3.5 The sensitivity of SiGe nanowire after the different of oxygen/nitrogen
3.6.3 The raise of sensitivity after better oxidation time and structure
According to the previous conclusions, we would find some good conditions to compare. We already knew that N2 13% better than other ratio,
so we possibly focused on the condition of N2 13%. From the Fig. 3-52, Fig.
3-53 and Fig. 3-54, we could obviously observe the best sensitivity under oxidation time of five minutes, also could clearly observe the better sensitivity on the condition of 200Å of the oxide layer by deposition. So, we would again focus on the condition of 200Å of the oxide layer by deposition.
The variation of percentage was shown in Fig. 3-55. We already introduced the calculation of percentage in above sections, and then please refer the section of 3.4.3. The sensitivity of 20% concentration of Ge at five minutes oxidation time raised 150%. And as previously described and discussion, the sensitivity of 20% concentration of Ge by 200Å oxide layer had better than others, especially at five minutes.
Chapter 4
Conclusions
We could summarize the following result according to the research from previous experiment:
1. APTMS generated bond with BS3 and had the electrical response.
2. We successfully fabricated the SiGe nanowire by multi-layer structures, which were oxide, SiGe and Si-on-insulator, respectively. Furthermore, we exploited our previous stacked structure, which were 200Å 7%, 200Å 14%, 200Å 20%, 400Å 7% and 400Å 14%, and then combined the top of oxide layer by PECVD. The thickness of oxide layer by deposition was 100Å and 200Å . Above of all, they had the electrical response after APTMS modification.
3. In the case of oxidation time for three minutes, we found the multi-layer structure, which were oxide layer of 200Å , Ge content of 20% and amorphous Si 200Å that had the better sensitivity.
4. In the oxidation process flew in different proportion of nitrogen, which was 0% of nitrogen, 13% of nitrogen and 100% of nitrogen at oxidation time of three minutes, and the fabrication of nanowire was multi-layer structure. The previous study of our group had the same result on different proportion of nitrogen. The 13% of nitrogen had the better
sensitivity in any multi-layer structure.
5. Under different oxidation time, we successfully found the better sensitivity at five minutes. The conclusions of under different oxidation time were not corresponding on our previous experiments. The main reason was that we deposited oxide before oxidation. The oxide layer could reduce oxidation rate to lead more Ge accumulation on surface and suppress Ge diffuse to buried oxide.
6. In all of conditions, the structure of 200Å oxide layer, Ge content of 20%
and amorphous Si 200Å on oxidation of 13% of nitrogen at five minutes had the best sensitivity.
Chapter 5
Future Works
Even though the sensitivity increased in my research, but there should be more methods to enhance the sensitivity. In the future works, we can focus on thicker top of oxide layer by deposition and more Ge content.
Combination of new conditions, it maybe raised the sensitivity. Furthermore, the top of oxide layer was by PECVD and the chamber flew into N2O and SiH4. We have a reasonable doubt that N2 plasma maybe could repair defect.
Perhaps, we could exploit the machine of PECVD to do N2 plasma treatment.
Fig. 1-1 Numerical simulation result of the relationship between the response time (ts) and the detectable concentration (ρ0) of a DNA sensor [2]
Fig. 1-2 Nanowire growth process [5]
Fig. 1-3 The SEM images of SiNWs [6]
Fig. 1-4 (a)Schematic illustration of vapor-liquid-solid nanowire gowth mechanism including three stages. (b) To show the compositional and phase evolution during the nanowire growth process. [7]
.
