GaN growth by a controllable RF-excited nitrogen source

Hove, J. M. Van; Cosimini, G. J.; Nelson, Erik; Wowchak, A. M.; Chow, P. P.

doi:10.1016/0022-0248(95)80071-j

Cited by 46 publications

(13 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in the SEM micrograph in Figure 1a, undoped or n-type doped MBE grown GaN exhibits a "wormy" structure. This surface structure has been previously reported and the degree of texture can be minimized, although not eliminated, through changes in the nitrogen plasma source operating conditions [8,9,10,13,14]. The MOCVD grown undoped material is smooth and uniform as shown in Figure 1b.…”

Section: Epitaxial Layer Surface Morphology and Magnesium Dopingsupporting

confidence: 76%

“…Initially, this was attributed to the unavailability of an appropriate source of active nitrogen species for MBE [1]. Through the development of nitrogen rf plasma sources for MBE, the quality of the resulting epitaxial layers has improved [7,8,9,10]. Despite these advances, demonstration of high quality vertical devices such as laser diodes or high brightness LEDs grown by MBE has not occurred [8,11].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Critical Comparison Between MOVPE and MBE Growth of III-V Nitride Semiconductor Materials for Opto-Electronic Device Applications

Johnson

Brown

et al. 1999

MRS Internet j. nitride semicond. res.

View full text Add to dashboard Cite

A systematic study of the growth and doping of GaN, AlGaN, and InGaN by both molecular beam epitaxy (MBE) and metal-organic vapor phase epitaxy (MOVPE) has been performed. Critical differences between the resulting epitaxy are observed in the p-type doping using magnesium as the acceptor species. MBE growth, using rf-plasma sources to generate the active nitrogen species for growth, has been used for III-Nitride compounds doped either n-type with silicon or p-type with magnesium. Blue and violet light emitting diode (LED) test structures were fabricated. These vertical devices required a relatively high forward current and exhibited high leakage currents. This behavior was attributed to parallel shorting mechanisms along the dislocations in MBE grown layers. For comparison, similar devices were fabricated using a single wafer vertical flow MOVPE reactor and ammonia as the active nitrogen species. MOVPE grown blue LEDs exhibited excellent forward device characteristics and a high reverse breakdown voltage. We feel that the excess hydrogen, which is present on the GaN surface due to the dissociation of ammonia in MOVPE, acts to passivate the dislocations and eliminate parallel shorting for vertical device structures. These findings support the widespread acceptance of MOVPE, rather than MBE, as the epitaxial growth technique of choice for III-V nitride materials used in vertical transport bipolar devices for optoelectronic applications.

show abstract

Section: Epitaxial Layer Surface Morphology and Magnesium Dopingsupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

A Critical Comparison Between MOVPE and MBE Growth of III-V Nitride Semiconductor Materials for Opto-Electronic Device Applications

Johnson

Brown

et al. 1999

MRS Internet j. nitride semicond. res.

View full text Add to dashboard Cite

show abstract

“…8 A low temperature AlN buffer was grown after nitridation of the sapphire. The substrate temperature was then increased to 750°C for the 2-m-thick GaN growth which was done under slightly Ga-rich flux ratios.…”

