ARDE in Via Etching - (PPT)

摘要

Oxide ER is a strong function of the AR. Decreasing from 6900 A/min at 0.5:1 aspect ratio to 5500 A/min at 1.5:1 aspect ratio; Selectivity of oxide to TiN at bottom of 15,000 A deep via is 5.6:1. Oxide ER = 5050 A/min, TiN ER = 890 A/min.; Oxide etch rate in the via hole is 25% lower than the etch rate in a bond pad. If bond pad etch rates were used to set recipe etch times the time would be under estimated and under etching could occur; Percent over etch for the deepest via is 33% and the shallowest via is 64%. Could impact ability to strip polymer.