Study of surface kinetics in PECVD chamber cleaning using remote plasma source

The scope of this research work is to characterize the Transformer Coupled Toroidal Plasma (TCTP); to understand gas phase reactions and surface reactions of neutrals in the cleaning chamber by analyzing the concentration of neutrals in downstream cleaning process chamber; and to make a global model that predicts the partial pressure of active species in the cleaning chamber. The final goal is to set-up an optimal cleaning process using the results from the experiment and the global model. The first object is to characterize the TCTP and the power consumed by plasma is measured as one approach to the characterization of plasma. MKS Astex plasma source has a very high power density. Compared to a typical industrial plasma source, the power density of the TCTP source is two orders of magnitude higher. The extremely high power density makes the plasma source very unique and its parameters very different from other plasma sources. It is discussed that there are several factors that affect the plasma power consumption. One factor is the flow rate of inlet gas and the elevated pressure due to the high flow rate of inlet gas increases the power consumption. Experimentally it is observed that the plasma power is linearly dependent upon the plasma source pressure, not upon the process chamber pressure. Another factor of controlling the power consumption is the resistivity of gases. For example, the bonding energy of N-F in NF3 gas is different from the bonding energy of C-F bonding in C2F6. Experimental result shows that C2F6 + 02 gas requires more power than NF3 gas to dissociate in the plasma due to the different resistivity. The second object is to understand gas phase reactions and surface reactions among neutrals in the cleaning chamber. The effect of nitric oxide as a silicon nitride etching enhancement factor is discussed.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• An, Ju Jin

Advisor dc:contributor.advisor

• Herbert H. Swain.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/43204

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/43204