Lampoly etch profiles

Courtesy of Rishi Kant (Coral name: rik)

Performed: 11/18/08

Wafer: Silicon substrate patterned with a thermal oxide hard mask (6000 angstroms thick).

Etch: Standard Recipe 1, with 300 seconds in the Main Etch.

Thermal Oxide Etch Rate: 240 A/min, excellent uniformity (50 A total thickness variation across the wafer)

Single Crystal Silicon Etch Rate: 2900 – 3400 A/min, depending on feature size (loading effect.)

Observations: Isolated structures show very good sidewall profiles. Etching holes yields sloped and W-shaped profiles depending on the size of the holes (this is historically normal.)

Isolated structures