Understanding of a new approach for silicon nitride spacer etching using gaseous hydrofluoric acid after hydrogen ion implantation

作者：Ah Leung Vincent^*; Pollet Olivier; Posseme Nicolas; Barros Maxime Garcia; Rochat Nevine; Guedj Cyril; Audoit Guillaume; Barnola Sebastien

来源：Journal of Vacuum Science and Technology A, 2017, 35(2): 021408.

DOI：10.1116/1.4977077

Silicon nitride spacer etching is one of the most critical step for the fabrication of CMOS transistors in microelectronics. It is usually done by plasma etching using a fluorocarbon based chemistry. However, from the 14 nm technology node and beyond, this etching process no longer allows the etch specifications to be reached (nonformation of a foot, poor critical dimension control below 1 nm). To overcome this issue, a new process was developed. It consists of two steps: in a first step, the silicon nitride film is modified by light ion implantation (hydrogen), and then followed by a removal step of this modified film by hydrofluoric acid (HF). In this paper, the authors propose to remove the implanted/modified silicon nitride using gaseous HF and understand the associated etching mechanisms using infrared spectroscopy and x-ray photoelectron spectroscopy at different stages of the process sequence (after implantation/modification, gaseous HF process, and post-treatment).

• 出版日期2017-3
• 单位中国地震局