Characterization in Silicon Processing

boundaries, which results in lower

than

anticipated carrier concentrations (higher

resistivities)

and grain boundaries

that

oxidize rapidly. Identification of this situ-

ation requires careful

analysis

with a high spatial resolution technique to map the

phosphorus

distribution, such as dynamic SIMS with a field emission ion source,

or, if the

phosphorus

level is high enough, EDS mapping in a TEM.

In situ doping during deposition is receiving increased attention. There are

prob-

lems

with in situ doping such as reduced deposition rates,

dopant

incorporation

and distribution, impurity incorporation from the

dopant

source, and

dopant

uni-

formit