Semiconductor device manufacturing: process – Making field effect device having pair of active regions...
Reexamination Certificate
1998-10-27
2001-04-24
Monin, Jr., Donald L. (Department: 2814)
Semiconductor device manufacturing: process
Making field effect device having pair of active regions...
C438S003000, C438S167000, C257S295000, C257S314000
Reexamination Certificate
active
06221699
ABSTRACT:
FIELD OF INDUSTRIAL APPLICATIONS
This “high speed infrared optical field effect transistor (FET)” uses titanic acid lead to form the ferroelectric thin film. Its design incorporates the high mobility of high speed bulk channel field effect transistors for greater effectiveness. The sensor has a wide range of applications including scientific, commercial and military applications, including laser detection, missile guidance, spectrum analysis, remote control, burglar alarm and thermoimage detection.
TECHNICAL BACKGROUND OF THE INVENTION
There are two main types of infrared sensor. 1) Thermoelectric sensors, and 2) quantum sensors. Thermoelectric sensors are superior to quantum sensors because:
1. They are able to operate at room temperature; Quantum sensors require a low temperature environment between −100° C.~−200° C. to operate.
2. Rapid response; Response time for thermoelectric sensors is faster than that for Golay cells (see Computers & Telecommunications, Volume 21, p.265, M. Okuyama, 1985).
Referring to Addison Wesely (John P. Uyemura, p.21 Chapter 1) reveals that traditional thermoelectric FETs which use surface channel designs suffer from scattering on the transistor surface and traps created during fabrication which reduce mobility.
According to M. Okuyama(Computers & Telecommunications and Ferroelectrics volume 63, p.243, 1985), the rise time of traditional thermoelectric FETs is 3.5 &mgr;S and electrical current is less than 1 &mgr;A. As direct switching is not possible, an amplifier is required, which delays switching time.
SUMMARY OF THE INVENTION
The main purpose of this invention is to provide a high speed and sensitive infrared optical FET that operates at room temperature, in this case by using rapid bulk channel structure of metal/ferroelectric thin film/semiconductor. The second purpose is to accommodate fabrication of VLSI for infrared optical FET which can also be developed as integrated IR OEIC.
The use of surface channels in conventional thermoelectric FETs is the reason behind their lower mobility and slower switching time. The inventor discovered that bulk channels can reduce equivalent resistance; furthermore, infrared rays cause compensatory charge variation in the depletion layer of components; this compensatory change is equivalent of its ferroelectric capacitance series with depletion capacitance. The compensatory charge variation of traditional surface channel FET is located at the inversion layer, and equivalent capacitance is only ferroelectric capacitance. According to the comparative method found in Physics of Semiconductor Devices(S.M.Sze, 1981),the developed infrared sensors using ferroelectric thin film will have lower equivalent capacitance.
Because the developed infrared optical FETs using ferroelectric thin film have lower resistance and capacitance, response speed is faster than that of conventional FETs. Additionally, its electrical current is significantly increased to reach above 100 &mgr;A, making it more sensitive.
REFERENCES:
patent: 4074302 (1978-02-01), Brewer
patent: 4245230 (1981-01-01), Kwok et al.
patent: 4598305 (1986-07-01), Chiang et al.
patent: 4814844 (1989-03-01), Bluzer
patent: 4865427 (1989-09-01), Kingston et al.
patent: 5189593 (1993-02-01), Ooi
patent: 5248564 (1993-09-01), Ramesh
patent: 5331187 (1994-07-01), Ogawa
patent: 5418389 (1995-05-01), Watanabe
patent: 5449935 (1995-09-01), Nakamura
patent: 5502488 (1996-03-01), Nagasaki et al.
patent: 5515311 (1996-05-01), Mihara
patent: 5548475 (1996-08-01), Ushikubo et al.
patent: 5567979 (1996-10-01), Nashimoto et al.
patent: 5572052 (1996-11-01), Kashihara et al.
patent: 5623439 (1997-04-01), Gotoh et al.
patent: 5686745 (1997-11-01), Lin et al.
patent: 5874755 (1999-02-01), Ooms et al.
patent: 61-97871 (1986-05-01), None
patent: 62-4370 (1987-01-01), None
patent: 5-235268 (1993-09-01), None
patent: 6-21477 (1994-01-01), None
Chen et al., “An Infrared Optical Field Effect Transistor with High Speed Response”, Appl. Phys. Lett. 68(3), pp. 1-2, Jan. 15, 1996.
“Matsushita Uses PbTiO3Thin Film for High Response Speed Pyroelectric IR Imager”, Nikkei Electronics Asia, pp. 36-37, Jan. 1993.
Chen Fu-Yuan
Chen Jiann-Ruey
Fang Yean-Kuen
Brown Pinnisi & Michaels PC
Monin, Jr. Donald L.
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