الفهرس | Only 14 pages are availabe for public view |
Abstract In this thesis we suggested a new MOSFET device that is realized by using the known MOSFET technology with a Graded Band Gap channel (GBGC) in the longitudinal direction from the source to drain with the greater band gap at the source side and the smaller one at the drain side. This graded band gap can be achieved by implanting atoms .---~--·· -- ... of a material which has a smaller band gap energy than silicon like Ge. The fractional ratio of the implanted atoms increases with the position x towards the drain. This architectural feature of the graded energy band along the channel has the following advantages; i) inducing an internal electric field that accelerates the electrons faster from the source to the drain. ii) reduction of the pot~ntial barrier of the source-channel junction, and iii) overcoming most mobility degradation mechanisms. The previous reasons make it possible to have a GBGC MOSFET that is faster and has a higher cut-off frequency than normal MOSFET. Moreover the GBGC structure improves the noise figure, decreases the high resistance hot zone which often exits besides the drain due to a high conductivity beside the drain region and consequently; .1 suppresses the possibility of thermal and carrier heating and hence the .’.\ , probability of bulk and/or surface breakdown. A new circuit technique has been introduced to simulate the GBGC MOSFET using SPICE. |