METHOD OF FORMING THE GATE WITH THE LELE DOUBLE PATTERN

摘要

The invention relates to microelectronic technology and, more specifically, relates to a method of forming a gate with a LELE double pattern. The method adopts an ONO structure (Oxide-SiN-Oxide). The ONO structure is exposed twice, and the advanced patterning film is used as a mask in the processing of polysilicon etching. The ONO structure is used to replace the traditional hardmask of silicon oxide, and the substructure of ODL (Organic Under Layer) which is based on the spin-on, and the middle layer structure of SHB (Si-based hardmask). The method saves cost and improves the process of advanced patterning film as a mask with the nodes in 40 nm and above which is applied to the process with the nodes in 22/20 nm and below. Consequently, the maturity and stability of the process for poly gate with the nodes in 22/20 nm and below are improved.

主权项

1. A method of forming a gate with a Litho-Etch-Litho-Etch (LELE) double pattern, wherein said method comprises the following steps:
depositing an advanced patterning film layer and a hardmask layer on a semiconductor substrate which is provided with a gate layer structure; etching the hardmask layer by an etching process to form a hardmask structure; etching the advanced patterning film by using the hardmask structure as a mask for forming an advanced patterning mask and stopping etching of the advanced patterning film at the upper surface of the gate layer structure; and etching the gate layer structure by the advanced patterning mask for forming gate structures and stopping the etching of the gate layer structure at the upper surface of the semiconductor substrate.