Figure 5.

HR-TEM images of the pattern transfer process. (a) Bright-field cross-section image of the periodic HfO₂ stripe pattern. (b) Close-up view of an etched trench. The GaAs surface structure appears modified by the plasma etch. The formation of a sloped sidewall can also be seen. (c) Close-up view of a 100-nm-wide HfO₂ mesa stripe. The formation of an approximately 10-nm-wide foot due to mask erosion is observed on both sides of the HfO₂ mesa.