Patterning Challenges in Microelectronics

International audienc

Gate patterning strategies to reduce the gate shifting phenomenon for 14 nm fully depleted silicon-on-insulator technology

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Cleaning chamber walls after ITO plasma etching process

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New CH 4 -N 2 dry etch chemistry for poly(methyl methacrylate) removal without consuming polystyrene for lamellar copolymers application

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Block copolymer selectivity: A new dry etch approach for cylindrical applications

International audienceA critical challenge for directed self-assembly of block copolymers is the selectivity between the two polymer phases. Polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) is one of the most studied block-copolymers to reach sub-20 nm patterns. A very high PMMA/PS selectivity (>10:1) is required to conserve a sufficient PS pattern thickness allowing pattern transfer to sublayers. In this paper, the authors propose to develop a chemistry allowing a full PMMA removal without PS consumption. It is based on CO and CO-H 2 cycles allowing to get a very high etch control. The proposed etch mechanisms have been understood thanks to x-ray photoelectron spectroscopy analyses performed on blanket wafers. Finally, this new etch process has been validated on the cylindrical PS-b-PMMA patterned structure. Published by the AVS

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

International audienceSilicon 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)

Porous SiOCH Integration: Etch Challenges With a Metallic Hard Mask Approach

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