Angular dependent XPS study of surface band bending on Ga-polar n-GaN

Huang, Rong; Liu, Tong; Zhao, Yanfei; Zhu, Yifan; Huang, Zhiwen; Li, Fangsen; Liu, Jianping; Zhang, Liqun; Zhang, Shuming; Dingsun, An; Yang, Hui

doi:10.1016/j.apsusc.2018.01.196

Cited by 62 publications

(32 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1(b). The energy difference of ( E CL − E V ) bulk is calculated to be 17.48 eV, which is consistent with the values reported for bulk GaN 17–20 .…”

Section: Resultssupporting

confidence: 89%

Precise determination of surface band bending in Ga-polar n-GaN films by angular dependent X-Ray photoemission spectroscopy

Zhao

Gao

Huang

et al. 2019

Sci Rep

Self Cite

View full text Add to dashboard Cite

We present a systematic study of surface band bending in Ga-polar n-GaN with different Si doping concentrations by angular dependent X-ray photoelectron spectroscopy (ADXPS). The binding energies of Ga 3d and N 1 s core levels in n-GaN films increase with increasing the emission angle, i. e., the probing depth, suggesting an upward surface band bending. By fitting the Ga 3d core level spectra at different emission angles and considering the integrated effect of electrostatic potential, the core level energy at the topmost surface layer is well corrected, therefore, the surface band bending is precisely evaluated. For moderately doped GaN, the electrostatic potential can be reflected by the simply linear potential approximation. However, for highly doped GaN samples, in which the photoelectron depth is comparable to the width of the space charge region, quadratic depletion approximation was used for the electrostatic potential to better understand the surface band bending effect. Our work improves the knowledge of surface band bending determination by ADXPS and also paves the way for studying the band bending effect in the interface of GaN based heterostructures.

show abstract

“…1(b). The energy difference of ( E CL − E V ) bulk is calculated to be 17.48 eV, which is consistent with the values reported for bulk GaN 17–20 .…”

Section: Resultssupporting

confidence: 89%

Precise determination of surface band bending in Ga-polar n-GaN films by angular dependent X-Ray photoemission spectroscopy

Zhao

Gao

Huang

et al. 2019

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…This higher binding energy shi of the Ga 3d core level signies a decrease in the upward surface band bending, as shown in the schematic band diagram (Fig. 6), [31][32][33] and results in a lowering of the barrier height and contact resistance. 31,32 An additional peak observed at À5.70 eV upon deposition of the Ag nanoparticles corresponds to the degenerately occupied electron states in the conduction band of the Ag/GaN system.…”

Section: Resultsmentioning

confidence: 90%

Charge transfer-induced enhancement of a Raman signal in a hybrid Ag–GaN nanostructure

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Subsequently, they (N1 and N2) were cleaned in acid solution (HCl: H 2 O 2 : H 2 O = 1:1:5) for 20 min and then followed by alkaline solution (48% KOH, 80 °C) for 15 min. Thereafter, N2 samples were further treated by inductively coupled plasma (ICP) for 30 s with 18 sccm Cl 2 , 1000 W ICP power, and 50 W RF power, which was optimized to form good Ohmic contact between GaN and metal Ti 30 . The uniform metal layers of Ti and Pd were sequentially deposited on N1 and N2 samples in an ultra-high vacuum (UHV) magnetron sputter chamber with a base pressure of 5 × 10 −10 Torr.…”

Section: Methodsmentioning

confidence: 99%

Ion Sputter Induced Interfacial Reaction in Prototypical Metal-GaN System

Huang

Liu

et al. 2018

Sci Rep

Self Cite

View full text Add to dashboard Cite

Contact property is now becoming to be a key factor for achieving high performance and high reliability in GaN-based III-V semiconductor devices. Energetic ion sputter, as an effective interface probe, is widely used to profile the metal/GaN contacts for interfacial analysis and process optimization. However, the details of ion-induced interfacial reaction, as well as the formation of sputter by-products at the interfaces are still unclear. Here by combining state-of-the-art Ar+ ion sputter with in-situ X-ray photoelectron spectroscopy (XPS) and ex-situ high resolution transmission electron microscopy (HRTEM), we have observed clearly not only the ion-induced chemical state changes at interface, but also the by-products at the prototypical Ti/GaN system. For the first time, we identified the formation of a metallic Ga layer at the GaOx/GaN interface. At the Ti/GaOx interface, TiCx components were also detected due to the reaction between metal Ti and surface-adsorbed C species. Our study reveals that the corresponding core level binding energy and peak intensity obtained from ion sputter depth profile should be treated with much caution, since they will be changed due to ion-induced interface reactions and formation of by-products during ion bombardment.

show abstract

Angular dependent XPS study of surface band bending on Ga-polar n-GaN

Cited by 62 publications

References 24 publications

Precise determination of surface band bending in Ga-polar n-GaN films by angular dependent X-Ray photoemission spectroscopy

Precise determination of surface band bending in Ga-polar n-GaN films by angular dependent X-Ray photoemission spectroscopy

Charge transfer-induced enhancement of a Raman signal in a hybrid Ag–GaN nanostructure

Ion Sputter Induced Interfacial Reaction in Prototypical Metal-GaN System

Contact Info

Product

Resources

About