SOI Wafers

SOI (silicon-on-insulator) is a semiconductor technology which enables a full isolation of each electronic component on an integrated circuit by using a buried oxide layer. The heart of a SOI wafer is an ultra-thin, monocrystalline, conductive layer on a silicon wafer. All electronic operations take place, on this isolated layer, enabling higher switching frequencies and lower power consumption all the while avoiding unwanted heat production. SOI chips have been used recently in consumer goods and applications, such as computing, gaming, automotive, networking and imaging, as well as generally in devices requiring ultra low power consumption.

LowTemp™ plasma activation is suitable for applications such as silicon direct bonding for manufacturing: SOI (Silicon-on-Insulator), strained silicon, GeOI (Germanium-on-Insulator), compound semiconductor applications and MEMS devices.

By applying plasma activation, the surface chemistry of two materials to be bonded can be tailored to allow the formation of stronger chemical bonds than those achievable with non-activated surfaces. The plasma activation is enabling low temperature (<400°C) wafer bonding and stress/damage free annealing of thermally mismatched materials.

EV Group's plasma activation has been proven not to affect surface roughness and to be fully CMOS compatible. TEM cross sectional analysis of the bonded interface reveals a smooth, compact oxide layer with no transition between thermal and native oxide.

Please see our related product EVG®810LT for detailed information.

 


Bonding energy measurement on wafer pair with dedicated oxide thickness. Courtesy of LETI.


Maximum bond strengh at low annealing temperature: Bond interface stronger than oxide layer, oxide transfer from one wafer to the other. Courtesy of LETI.