In situ Remote H-Plasma Cleaning of Patterned Si-SiO2 Surfaces.

A RF H‐plasma exposure was used to clean the surface of patterned wafers. The areal coverage of to bare Si was 4 to 1, and the patterns were long strips, small squares, and large open regions. The plasma‐surface etching was monitored by residual gas analysis (RGA). The RGA spectra indicated etching of the Si surface at temperatures below 400°C and no detectable by‐products due to interactions with the regions for temperatures <450°C. The patterned surfaces were characterized with low energy electron diffraction (LEED) (from the bare Si regions) and atomic force microscopy (AFM). The LEED patterns indicate and surface symmetries at 300 and 450°C, respectively. The sharpness of the LEED patterns as well as the reconstruction indicated that the H‐plasma cleaned the bare Si regions. In addition, AFM measurements indicated that the Si and surface rms roughnesses do not vary significantly due to the H‐plasma exposure. It can be concluded from the RGA and AFM data that the remote H‐plasma process at 450°C cleaned the surface and did not significantly react with either the Si or regions.