An electrode for a plasma processing apparatus is provided. The electrode comprises: a first conductive member; and a second member disposed in the first member and made of a material having a secondary electron emission coefficient different from a secondary electron emission coefficient of the first member.

Embodiments described herein relate to apparatus and methods for performing electron beam reactive plasma etching. In one embodiment, an apparatus for performing EBRPE processes includes an electrode formed from a material having a high secondary electron emission coefficient. The electrode has an electron emitting surface disposed at a nonparallel angle relative to a major axis of a substrate assembly. The EBRPE apparatus may further comprise a capacitive or inductive coupled plasma generator. In another embodiment, methods for etching a substrate include generating a plasma and bombarding an electrode with ions from the plasma to cause the electrode to emit electrons. The electrons are accelerated toward a substrate to induce directional etching of the substrate. During the EBPRE process, the substrate or electrode is actuated through a process volume during the etching.

An electrode for a plasma processing apparatus is provided. The electrode comprises: a first conductive member; and a second member disposed in the first member and made of a material having a secondary electron emission coefficient different from a secondary electron emission coefficient of the first member.

A laser system for generating secondary radiation through interaction of a focused primary laser beam with a target material includes a laser beam source for providing a raw laser beam, and a beam guidance device for forming the focused primary laser beam from the raw laser beam. The focused primary laser beam is directed towards a target region in order to interact with the target material arranged in the target region. The beam guidance device includes a beam focusing device configured to form the primary laser beam by focusing a laser beam entering the beam focusing device, which corresponds to the raw laser beam. The beam focusing device includes at least two mirror elements spaced apart from one another. The beam focusing device has a numerical aperture between 0.001 and 0.01 provided that the primary laser beam propagates in a medium with a refractive index of less than 1.01.