Metal Migration Induced Breakdown from Gate Contact in Bulk FinFET Devices

Abstract

Bulk fin field-effect transistor (FinFET) devices with excellent gate control ability are promising to succeed the planar devices under Moore’s law. With the scaling down of the feature size, the reliability of the FinFET device becomes an urgent issue. Also, the miniaturized three-dimensional structure of bulk FinFET makes the failure characterization more challenging. In this paper, we carried out the direct current (DC) breakdown and transmission line pulse (TLP) breakdown in the bulk FinFET. Corresponding microstructural and chemical elements’ differences between gate contact and gate electrode are characterized by transmission electron microscopy (TEM). For both experiments, the fin nearest to gate contact is completely damaged under electrical stressing. The destruction of DC is more serious, which has a large area fusion with metal migration. The TLP damage is local and tends to form a void. The gate contact structure is intact with slight elements’ migration. This work paves a guideline for the reliability improvements of FinFET.