SelectiveWet Etching of Silicon Germanium in Composite Vertical Nanowires
2019
Silicon germanium(SixGe1–x or SiGe) is an important semiconductor material for the fabrication of nanowire-based gate-all-around transistors in the next-generation logic and memory devices. During the fabrication process, SiGe can be used either as a sacrificial layer to form suspended horizontal Si nanowires or, because of its higher carrier mobility, as a possible channel material that replaces Si in both horizontal and vertical nanowires. In both cases, there is a pressing need to understand and develop nanoscale etching processes that enable controlled and selective removal of SiGe with respect to Si. Here, we developed and tested solution-based selective etching processes for SiGe in composite (SiNx/Si0.75Ge0.25/Si) vertical nanowires. The etching solutions were formed by mixing acetic acid (CH3COOH), hydrogen peroxide (H2O2), and
hydrofluoric acid(HF). Here, CH3COOH and H2O2 react to form highly oxidizing
peracetic acid(PAA or CH3 CO3H). The
hydrofluoric acidserves both as a catalyst for PAA for...
Keywords:
-
Correction
-
Source
-
Cite
-
Save
47
References
15
Citations
NaN
KQI