N + Si
(a) (b)
Fig. 2-4 (a) Cross section of bottom-contact OTFT (b) plan view of the device
N+Si PoCol
3 doping
Thermal oxidation
Patterned P.R for lift-off process
Deposition of S/D contacts
Lift-off process Thermal oxide
N+Si
Thermal oxide
N+Si
P.R
AL
Thermal oxide
N+Si
P.R
Pt
Thermal oxide
ALPt ALPt
N+Si
P3HT Thermal oxide
ALPt ALPt
N+Si
Deposition of P3HT by
spin-coating
Fig. 2-5 Process flow of bottom-contact OTFT Fig. 2-6-1 Process flow of bottom-contact OTFT with patterned gate oxide
Fig. 2-6-2 Process flow of bottom-contact OTFT with patterned gate oxide
Fig. 2-7 Operation of OTFT [12] (a) No-bias (b) Accumulation mode (c) Depletion mode (d) Non-uniform charge density (e) Pinch-off of channel (f) and (g) Growth of the depletion zone.
-4 -2 0
Fig. 2-8 Typical FET-like Id-Vd curve: (a) Linear region when Vd is small (b) Saturated region when Vd is large
-20
Fig. 2-9 (a) Typical Id-Vg curve of P3HT OTFT: Ig increases with increasing negative gate bias (b) Mobility of P3HT OTFT increases with increasing negative gate bias then decreased due to surface scattering effect.
Fig. 2-10 Source and gate leakage current versus gate bias
(a)
-20 -15
Fig. 2-11 Influence of gate leakage current on Id-Vd: (a) TC OTFT with W/L = 5000µm/30µm (b) TC OTFT with W/L = 100µm/30µm
(a) (b) (c)
(d) (e) (f)
Fig. 2-12 Id-Vg curve of patterned and non-patterned P3HT BC OTFT with (a) W/L = 10000µm/10µm (b) W/L = 5000µm/10µm (c) W/L = 1000µm/10µm (d) W/L = 1000µm/25µm (e) W/L = 10000µm/50µm (f) W/L = 100µm/50µm
(a) (b)
(c)
Fig 2-13 Id-Vd curve of BC OTFT with (a) non-patterned oxide (b) patterned oxide (c) patterned oxide and P3HT film
0 50 100 150 200
1.1x10-2 1.2x10-2 1.3x10-2 1.4x10-2 1.5x10-2 1.6x10-2 1.7x10-2 1.8x10-2
mobility(cm2 /V*s)
channel length(µm)
linear mobility Vd= -5 V TC-Ni W=5000µm
Fig.2-14 Motility of TC OTFT with Ni S/D contacts versus channel length
Fig.2-15 Threshold voltage of TC OTFT with Ni S/D contacts versus channel length
Fig. 2-16 On-off ratio versus time measured by definition: (a) I on (Vg = Vd < 0)/ I off
Fig.2-17 Mobility of BC OTFT w
(Vg=0,Vd<0) (b) Ion(accumulation mode)/ I off (depletion mode)
20 30 40 50 60 70 80 90 100 110 1.0x10-3
2.0x10-3 3.0x10-3 4.0x10-3 5.0x10-3
Vd= -5v W/L= (µm/µm)
100/50 300/50 500/50
mobility(cm2 /V*s)
Temp (C)
BC-Pt
ith Pt S/D contacts measured under different operation temperature
(a) (b)
(c)
Fig. 2-18 Conductivity of P3HT film versus op on temperature measured from BC OTFTs (a)
)
Fig. 2-19 Conductivi µm /10µm
erati
with channel length of 50µm (b) with channel width of 1000µm (c) with channel length of 10µm
(a (b) ty and mobility of P3HT versus time with device (a) W/L= 1000 (b) W/L= 5000µm /10µm
Fig. 2-20 Mobility of BC OTFT with Pt S/D contacts versus time
(a)
Fig. 3-21 Threshold voltage of BC OTFT versus time with (a) the same channel width of 1000µm (b) the same channel len
(b)
gth of 10µm
(a) (b)
Fig. 3-22 Field-effect mobility plotted against the bulk conductivity from (a) experiment result of P3HT (b) some conducting polymers (from [12])
(a) (b)
Fig. 3-23 Contact resistance of TC OTFT with Pt S/D contacts measured when device is operated in (a) linear region (b) saturated region
(a) (b)
Fig. 3-24 Contact resistance of TC OTFT with Ni S/D contacts measured when device is operated in (a) linear region (b) saturated region
Fig. 3-25 Channel resistance of TC OTFT with Ni S/D contacts versus gate bias
(a) (b) Fig. 3-26 (a) Id-Vd curve (b) Id-Vg curve of TC OTFT with Al S/D contacts
Fig. 3-27 Original and corrected mobility of TC OTFT with Ni S/D contacts versus gate bias
Fig. 3-28 The mobility of TC OTFT with Ni S/D contacts and different P3HT film thickness versus channel length
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成果自評
Electronics and Material Symposium (EDMS), pp. 5, 2003.