METHOD FOR ETCHING FEATURES IN A STACK

The invention relates to a method for etching features in a stack, and particularly provides a method for etching features in a stack below a carbon containing mask. The stack is cooled to a temperature below -20 DGE C. An etch gas is provided comprising a free fluorine providing component, a hydrogen containing component, a hydrocarbon containing component, and a fluorocarbon containing component. Plasma is generated from the etch gas. A bias is provided with a magnitude of at least about 400 volts to accelerate ions from the plasma to the stack. Features are selectively etched in the stack with respect to the carbon containing mask. 本发明涉及用于在堆叠层中蚀刻特征的方法。提供了一种用于在含碳掩模下方的堆叠层中蚀刻特征的方法。将堆叠层冷却至低于-20℃的温度。提供蚀刻气体，其包含提供游离氟的组分、含氢组分、含烃组分和含碳氟化合物组分。由该蚀刻气体生成等离子体。提供幅值为至少约400伏的偏压，以加速离子从等离子体到达堆叠层。相对于含碳掩模，在堆叠层中选择性地蚀刻特征。