AVS 52nd International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoP

Paper PS-MoP15
Etching of Titanium Nitride

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Plasma Science and Technology Poster Session
Presenter: D. Wu, Air Products and Chemicals, Inc.
Authors: D. Wu, Air Products and Chemicals, Inc.
B. Ji, Air Products and Chemicals, Inc.
E.J. Karwacki, Air Products and Chemicals, Inc.
Correspondent: Click to Email
Titanium nitride (TiN) has many emerging new applications within semiconductor industry. It is being employed as a diffusion barrier in contacts, vias, trenches, and interconnect stacks, as well as an electrode material. The film is typically deposited by way of a batch CVD technique within a quartz tube furnace at a temperature lower than 150ºC. A cleaning method that removes TiN deposits from the inner surfaces of the deposition chamber, but does not damage the furnace is urgently needed by the industry. In this paper we report on our efforts to develop an effective process for TiN deposition chamber cleaning. Using our lab reactor as a screening tool, a variety of reactive gases and process conditions has been screened. For example, we have tested a thermal process using NF3, Cl2, and 5%F2. In each case, a temperature of higher than 200ºC is needed to start the etching reaction. To reduce the required temperature, remote plasma is used together with the thermal process. The process using remote NF3 plasma etches TiN at a rate of 1000 nm/min with a TiN/SiO2 selectivity of 8 at 140ºC. Surface analysis is also conducted to understand the etching mechanism.