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Nanoscale electro-structural characterisation of ohmic contacts formed on p-type implanted 4H-SiC.

Frazzetto A, Giannazzo F, Lo Nigro R, Di Franco S, Bongiorno C, Saggio M, Zanetti E, Raineri V, Roccaforte F - Nanoscale Res Lett (2011)

Bottom Line: In particular, the surface roughness of the Al-implanted SiC regions annealed at 1700°C could be strongly reduced using a protective carbon capping layer during annealing.This latter resulted in an improved surface morphology and specific contact resistance of the Ti/Al ohmic contacts formed on these regions.The microstructure of the contacts was monitored by X-ray diffraction analysis and a cross-sectional transmission electron microscopy, and correlated with the electrical results.

View Article: PubMed Central - HTML - PubMed

Affiliation: Consiglio Nazionale delle Ricerche-Istituto per la Microelettronica e Microsistemi-Strada VIII, n, 5, Zona Industriale, 95121, Catania, Italy. fabrizio.roccaforte@imm.cnr.it.

ABSTRACT
This work reports a nanoscale electro-structural characterisation of Ti/Al ohmic contacts formed on p-type Al-implanted silicon carbide (4H-SiC). The morphological and the electrical properties of the Al-implanted layer, annealed at 1700°C with or without a protective capping layer, and of the ohmic contacts were studied using atomic force microscopy [AFM], transmission line model measurements and local current measurements performed with conductive AFM.The characteristics of the contacts were significantly affected by the roughness of the underlying SiC. In particular, the surface roughness of the Al-implanted SiC regions annealed at 1700°C could be strongly reduced using a protective carbon capping layer during annealing. This latter resulted in an improved surface morphology and specific contact resistance of the Ti/Al ohmic contacts formed on these regions. The microstructure of the contacts was monitored by X-ray diffraction analysis and a cross-sectional transmission electron microscopy, and correlated with the electrical results.

No MeSH data available.


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Bright field cross-section TEM images for Ti/Al ohmic contacts. Images for Ti/Al contacts annealed without capping layer (a) and with capping layer (b).
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Figure 5: Bright field cross-section TEM images for Ti/Al ohmic contacts. Images for Ti/Al contacts annealed without capping layer (a) and with capping layer (b).

Mentions: Cross-section TEM analysis allowed us to monitor the different microstructures of the contacts especially in the proximity of the interface. Figure 5a,b shows the cross-sectional TEM micrographs for samples annealed without and with a capping layer, respectively.


Nanoscale electro-structural characterisation of ohmic contacts formed on p-type implanted 4H-SiC.

Frazzetto A, Giannazzo F, Lo Nigro R, Di Franco S, Bongiorno C, Saggio M, Zanetti E, Raineri V, Roccaforte F - Nanoscale Res Lett (2011)

Bright field cross-section TEM images for Ti/Al ohmic contacts. Images for Ti/Al contacts annealed without capping layer (a) and with capping layer (b).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211209&req=5

Figure 5: Bright field cross-section TEM images for Ti/Al ohmic contacts. Images for Ti/Al contacts annealed without capping layer (a) and with capping layer (b).
Mentions: Cross-section TEM analysis allowed us to monitor the different microstructures of the contacts especially in the proximity of the interface. Figure 5a,b shows the cross-sectional TEM micrographs for samples annealed without and with a capping layer, respectively.

Bottom Line: In particular, the surface roughness of the Al-implanted SiC regions annealed at 1700°C could be strongly reduced using a protective carbon capping layer during annealing.This latter resulted in an improved surface morphology and specific contact resistance of the Ti/Al ohmic contacts formed on these regions.The microstructure of the contacts was monitored by X-ray diffraction analysis and a cross-sectional transmission electron microscopy, and correlated with the electrical results.

View Article: PubMed Central - HTML - PubMed

Affiliation: Consiglio Nazionale delle Ricerche-Istituto per la Microelettronica e Microsistemi-Strada VIII, n, 5, Zona Industriale, 95121, Catania, Italy. fabrizio.roccaforte@imm.cnr.it.

ABSTRACT
This work reports a nanoscale electro-structural characterisation of Ti/Al ohmic contacts formed on p-type Al-implanted silicon carbide (4H-SiC). The morphological and the electrical properties of the Al-implanted layer, annealed at 1700°C with or without a protective capping layer, and of the ohmic contacts were studied using atomic force microscopy [AFM], transmission line model measurements and local current measurements performed with conductive AFM.The characteristics of the contacts were significantly affected by the roughness of the underlying SiC. In particular, the surface roughness of the Al-implanted SiC regions annealed at 1700°C could be strongly reduced using a protective carbon capping layer during annealing. This latter resulted in an improved surface morphology and specific contact resistance of the Ti/Al ohmic contacts formed on these regions. The microstructure of the contacts was monitored by X-ray diffraction analysis and a cross-sectional transmission electron microscopy, and correlated with the electrical results.

No MeSH data available.


Related in: MedlinePlus