Development and Applications of Time of Flight Neutron Depth Profiling

Cady, Bingham ; Unlu, Kenan

Cornell University (United States)

关键词: Optical Properties;    Protons;    Surface Barrier Detectors;    Charged Particles;    Atoms;   

DOI  :  10.2172/838303
RP-ID  :  DOE/ID/13921
RP-ID  :  FG07-00ID13921
RP-ID  :  838303

美国|英语

来源: UNT Digital Library

【 摘 要 】

The depth profiles of intentional or intrinsic constituents of a sample provide valuable information for the characterization of materials. For example, the subtle differences in spatial distribution and composition of many chemical species in the near surface region and across interfacial boundaries can significantly alter the electronic and optical properties of materials. A number of analytical techniques for depth profiling have been developed during the last two decades. neutron Depth Profiling (NDP) is one of the leading analytical techniques. The NDP is a nondestructive near surface technique that utilizes thermal/cold neutron beam to measure the concentration of specific light elements versus their depth in materials. The depth is obtained from the energy loss of protons, alphas or recoil atoms in substrate materials. Since the charged particle energy determination using surface barrier detector is used for NDP, the depth resolution is highly dependent on the detectors an d detection instruments. The depth resolutions of a few tens of nm are achieved with available NDP facilities in the world. However, the performance of NDP needs to be improved in order to obtain a few A depth resolutions.