Ion implantation method for improving damage caused by hot carrier injection

Abstract

The invention provides an ion implantation method for improving damage caused by hot carrier injection. An ultraviolet processing step is added for a drain area before sidewall etching, so that a sidewall layer above the drain area and a sidewall layer above a source area are of different etching rates, the sectional width of the sidewall of a source is less than that of the sidewall of a drain, distances from doped ions of a drain end to a channel are prolonged, distances from doped ions of a source end to the channel and a substrate are prolonged, longitudinal electric field strength is reduced, and damage of a device caused by hot carrier injection is reduced.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an ion implantation method for improving hot carrier injection damage. Background technique [0002] The hot carrier effect is an important failure mechanism of MOS (metal oxide semiconductor) devices. With the shrinking of the size of MOS devices, the hot carrier injection effect of the devices becomes more and more serious. Taking a PMOS (P-type metal oxide semiconductor) device as an example, the holes in the channel are accelerated under the action of a high lateral electric field between the drain and source to form high-energy carriers, which collide with the silicon lattice. Generate ionized electron-hole pairs, the electrons are collected by the substrate to form a substrate current, most of the holes generated by the collision flow to the drain, but some holes are injected into the gate under the action of the vertical electric field The formation of gate curr...

AI Technical Summary

Problems solved by technology

[0003] Hot carriers will break the energy bond at the interface between the silicon substrate and the silicon dioxide gate oxygen, and generate interface states at the interface between the silicon substrate and the silicon dioxide gate oxygen, resulting in device performance, such as threshold voltage, transconductance, and linearity. The degradation of the current in the region / saturation region will eventually cause the failure of the MOS device

Images