臺灣博碩士論文加值系統

在真空微電子中，大多數新的技術需要使用圓錐型且尖銳的尖端作為一個電子的發射體。在本論文中，我們將改善發射體的曲率半徑和高度及圓錐角度以有效達到增強場增強因子(field enhancement factor β)。再本實驗中，我們開發一種製造程序是利用一個純的SF6和一個混合的SF6和O2作為等向性乾式蝕刻氣體，然後再經由熱氧化的技術去改善發射體的幾何形狀。我們也成功地製作出曲率半徑為5nm，高度為4.4um，圓錐角度為30°的發射體。而在10uA時，啟動電場為4.8 V/um，而在最大電場時(電壓為1100V)，相對的最大電流密度為60.4 uA/cm2。

A number of new technologies require the use of conical and sharp tips to serve as electron emitters in the vacuum microelectronics. In this paper, we improved radius of curvature, height and cone angle of emitters, in order to reach the enhancement result of field enhancement factor (β). In this experiment, we developed a fabrication process to improve geometry of emitter by employing isotropic dry etching in pure SF6 and a mixture of SF6 and O2 followed by thermal oxidation technique. In the end, we successfully achieved excellent conical emitters with 5-10 nm radius of curvature, 4.4 um height, 60° cone angle. The conical silicon emitters current-voltage characteristics shows that Eto = 4.8 V/um (turn-on electrics field) compare with 10 uA/cm2, maximum current density J = 60.4 uA/cm2 at E = 8.14V/um (Voltage:1100v).

Contents
Abstract (in Chinese)------------------------------------I
Abstract (in English) ----------------------------------II
Acknowledgement-----------------------------------------IV
Contents-------------------------------------------------V
Figure Captions----------------------------------------VII
Table Captions------------------------------------------IX

Chapter 1 Introduction
1-1. History of Vacuum Microelectronics------------------ 1
1-2. The theory of field emission ----------------------- 3
Chapter 2 Experimental System Setup
2-1. Introduction---------------------------------------- 7
2-2. Photo-lithography----------------------------------- 8
2-3. Inductively Coupled Plasma etching and Plasma Enhanced Chemical Vapor Deposition systems
2.3.1 Plasma Enhanced Chemical Vapor Deposition---------- 9
2.3.2 Inductively Coupled Plasma etching systems ---------9
2.3.3 Etch Mechanism------------------------------------ 11
2-4. Thermal Oxidation-----------------------------------11
2-5. Scanning electron microscope----------------------- 12
2-6. Field Emission Measurement------------------------- 14
Chapter 3 Fabrication of Conical Silicon Field Emitters
3-1. Introduction--------------------------------------- 23
3-2. Fabrication Process-------------------------------- 24
3-3. Dry Etching --------------------------------------- 25
3-3.1 Effect of RF-Power ------------------------------- 25
3-3.2 Effect of SF6 Flow Rate--------------------------- 26
3-3.3 Effect of O2 Flow Rate---------------------------- 26
3-4. Forming of Conical Silicon Field Emitters---------- 27
3-5. Characterization of Field Emission----------------- 28
Chapter 4 Conclusion-------------------------------------49
Chapter 5 Future Work----------------------------------- 50
References-----------------------------------------------53

