Dual Silicides for Gate Channel Definition
Original Publication Date: 1985-Dec-01
Included in the Prior Art Database: 2005-Feb-19
Silicide compounds, e.g., TiSi2, have been proposed as contact materials in high-performance large-scale-integration silicon circuits. Usually the silicides are formed by depositing a metal layer onto the contacts, then reacting the metal and silicon at an appropriate temperature. For example, TiSi2 can be formed by reacting a layer of Ti on Si between 500 to 600ŒC. One problem in using the silicide contact comes from its growth along the lateral direction. As illustrated in Fig. 1, the lateral growth 10 of the contact silicides 12 under the oxide 14 will reduce the effective width of the gate channel in a MOS device. If the lateral growth is not controlled, the channel width can be reduced sufficiently to cause electrical breakdown between the source and drain, rendering the MOS device inoperative.