A low-temperature scanning probe microscopy system with molecular beam epitaxy and optical access

TL;DR

This paper presents the design, construction, and testing of a low-temperature UHV SPM system with MBE and optical access, enabling high-resolution surface imaging and spectroscopy.

Contribution

It introduces a novel SPM system with integrated MBE and optical capabilities, featuring a rigid, optically accessible scanner head suitable for STM and AFM.

Findings

Resolved atomic structure of Au(111) surface.

Obtained dI/dV spectra at 5 K.

Grew 2D tellurium on Au(111) using MBE.

Abstract

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.