[1] Hyung Soo Uh, Sang Jik Kwon, and Jong Duk Lee, “A
Novel Fabrication Process of a Silicon Field Emitter
Array with Thermal Oxide as a Gate Insulator”, IEEE
Tran. Electron. Dev. Letter. vol. 16, p.488 (1995)
[2] Meng Ding, Han Kim, and Akintunde I. Akinwande,”
Highly Uniform and Low Turn-On Voltage Si Field
Emitter Arrays Fabricated Using Chemical Mechanical
Polishing”, IEEE Tran. Electron. Dev. Letter. vol.
21, p.66 (2000)
[3] D. Temple, “Recent progress in field emitter array
development for high performance applications”,
Mater. Sci. Eng., vol. R24, p. 185–239, 1999.
[4] H. F. Gray, “Field-emitter displays (FEDs) for
cockpit application”, Cockpit Displays, vol. 2219,
p.44–50, 1994.
[5] C. A. Spindt, “Microfabricated field-emission and
field-ionization sources”, Surf. Sci., vol. 266,
p.145–154, 1992.
[6] G. Bennig, H. Rohrer, C. Gerber, and E. Weibel, “7 x
7 reconstruction on Si( 111) resolved in real space”,
Phys. Rev. Lett., vol. 50, p. 120, 1983.
[7] H. H. Busta, J. E. Pogemiller, and B. J. Zimmerman,
“The field emission triode as a displacement/process
sensor”, J. Micromech. Microeng., p. 45, 1993.
[8] R. W. Wood, “A new form of cathode discharge and the
production of X-rays”, Together with some notes of
diffraction, Phys. Rev. 5(1), p.1-10 (1897)
[9] R. H. Fowler and L. W. Nordheim, “Electron emission
in intense electric fields”, Proc. Royal Soc.
(London). A119 (A781), p.173-181 (1928)
[10] E. W. Muller, Z. Techn. Physik 37 (22/23), p.838(1936)
[11] E. W. Muller, Z. Techn. Physik 106 (9/10), p.541(1937)
[12] F. M. Charbonnier, J. B. Barbour, J. L. Brewster, W.
P. Dyke, and F. J Grundhauer, “Intense nanosecond
electron beams”, Trans. IEEE NS-14(3), p.789-793
(1967)
[13] W. P. Dyke, and F. M. Charbonnier, “Advanced
electron tube techniques”, Proceeding of the VI
National Conference (1963)
[14] W. P. Dyke, “Advances in field emission”, Sci.
Amer. 210(1), 108 (1964)
[15] A. V. Crewe, D. N. Eggenbrger, J. Wall, and L. M.
Welter, “Electron gun using a field emission
source”, Rev. Sci. Instrum. 39(4), p.576 (1968)
[16] A. V. Crewe, J. Wall, and L. M. Welter, “High-
resolution scanning transmission electron
microscope”, J. Appl. Phys. 39(13), p.5861 (1968)
[17] B. Reihl and J. K.Gimzewski, “Field-emission
scanning Auger microscope (FESAM)”, Surf. Sci. 189,
36 (1987)
[18] N.Samoto et, “A stable high-brightness electron-gun
with Zr/W-tip for nanometer lithography”, 1.
Emission properties in Schottky-emission and thermal
field-emission regions, Jpn J. Appl. Phys. 24(6),
p.766 (1985)
[19] K.R. Shoulders, “Microelectronics using electron
beam activated machining techniques”, Adv. Computers
2 p.135 (1961)
[20] C. A. Spindt, “A thin film field emission cathode”,
J. Appl. Phys., vol. 39, p. 3504-3505, 1968.
[21] C. A. Spindt, I. Brodie, L. Humpnrey, and E. R.
Westerberg, “Electrical properties of thin-film
field emission cathodes with molybdenum cones”, J.
Appl. Phys., vol. 47, p. 5248, 1976.
[22] R. N. Thomas and H. C. Nathanson,” Photosensitive
field emission from Silicon point arrays”, Appl.
Phys. Lett., vol. 21, p. 384-386, 1972.
[23] G.H. Chen, R.Q. Cai, X.M. Song, and J.X. Deng,”
Preparation and field electron emission of
microcrystalline diamond deposited on a porous
silicon substrate”, Materials Science and
Engineering B107 p. 233–236 (2004)
[24] Chia-Fu Chen and Hui-Chen Hsieh,” Emission current
influence of gated structure and diamond emitter
morphologies in triode-type field emission arrays”,
Diamond and Related Materials 9 p.1257–1262 (2000)
[25] Jong-Lam Lee et.” The effect of Pd coating on
electron emission from silicon field emitter
arrays”, J. Appl. Phys., vol. 87, No. 10, p.15 (2000)
[26] Mohammad R. Rakhshandehroo, and Stella W. Pang,”
High Current Density Si Field Emission Device with
Plasma Passivation and HfC Coating”, IEEE
TRANSACTIONS ON ELECTRON DEVICES, vol. 46, p.792
(1999)
[27] D. W. Branston and D. Stephani,” Field Emission from
Metal-Coated Silicon Tips”, IEEE Tran. Electron.
