Browsing by Author "WU, JW"

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ANOMALOUS MOBILITY ENHANCEMENT IN HEAVILY CARBON-DOPED GAAS
(1994-05-15)
CHEN, HD
;
FENG, MS
;
LIN, KC
;
CHEN, PA
;
WU, CC
An anomalous mobility enhancement and metallic-type conductivity were observed in heavily carbon-doped GaAs grown by low-pressure metalorganic chemical vapor deposition. The 77 K mobility was slightly lower than that of 300 K for hole concentration between 1 x 10(18) and 4 x 10(18) cm-3. However, the 77 K mobility was enhanced from p > 4 X 10(18) cm-3, and the 300 K mobility slowly decreased with increasing hole concentration that ranged from 7 X 10(18) to 3 X 10(19) cm -3. As a result, the 77 K mobility was around 50%-60% greater than the 300 K mobility due to the metallic-type conductivity.
BACK-GATING EFFECTS ON THE GA0.1IN0.8P/INP/INGAAS HIGH-ELECTRON-MOBILITY TRANSISTOR
(1995-07-01)
LIN, KC
;
CHANG, CY
;
WU, CC
;
CHEN, HD
;
CHEN, PA
Pseudomorphic GaInP/InP/InGaAs high electron mobility transistors (HEMT) with improved Schottky contacts and excellent electrical characteristics are grown by low-pressure metal-organic chemical vapor deposition (LP-MOCVD) on the InP substrate. These HEMTs with 1.71 mu m gate length have an average extrinsic transconductance of 225 mS/mm. The back-gating effects of this device structure are investigated for the first time in this structure. Both positive and negative bias are applied to the ohmic and Schottky back-gate contacts of these devices. The positive back-gate bias has no effect on the drain current or the output transconductances of these devices. The effect of the negative back-gate bias is very similar to that when negative bias is applied on the gate of these HEMTs.
CATION SOURCE DEPENDENCE OF GA0.5IN0.5P GROWTH-RATE BY LOW-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION
(1994-06-15)
WU, JW
;
CHANG, CY
;
LIN, KC
;
CHAN, SH
;
CHEN, HD
The Ga0.5In0.5P epilayer was grown by low-pressure metalorganic chemical vapor deposition. Trimethylgallium and triethylgallium were used as the gallium source's, while trimethylindium and ethyldimethylindium were used as the indium sources. The use of triethylgallium incorporated with trimethylindium enhanced the growth rate of Ga0.5In0.5P as compared to incorporation with ethyldimethylindium. While the use of trimethylgallium incorporated with ethyldimethylindium enhanced the growth rate of Ga0.5In0.5P significantly, as compared to incorporation with trimethylindium.
PASSIVATION OF GAAS POWER FIELD-EFFECT TRANSISTOR USING ELECTRON-CYCLOTRON-RESONANCE CHEMICAL-VAPOR-DEPOSITION SILICON-NITRIDE TECHNIQUE
(1994-12-01)
CHANG, EY
;
LIN, KC
;
WU, JW
;
CHEN, TH
;
CHEN, JS
Monolithic microwave integrated circuit (MMIC) chips are typically passivated with dielectric films to improve their long-term environmental reliability. Improper passivation generally degrades chip performance and reduces wafer yield. This paper reports the change of metal-semiconductor field-effect transistor (MESFET) parameters after silicon nitride passivation using electron cyclotron resonance chemical vapor deposition (ECR-CVD). In general, the changes in the electrical parameters after passivation are small. Gate-drain breakdown voltage of the MESFET's after ECR-CVD passivation is significantly improved compared to that after PECVD. The microwave characteristics of the high-powered MESFET's passivated using ECR-CVD silicon nitride are also reported in this paper.
PHOTOLUMINESCENCE OF HEAVILY P-TYPE-DOPED GAAS - TEMPERATURE AND CONCENTRATION DEPENDENCES
(1994-04-01)
CHEN, HD
;
FENG, MS
;
CHEN, PA
;
LIN, KC
;
WU, JW
Photoluminescent (PL) properties of heavily carbon- and zinc-doped GaAs were investigated for concentration from 8 X 10(17) to 2.3 x 10(20) cm-3 and temperature from 300 K to 20 K. Both a band-to-band (B, B) peak and a band-to-acceptor (e, A) peak appeared at 300 K for the heavily p-type-doped GaAs PL spectra, even in degenerated GaAs. The variation of the intensities of the (e, A) peak and (B, B) peak with concentration and temperature was investigated, and the change in position of the two peaks at various concentrations and temperatures was observed. The rapid increase in linewidth with increasing concentration due to the appearance of a shoulder peak was also studied; this behavior is different from that of the shoulder peak in the PL spectrum from Zn-doped crystal.
