ELECTROSTATIC (LANGMUIR) PROBE MEASUREMENTS IN RF DRIVEN He, N2, BCl3, AND BCl3/N2 PLASMAS

A Langmuir probe diagnostic system was developed to measure the electron density distribution in BCl3/N2 mixtures to determine if an average electron energy increase might be partially responsible for the previously observed etch rate enhancement of GaAs with nitrogen addition. The system was validated in both helium and nitrogen plasmas. Probe measurements showed that as the nitrogen concentration in BCl3/N2 plasmas increased, the average electron energy actually decreased (5.52 eV @ 0% N2, 4.14 eV @ 30% N2, and 3.69 eV @ 60% N2). However, an increase in negative ion density was observed with nitrogen addition reaching a maximum at 40% N2. Although negative ions play no role in etching, this trend seems to correlate with the observed etch rate enhancement. A plausible explanation for both the increase in etch species and the increase in negative ion density is an increase in dissociation due to energy transfer from N2 metastables.

Grantor dc:publisher

University of Kansas

Year dc:date.issued

2008

Author dc:creator

• Pathak, Bogdan Amaru

Advisors dc:contributor.advisor

• Nordheden, Karen J.
• Hui, Rongqing

• Electronics and electrical engineering
• Physics
• Fluid and plasma
• Materials science engineering
• Langmuir probe
• Bcl3
• N2
• He
• Plasma
• Etching

Statement dc:rights

• This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.

Language dc:language.iso

EN

Dc Identifier Other

http://dissertations.umi.com/ku:2692

OAI identifier oai:identifier

oai:kuscholarworks.ku.edu:1808/4166