AVS 49th International Symposium
    Applied Surface Science Thursday Sessions
       Session AS-ThM

Paper AS-ThM6
DC Field Emission Analysis of GaAs and Plasma-source Ion Implanted Stainless Steel

Thursday, November 7, 2002, 10:00 am, Room C-106

Session: Practical Surface Science I
Presenter: C. Hernandez, Jefferson Lab
Authors: C. Hernandez, Jefferson Lab
T. Wang, Jefferson Lab
T. Siggins, Jefferson Lab
H.F. Dylla, Jefferson Lab
N.D. Theodore, College of William and Mary
D.M. Manos, College of William and Mary
C.E. Reece, Jefferson Lab
Correspondent: Click to Email
Field emission studies have been performed on a GaAs wafer and a sample of its stainless steel (SS) support electrode that are part of the new photocathode gun for the 10 kW upgrade FEL at Jefferson Lab. The objective of the studies presented here is to characterize the effect of both, the cleanliness of the wafer and the plasma source ion implanted layer on the electrode to suppress field emission. Field emission is the limiting factor to achieve the required 6 MV/m at the surface of the wafer. Potential field emitters are first located on the surface of 1-inch diameter samples with a DC field emission scanning apparatus at 60 MV/m, then each emitter is characterized by SEM equipped with EDS. The GaAs wafer was hydrogen cleaned before the study. The results show three emitters caused by indium contamination during wafer handling. The GaAs wafer thus shows good high voltage characteristics and the need to maintain cleanliness during handling. The SS sample is hand polished with diamond paste to a 1-micron surface finish, then implanted with N@sub 2@/SiO@sub 2@ in a plasma source ion implantation chamber in preparation for the field emission studies.@footnote 1@ @FootnoteText@ @footnote 1@This work is supported by the US Dept. of Energy and the Office of Naval Research.