MOSFET Structures With Reduced Hot Carrier Generation
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
As mobile carriers drift from source to drain in the channel region of a MOSFET, they are heated by the longitudinal electric field and some can become hot if the maximum electric field located near the drain is sufficiently high. These hot carriers cause reliability problems and degrade transistor performance because they can be injected into the gate insulator and get trapped to result in threshold voltage shift and lower transconductance. This disclosure describes MOSFET structures for reducing the generation of hot carriers. The basic principle is to lessen the maximum channel electric field by controlling the variation of the mobile charge density along the channel.