Investigations of photo-assisted conductive atomic force microscopy on III-nitrides

• Published in: Microelectronics Vol. 40; no. 2; pp. 353 - 356
• Main Authors: Chang, Mao-Nan, Lin, Ruo-Syuan, Liu, Hsueh-Hsing, Lin, Hung-Min, Lin, Hung-Cheng, Chyi, Jen-Inn
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2009
• Subjects: Dislocation; GaN; PA-CAFM; GaN; PA-CAFM; Dislocation
• ISSN: 1879-2391; 1879-2391
• DOI: 10.1016/j.mejo.2008.07.063

We have employed photo-assisted conductive atomic force microscopy (PA-CAFM) to obtain high-resolution current images on III-nitride surfaces. From the statistical results of current distribution, it is revealed that the full-width at half-maximum (FWHM) value is very sensitive to the dislocation density of III-nitride films even if the dislocation density is very low (∼108cm−2), suggesting that the FWHM value of current statistics can be an indicator of III-nitride quality. The results acquired by PA-CAFM are consistent with those obtained from etching-pit density and X-ray diffraction measurements. In addition, it is also revealed that PA-CAFM can observe the current distribution of InN dots without external bias influences, directly indicating the dependence of InN dots and dislocations. Our experimental results indicate that PA-CAFM is a promising method for investigating the electrical and structural properties of a nanometric area in III-nitride materials.