Silicon etch with passivation using chemical vapor deposition

摘要

A silicon layer is etched through a patterned mask formed thereon using an etch chamber. A fluorine (F) containing etch gas and a silicon (Si) containing chemical vapor deposition gas are provided in the etch chamber. The fluorine (F) containing etch gas is used to etch features into the silicon layer, and the silicon (Si) containing chemical vapor deposition gas is used to form a silicon-containing deposition layer on sidewalls of the features. A plasma is generated from the etch gas and the chemical vapor deposition gas, and a bias voltage is provided. Features are etched into the silicon layer using the plasma, and a silicon-containing passivation layer is deposited on the sidewalls of the features which are being etched. Silicon in the passivation layer primarily comes from the chemical vapor deposition gas. The etch gas and the chemical vapor deposition gas are then stopped.

主权项

1. A method of etching a silicon layer through a patterned mask formed thereon using an etch chamber in which the silicon layer is placed, the method comprising:
providing a fluorine (F) containing etch gas to etch features into the silicon layer and a silicon (Si) containing chemical vapor deposition gas to form a silicon-containing deposition layer on sidewalls of the features by premixing the etch gas and the chemical vapor deposition gas, the chemical vapor deposition gas containing siloxane vapor; generating a plasma from the etch gas and the chemical vapor deposition gas; providing a bias voltage; etching features into the silicon layer using the plasma through the patterned mask; depositing, using the plasma, a silicon-containing passivation layer on the sidewalls of the features which are being etched, wherein silicon in the passivation layer primarily comes from the chemical vapor deposition gas; and stopping the etch gas and the chemical vapor deposition gas,wherein the method is performed in a steady state such that the etching of the silicon layer and the depositing of the silicon-containing passivation layer occur simultaneously in a non-alternating manner.