The ion implantation effect on MIS-structure defects

The boron ion implantation effect on metal-isolator-semiconductor (MIS) structure SiO2 and SiO2 - PSG (phospho silicate glass) layer defects has been investigated. The test MIS capacitors of 1,5 mm2 area fabricated on phosphorus-doped (resistivity 4.5 Ω * cm) Si <100> wafers were studied. Silicon dioxide of thickness 100 nm was thermally grown in O2 at 1000OC with an addition of 3% HCl. The PSG films were 10 nm thick. In order to eliminate the gate insulator defect wafer area- and batch- variation effect on the obtained experimental results the insulating properties of MIS-structure insulator layers on the wafers that were fabricated in different batches and placed in the centre and periphery of the wafers were investigated. It was found that the gate insulator defects can widely vary from one wafer batch to another being similar for the wafers fabricated within one batch. The silicon dioxide defect value was determined to be of the same order within a wafer. Since the gate insulator defects value differs from batch to batch, the studies of the ion-implantation effect on the MIS-structure insulator layer defects were performed using the wafers oxidized within one batch. It was shown that the defects increase at silicon dioxide passivated by phospho silicate glass under ion implantation unlike the SiO2 films. Insulator layer defects on the operational wafers exceed the defects on the auxiliary wafers. These defects can be annihilated by thermal anneal