Dev. vol. 38, p.2329 (1991)
[28] ROBERT B. MARCUS, K. KEN CHIN, YUN YUAN, HONJUN
WANG,AND WILLIAM N. CARR, “Simulation and Design of
Field Emitters”, IEEE Tran. Electron. Dev. vol. 37,
p.1545 (1990)
[29] Takao Utsumi, “Vacuum Keynote Address
Microelectronics: What's New and Exciting”, IEEE
Tran. Electron. Dev. vol. 38, p.2276 (1991)
[30] Meng Ding, Guobin Sha, and Akintunde I. Akinwande,
“Silicon Field Emission Arrays With Atomically Sharp
Tips: Turn-On Voltage and the Effect of Tip Radius
Distribution”, IEEE Tran. Electron. Dev. vol. 49,
p.2333 (2002)
[31] Richard G.Forbes, C.J. Edgcombe, U.Valdre, “Some
comments on models for field enhancement”,
Ultramicroscopy 95 (2003) 57–65.
[32] J.F. Mologni, M.A.R. Alves, E.S. Braga, “Numerical
study on performance of pyramidal and conical
isotropic etched single emitters”, Microelectronics
Journal 37 (2006) p.152–157.
[33] S.M. Sze, Physics of Semiconductor Devices, Wiley,
New York, 1981.
[34] R. E. Burgess, H. Kroemer, and J. M. Honston,
“Corrected value of Fowler-Norheim field emission
function v(y) and s(y)”, Phys. Rev., vol. 1, No. 4,
p. 515, 1953.
[35] M.A.R. Alves, D.F. Takeuti, E.S. Braga. “Fabrication
of sharp silicon tips employing anisotropic wet
etching and reactive ion etching”, Microelectronics
Journal 36 (2005) p.51–54
[36] D.F. Takeuti, M.N. Tirolli, C.L. Danieli, M.A.R.
Alves_, E.S. Braga, P.H.L.de Faria. “Fabrication of
silicon field-emission arrays using masks of
amorphous hydrogenated carbon films”,
Microelectronics Journal 38 (2007) p.31–34
[37] M. R. Rakhshandehroo, J. W. Weigold, W.-C. Tian, and
S. W. Pang. “Dry etching of Si field emitters and
high aspect ratio resonators using an inductively
coupled plasma source”, J. Vac. Sci. Technol. B 16,
p.5, 1998.
[38] D. Resnik, D. Vrtacnik, U. Aljancic, M. Mozek, S.
Amon. “Different aspect ratio pyramidal tips
obtained by wet etching of (100) and (111) silicon",
Microelectronics Journal 34 (2003) p.591–593.
[39] T. S. Ravi, R. B. Marcus, and D. Liu, “Oxidation
sharpening of silicon tips”, J. Vac. Sci. Technol.
B, Microelectron., vol. 9, no. 6, pp.2733–2737, 1991.
[40] S.M. Sze, Semiconductor Devices of Physics and
Technology, Wiley, New York, 2nd Edition 2002.
[41] Hong Xiao, translated by J.J. Lo & D.C. Cheng,
Introduction to Semi-Conductor Process, Eurasia, 2000.
[42] C.A. Spindt, C.E. Holland, A. Rosengreen, I. Brodie,
“Field-Emitter Arrays for Vacuum Microelectronics”,
IEEE Tran. Electron. Dev. vol. 38, p.2355 (1991)
[43] IVOR BRODIE, and PAUL RICHARD SCHWOEBEL, “Vacuum
Microelectronic Devices”, IEEE Proc. vol. 82,
p.1006 (1994).
[44] H. H. Busta, J. E. Pogemiller and B. J. Zimmerman,
“The field emitter triode as a I displacement/pressure
sensor”, J. Micromech Microeng. (3) p.49-56, 1993.
[45] D. Palmer, H. F. Gray, J. Mancusi, D. Temple, and C.
Ball, J. L. Shaw, G. E. McGuire”Silicon field
emitter arrays with low capacitance and improved
transconductance for microwave amplifier
applications”, J. Vac. Sci. Technol. B 13(2), p.576,
1995 .
[46] Yasushi Toma, Seigo Kanemaru, and Junji Itoh,
“Electron-beam characteristics of double-gated Si
field emitter arrays”, J. Vac. Sci. Technol. B 14
(3), p.1902, 1996.
[47] K. L. Jensen, “Field emitter arrays for plasma and
microwave source applications”, Phys. Plasmas, vol.
6, p.2241, 1999.
[48] Takao Utsumi, “Vacuum Keynote Address
Microelectronics: What’s New and Exciting”, IEEE
Tran. Electron. Dev. vol. 38, p.2276 (1991)
[49] J.F. Mologni, M.A.R. Alves, E.S. Braga, “Numerical
study on performance of pyramidal and conical
isotropic etched single emitters”, Microelectronics
Journal 37 (2006) p.152–157.
[50] E. C. Boswell and P. R. Wilshow, “ Emission
characteristics and morphology of wet etched cathodes
in p-type silicon”, J. Vac. Sci. Technol. B 11,
p.412 1993.
[51] Johann W. Bartha, Johann Greschner, M. Puech and P.
Maguin,"Low temperature etching of Si in high density
plasma using SF6/O2”,
Microelectronic Engineering 27 (1995) p.453-456