Fig. 1-5 The process of nanoimprint lithography [10]
Fig. 1-6 Schematic view of the NW transfer steps by trilayer NIL on The imprinted SU8/SiO2 IPMMA structure [11]
Fig. 1-7 (a)–(d) Key fabrication flow, (f) top view of the device structure, and(e) cross-sectional view along the dashed line A to B in (f) [12]
Fig. 1-8 (A) Schematic illusrating the conversion of a NWFET into NW nanosensors for pH sensing. (B) Real-time detection of the conductance for an APTES modified SiNW for pHs from 2 to 9 (C) Plot of the conductance versus pH (D) The conductance of unmodified SiNW (red) versus pH. The dashed green curve is a plot of the surface charge density for silica as a function of pH [14]
Fig. 1-9 Schematic representation of the fabrication process of SiNW arrays with fluidic channels [15]
Fig. 1-10 Schematic representation of the principle of the SiNW array biosensor for DNA [15]
Fig. 1-11 Tilted view image of Pd nanowires on Si substrate [16]
Fig. 1-12 Schematic diagram of Pd nanowire hrdrogen sensor fabricated [16]
Fig. 1-13 Nanowire-based detection of single viruses. (Left) Schematic shows two nanowire devices specific binding of a single virus to the receptors on nanowire 2 produces a conductance change (Right) characteristic of the surface charge of the virus only in nanowire 2 [18]
Fig. 1-14 Selective detection of single viruses. Conductance (Upper) and optical (Lower) data recorded simultaneously vs. time for a single silicon nanowire device after introduction of influenza A solution [18]
Fig. 1-15 (A) I-Vd curves of In2O3 nanowire sensors before and after exposure to 1% NH3.(Inset) Energy band diagrams of heavily doped In2O3 and NH3 molecules. (B) I-Vd curves of In2O3 nanowire sensors before and after exposure to 1% NH3. (Inset) Energy band diagrams of lightly doped In2O3 and NH3
molecules [28]
Fig.1- 16 Electrical responses of an unmodified polymer nanowire (A) to 100 nM biotin-DNA (single stranded) and avidin-embedded polypyrrole (200 nm) nanowires to 1 nM (B) and 100 nM (C) biotin-DNA. The responses were recorded on two separate polypyrrole-avidin nanowires [29]
Fig. 1-17 Two methods for preparing metal nanowires based on electrochemical step-edge decoration. a) Electrodeposition of an electronically conductive metal oxide nanowires followed by reduction in hydrogen. b) Direct electrodeposition of metal nanowires. [34]
Fig. 1-18 Current response of a palladium nanowire-based H2 sensor under exposure to hydrogen/nitrogen mixtures [35]
Fig. 1-19 Simulated conductance values as a function of the surface potential for the 200-nm-wide and 50-nm-wide wires [36]
Fig. 1-20 Ternary phase diagram for the Si-Ge-O system at 1000 K and1 bar, calculated based on the thermochemical data [39, 40]
Fig. 2-1 SiO2 grew 5000Å on Si substrate
Fig. 2-2 Mask#1: Etch SiO2 3000Å
Fig. 2-3 Deposit amorphous Si on SiO2
Fig. 2-4 Deposit amorphous SiGe on amorphous Si
Fig. 2-5 Mask#2: Define nanowire on the sidewall
Fig. 2-6 Mask#3: Etch unwanted sidewall nanowire
Fig. 2-7 Deposit SiO2 by PECVD
Fig. 2-8 Implant Boron-fluoride (BF2
49+) into SiGe nanowires after oxidation and DHF treatment
Fig. 2-9 Deposit Al 5000Å on the devices
Fig. 2-10 Mask#4: Define the Al contact position
Fig. 2-11 The device view from top position
Fig. 2-12 The modification of surface by APTMS and linked by BS3
Fig. 3-1 The oxidation of stacked structures under different combination of nitrogen and oxygen for three, five, seven, and ten minutes
Fig. 3-2 SEM images of amorphous Si 200Å and 7% of Ge concentration
Fig. 3-3 SEM images of amorphous Si 200Å and 14% of Ge concentration
Fig. 3-4 SEM images of amorphous Si 200Å and 20% of Ge concentration
Fig. 3-5 SEM images of amorphous Si 400Å and 7% of Ge concentration
Fig. 3-6 SEM images of amorphous Si 400Å and 14% of Ge concentration
Fig. 3-7 TEM images of amorphous Si 200Å and 7% of Ge concentration
Fig. 3-8 TEM images of amorphous Si 200Å and 14% of Ge concentration
