摘要 |
A process for etching silicon nitride from a multilayer structure which uses an etchant gas including a fluorocarbon gas, a hydrogen source, and a weak oxidant. A power source, such as an RF power source, is applied to the structure to control the directionality of the high density plasma formed by exciting the etchant gas. The power source that controls the directionality of the plasma is decoupled from the power source used to excite the etchant gas. The fluorocarbon gas is selected from CF4, C2F6, and C3F8; the hydrogen source is selected from CH2F2, CH3F, and H2; and the weak oxidant is selected from CO, CO2, and O2.
|