.0
-0.5
0.0
0.5
1.0
-0.06
-0.04
-0.02
0.00
0.02
dI/dV (A/V)
Al-AlOx-Al
Ni-NiOx-Ni
Al-AlOx-Pt
Voltage (V)