Fig. 3-9 TEM images of amorphous Si 200Å and 20% of Ge concentration
Fig. 3-10 TEM images of amorphous Si 400Å and 7% of Ge concentration
Fig. 3-11 TEM images of amorphous Si 400Å and 14% of Ge concentration
1.34x10-5 1.35x10-5 1.36x10-5 1.37x10-5 1.38x10-5 1.39x10-5 1.40x10-5 1.41x10-5 1.42x10-5 1.43x10-5 1.44x10-5 1.45x10-5
G (S)
Si0.86Ge0.14 N2 0%
Amorphous 200Å PE oxide 100Å L=11um
Normal Water Water+ Water+
APTMS APTMS+
BS3
Fig. 3-12 The conductance of the PE oxide 100Å on 200Å 14%
-6
-10 -5 0 5 10
0.0
0.0
Fig. 3-19 The comparison sensitivity between PE oxide 100Å , 200Å and without PE oxide on 200Å 14% N20%
-10 -5 0 5 10
-10 -5 0 5 10
7% 14% 20%
Fig. 3-26 The sensitivity with different concentration of Ge and different structures
0
0
0.0
0
Fig. 3-34 The sensitivity of different ratio of nitrogen at 3 min
0
Fig. 3-35 The sensitivity of different ratio of nitrogen at 5 min
0.0
Fig. 3-36 The sensitivity of different ratio of nitrogen at 7 min
0.0
Fig. 3-37 The sensitivity of different ratio of nitrogen at 10 min
0
-5
0.0
no treament 3min 5min 7min 10min
Fig. 3-41 The sensitivity on N2 13% and 200Å 7% under different
no treatment 3min 5min 7min 10min
Fig. 3-42 The sensitivity on N2 13% and 200Å 14% under different minutes
0.0 0.5 1.0 1.5 2.0 2.5 3.0
3.5 N2 13% 200Å 20%
S (%)
no treatment 3min 5min 7min 10min
Fig. 3-43 The sensitivity on N2 13% and 200Å 20% under different minutes
0.0 0.5 1.0 1.5 2.0 2.5 3.0
3.5 N2 13% 400Å 7%
S (%)
no treatment 3min 5min 7min 10min
Fig. 3-44 The sensitivity on N2 13% and 400Å 7% under different minutes
0.0
no treatment 3min 5min 7min 10min
Fig. 3-45 The sensitivity on N2 13% and 400Å 14% under different
Fig. 3-46 The sensitivity with different thickness of oxide on N2 13% and 200Å 7% under different minutes
0
Fig. 3-47 The sensitivity with different thickness of oxide on N2 13% and 200Å 14% under different minutes
0
Fig. 3-48 The sensitivity with different thickness of oxide on N2 13% and 200Å 20% under different minutes
0.6
Fig. 3-49 The sensitivity with different thickness of oxide on N2 13% and poly silicon under different minutes
0.0
Fig. 3-50 The sensitivity with different thickness of oxide on N2 13% and 400Å 7% under different minutes
0
Fig. 3-51 The sensitivity with different thickness of oxide on N2 13% and 400Å 7% under different minutes
2.0 7% under different oxidation time
3.2 14% under different oxidation time
1 20% under different oxidation time
20 40 60 80 100 120 140 160
3min 5min 7min 10min N2 13%
PE oxide 200Å
Amorphous 200Å Si
0.93Ge0.07 Si0.86Ge0.14 Si0.80Ge0.20
Percentage (%)
Fig. 3-55 The variation of percentage on different Ge concentration under different oxidation time
Reference
[1] Z. Gao, A. Agarwal, A. D. Trigg, N. Singh, C. Fang, C.H. Tung and K.D. Buddharaju, “SILICON NANOWIRE ARRAYS FOR ULTRASENSITIVE LABEL-FREE DETECTION OF DNA” Anal.
Chem., 79 (9), pp. 3291–3297, 2007..
[2] P. R. Nair, and M. A. Alam, “Performance limit of nanobiosensors,”
Applied Physics Letters, vol. 88, no. 23, 2006.
[3] Fernando Patolsky, Gengfeng Zheng, Charles M.
Lieber,“NANOWIRE-BASED BIOSENSORS,” Analytical Chemistry, pp. 4260-4269, July 1, 2006
[4]
V.J. Gadgil, H.D. Tong, Y. Cesa, M.L. Bennink,
“Fabrication of nanostructures in thin membranes with focused ion beam technology,”
Surface & Coatings Technology 203 pp. 2436–2441, 2009.
[5] Alfredo M. Morales, Charles M. Lieber, “A Laser Ablation Method for the Synthesis of Crystalline Semiconductor Nanowires,” Science Vol.
279. no. 5348, pp. 208-211, 1998.
[6] H Pan, S Lim, C Poh, H Sun, XWu, Y Feng, J Lin, “Growth of Si sequence-specific DNA sensing: device fabrication and simulation,”
Applied Physics a-Materials Science & Processing, vol. 80, no. 6, pp.
1257-1263, Mar, 2005.
[9] W.Xihua, C.Yu, and A. G. Katherine, “Silicon based nanochannel glucose sensor,” Applied Physics Letters, vol. 92, no. 1, pp. 013903, 2008.
