Atomic hydrogen cleaning of semiconductor photocathodes

Conference · Sun Jun 01 04:00:00 EDT 1997

OSTI ID:489686

Sinclair, C K; Poelker, B M; Price, J S ^[1]

---

1. Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

Negative Electron Affinity (NEA) semiconductor photocathodes are widely used for the production of polarized electron beams, and are also useful for the production of high brightness electron beams which can be modulated at very high frequencies. Preparation of an atomically clean semiconductor surface is an essential step in the fabrication of a NEA photocathode. This cleaning step is difficult for certain semiconductors, such as the very thin materials which produce the highest beam polarization, and those which have tightly bound oxides and carbides. Using a small RF dissociation atomic hydrogen source, the authors have reproducibly cleaned GaAs wafers which have been only degreased prior to installation in vacuum. They have consistently prepared very high quantum efficiency photocathodes following atomic hydrogen cleaning. Details of their apparatus and most recent results are presented.

• Research Organization: Southeastern Universities Research Association, Inc., Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 489686
• Report Number(s): DOE/ER/40150--1141; CONF-970503--32; JLAB-ACC--97-12; ON: DE97006513
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
AFFINITY
ELECTRON SOURCES
GALLIUM ARSENIDES
HYDROGEN
PHOTOCATHODES
SURFACE CLEANING