Proximity gettering design of silicon wafers using silicon hydride and hydrocarbon mixture molecular ion implantation technique

We developed a novel hybrid-molecular-ion-implantation technique for proximity gettering to reduce the carbon dose. In this molecular-ion-implantation technique, a molecular ion beam with a mixture of silicon hydride and hydrocarbon-molecular-ions is used. We found that 150 nm silicon {111} extrinsic Frank-type dislocation loops in the ion-implanted region are formed by this technique after epitaxial growth. Nickel and copper gettering test results showed that the ion-implanted region can getter Ni and Cu contaminants that diffused from the wafer surface at a carbon dose lower than those in hydrocarbon-molecular-ion-implanted wafers. We determined by energy dispersive x-ray (EDX) observation that end of range defects (EOR) act as gettering sites. We speculate two types of gettering induced by this technique: the relaxation-type gettering caused by EOR defects and the segregation-type gettering caused by the high concentration of carbon around EOR defects.

Automated summary

The novel hybrid molecular ion implantation technique for proximity gettering effectively reduced carbon dose by forming silicon extrinsic Frank-type dislocation loops after epitaxial growth. Nickel and copper gettering test results showed that the ion-implanted region can capture Ni and Cu contaminants with lower carbon dose compared to hydrocarbon-molecular-ion-implanted wafers. The end of range defects (EOR) were observed to act as gettering sites, suggesting relaxation-type and segregation-type gettering induced by this technique.