Browsing by Author "HSU, WC"

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2-DIMENSIONAL ELECTRON GASES IN DELTA-DOPED GAAS/IN0.25GA0.75AS/GAAS HETEROSTRUCTURES
(1991-06-10)
LIN, W
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HSU, WC
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WU, TS
;
CHANG, SZ
;
WANG, C
Delta-doped (delta-doped) GaAs/In0.25Ga0.75As/GaAs strained-layer modulation-doped field-effect transistor (delta-SMODFET) structures grown by the low-pressure metalorganic chemical vapor deposition (LP-MOCVD) technique have been studied for the first time. The delta-doped GaAs, adopted as the electron supplier, was obtained by a stop-growth process so that a very thin and heavily doped layer (1.9 X 10(13) cm-2) can be realized. Experimental results show that a structure with an 80 angstrom In0.25Ga0.75As layer as the active channel and an 80 angstrom spacer layer demonstrated the highest two-dimensional electron gases mobility of 26 800 cm2/V s. This structure is easy to achieve by the LP-MOCVD method because the growth of AlGaAs is avoided and is promising for high performance FETs.
CHARACTERISTICS OF GRADED-LIKE MULTIPLE-DELTA-DOPED GAAS FIELD-EFFECT TRANSISTORS
(1995-05-08)
KAO, MJ
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HSU, WC
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HSU, RT
;
WU, YH
;
LIN, TY
HIGH CARRIER DENSITY AND MOBILITY IN GAAS/INGAAS/GAAS DOUBLE DELTA-DOPED CHANNELS HETEROSTRUCTURES
(1995-01-01)
KAO, MJ
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HSU, WC
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SHIEH, HM
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LIU, WC
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CHANG, CY
Double-quantum-well GaAs/InGaAs/GaAs pseudomorphic heterostructures by delta-doping the InGaAs channels are demonstrated for the first time. A very high carrier density of more than 1 x 10(13) cm-2 along with an enhanced mobility of 2100 cm2/V.s at 300 K are achieved. Influences of barrier thickness on the carrier densities and mobilities are also investigated.
MBE GROWN UNDOPED SUPERLATTICE GATE AND MODULATION-DOPED BUFFER STRUCTURE FOR POWER FET APPLICATIONS
(1989-06-01)
LIU, WC
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HSU, WC
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LOUR, WS
;
WANG, RL
;
CHANG, CY
THE DELTA-DOPED IN0.25GA0.75AS/GAAS PSEUDOMORPHIC HIGH ELECTRON-MOBILITY TRANSISTOR STRUCTURES PREPARED BY LOW-PRESSURE METAL ORGANIC-CHEMICAL VAPOR-DEPOSITION
(1991-06-01)
CHANG, CY
;
LIN, W
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HSU, WC
;
WU, TS
;
CHANG, SZ
The (800 angstrom)GaAs/In0.25Ga0.75As/(0.5-mu-m) GaAs strain layers with delta-doping in the GaAs cap layer were fabricated without using AlGaAs layers. Triethylgallium (TEG), trimethylindium (TMI), arsine (AsH3) and silane (SiH4) were used as the sources and dopants in these structures grown by the low-pressure metalorganic chemical vapor deposition (LP-MOCVD) technique for the first time to study these structures. The delta-doping was obtained by a stop-growth process by which a very thin and heavily doped layer (1.86 x 10(13) cm-2) can be realized. For the (delta-doped) GaAs/In0.25Ga0.75As/GaAs high electron mobility transistor (HEMT) structures, the concentration of two-dimensional electron gas (2-DEG) and the Hall mobilities were investigated. Experimental results show that a structure with (80 angstrom) In0.25Ga0.75As as the active channel and with a 70 angstroms spacer layer revealed the highest 2-DEG concentration and mobility product of 5.5 x 10(16) V-1.s-1 at a temperature of 77 K. These structures are easy to achieve by the LP-MOCVD mechod and are promising for high-performance field effect transistors (FETs).
THE DOPED QUANTUM WELL GATE FET FABRICATED BY LOW-PRESSURE MOCVD
(1988-12-01)
LIN, W
;
LEI, MD
;
CHANG, CY
;
HSU, WC
;
DI, LB