Boron membranes for x-ray spectroscopy

Purpose and goal

The purpose of the project was to realize thin films constituted of boron so that membranes for soft x-ray spectroscopy of liquids and gases could be created. Two main parts of the project were to create boron components to be utilized in the subsequent deposition of thin films. Suitable components with a boron content of approximately 50% was attained and thin films were deposited using such components. The rate of deposition was very low and the composition of the thin film was probably somewhat less than that of the boron source component.

Expected results and effects

Graphite cups were created, filled with boron. The boron and the graphite react at high temperature to form compounds. Importantly, it was possible to drastically reduce the content of oxygen on the boron grains. The graphite cups were made to fit in a thin film deposition system. It was possible to operate the deposition system using the boron-filled graphite cup, but the rate of deposition proved to be very low. To attain useful results, it will be necessary to continue the process development. The project has created a good base for this continued work.

Planned approach and implementation

The logic sequence of action were to first manufacture the boron components and subsequently use them in the thin film deposition system. In practice it became necessary to run the two projects partially in parallel, since the creation of the boron components proved very challenging and at the same time one part of the modifications on the deposition system needed a lot of preparation. It might have been better to run two consecutive projects in series, to be able to better focus on each challenge.