Section: ͓S0003-6951͑00͒02825-4͔mentioning

confidence: 99%

Conductivity and Hall-effect in highly resistive GaN layers

Kordoš¹,

Javorka²,

Morvič

et al. 2000

Applied Physics Letters

View full text Add to dashboard Cite

Highly resistive GaN layers grown by molecular beam epitaxy are characterized by temperature dependent conductivity and Hall effect measurements. Samples with 300 Х3ϫ10 3 ⍀ cm show room temperature Hall mobility of 22 and 35 cm 2 V Ϫ1 s Ϫ1 and have a temperature dependence H ϳT x with xϭ0.9 and 0.5. This is in contradiction to a sample with 300 Х32 ⍀ cm which has a room temperature mobility of 310 cm 2 V Ϫ1 s Ϫ1 and a H ϳT x with xϭϪ1.4. The same activation energy of 0.23 eV, attributed to donor-like defects, is found for all three samples investigated. Temperature dependent conductivity data can be reasonably fitted considering band conduction. The presence of various hopping mechanisms is discussed. © 2000 American Institute of Physics. ͓S0003-6951͑00͒02825-4͔Highly resistive GaN buffer layers are important for field-effect transistor and high electron mobility transistor structures to avoid a parallel conductive channel that degrades device performance. However, not much is reported about their preparation and transport properties. Layers with resistivity of 14, 3ϫ10 3 , and 10 6 ⍀ cm were previously prepared by varying the stoichiometry during molecular beam epitaxial ͑MBE͒ growth.1 Another possibility to obtain high resistive GaN layers is by acceptor doping. MBE grown C-doped layers 2 and hydride vapor phse epitaxial Zn-doped layers 3 with resistivity of 10 6 and 10 12 ⍀ cm, respectively, have been reported. Unfortunately, carrier concentration and mobility data on samples with resistivity higher than 14 ⍀ cm are not present in the literature due to the use of conductive substrates, 3 or unmeasurable Hall coefficients. 1,4Hopping conduction, with extremely low Hall mobility H Ͻ1 cm 2 V Ϫ1 s Ϫ1, is assumed to be responsible for the latter case.1,5 When the concentrations of the autodoping centers and the deep defects are comparable, the layer becomes highly resistive and conduction by hopping among deep centers might occur. Additional models taking into account scattering on charged dislocations resulting in reduced mobility have been proposed. 6,7 To extend the knowledge of carrier transport behavior in GaN layers, we report in this letter on the temperature dependent conductivity and Hall effect measurements on highly resistive GaN layers grown by MBE.The undoped GaN layers were grown on sapphire substrates by MBE using a radio frequency atomic nitrogen plasma source.8 A low temperature AlN buffer was grown after nitridation of the sapphire. The substrate temperature was then increased to 750°C for the 2-m-thick GaN growth which was done under slightly Ga-rich flux ratios. High resolution x-ray diffraction measurements showed a reasonable layer quality with Х7 arc min full width at half maximum of the ͑0002͒ scan.9 Samples of about 6ϫ6 mm 2 were cut from each wafer and In contacts were alloyed at 850°C after appropriate surface cleaning. The ohmic behavior of the contacts was confirmed by current-voltage characteristics. Accurate temperature dependent conductivity and low magnetic field (Bϭ0.5 T͒ Hall eff...

show abstract

“…The GaN p-i-n ultraviolet (UV) photodiodes were grown on (0001) basal-plane 3-inch sapphire substrates by molecular beam epitaxy (MBE) using an RF atomic nitrogen plasma source [4]. Details of the growth process have been previously reported [5][6].…”

Section: Methodsmentioning

confidence: 99%

Uniformity and Performance Characterization of GaN p-i-n Photodetectors Fabricated from 3-Inch Epitaxy

Hickman

Klaassen

Hove

et al. 1999

MRS Internet j. nitride semicond. res.

View full text Add to dashboard Cite

Gallium nitride wafer epitaxy on large diameter substrates is critical for the future fabrication of large area UV linear or 2D imaging arrays, as well as for the economical production of other GaN-based devices. Typical group III-nitride deposition is now performed on 2-inch diameter or smaller sapphire substrates. Reported here are visible blind, UV GaN p-i-n photodetectors which have been fabricated on 3-inch diameter (0001) sapphire substrates by RF atomic nitrogen plasma MBE. The uniformity across the wafer of spectral responsivity and shunt resistance (R 0 ) for the p-i-n photodetectors has been characterized. Spectral responsivity and 1/f noise as a function of temperature exceeding 250°C will be presented for the GaN p-i-n photodetectors. Spectral response with >0.17 A/W at peak wavelength and having 4-6 orders of magnitude visible rejection has been achieved.

show abstract

GaN growth by a controllable RF-excited nitrogen source

Cited by 46 publications

References 8 publications

A Critical Comparison Between MOVPE and MBE Growth of III-V Nitride Semiconductor Materials for Opto-Electronic Device Applications

A Critical Comparison Between MOVPE and MBE Growth of III-V Nitride Semiconductor Materials for Opto-Electronic Device Applications

Conductivity and Hall-effect in highly resistive GaN layers

Uniformity and Performance Characterization of GaN p-i-n Photodetectors Fabricated from 3-Inch Epitaxy

Contact Info

Product

Resources

About