Minimum charge FET fabricated on an ultrathin silicon on sapphire wafer
US5895957A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1997 |
| Grant date | Apr 20, 1999 |
| Priority date | — |
| Expiry date | Jan 3, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76281
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process is disclosed for preparing a silicon-on-sapphire wafer suited for fabrication of fully depleted field effect transistors. A fully depleted field effect transistor (FET) which has minimum parasitic charge in the conduction channel and a process to make same are described. The device is made in and relies on the silicon layer on sapphire which has minimal charge intentionally introduced into the conduction channel. Both N-type and P-type transistors are described. Methods for defining threshold voltage are also described. Specific examples of the devices are presented including specific materials selections for threshold voltage options. Manufacturing processes are described, including a preferred embodiment based on ultra thin silicon on sapphire. The devices can be fabricated using conventional silicon techniques; both silicided and non-silicided versions are presented. Advantages include threshold voltages determined by fundamental material properties; high performance devices due to reduced carrier scattering, low transverse electric fields and elimination of the body effect; threshold voltages virtually independent of temperature; simplicity of modeling due to reductio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.