Browsing by Author "GUO, JD"

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EFFECTS OF COLUMN-III ALKYL SOURCES ON DEEP LEVELS IN GAN GROWN BY ORGANOMETALLIC VAPOR-PHASE EPITAXY
(1995-09-18)
LEE, WI
;
HUANG, TC
;
GUO, JD
;
FENG, MS
;
材料科學與工程學系
Two different kinds of n-type GaN films were prepared by organometallic vapor phase epitaxy, one by using trimethylgallium (TMGa) and another by using triethylgallium (TEGa) as the alkyl source. Schottky diodes with well-behaved current-voltage and capacitance-voltage characteristics were fabricated. Deep-level transient spectroscopy studies were performed on these samples. Three distinct deep levels, labeled E1, E2, and E3, were measured in the film grown with TMGa, with an activation energy of 0.14, 0.39, and 1.63 +/- 0.3 eV, respectively. Only one level, E3, was observed in the film prepared with TEGa. (C) 1995 American Institute of Physics.
EFFECTS OF COLUMN-III ALKYL SOURCES ON DEEP LEVELS IN GAN GROWN BY ORGANOMETALLIC VAPOR-PHASE EPITAXY
(1995-09-18)
LEE, WI
;
HUANG, TC
;
GUO, JD
;
FENG, MS
;
材料科學與工程學系
Two different kinds of n-type GaN films were prepared by organometallic vapor phase epitaxy, one by using trimethylgallium (TMGa) and another by using triethylgallium (TEGa) as the alkyl source. Schottky diodes with well-behaved current-voltage and capacitance-voltage characteristics were fabricated. Deep-level transient spectroscopy studies were performed on these samples. Three distinct deep levels, labeled E1, E2, and E3, were measured in the film grown with TMGa, with an activation energy of 0.14, 0.39, and 1.63 +/- 0.3 eV, respectively. Only one level, E3, was observed in the film prepared with TEGa. (C) 1995 American Institute of Physics.
RAMAN-SCATTERING OF SE-DOPED GALLIUM NITRIDE FILMS
(1995-10-01)
KUO, HR
;
FENG, MS
;
GUO, JD
;
LEE, MC
;
材料科學與工程學系
Raman spectra of Se-doped gallium nitride films have been measured for the first time with good resolution and a wide range of excitation wavelengths. The signals from both buffer layer and epilayer are identified unambiguously. We have observed not only the resonant scattering related to the transition below the band gap but also the phonon-plasmon coupling due to the doping effect. The carrier concentration obtained from lineshape fitting is consistent with that from Hall measurements. By comparing the Raman shifts with those of other nitrides and gallium compounds, we found that most of them are almost linearly proportional to the square root of reciprocal masses. The bonding strengths are thus inferred from the slopes.
SE-DOPED GAN FILMS GROWN BY LOW-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION
(1995-10-01)
GUO, JD
;
FENG, MS
;
PAN, FM
;
材料科學與工程學系
;
電子工程學系及電子研究所
Se-doped GaN films are grown for the first time by low-pressure metalorganic chemical vapor deposition (LP-MOCVD), in which H2Se is used as the Se source sas. Effects of Se doping on electrical properties of GaN films are reported. Se atoms tend to out-diffuse to the surface of the GaN film at high tempi rature. The N atomic percentage is influenced by the incorporation of H2Se in the MOCVD process. The carrier concentration was found to be significantly affected by the surface defects which develop at high H2Se dosages. The highest free electron concentration obtained is about 1.5 x 10(18) cm(-3). Increasing the growth temperature from 1000 degrees C to 1050 degrees C reduces the maximum carrier concentration to about 7x10(17) cm(-3).
STUDY OF SCHOTTKY BARRIERS ON N-TYPE GAN GROWN BY LOW-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION
(1995-10-30)
GUO, JD
;
FENG, MS
;
GUO, RJ
;
PAN, FM
;
CHANG, CY
Schottky barriers on n-type GaN films grown by low-pressure metalorganic chemical vapor deposition are characterized and derived. A thin Pt or a Pd layer is deposited by electron-gun evaporation to form Schottky contacts in a vacuum below 1X10(-6) Torr. The Schottky barrier heights of Pt on the n-GaN film are determined to be 1.04 and 1.03 eV by current-voltage (C-V) and current density-temperature (J-T) measurements, respectively. Also based on C-V and J-T measurements, the measured barrier height of Pd on n-GaN is 0.94 and 0.91 eV, respectively Schottky characteristics of Pt and Pd observed in the experiment are compared with those of Au and Ti in previous reports. (C) 1995 American Institute of Physics.
STUDY OF SCHOTTKY BARRIERS ON N-TYPE GAN GROWN BY LOW-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION
(1995-10-30)
GUO, JD
;
FENG, MS
;
GUO, RJ
;
PAN, FM
;
CHANG, CY
Schottky barriers on n-type GaN films grown by low-pressure metalorganic chemical vapor deposition are characterized and derived. A thin Pt or a Pd layer is deposited by electron-gun evaporation to form Schottky contacts in a vacuum below 1X10(-6) Torr. The Schottky barrier heights of Pt on the n-GaN film are determined to be 1.04 and 1.03 eV by current-voltage (C-V) and current density-temperature (J-T) measurements, respectively. Also based on C-V and J-T measurements, the measured barrier height of Pd on n-GaN is 0.94 and 0.91 eV, respectively Schottky characteristics of Pt and Pd observed in the experiment are compared with those of Au and Ti in previous reports. (C) 1995 American Institute of Physics.