Method to reduce ground-plane poisoning of extremely-thin SOI (ETSOI) layer with thin buried oxide
View Patent ↗The present disclosure, which is directed to ultra-thin-body-and-BOX and Double BOX fully depleted SOI devices having an epitaxial diffusion-retarding semiconductor layer that slows dopant diffusion into the SOI channel, and a method of making these devices. Dopant concentrations in the SOI channels of the devices of the present disclosure having an epitaxial diffusion-retarding semiconductor layer between the substrate and SOI channel are approximately 50 times less than the dopant concentrations measured in SOI channels of devices without the epitaxial diffusion-retarding semiconductor layer.
1. An ultra-thin-body-and-buried-oxide (BOX) fully depleted SOI device comprising a first doped substrate; an epitaxial semiconductive layer comprising SiC and/or SiGe on top of and in direct contact with the first doped substrate; a thin oxide layer on top of and in direct contact with the epitaxial semiconductive layer; and an SOI channel layer on top of and in direct contact with the thin oxide layer; wherein the epitaxial semiconductive layer slows the rate of dopant diffusion from the substrate into the SOI channel.
2. A complimentary-symmetry metal-oxide-semiconductor (CMOS) device comprising the ultra-thin-body-and-buried-oxide (BOX) fully depleted SOI device according to claim 1 .
3. The ultra-thin-body-and-buried-oxide (BOX) fully depleted SOI device of claim 1 , wherein the rate of dopant diffusion from the substrate into the SOI channel is slowed by about 50 times in comparison to an ultra-thin-body-and-buried-oxide (BOX) fully depleted SOI device without the epitaxial semiconductive layer.
4. A complimentary-symmetry metal-oxide-semiconductor (CMOS) device comprising the ultra-thin-body-and-buried-oxide (BOX) fully depleted SOI device according to claim 3 .
5. The ultra-thin-body-and-buried-oxide (BOX) fully depleted SOI device of claim 3 , wherein the dopant is boron.
6. The ultra-thin-body-and-buried-oxide (BOX) fully depleted SOI device of claim 1 , wherein the epitaxial semiconductive layer is about 10 to about 30 nanometers thick.