SiGen gets patent for strained silicon process
Silicon Genesis (SiGen), the US company that is developing strained-silicon technology for next-generation semiconductors, has been awarded a US patent covering a key aspect of the wafer fabrication process.
US patent 6,790,747 is entitled "Method and device for controlled cleaving process" and it describes a layer-transfer process that could be used to manufacture chips for high-speed, low-power semiconductor applications in the future.
Silicon device manufacturers are looking to strained-silicon solution to extend the rule of Moore s Law in future generations of chip technology (see related story).
According to SiGen, one of the limitations that has prevented mainstream adoption of the technology thus far is the continued presence of germanium in the substrate and high defect levels in the device film.
SiGen s patented process uses the layer transfer approach to mount a film of strained silicon onto a target substrate, forming a "stressed region at a selected depth below the surface".
The process is said to be applicable to the manufacture of both a strained silicon layer on top of a bulk silicon substrate, and strained silicon-on-insulator technology.
The low-temperature processing inherent in the method also limits the germanium diffusion and defect propagation effects present in other, higher-temperature, methods, says SiGen.
"Coupled with our high-yield layer-transfer process and our new uniaxial strain technology, this new capability will allow SiGen to offer the best solutions for next-generation engineered substrates," claimed SiGen president Francois Henley. "We believe that these structures will be utilized in mainstream semiconductor applications."