REACTIVE ION ETCH OF GAAS AND ALGAAS USING BCL3, SICL4 AND SF6, INSTEAD OF CCL2F2
(1994)
WU, JW
;
CHANG, CY
;
LIN, KC
;
CHANG, EY
;
HWANG, JH
REACTIVE ION ETCHING OF GAINP, GAAS, AND ALGAAS
(1995-04-01)
WU, JW
;
CHANG, CY
;
CHANG, EY
;
CHANG, SH
;
LIN, KC
We have investigated the reactive ion etching of GaInP, GaAs, and AlGaAs. High etching selectivity of GaAs to AlGaAs (or to GaInP) can be achieved due to the formation of aluminum fluoride (AlF3) and indium fluoride (InF3) using a BCl3/SF6 mixture. By using a CH4/H-2 mixture, a polymer film is accumulated on the GaAs surface after reactive ion etching. This polymer film inhibits the reactive ion etching of GaAs. There is no polymer film accumulated on the surface of GaInP. The polymer deposited on the surface of GaInP is removed as the etching products are being removed. Hence, a high etching selectivity of GaInP to GaAs can be achieved by using a CH4/H-2 mixture.
SILICON DELTA-DOPING OF GAINP GROWN BY LOW-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION
(1995-09-01)
WANG, CJ
;
WU, JW
;
CHAN, SH
;
CHANG, CY
;
SZE, SM
Silicon delta doping in GaInP material has been demonstrated by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) and characterized by Hall-effect and capacitance-voltage (C-V) measurements. The mobility enhancement of delta-doped samples over their corresponding uniformly doped samples was observed. High sheet carrier density of N-S=1.21 x 10(13) cm(-2) could be obtained. A sharp carrier distribution profile with the full width at half maximum of 25 Angstrom has been achieved.
SILICON DELTA-DOPING OF GAINP GROWN BY LOW-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION
(1995-09-01)
WANG, CJ
;
WU, JW
;
CHAN, SH
;
CHANG, CY
;
SZE, SM
Silicon delta doping in GaInP material has been demonstrated by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) and characterized by Hall-effect and capacitance-voltage (C-V) measurements. The mobility enhancement of delta-doped samples over their corresponding uniformly doped samples was observed. High sheet carrier density of N-S=1.21 x 10(13) cm(-2) could be obtained. A sharp carrier distribution profile with the full width at half maximum of 25 Angstrom has been achieved.
THE RELIABILITY OF MULTILEVEL METALLIZATION ON INGAAS/GAAS LAYERS
(1994)
CHANG, EY
;
CHEN, JS
;
WU, JW
;
LIN, KC
;
材料科學與工程學系
THE SELECTIVITY OF REACTIVE ION ETCH OF GA0.51IN0.49P/GAAS
(1994)
WU, JW
;
CHAN, SH
;
LIN, KC
;
CHANG, CY
;
CHANG, EY
THE THERMAL-STABILITY OF OHMIC CONTACT TO N-TYPE INGAAS LAYER
(1995-02-01)
WU, JW
;
CHANG, CY
;
LIN, KC
;
CHANG, EY
;
CHEN, JS
The thermal stability of ohmic contact to n-type InGaAs layer is investigated. When Ni/Ge/Au is used as the contact metal, the characteristics of the ohmic contact are degraded after thermal treatment. The specific contact resistance of (Ni/Ge/Au)-InGaAs ohmic contact after annealing at 450 degrees C is about 15 times larger than that of as-deposited sample. This is due to the decomposition of InGaAs and the interdiffusion of Ga and Au.-A new phase of Au4In appears after annealing at 300 degrees C. While in the case of Ti/Pt/Au, Au does not penetrate into the InGaAs layer as revealed by secondary ion mass spectroscopy. The specific contact resistance of(Ti/Pt/Au)-InGaAs ohmic contact after annealing at 450 degrees C is eight times larger than that of as-deposited sample. Therefore, the thermal stability of(Ti/Pt/Au)-InGaAs ohmic contact is better than that of(Ni/Ge/Au)-InGaAs ohmic contact.