A scanning tunneling microscope using dual-axes inchworms for the observation of a cleaved semiconductor surface

Abstract

We have constructed a new scanning tunneling microscope (STM) that uses x and z inchworms for micropositioning in an ultrahigh vacuum environment. One (z inchworm) is for approaching the tip to the sample surface and the other (x inchworm) is for both cleaving the sample and moving the sample to positions of interest. We have demonstrated that this STM is very useful for observing the cross section of a thin epitaxial layer, such as the cleaved (110) surface of a Ga0.47In0.53As/InP multiquantum well (MQW) structure. The STM image of GaInAs well layers and InP barrier layers has been shown to reflect the feature of the MQW potential. Moreover, we have obtained images of the filled states on the group-V anions in the GaInAs and InP layers.

An ultra‐rigid close‐stacked piezo motor for harsh condition scanning probe microscopy

“…In general, an ideal piezo motor for a high performance SPM should meet the following conditions: simple structure (high reliability), low‐voltage to control (i.e., low threshold voltage, which brings low noise and high precision), compact (low thermal drift and extreme condition compatible), and rigid (vibration resistant). However, most piezo motor types have nonnegligible disadvantages: Inchworm (Berndt et al ., ; Shimizu et al ., ; Kato et al ., ; Cusin et al ., ) is complicated and requires high machine tolerance; The Pan style (Pan et al ., ) motor is somewhat complicated with lower blocking force (thus lower output force) since it relies on shear displacement; the inertial motor (Pohl, ; Judy et al ., ; Howald et al ., ; Zesch et al ., ) is less rigid and produces small output force because the inertial force used is typically weak.…”