[10] Stephen Y. Chou,a) Peter R. Krauss, and Preston J. Renstrom,
“Nanoimprint lithography,” IEEE, vol. 14, pp. 4129-4133, 1996.
[11] Jing Wan, Shao-Ren Deng, Yifang Chen, Ejaz Huq, Ran Liu, Xin-Ping Qu, “Trilayer nanoimprint fabrication and simulation of the silicon nanowire sensor for gas detection, ” 2009 4th IEEE 77 International Conference on Nano/Micro Engineered and Molecular Systems, pp.
1013-1016, 2009.
[12] H. C. Lin, M. H. Lee, C. J. Su, “A Simple and Low-Cost Method to Fabricate TFTs With Poly-Si Nanowire Channel,” Electron Device Letters, IEEE, vol. 26, no. 9, pp. 643-645, 2005.
[13] K. Dae-Hwan, S. Suk-Kang, K. Kyung-Rok, “Silicon single-electron transistors with sidewall depletion gates and their application to dynamic single-electron transistor logic,” Electron Devices, IEEE Transistors, vol. 49, no. 4, pp. 627-635, 2002.
[14] Y. Cui, Q. Wei, H. Park and Charles M. Lieber , “Nanowire Nanosensors for Highly Sensitive and Selective Detection of Biological and Chemical Species,” Science, vol. 293, no. 5533, pp. 1289-1292, August 17, 2001.
[15] Zhiqiang Gao,* Ajay Agarwal, Alastair D. Trigg, Navab Singh, Cheng Fang, Chih-Hang Tung, Yi Fan, Kavitha D. Buddharaju, and Jinming Kong, “Silicon Nanowire Arrays for Label-Free Detection of DNA,”
Analytical. Chemistry, vol. 79, no. 9, pp. 3291-3297, 2007.
[16] Kyun Tae Kim, Sang Jun Sim, and Sung Min Cho, “Hydrogen Gas Sensor Using Pd Nanowires Electro-Deposited Into Anodized Alumina
Template,” IEEE, vol. 6, no. 3, pp. 509-513, 2006.
[17] Wayne U. Wang, Chuo Chen, Keng-hui Lin, Ying Fang, and Charles M.
Lieber, “Label-free detection of small-molecule–protein interactions by using nanowire nanosensors,” PNAS, vol. 102, no. 9, pp. 3208-3212, 2005.
[18] Fernando Patolsky, Gengfeng Zheng, Oliver Hayden, Melike Lakadamyali, Xiaowei Zhuang, and Charles M. Lieber, “Electrical detection of single viruses,” PNAS, vol. 101, no. 39, pp. 14017-14022, 2004.
[19] M. A.-H. Safaa, R. T. Al-Mofarji, and P. Klason, “Zinc oxide nanorods grown on two-dimensional macroporous periodic structures and plane Si as a pH sensor,” Journal of Applied Physics, vol. 103, no. 1, 2008.
[20] M. L. Y. Liu, “Growth of Aligned Square-Shaped SnO2 Tube Arrays,”
Advanced Functional Materials, vol. 15, no. 1, pp. 57-62, 2005.
[21] F. Patolsky, G. Zheng, O. Hayden, “Electrical detection of single viruses,”Proceedings of the National Academy of Sciences, vol. 101, no.
39, pp. 14017-14022, 2004.
[22] Z. Gao, A. Agarwal, A. D. Trigg, “Silicon Nanowire Arrays for Label-Free Detection of DNA,” Analytical Chemistry, vol. 79, no. 9, pp.
3291-3297, 2007.
[23] G. Zheng, F. Patolsky, Y. Cui, “Multiplexed electrical detection of cancer markers with nanowire sensor arrays,” Nat Biotech, vol. 23, no. 10, pp.
1294-1301, 2005.
[24] Peter K. Stoimenov, Rosalyn L. Klinger, George L. Marchin, and Kenneth J. Klabunde, “Metal Oxide Nanoparticles as Bactericidal Agents,” American Chemical Society, vol. 18, no. 17, pp. 6679-6686, 2002.
[25] J. Liu, X. Wang, Q. Peng, “Vanadium Pentoxide Nanobelts: Highly
Selective and Stable Ethanol Sensor Materials,” Advanced Materials, vol. 17, no. 6, pp. 764-767, 2005.
[26] Pho Nguyen,† Hou T. Ng, Toshishige Yamada, Michael K. Smith, Jun Li, Jie Han, and M. Meyyappan, “Direct Integration of Metal Oxide Nanowire in Vertical Field-Effect Transistor,” Nano Letters, vol. 4, no. 4, pp. 651-657, 2004.
