Paper VT-TuP6
A Compact Deposition Chamber Design for Low Temperature Growth of Ultra-Thin Crystalline Films on Metal-Insulator-Semiconductor Devices

Tuesday, October 21, 2008, 6:30 pm, Room Hall D

Fabricating ultra-thin crystalline metal films is especially important in new studies of ballistic electron transport at interfaces and energetic processes of atoms on surfaces. In order to probe physics at the atomic level without contamination these studies require that homogeneous, atomically ordered, and defect free thin films be deposited in the same ultra-high vacuum (UHV) system where they will be studied. With this constraint in mind, we have designed and built a compact deposition chamber that allows for in situ growth and analysis of atomically ordered epitaxial metal layers which are only a few monolayers thick. This UHV deposition chamber is attached to a port on the fast exchange load lock (FELL) of our Omicron variable temperature STM (VT-STM) and has an internal volume of 476 cm³. It contains an evaporation gun slot that can be equipped with either an electron beam evaporator or a simple thermal evaporator. The target substrates used for deposition are compatible with the VT-STM design and are held in place at the center of the deposition chamber in a specially-designed clamping slot fabricated into an oxygen-free high-conductivity copper stage. The copper sample stage facilitates rapid cooling of the substrates to the temperatures required for crystalline film growth. This is done using a continuous flow of liquid nitrogen through the hollowed out interior of the sample stage. Following film growth, samples can be kept under vacuum and transferred into the FELL via a rotary-linear manipulator and then directly into the VT-STM chamber for analysis. Our compact chamber design has made the VT-STM system more effective for measurements of as-grown surfaces and interfaces, and its low cost and ease of use should be of special interest to other physicists, chemists, and engineers with similar research goals.