Nanoscale Wet Etching of Physical-Vapor-Deposited Titanium Nitride and Its Application to Sub-30-nm-Gate-Length Fin-Type Double-Gate Metal-Oxide-Semiconductor Field-Effect Transistor Fabrication

摘要

The nanoscale wet etching of physical-vapor-deposited (PVD) titanium nitride (TiN) and its application to sub-30-nm-gate-length fin-type double-gate metal-oxide-semiconductor field-effect transistor (FinFET) fabrication are systematically investigated. It is experimentally found that PVD-TiN side-etching depth can be controlled to be one-half of PVD-TiN thickness with precise time control using an ammonium hydroxide (NH_4OH): hydrogen peroxide (H_2O_2): deionized water (H_2O) = 1:2:5 solution at 60 ℃. Using the developed nanoscale PVD-TiN wet etching technique, sub-30-nm-physical-gate-length FinFETs, 100-nm-ta!l fin-channel complementary MOS (CMOS) inverters and static random access memory (SRAM) half-cells have successfully been fabricated and demonstrated. These experimental results indicate that the developed nanoscale PVD-TiN wet etching technique is very useful for tall fin-channel CMOS fabrication.