IRRADIATION DAMAGES IN ELECTRON BEAM LITHOGRAPHY

The irradiation damages to Al gate MOS capacitors in electron beam lithography (EBL) and the effects of annealing on damages at low temperature (500℃) are given. The degrees of damages depend on the eleetron energies (10-30keV) and the charge dosages (10-6-10-3Ccm-2). The research on the effects of high energy (30keV) and large dosage (10-3 Ccm-2) on damages is important and useful to EBL with vapor development and without devolopment. The damages of concentrations of interface states can reach one to two orders f magnitude. Under constant charge dosages, the damages of flat-band voltages are independent of the variations of the electron energies in certain energy ranges; and under constant electron energies, the damages of concentrations of interface states are independent of the variations of charge dosage in certain dosage ranges. The annealing can eliminate the damages of the flatband voltages, but can not eliminate completely the damages of the concentrations of the interface states.