Active solid-state devices (e.g. – transistors – solid-state diode – Heterojunction device – Between different group iv-vi or ii-vi or iii-v compounds...
Reexamination Certificate
2003-04-23
2004-04-20
Elms, Richard (Department: 2824)
Active solid-state devices (e.g., transistors, solid-state diode
Heterojunction device
Between different group iv-vi or ii-vi or iii-v compounds...
C257S115000, C257S198000, C257S523000, C257S616000, C257S347000, C257S197000
Reexamination Certificate
active
06724020
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device and a power amplifier using the same.
In recent years, with the rapid growth in demand for mobile communication equipment, research and development of compound semiconductor devices for power amplifiers used in mobile communication equipment has been actively conducted. As one of such compound semiconductor devices, a hetero junction bipolar transistor (hereinafter called “HBT”) which has a high current drivability has been used.
AlGaAs has been widely used as a material for HBT emitter layers. However, there is an increasing trend to develop HBTs which use InGaP instead of AlGaAs because the former is more reliable in use over a long period that the latter. An example of an HBT which uses an InGaP emitter layer has been disclosed, for example, in Japanese Patent Laid-Open Publication No. 07-106343.
This prior art is illustrated in FIG.
15
. An n-type GaAs emitter protective layer
306
is formed on an n-type InGaP emitter layer
305
; an SiO
2
side wall
313
is formed on the area of the n-type GaAs emitter protective layer
306
which corresponds to the guard ring
312
of the n-type InGaP emitter layer
305
. The n-type GaAs emitter protective layer
306
prevents direct contact between the n-type InGaP emitter layer
305
and the SiO
2
side wall
313
, thereby avoiding an increase in a leakage current.
SUMMARY OF THE INVENTION
The present invention has an object to provide a semiconductor device in which, in a bipolar transistor having an emitter layer consisting of a semiconductor containing indium, a GaAs emitter protective layer is not used as a protective layer for preventing an increase in a leakage current between the emitter and base, and also provide a power amplifier using the same.
The above-said object can be achieved by covering the emitter layer guard ring surface of the bipolar transistor having an emitter layer consisting of a semiconductor containing indium, with a protective insulating film which contains silicon (Si) and oxygen (O) and has a density of oxygen of less than 7×10
22
cm
−3
.
It is also acceptable that the density of oxygen of the protective insulating film is 3×10
22
cm
−3
is or less, or 8×10
21
cm
−3
or less.
Also, the protective insulating film may further contain nitrogen (N) or hydrogen (H) as well.
REFERENCES:
patent: 4731340 (1988-03-01), Chang et al.
patent: 4800415 (1989-01-01), Simmons et al.
patent: 4996165 (1991-02-01), Chang et al.
patent: 5185274 (1993-02-01), Chang et al.
patent: 5682046 (1997-10-01), Takahashi et al.
patent: 5780922 (1998-07-01), Mishra et al.
patent: 5837589 (1998-11-01), McNamara et al.
patent: 5907165 (1999-05-01), Hamm et al.
patent: 6043520 (2000-03-01), Yamamoto et al.
patent: 6392258 (2002-05-01), Hirata et al.
patent: 07-106343 (1994-07-01), None
Yutaka Kamei, Makoto Baba and Shigetaka Fujita, “space Charge in Polyimide Film after Water Absorption”, Proceedings of the 6thInternational Conference on Properties and Applications of Dielectric Materials (Jun. 21-26, 2000).
Imamura Yoshinori
Ohbu Isao
Oka Tohru
Takazawa Hiroyuki
A. Marquez, Esq. Juan Carlos
Elms Richard
Fisher Esq. Stanley P.
Menz Doug
Reed Smith LLP
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