J. Electro.Soc.Vol.119, pp.948, 1972
I- line lithography and BOE etching
Ni 5nm deposition
Fig. 2.2: TFTs fabrication (type A)
Ni 5nm
550℃ 24hours with N2
PECVD SiO2 200nm
Fig. 2.3: TFTs fabrication (type B)
550℃ 24hours with N2
600℃ 12hours with N2
PECVD SiO2 200nm
MILC 550C several hours with different channel thickness
TIME (HR)
0 5 10 15 20 25
MILC length (um)
0 10 20 30 40 50 60
time vs Channel 500 A time vs Channel 1000 A
Fig. 3.1 Observed MILC length as a function of time. Thickness of the Si films is 50 nm or 100 nm.
MILC open window size vs MILC Length after 550C 24hours
5X__ (um2)
0 20 40 60 80 100
MILC Length (um)
0 10 20 30 40 50 60
WINDOW SIZE vs MILC Length
MILC length
Fig. 3.2 MILC length as a function of open window size. The sample was annealed at 550℃ for 24 hours.
Fig. 3.3 Schematic model for the explanation of MILC window size effect.
MILC length for 500.525.550C
TIME(hour)
0 5 10 15 20 25
MILC length(um)
0 10 20 30 40 50 60 70
window size 5X5 um2 5X10
5X20 5X50 5X100
500C 525C 550C
Fig. 3.4 MILC length as a function of annealing time with seeding window size as parameter for two different annealing temperatures.
Fig. 3.5 An exemplary layout for devices used to investigate the effect of channel length on device performance. Major dimensional parameters are also illustrated.
Vg(V)
Fig. 3.6 Transfer characteristics of MILC TFT (Type-A) at Vd=5V and 0.1V with
various channel length. The channel width is 20um.
Vg(V)
Fig. 3.7 Re-plot of Fig. 3.6 normalized to channel length.
Table3.1Major electrical parameters extracted from the transfer curves measured at Vd =0.1V in Fig. 3.6. Definition of the Effective (Eff) Vd is given in Eq.3-1.
L(um) Mobility(cm2/V*s) Vth(V) SS (V/dec) Eff Vd(V)
10 61.5 4.32 1 0.057347
5 49.2 3.99 0.95 0.04444
2 35.55 3.76 0.962 0.023281
1 24.76 4.05 0.994 0.008176
0.6 18.86 4.25 1.041 0.000494
One side MILC(A) 550C24HR
Fig. 3.8 Measured total device resistance R versus drawn channel length L of MILC TFTs (Type-A) with only one MILC open window at source region. Channel width W is 20 um.
Fig. 3.9 Measured total device resistance R versus drawn channel length L of SPC poly-Si TFTs with S/D activation steps same as MILC devices in Fig. 3-8.
D
Fig. 3.10 MILC TFTs with (A) one-side and (B) two-side MILC open window arrangement.
Fig. 3.11 Transfer characteristics of MILC TFTs (Type-A) with one-side and two-side MILC open windows.
Two side MILC(A) 550C24HR
channel length(um)
-4 -2 0 2 4 6 8 10 12
Resistance(ohm)
0 20000 40000 60000 80000
Rsd≒13K
Vgs=3V Vgs=6V Vgs=9V Plot Regr
Fig. 3.12 Measured total channel resistance R versus drawn channel length L of MILC TFT (Type-A) with two-sided MILC open windows. Channel width of the device is 20 um.
Fig. 3.13 An exemplary layout for devices used to investigate the effect of channel width on device performance. Major dimensional parameters are also illustrated.
Vg(V)
Fig. 3.14 Transfer characteristics of MILC TFT (Type-A) with various channel width
but identical channel length of 2um.
MILC(A) 550C24HR L=2um VD=5V 0.1V
Vg(V)
Fig. 3.15 Normalized transfer characteristics of MILC TFTs (Type-A) with various channel width but identical channel length of 2um.
Table 3.2 Major electrical parameters extracted from the transfer curves measured at Vd = 0.1 V in Fig. 3.14.
W(um) (L=2um) Mobility(cm2/V*s) Vth(V) SS(min)(V/dec)
20 35.55 3.76 0.962
Vg vs Id S/D reversed Vd=5V
Vd=0.1V
Fig. 3.16 Transfer characteristics of a MILC TFT (Type-A, L/W=10um/20um)under forward and reverse modes of measurements.
