Controlled-atmosphere chamber for atomic force microscopy investigations

The present work describes a simple chamber suitable for morphological inve stigations by implementing the atomic force microscopy (AFM) in controlled experiments. The novelty of our application stems from proposing an open sy stem located in between the expensive, ultra-high-vacuum instruments and th ose working in air conditions, both available on the market. The former are in fact designed to obtain a detailed inspection of the samples and to dev elop particular geometries on them, by means of nanolithography or nanomani pulation, while the latter are designed for and used in all the situations in which the environmental conditions do not cause artifacts, problems, or formation of spurious particles on the samples during imaging. We have deve loped an ad hoc system based on a high-vacuum chamber (up to 10(-6) Torr), which allows us to work under controlled-atmosphere conditions. The system, therefore, can be used with most of the samples which suffer from higher p ressures, and exploits all the benefits arising from a controlled environme nt. We have equipped the chamber with an AFM and a sample-holder/mover. An external X-Y-Z motion controller, completely automated, allows the easy pos itioning of the sample under the sensing cantilever and the consequent rela tive approach. Experiments with the proposed system are presented, in which the control of environmental conditions during AFM measurements has been i nvestigated with satisfactory results. (C) 2000 American Institute of Physi cs. [S0034-6748(00)03606-6].