Silane and Ammonia Surface Passivation Technology for High-Mobility \hbox\hbox\hbox MOSFETs

• Published in: IEEE transactions on electron devices Vol. 57; no. 5; pp. 973 - 979
• Main Authors: Chin, Hock-Chun, Liu, Xinke, Gong, Xiao, Yeo, Yee-Chia
• Format: Journal Article
• Language: English
• Published: IEEE 01.05.2010
• Subjects: Annealing; High mobility; high- k; Indium gallium arsenide; InGaAs; Logic gates; metal-oxide-semiconductor field-effect transistor (MOSFET); MOSFET circuits; MOSFETs; Passivation; Surface morphology; surface passivation
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2010.2044285

We report the integration of silane and ammonia (SiH 4 + NH 3 ) surface passivation technology to realize high-quality gate stack on a high-mobility In 0.53 Ga 0.47 As compound semiconductor. Vacuum anneal at 520°C desorbs the native oxide while preserving the surface morphology and material composition of In 0.53 Ga 0.47 As. By incorporating SiH 4 + NH 3 passivation, a thin silicon oxynitride (SiO x N y ) interfacial layer was formed during high- k dielectric deposition. In 0.53 Ga 0.47 As n-MOSFETs with SiH 4 + NH 3 passivation demonstrate significantly reduced subthreshold swing and off-state leakage current I off in comparison with control In 0.53 Ga 0.47 As n-MOSFETs without passivation. This is due to significant reduction of interface state density D it . Improvement in carrier mobility over the control In 0.53 Ga 0.47 As n-MOSFETs was also achieved with SiH 4 + NH 3 passivation.