Plasma Prep X Parallel Plate Plasma Etcher

Overview

The Plasma Prep X is a parallel-plate RF plasma etcher built primarily for the anisotropic removal of glass passivation layers during failure analysis in the solid-state electronics industry. Unlike a barrel-design etcher, its top-mounted, water-cooled parallel plate electrodes produce a more directional etch, which avoids the undercutting that isotropic barrel etching causes on fine device features. The system accepts wafers up to 7 inches in a 10 inch diameter by 5.5 inch high work chamber and provides two independently controlled gas inputs. It is typically run with carbon tetrafluoride or another reactive fluorine gas as the primary process gas. Chamber material, Pyrex or quartz, is selected based on the process gas in use.

Parallel-Plate, Anisotropic Etching

Because the electrode is positioned at the top of the chamber, the Plasma Prep X produces a more orientated etch than a barrel-design system, making it well suited to passivation layer removal where undercutting must be avoided. For deeper vertical etching, SPI recommends stepping up to the Plasma Prep RIE instead.

Dual Independent Gas Control

Two separate gas inputs, each controlled by its own needle valve, allow gases to be run separately or together depending on the etch chemistry required. RF power is continuously variable from 1 to 150 watts at 13.56 MHz through a crystal-controlled oscillator.

Large-Format Chamber

The 10 inch diameter by 5.5 inch high work chamber accommodates wafers up to 7 inches, making the system suitable for larger-format failure analysis samples than the compact Plasma Prep III can handle. Water-cooled 125 mm electrodes require a cooling water flow of 2 to 4 liters per minute to protect the forward power plate.

System Requirements

The basic system ships without a water circulator or vacuum pump; SPI recommends a small water chiller and a Pfeiffer Vacuum DUO 10 rotary vane pump, or a turbo option that requires no additional external pump.

Common Specifications

Model Comparison