Silyl ether modified polynorbornene is a new class of dielectric polymer materials of interest electronic packaging ether modified polynorbornene is a new class of dielectric polymer materials of interest in electronic packaging and other applications. This work is focused on the reactive ion etching of polynorbornenes in oxygen, oxygen/fluoroform, and oxygen/fluoroform/argon plasmas. The etch rate, amount and nature of the residue, and etch undercut rate have been investigated for different plasma parameters, such as pressure, plasma power, and gas composition. X-ray photoelectron spectroscopy and scanning electron microscopy were used to characterize the residue. Several techniques were used to reduce the etch residue and undercut.