| Abstract: | Wafer scale oblique angle etching of a semiconductor substrate is
performed in a conventional plasma etch chamber by using a fixture that
supports a multiple number of separate Faraday cages. Each cage is formed
to include an angled grid surface and is positioned such that it will be
positioned over a separate one of the die locations on the wafer surface
when the fixture is placed over the wafer. The presence of the Faraday
cages influences the local electric field surrounding each wafer die,
re-shaping the local field to be disposed in alignment with the angled
grid surface. The re-shaped plasma causes the reactive ions to follow a
linear trajectory through the plasma sheath and angled grid surface,
ultimately impinging the wafer surface at an angle. The selected geometry
of the Faraday cage angled grid surface thus determines the angle at with
the reactive ions will impinge the wafer. |