[27] Y. Zhang, A. Kolmakov, Y. Lilach, “Electronic Control of Chemistry and Catalysis at the Surface of an Individual Tin Oxide Nanowire,” J. Phys.
Chem. B, vol.109, no. 5, pp. 1923-1929, 2005.
[28] Chao Li, Daihua Zhang, Xiaolei Liu, Song Han, Tao Tang, Jie Han, and Chongwu Zhou, “In2O3 nanowires as chemical sensors,” Applied Physics Letters, vol. 82, no. 10, pp. 1613-1615, 2003.
[29]Kumaran Ramanathan, Mangesh A. Bangar, Minhee Yun, Wilfred Chen, Nosang V. Myung, and Ashok Mulchandani, “Bioaffinity Sensing Using Biologically Functionalized Conducting-Polymer Nanowire,” J. AM.
CHEM. SOC, vol.127, no. 2, pp. 496-497, 2005.
[30] B. J. Murray, E. C. Walter, and R. M. Penner, “Amine Vapor Sensing with Silver Mesowires,” Nano Letters, vol. 4, no. 4, pp. 665-670, 2004.
[31] C. Z. Li, H. X. He, and A. Bogozi, “Molecular detection based on conductance quantization of nanowires,” Applied Physics Letters, vol.
76, no. 10, pp. 1333-1335, 2000.
[32] X. Wang, and C. S. Ozkan, “Multisegment nanowire sensors for the detection of DNA 77 molecules,” Nano Letters, vol. 8, no. 2, pp.
398-404, 2008.
[33] B. W. Maynor, S. F. Filocamo, and M. W. Grinstaff, “Direct-Writing of Polymer Nanostructures: Poly(thiophene) Nanowires on Semiconducting and Insulating Surfaces,” J. Am. Chem. Soc., vol.
124,no. 4, pp. 522-523, 2002.
[34] Erich C. Walter, Michael P. Zach, Benjamin J. Murray, Koji Inazu, John C. Hemminger, and Reginald M. Penner, “Metal Nanowire Arrays by Electrodeposition,” ChemPhysChem, vol. 4, no. 2, pp. 131-138, 2003.
[35] E. C. Walter,1 R. M. Penner,1 H. Liu,1 K. H. Ng,1 M. P. Zach1 and F.
Favier, “Sensors from electrodeposited metal nanowires,” Surf. Interface Anal, vol. 34, pp. 409-412, 2002.
[36] Z. Li, B. Rajendran, T. I. Kamins, “Silicon nanowires for sequence-specific DNA sensing: device fabrication and simulation,”
Applied Physics a-Materials Science & Processing, vol. 80, no. 6, pp.
1257-1263, 2005.
[37] I. Heller, A. M. Janssens, J. Mannik, “Identifying the Mechanism of Biosensing with Carbon Nanotube Transistors,” Nano Letters, vol. 8, no.
2, pp. 591-595, 2008.
[38] Y. Kun, W. Hui, Z. Kai, “Gold nanoparticle modified silicon nanowires as biosensors,” Nanotechnology, no. 11, pp. S76, 2006.
[39] A. Tae-Hang, Y. In-Seok, and K. Tae-Kyun, “Effects of Ge Content on the Oxidation Behavior of Poly-SiGe Layers for Gate Electrode
[41] P. R. Nair, and M. A. Alam, “Design considerations of silicon nanowire biosensors,”IEEE Transactions Electron Devices, vol. 54, no. 12, pp.
3400-3408, 2007.
[42] F. K. LeGoues, R. Rosenberg, and T. Nguyen, “Oxidation studies of
SiGe,” Journal of Applied Physics, vol. 65, no. 4, pp. 1724-1728, 1989.
簡 歷
姓 名: 謝 政 廷 性 別: 男
出生年月日: 75 年 12 月 31 日 出 生 地: 新 北 市
住 址: 新北市三峽區大仁路66巷18號2樓 學 歷:
台北市立松山高級中學 (民國91年 9月~民國94年6月) 國立東華大學物理學系 (民國94年 9月~民國98年6月) 國立交通大學電子研究所 (民國98年 9月~民國100年9月) 碩士論文:
應用多層次結構製作之矽鍺奈米線於生物感測元件上之靈敏度研究 The study of the sensitivity of SiGe nanowire bio-sensor device fabricated with multi-layer (oxide/SiGe/Si-on-insulator) structure