TITLE

Dislocation density in GaN determined by photoelectrochemical and hot-wet etching

AUTHOR(S)
Visconti, P.; Jones, K. M.; Reshchikov, M. A.; Cingolani, R.; Morkoc¸, H.; Molnar, R. J.
PUB. DATE
November 2000
SOURCE
Applied Physics Letters;11/27/2000, Vol. 77 Issue 22
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Defects in GaN layers grown by hydride vapor-phase epitaxy have been investigated by photoelectrochemical (PEC) etching, and by wet etching in hot H[sub 3]PO[sub 4] acid and molten potassium hydroxide (KOH). Threading vertical wires (i.e., whiskers) and hexagonal-shaped etch pits are formed on the etched sample surfaces by PEC and wet etching, respectively. Using atomic-force microscopy, we find the density of "whisker-like" features to be 2x10[sup 9] cm[sup -2], the same value found for the etch-pit density on samples etched with both H[sub 3]PO[sub 4] and molten KOH. This value is comparable to the dislocation density obtained in similar samples with tunneling electron microscopy, and is also consistent with the results of Youtsey and co-workers [Appl. Phys. Lett. 73, 797 (1998); 74, 3537 (1999)]. © 2000 American Institute of Physics.
ACCESSION #
4415090

 

Related Articles

  • Bias-assisted photoelectrochemical etching of p-GaN at 300 K. Borton, J. E.; Borton, J.E.; Cai, C.; Nathan, M. I.; Nathan, M.I.; Chow, P.; Van Hove, J. M.; Van Hove, J.M.; Wowchak, A.; Morkoc, H. // Applied Physics Letters;8/21/2000, Vol. 77 Issue 8 

    Photoelectrochemical (PEC) etching of p-type GaN has been realized in room temperature, 0.1 M KOH solutions. PEC etching of GaN was achieved by applying a positive bias to the surface of the p-GaN layer through a deposited titanium mask. The applied bias reduces the field at the semiconductor...

  • Gallium nitride whiskers formed by selective photoenhanced wet etching of dislocations. Youtsey, C.; Romano, L. T.; Adesida, I. // Applied Physics Letters;8/10/1998, Vol. 73 Issue 6, p797 

    Gallium nitride is used to fabricate high brightness blue and green light-emitting diodes in spite of high densities of extended structural defects. We describe a photoelectrochemical etching process that reveals the dislocation microstructure of n-type GaN films by selectively removing material...

  • Free-standing, optically pumped, GaN/InGaN microdisk lasers fabricated by photoelectrochemical etching. Haberer, E. D.; Sharma, R.; Meier, C.; Stonas, A. R.; Nakamura, S.; DenBaars, S. P.; Hu, E. L. // Applied Physics Letters;11/29/2004, Vol. 85 Issue 22, p5179 

    GaN-based, mushroom-shaped microdisk lasers were fabricated using band-gap selective photoelectrochemical etching. The optically pumped microdisks had well-defined, distinct modes at excitation powers ranging from about 8 to 16 W/cm2. Modal linewidths of 0.09 nm were reported, which was near the...

  • Effect of photoelectrochemical oxidation on properties of GaN epilayers grown by molecular beam epitaxy. Fu, D. J.; Kang, T. W.; Yuldashev, Sh. U.; Kim, N. H.; Park, S. H.; Yun, J. S.; Chung, K. S. // Applied Physics Letters;2/26/2001, Vol. 78 Issue 9, p1309 

    GaN epilayers grown by molecular beam epitaxy were photoelectrochemically (PEC) oxidized in an aqueous KOH solution. The oxidation effect was investigated by defect-related photoconductivity and photoluminescence. The PEC treated GaN show decreased extrinsic photoresponse and concentration of...

  • Photoelectrochemical etching measurement of defect density in GaN grown by nanoheteroepitaxy. Ferdous, M. S.; Sun, X. Y.; Wang, X.; Fairchild, M. N.; Hersee, S. D. // Journal of Applied Physics;5/1/2006, Vol. 99 Issue 9, p096105 

    The density of dislocations in n-type GaN was measured by photoelectrochemical etching. A 10× reduction in dislocation density was observed compared to planar GaN grown at the same time. Cross-sectional transmission electron microscopy studies indicate that defect reduction is due to the...

  • Electrodeless wet etching of GaN assisted with chopped ultraviolet light. Hwang, Z.H.; Hwang, J.M.; Hwang, H.L.; Hung, W.H. // Applied Physics Letters;5/10/2004, Vol. 84 Issue 19, p3759 

    Electrodeless photoelectrochemical (PEC) etching of GaN was studied in a K2S2O8/KOH solution irradiated with ultraviolet (UV) light either continuously or periodically. The rate of recombination of electrons and holes at dislocation defects is greater than for crystalline GaN, resulting in a...

  • Vertically oriented GaN-based air-gap distributed Bragg reflector structure fabricated using band-gap-selective photoelectrochemical etching. Sharma, R.; Haberer, E. D.; Meier, C.; Hu, E. L.; Nakamura, S. // Applied Physics Letters;8/1/2005, Vol. 87 Issue 5, p051107 

    A three-period vertically oriented GaN-based air-gap distributed Bragg reflector structure was fabricated using band-gap-selective photoelectrochemical (PEC) etching. The epitaxial structure consisted of an Al0.08Ga0.92N/(In0.04Ga0.96N/In0.07Ga0.93N) superlattice structure, wherein the InGaN...

  • Cathodoluminescence microscopy and spectroscopy of GaN epilayers microstructured using surface charge lithography. Díaz-Guerra, C.; Piqueras, J.; Volciuc, O.; Popa, V.; Tiginyanu, I. M. // Journal of Applied Physics;7/15/2006, Vol. 100 Issue 2, p023509 

    Cathodoluminescence (CL) microscopy and spectroscopy have been used to investigate the optical properties of GaN microstructures patterned by Ar+ ion irradiation and subsequent photoelectrochemical (PEC) etching. Monochromatic CL images and CL spectra reveal an enhancement of several...

  • Effect of substrate temperature on the photoelectrochemical responses of Ga and N co-doped ZnO films. Shet, Sudhakar; Kwang-Soon Ahn; Heli Wang; Nuggehalli, Ravindra; Yanfa Yan; Turner, John; Al-Jassim, Mowafak // Journal of Materials Science;Oct2010, Vol. 45 Issue 19, p5218 

    Ga–N co-doped ZnO thin films with reduced bandgaps were deposited on F-doped tin-oxide-coated glass by radio-frequency magnetron sputtering at different substrate temperatures in mixed N2 and O2 gas ambient. We found that Ga–N co-doped ZnO films exhibited enhanced crystallinity...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics