dc field-emission analysis of GaAs and plasma-source ion-implanted stainless steel
Field-emission studies have been performed on a GaAs wafer and a sample of its stainless-steel (SS) support electrode that are part of a photocathode gun for the 10 kW Upgrade infrared free electron laser 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 in. diameter samples with a dc scanning field-emission microscope at 60 MV/m, then each emitter is characterized in a scanning electron microscope equipped with an energy dispersive spectrometer. 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-m surface finish, then implanted with N2/SiO2 in a plasma-source ion-implantation chamber in preparation for the field-emission studies.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE - Office of Energy Research (ER)
- DOE Contract Number:
- AC05-84ER40150
- OSTI ID:
- 860983
- Report Number(s):
- JLAB-ACT-03-126; DOE/ER/40150-3640; TRN: US200601%%563
- Journal Information:
- Journal of Vacuum Science & Technology A, Vol. 21, Issue 4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Surface science analysis of GaAs photocathodes following sustained electron beam delivery
Limitations on the use of scanning probe microscopy for the measurement of field emission from copper surfaces