AVS 63rd International Symposium & Exhibition
    Plasma Science and Technology Thursday Sessions
       Session PS-ThP

Paper PS-ThP13
Down Stream Plasma Ash Process Impact on Metal Electrode Oxidation and Nitridation for 10nm and Below Logic Technology

Thursday, November 10, 2016, 6:00 pm, Room Hall D

Session: Plasma Science and Technology Division Poster Session
Presenter: Shawming Ma, Mattson Technology
Authors: B. Elliston, Mattson Technology
G. Kishko, Mattson Technology
V. Vaniapura, Mattson Technology
V.P. Nagorny, Mattson Technology
S. Ma, Mattson Technology
Correspondent: Click to Email
For the semiconductor process flow with advanced nodes below 10nm, it is desired to remove the photoresist on top of metal electrodes, such as TiN, with minimum oxidation and nitridation. In general, the resist is typically removed by plasma strip followed by wet clean or by plasma strip or wet strip only. To minimize and control the oxidation, it is desired to use a non-oxygen chemistry. In this paper, detailed surface characterization methods including surface sheet resistance (Rs), optical ellipsometry, X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and Electron Energy Loss Spectroscopy (EELS) are used to evaluate the surface oxidation and nitridation under various hardware and process conditions. It is identified that the grounded Faraday shield is critical to reducing tube erosion from the Inductive Coupled Plasma (ICP) coil’s strong electric field which may an contribute to less wafer surface oxidation. Current modeling suggests the tube’s erosion from high electric fields inside the source may contribute small amounts of oxygen that induces more wafer oxidation on wafers, even when a non-oxygen chemistry is used. In addition, extended que times can affect the post oxidation measurements . Possible hardware and process solution are also discussed to minimize metal oxidation and nitridation.