A novel ALD SiBCN low-k spacer for parasitic capacitance reduction in FinFETs

FinFET has become the mainstream logic device architecture in recent technology nodes due to its superior electrostatic and leakage control [1,2,3,4]. However, parasitic capacitance has been a key performance detractor in 3D FinFETs. In this work, a novel low temperature ALD-based SiBCN material has been identified, with an optimized spacer RIE process developed to preserve the low-k value and provide compatibility with the down-stream processes. The material has been integrated into a manufacturable 14nm replacement-metal-gate (RMG) FinFET baseline with a demonstrated ~8% performance improvement in the RO delay with reliability meeting the technology requirement [4]. A guideline for spacer design consideration for 10nm node and beyond is also provided based on the comprehensive material properties and reliability evaluations.