  A low-temperature ultra-high vacuum scanning probe microscopy (SPM) system
with molecular beam epitaxy capability and optical access was conceived, built,
and tested in our lab. The design of the whole system is discussed here, with
special emphasis on some critical parts. We made an SPM scanner head with a
modified Pan-type design, enclosed by a double-layer cold room under a bath
type cryostat. The scanner head is very rigid, compatible with optical access
paths, and can accommodate both scanning tunneling microscope (STM) tips and
atomic force sensors. Two piezo-actuated focus-lens stages are mounted on the
two sides of the cold room to couple light in and out. To demonstrate the
system performance, we performed STM and scanning tunneling spectroscopy
studies. The herringbone reconstruction and atomic structure of Au(111) surface
were clearly resolved. The dI/dV spectra of an Au(111) surface were obtained at
5 K. In addition, a periodic 2D tellurium (Te) structure was grown on Au(111)
surface using MBE.
