SELF-ALIGNED PRECISE HIGH SHEET RHO RESISTOR FOR MIXED-SIGNAL APPLICATION

摘要

A new method is provided for the creation of a resistiveload in a semiconductor device whereby the semiconductor devicefurther contains gate electrodes and a capacitor. Fieldisolation regions separate the active areas; a thin layer ofgate oxide is created over these active regions. A first layerof dielectric is deposited, used for the gate electrode, for thebottom plate of the adjacent capacitor and for the resistor ofhigh ohmic value. The gate poly is doped (in the first layer ofdielectric); optionally the bottom plate of the capacitor can bedoped. A second dielectric layer is deposited for the dielectricof the capacitor; a third layer of dielectric is deposited,patterned and etched to form the capacitor top plate. Thecapacitor (dielectric and bottom plate), poly gates and the loadresistor are patterned; the LDD regions for the transistors arecreated. The (gate, capacitor, resistor) spacers are formed,during and as part of the etch of the gate spacers a resistivespacer (called spacer since it serves to space or separate thetwo contact points of the resistor) is formed. The source/drainimplants for the gate electrodes are performed therebyconcurrently performing (self-aligned, due to the resistorspacer) implants for the contact regions of the resistor. Allcontacts (gate poly, source/drain and two contact points on theresistor) are salicided to achieve lower contact resistance.