Vg(V)
Vg vs Id one step anneal Vg vs Id two step anneal
Fig. 3.17 Transfer characteristics of MILC TFTs (Type-A, L/W=10 um/20 um) processed with one- and two-step S/D anneal.
one step anneal two step anneal
Id(minima for Vd=5V)(A)
Fig. 3.18 Distribution of minimum drain current at Vd=5V for devices with one- and two-step S/D anneal.
one step anneal two step anneal
Id(Vg=20V Vd=5V)(A)
0.00014 0.00016 0.00018 0.00020 0.00022 0.00024 0.00026 0.00028
Fig. 3.19 Distribution of minimum drain current at Vd=5V and Vg = 20V for devices with one- and two-step S/D anneal.
one step anneal two step anneal
SSmin(Vd=0.1V)(V/deg)
0.85 0.90 0.95 1.00 1.05 1.10 1.15
Fig. 3.20 Distribution of subthreshold swing at Vd=0.1V for devices with one- and two-step S/D anneal.
W/L=20um/10um
fresh NH3 1HR NH3 2HR
Minima Id(A)
W/L=20um/10um Vd=5V Vg=-10V
fresh NH3 1HR NH3 2HR
Id(A)
Fig. 3.21 Characteristics of MILC TFTs (Type-A) before and after NH3 plasma treatment: (a) transfer characteristics, (b) minimum Id at Vd=5V, and (c) leakage current at Vd=5V and Vg=-10V.
Fig. 3.22 Transfer characteristics of MILC TFTs (Type-B 550℃) with various channel length but identical channel width of 20um. Vd=5V and 0.1V.
W=20um VD=5V 0.1V
Fig. 3.23 Transfer characteristics of MILC TFTs (Type-B) shown in last figure normalized with the channel length.
Table 3.3 Major electrical parameters extracted from transfer curves measured at Vd = 0.1 V in Fig. 3.22. Definition of the Effective (Eff) Vd is given in Eq. (3-1).
L(um)W=20um Mobility(cm2/V*s) Vth(V) Eff Vd(V) SS(min)(V/dec)
10 58 0.85 0.092776 1.272
5 47.06 0.92 0.088318 1.31
2 44.16 1.03 0.074741 1.309
1 37.42 0.93 0.061423 1.322
one side MILC(B) 550C24HR
channel length(um)
-2 0 2 4 6 8 10
Resistance(ohm)
0 10000 20000 30000 40000 50000
Vgs=3V Vgs=6V Vgs=9V Plot Regr Rsd≒1.12KΩ
Fig. 3.24 Measured total device resistance R versus drawn channel length L of MILC TFTs (Type-B) with only one MILC open window at source region. Channel width W is 20 um.
SPC control sample(B)
Fig. 3.25 Measured total device resistance R versus drawn channel length L of SPC TFTs which received the same S/D annealing treatment as MILC process Type-B.
SPC(B) W=20um VD=5V 0.1V
Fig. 3.26 Transfer characteristics of SPC poly-Si TFTs normalized with the channel length.
MILC(B) 550CN24HR L=2um with varies W
MILC(B) 550C24HR L=2um VD=5V 0.1V
Vg(V)
Fig. 3.27 (a) Transfer characteristics for MILC TFTs (Type-B) with various channel width but identical channel length of 2um (b) Transfer characteristics of the devices normalized with the channel width.
Table 3.4 Major electrical parameters extracted from transfer curves measured at Vd = 0.1 V in Fig.3.27(a).
W(um)L=2um Mobility(cm2/V*s) Vth(V) SS(min)(V/dec)
20 44.16 1.03 1.309
10 45.43 2.14 1.331
5 54.39 2.4 1.311
2 63.57 2.32 1.279
1 65.78 2.66 1.342
0.6 93.17 1.7 1.192
Fig. 3.28 Illustration of the appearance of parasitic channels on the sidewall of the active layer.
SPC(B) L=10um VD=5V 0.1V
Fig. 3.29 Transfer characteristics of SPC poly-Si TFTs normalized with the channel width.
Table 3.5 Major electrical parameters extracted from transfer curves measured at Vd = 0.1 V in Fig.3. 29.
