Practical Surface Treatments and Surface Chemistry of n-Type and p-Type GaN

Uhlrich, John J.; Grabow, Lars C.; Mavrikakis, Manos; Kuech, T. F.

doi:10.1007/s11664-007-0348-5

Cited by 29 publications

(26 citation statements)

References 40 publications

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“…As largely reported for the GaN(0001) surface, HCl etching decreases to low levels the areal concentration of typical surface contaminants (C and O) [Ref. [18], section 3.1] and prevents reoxidation [21]. The subsequent annealing step reduces the amount of residual Cl left after HCl etching [21,22].…”

mentioning

confidence: 62%

Electronic properties of air-exposed GaN(11-00) and (0001) surfaces after several device processing compatible cleaning steps

Auzelle

Ullrich

Hietzschold

et al. 2019

Applied Surface Science

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mentioning

confidence: 62%

Electronic properties of air-exposed GaN(11-00) and (0001) surfaces after several device processing compatible cleaning steps

Auzelle

Ullrich

Hietzschold

et al. 2019

Applied Surface Science

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“…Further spectroscopic characterization is performed on the n-type Ga-polar GaN samples to understand changes in the surface composition during solution exposure. More specifically, we carried out X-ray photoelectron spectroscopy (XPS) characterization with the intent of quantifying oxide formation 20 in air and in solution before and after UV exposure. The solution used in these studies is Dulbecco’s modified Eagle’s medium (DMEM), which is suitable for the growth of PC12 cells.…”

Section: Results and Discussionmentioning

confidence: 99%

Noninvasive Stimulation of Neurotypic Cells Using Persistent Photoconductivity of Gallium Nitride

et al. 2018

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The persistent photoconductivity (PPC) of the n-type Ga-polar GaN was used to stimulate PC12 cells noninvasively. Analysis of the III–V semiconductor material by atomic force microscopy, Kelvin probe force microscopy, photoconductivity, and X-ray photoelectron spectroscopy quantified bulk and surface charge, as well as chemical composition before and after exposure to UV light and cell culture media. The semiconductor surface was made photoconductive by illumination with UV light and experienced PPC, which was utilized to stimulate PC12 cells in vitro. Stimulation was confirmed by measuring the changes in intracellular calcium concentration. Control experiments with gallium salt verified the stimulation of neurotypic cells. Inductively coupled plasma mass spectrometry data confirmed the lack of gallium leaching and toxic effects during the stimulation.

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“…Comparative results show that HCl is the most efficient concerning surface oxygen coverage decrease and HF for carbon reduction [11]. GaN surfaces treated with HCl are contaminated with Cl atoms which occupy dangling bonds left by some of the oxygen atoms and prevent re-oxidation process [10,12]. Given that wet etching techniques cannot completely remove the oxygen and carbon contamination, methods such as annealing under ultrahigh vacuum (UHV) or an ion bombardment need to be introduced to obtain clean surfaces.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Oxygen and Carbon Contaminants on the Valence Band of p-GaN(0001)

et al. 2019

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Mg-doped GaN(0001) epitaxial layers, grown by molecular beam epitaxy in a setup interconnected with an analytic chamber, were analysed by means of X-ray photoelectron spectroscopy to study their physicochemical properties under different preparation methods. Investigations were carried out for the following samples: asgrown, air-exposed and treated with isopropanol (IPA) or HCl, and in situ cleaned. The X-ray photoelectron spectroscopy results confirmed that the air-exposed samples are contaminated with oxygen and carbon atoms, which can be removed only by in situ cleaning. The valence band maximum varies in the range from 1.2 eV to 2.7 eV below the Fermi level for the as-grown and ex situ prepared samples, respectively. The valence band maximum for in situ cleaned sample is located at 1.7 eV below the Fermi level.

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Practical Surface Treatments and Surface Chemistry of n-Type and p-Type GaN

Cited by 29 publications

References 40 publications

Electronic properties of air-exposed GaN(11-00) and (0001) surfaces after several device processing compatible cleaning steps

Electronic properties of air-exposed GaN(11-00) and (0001) surfaces after several device processing compatible cleaning steps

Noninvasive Stimulation of Neurotypic Cells Using Persistent Photoconductivity of Gallium Nitride

The Influence of Oxygen and Carbon Contaminants on the Valence Band of p-GaN(0001)

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