Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences

COLLEGE OF ENGINEERING

UC Berkeley

   

2008 Research Summary

Al-2%Si Induced Crystallization of Silicon for Integrated MEMS Technology (AIC4U)

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Joanna Lai, Frank DelRio, Rhesa Nathanael, Roya Maboudian and Tsu-Jae King Liu

Polycrystalline Silicon (poly-Si) thin films are the desired material for micro/nano-electro-mechanical systems (M/NEMS) due to the excellent mechanical properties of Silicon. However, typical poly-Si deposition temperatures (600oC) exceed the allowable temperature for MEMS integration on top of CMOS electronics. We have shown that Al-2%Si induced crystallization (AIC) of Silicon films has been shown to lower the crystallization temperature of Si down to 300°C for one hour [1].

We are investigating the use of the AIC process to fabricate low-temperature poly-Si M/MEMS structures for integration on CMOS electronics. We are studying the mechanical properties of the poly-Si film formed by the AIC process. Poly-Si M/NEMS devices compatible with CMOS electronics will finally be achievable with this low-temperature fabrication process.

[1]
F. W. DelRio et al., "Al-2%Si Induced Crystallization of Amorphous Silicon," Electrochemical and Solid-State Letters, Vol. 10, No. 11, October 2007, pp. H337-H339.