Research promises faster, cheaper microchips

The University of Newcastle upon Tyne, UK has joined forces with Atmel to create 'strained silicon' microchips, which involves adding a material called germanium to the traditional silicon used in semiconductor manufacturing.

The developers claim this process could produce cheaper, faster and more reliable chips.

Potential applications include low power chips, analog and low noise RF components. It could compete with more costly technologies (GaAs), enabling for example all silicon mobile communications products.

It is compatible with and complementary to other contemporary innovation such as copper interconnect, low-k dielectrics, metal gates, Sol, etc.

The strain increases electron mobility leading to higher current in transistors. It is achieved by aligning atoms in a silicon film of thickness 10-30 nm with an underlying thick layer of unstrained silicon germanium (SiGe) alloy.

Tensile strain in the silicon layer is engineered by the germanium concentration, which increases the separation of atoms in the alloy. Strained Si technology, aimed at the CMOS market, differs from existing SiGE technology used to engineer energy band gaps and so increase the gain of heterojunction bipolar transistors.

Particular challenges relate to the high temperatures used in CMOS processing and the limited thickness of strained silicon possible due to its strain energy.