Low temperature fabrication and doping concentration analysis of Au/Sb ohmic contacts to n-type Si

作者：Liu, J. Q.; Wang, C.; Zhu, T.; Wu, W. J.; Fan, J.; Tu, L. C.^*

来源：AIP Advances, 2015, 5(11): 117112.

DOI：10.1063/1.4935442

• CURRENT-VOLTAGE CHARACTERISTICS
• INTEGRATED-CIRCUITS
• SCHOTTKY DIODE
• SILICON
• RESISTANCE
• BARRIERS
• DEVICES
• CMOS
• ANTIMONY
• ATOMS

This paper investigates low temperature ohmic contact formation of Au/Sb to n-type Si substrates through AuSb/NiCr/Au metal stacks. Liquid epitaxy growth is utilized to incorporate Sb dopants into Si substrate in AuSi melt. The best specific contact resistivity achieved is 0.003 Omega.cm(2) at 425 degrees C. Scanning electron microscopy (SEM) reveals inverted pyramidal crater regions at the metal/semiconductor interface, indicating that AuSi alloying efficiently occurs at such sites. Secondary ion mass spectroscopy (SIMS) shows that Sb atoms are successfully incorporated into Si as doping impurities during the anneal process, and the Sb doping concentration at the contact interface is found to be higher than the solid solubility limit in a Si crystal. This ohmic contacts formation method is suitable for semiconductor fabrication processes with limited thermal budget, such as post CMOS integration of MEMS.

• 出版日期2015-11
• 单位华中科技大学