Charge Transport Laboratory

Cook Hall, 1163
Laboratory Director: Mark Hersam, MSE

The Charge Transport Laboratory includes equipment to perform DC electrical measurements on a wide variety of samples, including electrical conductivity measurements and device characterization. A new four-point probe station has been installed, which includes high-precision movement, a 120X microscope for probe positioning, a vacuum chuck, and a full light enclosure. A fixed inline four-point probe is also available for simplified electrical conductivity measurements on bulk samples or thin films. Two Keithley 2400 source meters are provided for the measurements and can be operated using custom software on the connected PC.

Typical measurements performed include sheet resistance measurements on thin films, conductivity measurements of nanopatterned regions, field-effect transistor characterization, and electronic characterization of light-sensitive samples.

The new four-point probe station is an M150 Benchtop Station by Cascade Microtech, Inc. The stage has 155mm of high precision XY motion and 5mm of Z-motion as well as a vacuum chuck. A Leica S6 D StereoZoom Microscope with up to 120X magnification and lighting is included for accurate positioning of the tungsten probes. The probe station is enclosed in a light tight enclosure and is connected to two Keithley 2400 Source Meters controlled by a PC. LabView software is provided for common electrical measurements. The inline four-point probe consists of four tungsten probes with 1mm separation and spring action for making contact with samples. The coarse Z-position of the probes is also adjustable for measuring larger samples.