The Removal of Thin Oxygen and Carbon Surface Films by H₂/Ar Plasmas as Characterized by Low kV EDS

Improved Scanning Electron Microscope (SEM) vacuum conditions have been of considerable interest during the past decade, especially as low landing energies are employed to perform surface sensitive imaging [1][2][3]. To further improve instrument performance plasma cleaning can be applied. In general, the cleaning chemistry is a plasma formed from laboratory air (nitrogen+oxygen). TEM and SEM samples can be cleaned ex-situ with this plasma. Alternatively, other gas mixtures have been reported such as 75% Argon + 25% Oxygen [4]. In this study, we report on the use of 95% Argon + 5% Hydrogen mixture for the removal of carbon and oxygen containing films on Indium using low Energy Dispersive Spectroscopy (EDS). This gas mixture is not pyrophoric and is well suited for the laboratory environment.