W(um)L=10um Mobility(cm2/V*s) Vth(V) SS(min)(V/dec)
10 19.73 6.41 1.992
5 20.08 6.35 1.997
2 23.21 5.99 1.996
1 27.38 5.69 2.017
MILC(B) 550C W/L=20um/10um
Fig. 3.30 Transfer characteristics of Type-B devices with and without plasma treatment.
Table 3.6 Major electrical parameters extracted from transfer curves in Fig. 3.30.
W/L=20/10 Mobility(cm2/V*s) Vth(V) SS(min)(V/dec) Id minima(Vd=5V)(pA)
Fresh 58.0 0.85 1.272 66.280
NH3 1HR 58.65 2.11 1.392 47.760
NH3 2HR 75.03 -0.89 0.78 35.045
Activation energy
W/L=20um/10um Vd=5V
Fig. 3.31 Activation energy of MILC TFTs: (a) Type-A under forward and reverse modes of measurements, (b) Type-B under forward and reverse modes of measurements, and (c) comparisons of the three types of devices.
W/L=20um/10um
Fig. 3.32 Transfer characteristics of Type-A, Type-B, and SPC TFTs.
Fig. 3.33 Schematic of HC-TFT test structure.
Table 3.7 Major structural parameters of HC-TFT. (unit: um) Device
No.
LG WG WC WS WM WD WO DA DB DC DD
BE1_1 21.4 12 10 5 5 5 5 3 0.2 5 1
BA1 5 7 5 1 1.4 1 5 0.6 0.2 5 1
BB1 5 17 15 1 1.4 1 5 0.6 0.2 5 1
MILC(type-B 550C) BE1_1 W/L= Vd=5V 0.1V
Vg(V)
-10 0 10 20
Id(A)
10-13 10-12 10-11 10-10 10-9 10-8 10-7 10-6 10-5 10-4
SD Reverse SD Forward Vd=5V
Vd=0.1V
Fig. 3.34 Transfer characteristics of the main transistor in a HC device (BE1_1) under forward and reverse modes of measurements.
MILC(type-B 550C) BE1_1
Fig. 3.35 Transfer characteristics of the three monitor transistors in a HC device.
(BE1_1).
Table 3.8 Major electrical parameters extracted from the transfer curves in Fig. 3.34 and Fig. 3.35
Main reverse 33.12 5.63 8.56 112.08 1.67
Main forward 33.12 5.71 14.37 74.45 1.685
Activation energy
Fig. 3.36 Activation energy of leakage current for the three monitor transistors in a HC-TFT device (BE1_1).
Fig. 3.37 Extracted density-of-states for the three monitor transistors in a HC-TFT (BE1_1).
(a)
(b)
(c)
Fig. 3.38 SEM pictures after Secco etching taken in the channel regions of (a)ST, (b)MT and (c)DT in a HC-TFT (BE1_1).
MILC(type-B 550C) BA1
Fig. 3.39 Transfer characteristics of the main transistor in a HC device (BA1) under forward and reverse modes of measurements.
MILC(type-B 550C) BA1
Fig. 3.40 Transfer characteristics of the three monitor transistors in a HC device (BA1).
MILC with α-Si residues Full MILC
Fig. 3.41 An OM picture of the MILC region near a 5umX10um MILC seeding window after annealing at 550℃ for 24Hr.
BA1 Activation energy
Fig. 3.42 Activation energy of leakage current for the three monitor transistors in a HC-TFT device (BA1).
Fig. 3.43 Transfer characteristics of the main transistor in a HC device (BB1) under forward and reverse modes of measurements.
MILC(type-B 550C) BB1
Fig. 3.44 Transfer characteristics of the three monitor transistors in a HC device.
(BB1).
Fig. 3.45 Activation energy of leakage current for the three monitor transistors in a HC-TFT device (BB1).
簡歷
姓名 ：王偉銘 性別 ：男
生日 ：72.02.20 出生地 ：台北市 籍貫 ：台北市
地址 ：台北市寧波西街 181 巷 42 號 3 樓 學歷 ：
台北市立成功高中 1998.09~2001.06 國立交通大學 電信工程學系 2001.09~2005.06 國立交通大學 電子研究所 2005.09~2008.06 論文題目： 以金屬誘發側向結晶之多晶矽薄膜電晶體的製作與分析
Fabrication and Analysis of Poly-Si TFTs by Metal Induced Lateral Crystallization Technology