Two-dimensional dopant profiling of gallium nitride p–n junctions by scanning capacitance microscopy

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 372; pp. 67 - 71
• Main Authors: Lamhamdi, M., Cayrel, F., Frayssinet, E., Bazin, A.E., Yvon, A., Collard, E., Cordier, Y., Alquier, D.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2016
• Subjects: Atomic Force Microscopy; Capacitance; Dopant profiling; Dopants; Gallium nitride; Imaging; Ion implantation; Microscopy; Nitrides; Profiling; Scanning capacitance microscopy; Semiconductors; Two dimensional; Ion implantation; Atomic Force Microscopy; Scanning capacitance microscopy; Gallium nitride; Dopant profiling
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2016.01.013

Two-dimensional imaging of dopant profiles for n and p-type regions are relevant for the development of new power semiconductors, especially for gallium nitride (GaN) for which classical profiling techniques are not adapted. This is a challenging task since it needs a technique with simultaneously good sensitivity, high spatial resolution and high dopant gradient resolution. To face these challenges, scanning capacitance microscopy combined with Atomic Force Microscopy is a good candidate, presenting reproducible results, as demonstrated in literature. In this work, we attempt to distinguish reliably and qualitatively the various doping concentrations and type at p–n and unipolar junctions. For both p–n and unipolar junctions three kinds of samples were prepared and measured separately. The space-charge region of the p–n metallurgical junction, giving rise to different contrasts under SCM imaging, is clearly observed, enlightening the interest of the SCM technique.