本論文的研究主要是用脈衝式電漿製作非晶矽光檢測器。 論文分為兩主要部份：(1) 非晶矽薄膜的製作，(2)蕭特基型光檢測器的製作。
非晶矽薄膜的製程採用氫氣稀釋及脈衝式電漿方法製作，採用脈衝式電漿沉積薄膜其腔體粉塵量減少了許多。經由光學能隙以及光傳導率分析，非晶矽薄膜的沉積條件與特性如下：
A. 壓力：0.75torr.
B. 溫度：275℃
C. RF 功率：20w
D. 脈衝頻率：16.6667Hz.
E. SiH4：36sccm，H2：144 sccm
F. 光學能隙值約在 1.7~1.8 eV
G. 光傳導率值為 5×104
H. 為結構變數 R：0.05
由此沉積條件所製作出的a-Si:H 薄膜，具有高光傳導係數以及低缺陷密度。
非晶矽光檢測器的結構採用蕭特基結構以及MIS (Metal-Insulator-Semiconductor) 結構。其結構分別為：蕭特基二極體，玻璃/To/ a-Si:H(n-i)/金屬。金屬-絕緣層-半導體二極體，玻璃/To/ a-Si:H(n-i)/絕緣層/金屬。在論文中分別對二種結構製作出不同未摻雜層厚度及不同絕緣層厚度的光二極體。
在外加負5負電壓情形下，所有蕭特基二極體的光暗電導比約為10E4，而且光電流值均大於1uA。其光譜響應在可見光範圍具有良好性能，故元件可用來製作光偵測器。

The study of this thesis is to fabricate a-Si:H photo detector. Two main efforts of this thesis are (1) fabrication of a-Si:H films，(2) Schottky and M-I-S photo detector devices fabrication.
In order to reduce the influence of the particulate formation in the preparation of a-Si:H films，high hydrogen dilution ration and pulse RF power were used for a-Si:H films fabrication. The particulate formations were decreased by using the pulse RF power.
From analysis of the optical band gap and the photo to dark current ratio of a-Si:H film，the deposition conditions and the characteristics of a-Si:H films are as follows：

A. Pressure：0.75torr.
B. Temperature：275℃
C. RF power：20w
D. Pulse frequency：16.6667Hz.
E. SiH4：36sccm，H2：144sccm
F. The optical band gap was around 1.7-1.8eV
G. The photo to dark ratio was 5×105
H. The microstucture factor R：0.05

The configuration allows the deposition of high quality a-Si:H with a photosensitivity of 5×105，indicating the presence of low density of defects.
The device structures of a-Si:H photo detector are Schottky and MIS diodes. The structure of Schottky diode is glass/To/ metal. The structure of MIS diode is glass/To/a-Si:H(n-i)/insulator/metal. In this thesis，we prepared photodiode of different structures， different intrinsic layer thickness，and different insulator layer thickness. The photo to dark current ratio at -5v were about 10E3 and the thickness of I layer is 2500Ǻ.The photo to dark current ratio at -5v were about 7×10E3 and the thickness of I layer is 3000Ǻ.The photo to dark current ratio at -5v were about 10E4 and the thickness of I layer is 4000Ǻ.The photo to dark current ratio at -5v were about 8×10E3 and the thickness of I layer is 5000Ǻ.
The photo current of all the structures under the reverse bias larger than 1 V was over 1u A ，which could satisfy the requirement for the circuit design. The peaks of photo spectral response of the devices with I layer thickness of 2500Ǻ、3000 Ǻ、4000 Ǻ，and 5000 Ǻ were around 450nm，460nm，560nm，580nm.The photo spectral response of the devices was shown to be suitable for visible light detection.

[1] A.A.Howling, L. Sansonnens, J. L. Dorier, and Ch. Hollenstein. “Time resolved measurements of highly polymerized negative ions in radio frequency plasma deposition experiments”J. Appl. Phy. Vol.75(3).pp.1340-1353,1994
[2] T. Yoshida, H. Fujisawa, T. Hokaya and H. Sakai.“Film deposition process in pulse discharge CVD.”M.R.S Vol.219,pp.655-665
[3] E.Fortunato, R.Martins, Solid State Phenom. 44-46,1995
[4] Jyh-Wong Hong, Yu-Wen Chen, Wuu-Larng Laih, Y.K. Fang, C.Y.Chang, C.Gong,“The hydrogenated Amorphous Silicon Reach Though Avalanche Photodiodes.”IEEE Quantum Electronics. Vol.26,No.2,pp.208-284
[5] C.Y.Chen, A.Y.Cho, P.A. Garbinski, C.G.Bathea, and B.F.Levine.“Modulated barrier photodiode：A new majority-carrier photodetector.”Appl.Phys.Lett.Vol.39(4).pp.340-342,1981
[6] 陳治明，非晶半導體材料與器件，科學出版社，p.123~130
[7] K.D.Mackenzine, J.H.Burnett, J.R.Eggert, Y.M.Li, Z.LSun and W.Paul. “Comparison of the structural, electrical,and optical properties of amorphous silicon-germanium alloys produced form hydrides and fluorides. ”Phys.Rev B. Vol.38. pp.6120-6735,1988
[8] S.M.Sze, “Physics of Semiconductor Devices”,2nd Edition,
[9] A.A.Howling, Ch.Hollenstein, and P.J.Paris.“Direct visual observation of powder dynamics in RF plasma assisted deposition”Appl.Phys.Lett.Vol.59(12), 16 1991, pp.1409-1411,1991
[10] J.Robertson, J. Appl .phys .87,2608(2000)
[11] W. Beyer, H. Wagner, and H. Mell, MRS Symp. Proc. 49, 189 (1985)
[12] H. Fritzsche, M. Tanielian, C. C. Tsai, and P. J. Gaczi, J. Appl. Phys. 50, 3366(1979)
[13] Maurice H. Francombc “Thin Films and Nanostructures”vol.30 Academic press
[14] E. Fortunato, A. Malik, R. Martins, Sens. Actuators 46 (1998).
[15] V. Chu, Schottky Barriers on Amorphous Silicon and Amorphous Silicon-Germanium Alloys, UMI publisher, Princeton University 1990
[16] S. O. Kasap “Optoelectronics and Photonics Principles and Practices ” Prentice Hall (2001).