Plasma and Ion Etching for Failure Analysis. Part 2. The Etching of Plastic Encapsulant and Other Semiconductor Device Materials, Using the Technics Giga Etch 100-E Plasma Etch System

摘要

Plastic encapsulant, silicon, silicon dioxide, silicon nitride, and polyimide were plasma etched. Results show that the die of a plastic packaged integrated circuit can be exposed using an oxygen/carbon tetrafluoride plasma, without degrading the functionality of the device. The same process gases are shown to be capable of etching silicon, silicon dioxide, and silicon nitride. Optical emission spectroscopy was used to study the plasma during the etching of these materials. Polyimide was also etched by these gases and the etch rates for various percentage mixtures of oxygen and carbon tetrafluoride were measured. The highest achievable polyimide etch rate is 120 microns/hr with an 87 percent O2/13 percent CF4 plasma.