Silicon-on-Nothing (SON) MOSFET And Its Manufacturing Method

With the development of bulk silicon CMOS technology, the need for innovation in all aspects from material selection, device structures and processing technology, which is a channel strained silicon high mobility enhancement technology on behalf of, the new metal gate / high-k gate dielectric gate structure, and the new MOSFET structure to SOI, Fin FET as the representative of all become a mainstream technology 22 nm and below technology nodes.Compared to bulk silicon MOS devices, SOI MOSFET devices in various application areas have shown a huge advantage for ETSOI MOSFET devices, silicon film thickness naturally defines a source-drain junction depth, the channel when the device work in fully depleted state, thereby can improve the drain-induced barrier lowering(DIBL) and other short channel effect is also improved subthreshold characteristics of the device, reducing static power consumption of the circuit. ETSOI MOS device without channel doping, the channel mobility to avoid degradation caused by doping, thereby maintaining the threshold voltage stability. In addition, ETSOI MOS device substrate having a global buried oxide insulating layer, thereby reducing the parasitic junction capacitance between the drain and source diffusion region of the substrate, and the top silicon enables completely isolated, thus increasing the speed of the device, eliminating the latch. However, the global buried oxide insulating layer to ETSOI MOSFET device also brings two serious drawbacks, one floating body effect, the other is self-heating effects.To solve these problems, we propose a new type of quasi- SOI device structure of Silicon-on-Nothing(SON) MOSFET, such a device structure eliminates ETSOI MOSFET channel region below the buried oxide insulating layer through the top silicon layer and the silicon germanium substrate the end of the communication, and the source and drain regions is below the buried oxide insulating layer structure, thereby improving the self-heating effects and floating-body effect ETSOI MOSFET devices, and reduces the leakage current and power consumption of the device, to avoid the high cost of SOI wafers restrictions. As the device channel below the buried oxide insulating layer is silicon-germanium layer alternatives, both to improve the thermal performance of the device, while biaxially strained Si / Ge Si heterostructure channel allows the electron and hole mobilities have been significantly improved...