Effect of deposition condition on wet and dry etch rates of device quality inductively coupled plasma-chemically vapor deposited SiNx

Inductively coupled plasma-chemically vapor deposited (ICP-CVD) SiNx was grown on Si substrates using a SiH4/NH3/He chemistry at 150°C. The influence of source power, chamber pressure, rf chuck power and percentage SiH4 on the wet (in BOE) and dry (in ICP SF6/Ar discharges) etch rates of the SiNx was investigated. The dry etch rates are found to strongly increase with stress in the film above a threshold of ∼500 MPa, while the wet etch rates increase rapidly with source power, chamber pressure and hydrogen content.