Instrumentation of the High-Vacuum Atomic Force Microscope

The high-vacuum atomic force microscope (HV-AFM) is a useful tool that is used in various sample environments and achieve good Z axis sensitivity in a noncontact mode operation because the cantilever is free from hydrodynamic damping. The instrument is designed with the aims of minimizing the measuring time, simplifying the operation and achieving high performance. A pumping pressure of about 10 -4 Pa is obtainable within 15 min. To achieve easy operation, the optical lever deflection detection head is placed outside the vacuum chamber. The vibration isolation is achieved using an elastic damper and a magnetic-floating-type turbomolecular pump. This vibration isolation method works well enough to obtain the atomic-resolution image of a highly oriented pyrolytic graphite (HOPG) sample. We checked the sensitivity of the instrument using the noncontact mode of operation of a magnetic force microscope (MFM). The Z axis sensitivity in vacuum operation was compared with that in ambient operation. The quality factor increased by more than 25 times and the Z axis sensitivity increased by more than 10 times in vacuum operation (10 -4 Pa).